MetEd: Meteorology Education and Training. Operated by the COMET Program

Description:
This course provides two separate learning paths through modules and webcasts available on MetEd, reviewing key topics in winter weather forecasting. By using our Registration & Assessment system, you can track your progress in one or both parts of the course and receive a course completion certificate.

Estimated time to complete: 8-9 h

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Description:
Hazardous weather affects us all. To help local emergency managers cope with weather hazards they may face, the Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) offer a course titled Hazardous Weather and Flooding Preparedness. However, many people who make weather-related decisions are unable to attend this 2-3 day course.

The purpose of this Web-based course, Anticipating Hazardous Weather and Community Risk, is to provide background on weather and weather hazards for emergency managers and other decision makers. This course is intended to complement on-site courses offered by FEMA and NWS, so that they can focus on local hazards and community risk factors.

This course covers:

• Weather: How and why it forms
• Hazardous weather: Fact sheets on different phenomena
• Forecasting weather: The forecast process and products issued by the NWS
• Warning Partnership: How the NWS and emergency managers generate and communicate warnings
• Desktop Exercise: An opportunity to apply what you have learned in a flash flood scenario

FEMA Independent Study credit is available for those who complete the course and pass the exam. The subject matter experts for Anticipating Hazardous Weather and Community Risk are Randall C. Duncan, CEM - Sedgwick County (KS) Emergency Management, Bob Glancy - NWS, Bob Goldhammer - Polk County (IA) Emergency Management, Curt Nellis - County of Shenandoah (VA) Department of Fire and Rescue, John Ogren - NWS, and Bruce Sterling - Portsmouth (VA) Emergency Management.

Objectives:
• Explain basic processes that cause and/or signal hazardous weather
• List the main weather hazards and the factors that determine community risk
• Describe the basic weather forecasting process and its limitations
• Discuss various techniques for communicating information about weather hazards
• Distinguish which NWS forecast products are appropriate in various situations
• Analyze various source of information about a weather hazard and formulate a plan for dealing with a potential disaster

Estimated time to complete: 4-5 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2001-03-08

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Description:
This case exercise looks at a barrier jet event over central and eastern Colorado that took on historic significance in terms of snow amounts and variability in snow distribution. The module emphasizes the mechanisms for producing both very large accumulations and extreme small-scale variability. These mechanisms involved both dynamic and thermodynamic processes in this storm. Model and observed analyses and forecasts are considered in detail as the storm unfolds.

Objectives:
• Analyze a Rocky Mountain Front Range heavy precipitation event to determine the influence of a barrier jet on both precipitation type and amount.
• Forecast critical storm features in a barrier jet case, including winds and precipitation type and intensity.
• Monitor the development of the barrier jet features in the context of the larger-scale forcing.
• Examine the important processes governing the termination of the storm.

Estimated time to complete: 2-3 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2006-07-27

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Description:
This case exercise takes an in-depth look at a blowing snow event in the northern mainland of Canada. The case addresses specific low-level wind and snow conditions. Model data, satellite imagery, and observations are provided for assessing the potential for blowing snow and blizzard conditions as the event unfolds.

Objectives:
1. Review the winter climatology of this central Canadian region.
2. Recognize the specific low-level wind and snow conditions conducive to blowing snow/blizzard conditions.
3. Recognize the common synoptic patterns associated with a blowing snow event.
4. Consider the wind speed and direction forecasts for this event.
5. Examine the cessation of blowing snow conditions, from a forecasting standpoint.

Estimated time to complete: 60 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2004-11-08

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Description:
The goal of the EPV chart is to aid operational forecasters in predicting CSI and slantwise convection. The description includes links to the online chart, which is updated twice daily by the CMC, as well as a list of synoptic considerations that will support your use of the EPV chart in identifying regions favorable for CSI and slantwise convection.

Estimated time to complete: 20 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2002-01-05

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Description:
Cold Air Damming is part of the Mesoscale Meteorology Primer series. This module first presents a Navy forecast scenario prior to the development of a major cold air damming (CAD) event along the east slopes of the Appalachian Mountains. Then, from a conceptual standpoint, the classic CAD scenario is described in detail, both from an observational and modeling standpoint.

Objectives:
After completing this module, the learner should be able to do the following things:

Characterize cold air damming

• Identify the elements that are required for a CAD event.
• Identify sensible weather phenomena associated with cold air damming.
• Describe the nature and importance of overrunning winds in a CAD event.
• Describe the conditions leading to a barrier jet during a CAD event.
• Identify the origin of precipitation particles in a CAD event.
• Locate the deepest part of the pool of cold air in a CAD event.

Classify CAD events

• Recognize the three different types of CAD events.
• Recall the different cooling processes important to cold air damming.
• Describe the role different cooling processes play in the different types of CAD events.
• Match cooling processes to their respective causes.

Describe the climatology of cold air damming

• Identify geographically where CAD events occur.
• Remember the climatology of CAD events for the following:
• Seasonal occurrence,
• Probability of occurrence, and
• Duration of events

Identify a CAD event

• Identify a CAD event from synoptic MSLP, 850 mb, and 500 mb pressure charts.
• Identify a CAD event from soundings.
• Identify a CAD event from surface observations.
Forecast the start of a CAD event
• Using MSLP charts, identify the synoptic conditions that lead to cold air damming for the Appalachians and other mountain ranges, including the Rocky Mountains, Alps, and Andes.
• Identify atmospheric conditions that lead to terrain blocking and cold air damming.
• Recognize the limitations of forecast models in a predicting a CAD event.

Forecast the end of a CAD event

• Using synoptic charts, choose the charts that indicate dissipation of a CAD event in a 24-hour time frame.
• From soundings, recognize the atmospheric conditions leading to dissipation of a CAD event.
• Identify surface observations that indicate the dissipation of a CAD event.

Estimated time to complete: 1-1.5 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2001-06-18

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Description:
In this Webcast, Dr. James Steenburgh, working for the Department of Meteorology and the NOAA Cooperative Institute for Regional Prediction at the University of Utah, takes a look at cool-season orographic storms in western North America. He provides a brief microphysics review, an overview of cool-season orographic precipitation processes in several mountain ranges, and a look at forecasting tools and techniques. This Webcast is based on a classroom presentation given in Boulder, CO in December 2002.

Objectives:
• Improve knowledge of orographic precipitation processes and their geographical, climatological, and storm-to-storm variability.
• Build or enhance your orographic precipitation forecasting tool chest.
• Illustrate the strengths and weaknesses of quantitative precipitation forecasts by high-resolutions models in complex terrain.

Estimated time to complete: 1 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2004-08-09

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Description:
This module consists of four exercises where users identify surface features, distinguish clouds from snow on the ground, and determine cloud phase using multispectral analysis. The module also includes an overview of multispectral techniques available on many operational and research polar-orbiting satellites. A page with links to real-time polar-orbiting data and information is also included.

Objectives:
• State the properties of the 1.6 micrometer channel used in feature identification
• State the properties channels in the 3.5 to 4 micrometer region in feature identification
• List the advantages and limitations of the 1.6 micrometer channel in cloud identification
• List the advantages and limitations of the 1.6 micrometer channel in identifying snow on the ground
• List the advantages and limitations of channels in the 3.5 to 4 micrometer region for cloud identification
• List the advantages and limitations of channels in the 3.5 to 4 micrometer region in identifying snow on the ground
• Apply the properties of the visible, IR Window, 1.6 micrometer, and 3.7 micrometer channels to:
o Distinguish clouds from snow on the ground
o Determine the phase (ice or water) of clouds
o Detect the presence of fog
o Distinguish open water from ice-covered areas of lakes and rivers

Estimated time to complete: 1-2 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2002-07-03

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Description:
This module discusses the current theories of atmospheric conditions associated with aircraft icing and applies the theories to the icing diagnosis and forecast process. The contribution of liquid water content, temperature, and droplet size parameters to icing are examined. Identification of icing type, icing severity, and the hazards associated with icing features are presented. Tools to help diagnose atmospheric processes that may be contributing to icing and the special case of supercooled large drop (SLD) icing are examined and applied in short exercises.

The use of graphics, animations, and interactive exercises in Forecasting Aviation Icing: Icing Type and Severity helps the forecaster to gain an understanding of icing processes, to identify icing hazards, and to apply diagnosis and forecast tools as aids to evaluate and anticipate potential aircraft icing threats.

The subject matter expert for this module is Dr. Marcia Politovich of
NCAR/Research Applications Program.

This module is also available in French.

Objectives:
The goal of this training module is to help you improve your icing forecasts by

1. Becoming more familiar with the types, conditions, and hazards of aircraft icing.
2. Learning what factors determine icing type and severity, and how they interrelate.
3. Knowing what physical processes create favorable icing conditions.
4. Recognizing the types of mesoscale environments that generate such physical processes.
5. Learning some techniques to apply and patterns to look for when diagnosing data products for possible icing threats.

Performance Objectives

A. Aircraft Icing
1. Name and distinguish between the main types of in-flight aircraft icing; rank them in terms of potential hazard to aviation.
2. Describe the conditions under which the main types of in-flight aircraft icing form.
3. Name and distinguish between the four icing severity reporting categories used by pilots.

B. Icing Factors
1. Name the main factors that determine the type and severity of icing to expect in a given environment.
2. Identify ranges of values for liquid water content, temperature, and altitude that are most favorable to icing.
3. Describe the influence of droplet size on ice collection efficiency and accretion pattern.
4. Predict the most likely icing type and severity level to expect for given ranges of cloud liquid water content, temperature, and droplet size.

C. Icing Environments and Physical Processes
1. Describe the impact to icing of each of the six categories of water phase transitions.
2. Describe several of the most favorable synoptic and mesoscale environments for development of hazardous icing conditions:

• Three patterns that enhance cloud formation and hence icing potential
• Three environments that are especially conducive to supercooled large drop formation
• Two physical processes that support supercooled large drop formation
• Cloud-top conditions most favorable to supercooled large drop formation

D. Data Assessment
1. Assess the icing threat in various layers of skew T-log p diagrams.
2. Identify favorable areas and layers for supercooled large drop formation integrating:
• GOES 3.9 micron imagery
• Skew-T diagrams
• Profiler data
• WSR-88D reflectivity and velocity
• Surface precipitation observations

Estimated time to complete: 3-5 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 1998-03-13

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Description:
This Webcast is based on a COMET classroom presentation by Dr. Gary Lackmann at the 2nd MSC Winter Weather Course held in Boulder, Colorado on 22 February 2002. Dr. Lackmann reviews the basic thermodynamics of freezing and melting and how operational models represent these processes. He also touches upon the biases that occur in the models by looking at examples of melting snow aloft, melting snow at the surface, freezing aloft (ice pellets), and freezing rain. Dr. Lackmann is a faculty member in the Department of Marine, Earth, and Atmospheric Sciences at North Carolina State University.

Objectives:
1. Examine four thermodynamic scenarios closely, each of which produces a different precipitation situation.

2. Compare sounding, radar, and model signatures associated with these scenarios.

3. Compare the representation of these thermodynamic processes in operational models at and near the surface.

4. Become aware of potential problems with the model forecasts.

5. Examine the limiting processes and requirements for freezing rain.

Estimated time to complete: 35 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2002-07-03

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Description:
In a detailed 130 page report, Ivan Dubé of the Meteorological Service of Canada reviews the factors that contribute to snow density, and presents a new and improved algorithm based on data from Québec for diagnosing and predicting snow density. A verification of the algorithm is included, along with a few case examples. This document is in English as a .pdf file. A French version is also available: http://meted.ucar.edu/norlat/snowdensity/rapportneigeeau.pdf

Estimated time to complete: 10 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2003-12-18

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Description:
This webcast is based on a presentation by Dr. Moore MSC/COMET Winter Weather Workshop in Boulder, CO, 4 December 2002. In it, he covers the definition of the TROWAL and its role in heavy snow production in the form of bands primarily located to the northwest of the surface low. The various conveyor belts associated with mature winter cyclones are emphasized. The roles of mid-level frontogenesis and conditional symmetric instability in these systems are discussed in the context of heavy snow development.

Objectives:
1. Examine the structure of a mature midlatitude cyclone from the conveyor belt standpoint.

2. Understand how areas where equivalent potential vorticity < 0 are conducive to conditional symmetric instability and snowbands.

3. Demonstrate the positive interaction between frontogenesis and zones favorable for CSI.

4. Compare these features in two CONUS case studies.

Estimated time to complete: 45 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2003-09-23

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Description:
This Web-based learning module is the second title in a series of modules about the use of diagnostic tools to evaluate icing type and severity. Marcia Politovich of the NCAR Research Applications Program (RAP) is the principle subject matter expert. The module teaches how to assess surface observations, upper-air charts, and pilot reports (PIREPs) in order to diagnose the aviation icing environment. Topics include strengths, weaknesses, and appropriate uses of these data, data assessment methods, interpretation and evaluation of PIREPs, and a bottom-up procedure for integrated icing diagnosis at a particular location. This module includes numerous practice exercises allowing learners to improve their skills in icing assessment using these basic observational tools.

Objectives:
The goal of this training module is to help you improve your skill in using observational and pilot report data to locate areas and layers that are likely to have favorable conditions for in-flight aircraft icing.

Performance Objectives
Use surface observations to evaluate:
• precipitation location & type
• temperatures
• cloud cover & type, ceiling heights
• air mass configurations (indicated by fronts, low pressure centers, etc.)
Use upper-air charts and analyses to evaluate:
• cloud layers, cloud tops, likely cloud phase
• temperature structure
And interpret PIREPs to:
• identify location, altitude and time of icing reports
• identify icing type & severity reported
• assess the spatial extent of icing based on reports
Based on these:
• infer likely precipitation and temperature structure above a location
• locate likely areas and layers containing supercooled liquid water (SLW) & freezing precipitation
• assess applicability of PIREPs
• identify areas without icing PIREPs that are likely to contain icing conditions
• track trends and changes in icing conditions

Estimated time to complete: 1-2 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 1999-04-08

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Description:
Marcia Politovich of the NCAR Research Applications Program (RAP) is the principle subject matter expert for this
Web-based learning module. The module teaches how to assess vertical profiles of wind, temperature, dewpoint, and frost point in order to diagnose airmass characteristics, cloud layers, and possible aviation icing layers. Topics include strengths, weaknesses, and appropriate uses of rawinsonde and profiler data for assessment of aviation icing, icing characteristics of the different extratropical cyclone air masses, identification of dry and saturated layers and possible zones of favorable conditions for aircraft icing, and ice seeding and glaciation processes. If you wish, you may launch the module from this location. Note: This module requires use of the companion CD-ROM called The Icing Event of 6 March 1996.

Objectives:
The goal of this training module is to help you improve your skill in using sounding and profiler data to locate areas and layers that are likely to have favorable conditions for in-flight aircraft icing.

Performance Objectives

• Analyze skew-T diagrams and wind profile time series to identify the likely extratropical cyclone air masses influencing them.
• Describe the typical characteristics of the different extratropical cyclone air masses as they relate to aviation icing conditions.
• Analyze profiles of temperature, dewpoint, frost point, and winds in skew T-log p diagrams to identify dry and saturated layers and possible zones of favorable conditions for aircraft icing.
• Apply knowledge of ice seeding and glaciation processes to various cloud layer configurations to anticipate the evolution of icing conditions.
• Describe strengths, weaknesses, and appropriate uses of rawinsonde and profiler data for assessment of aviation icing.

Estimated time to complete: 1-2 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 1999-04-08

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Description:
This Webcast features Phil Schumacher, NWS Sioux Falls, South Dakota discussing the conditions that dictate the location of precipitation relative to inverted troughs. Phil presents a composite case study based on collaborative research with Dr. R. Weisman and others, as well as two examples of inverted trough events in the Central Plains. This presentation is based on his presentation at the MSC Winter Weather Course, December 2002, in Boulder, Colorado. The webcast is accompanied by a case exercise, Inverted Trough Case Exercise.

Objectives:
1. Describe inverted troughs and their associated precipitating features.
2. Present the results of a composite inverted trough study, based on the differences between inverted troughs that produce precipitation ahead vs. behind the trough.
3. Demonstrate the use of isentropic techniques in diagnosing important inverted trough features.
4. Look at several case studies demonstrating the impact of inverted troughs on precipitation distributions.

Estimated time to complete: 60 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2004-01-29

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Description:
This exercise follows the progression of a winter weather event across the Central Plains states beginning 1200 UTC on 7 March 1999. Each forecast question is accompanied by Eta model data and includes a forecast discussion by Phil Schumacher, NWS Sioux Falls, South Dakota. This exercise compliments the Webcast, Inverted Troughs and their Associated Precipitation Regimes, based on a presentation by Phil Schumacher at the MSC Winter Weather Course, December 2002, in Boulder Colorado.

Objectives:
1. Identify whether precipitation will be primarily ahead or behind an inverted by applying the conceptual model of inverted trough precipitation organization.

2. Use isentropic analysis to view the affect inverted troughs have on moisture transport and the implied lift associated with inverted troughs.

3. Use the conceptual model of inverted trough precipitation organization to determine the approximate beginning and ending time for significant precipitation associated with inverted troughs.

Estimated time to complete: 45 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2004-01-29

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Description:
This Webcast, presented by Dr. Jim Moore of St. Louis University, covers the advantages and applications of diagnosis and visualization of large-scale flow and vertical motion on surfaces of constant potential temperature. The movement of moisture along these surfaces is emphasized, as is the diagnosis of the components of vertical motion. Background mathematical concepts are presented, then illustrated with soundings, cross sections, and plan view analyses of data from multiple cases.

Objectives:
1. Understand the concepts of pressure advection and system relative flow.

2. Understand dynamic destabilization and associated environmental moistening.

3. Diagnose static stability, upper fronts and CSI in this framework.

4. Examine at frontogenesis and transverse jet streak circulations on vertical cross sections with analyzed potential temperature fields.

5. Examine the components of vertical motion in an isentropic framework.

6. Compare the advantages and disadvantages of isentropic analysis.

7. Examine a wintertime case study utilizing isentropic analysis.

Estimated time to complete: 1 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2002-11-19

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Description:
This Webcast is based on a presentation given by Dr. James T. Moore of Saint Louis University at the 5th Annual MSC/COMET Winter Weather Workshop on 30 November 2004 in Boulder, Colorado. Dr. Moore reviews many aspects of jet streak dynamics including convergence/divergence, ageostrophic winds, propagation, and coupled jets.

Objectives:
• Define "jetstreak"
• Note the divergence associated with upper-level waves
• Describe the relationship of divergence with vertical windshear
• Describe the relationship of the ageostrophic wind components with upper-level and low-level jets
• Compare the direct thermal circulation in the entrance region with the indirect thermal circulation in the exit region of an upper-level jet
• Identify how the curvature of an upper-level jet affects divergence and convergence
• Describe the impact thermal advection has on vertical motion and entrance and exit circulations
• Gain an understanding of the characteristics of unbalanced jets and coupled jets

Estimated time to complete: 50 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2005-04-25

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Description:
The Mesoscale Aspects of Winter Weather Forecasting effort is comprised of a growing series of in-depth case exercises bundled with supporting topics. This site provides access to the supporting topics seperate from the case exercises.

Estimated time to complete:

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2003-10-12

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Description:
Precipitation frequently falls and accumulates in discrete bands with accumulations that vary markedly over short distances. This module examines several mechanisms that result in mesoscale banded precipitation, focusing primarily on processes at work in midlatitude cyclones. The module starts with a review of the Norwegian and conveyor belt cyclone models. Then several banding processes are examined in detail, including deformation/frontogenesis, the Trowal (Trough of Warm Air Aloft), frontal merger, CSI/slantwise convection, and melting/evaporation-induced circulations. The module concludes with discussions of the representation of banded precipitation by NWP models and the detection of banded precipitation with satellite sensors.

Objectives:
After completing this module, the learner should be able to do the following things.


With regard to the general features of mesoscale banded precipitation:

* Recall the operational definition of a precipitation band

* Describe the relationship between instantaneous and accumulated bands of precipitation

* Recall the basic requirements for precipitation and the role of atmospheric stability


With regard to the association between midlatitude cyclones and mesoscale banded precipitation:

* Recall and describe the different types of fronts in the Norwegian cyclone model

* Describe the typical precipitation field associated with each kind of front

* Distinguish an anafront from a katafront in forecast products

* Distinguish a cold occluded front from a warm occluded front in forecast products

* Recall and describe the types of air streams in the conveyor belt model of midlatitude cyclones

* Describe the relationship between air streams and fronts

* Describe the relationship between air streams and mesoscale banded precipitation

* Recognize different air streams in satellite images and forecast products

* Recall what a trowal is and where it occurs

* Describe the relationship between the trowal and banded precipitation

* Describe the trowal signature in forecast products

* Locate a trowal on satellite images and forecast products


With regard to processes that lead to mesoscale banded precipitation.

* Define the terms: deformation, frontogenesis, frontolysis

* Describe how deformation leads to frontogenensis

* Describe the vertical motions associated frontogenesis

* Describe how frontogenesis leads banded precipitation

* Recognize and diagnose deformation and frontogenesis in forecast products

* Describe circulations induced by melting and evaporation in the lower tropsphere

* Describe the relationship between melt/evaporation-induced circulations, frontogenesis, and banded precip

* Recognize and diagnose banded precipitation forced by melt/evaporation-induced circulations in forecast products

* Define frontal merger

* Describe the difference between frontal merger and frontal occlusion

* Describe a typical synoptic setting for frontal merger and its relationship with midlatitude cyclones

* Describe the relationship between frontal merger and banded precipitation

* Recognize and diagnose frontal merger in forecast products

* Describe the relationship between CSI and slantwise convection

* Describe the atmospheric conditions conducive to CSI

* Describe what atmospheric conditions lead to low inertial stability

* Recognize and diagnose CSI and slantwise convection with cross-sectional analysis.


With regard to the simulation of mesoscale banded precipitation by NWP models:

* Given the grid spacing determine the grid resolution

* Describe the characteristics of a hydrostatic atmosphere

* State why high-resolution NWP models need to be non-hydrostatic

* Describe the need for parameterization in NWP models

* Describe the pros and cons of parameterization versus explicit treatment of processes

* Describe the difference between prognostic and diagnostic moisture physics and the benefits of each

* Characterize COAMPS and NOGAPS


With regard to the detection of mesoscale banded precipitation by satellite sensors:

* Describe the benefits and drawbacks of satellite estimates of precipitation

* Recall at least 4 satellite sensors that measure precipitation

* Describe the benefits and drawbacks of the GOES Precipitation Index

* Describe the benefits and drawbacks of precipitation estimates derived from microwave sensors

* Describe how a blended precipitation product is derived

Estimated time to complete: 3 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2005-06-24

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Description:
This case study is the first in the Mesoscale Aspects of Winter Weather Forecasting module series. The case is presented as a series of challenging forecast questions followed by a more traditional case study presentation. Included in the exercise is a rich set of data products and a series of background materials on lake/ocean effect snow and winter microphysics processes.

Objectives:
• Recognize the necessary synoptic precursors for an ocean effect snow
event off the east coast of New England and Atlantic Canada.
• Identify the mesoscale factors that lead to the establishment of ocean effect snow bands.
• Recognize ocean effect snow bands from satellite and radar
displays.
• Recognize the potential for enhancement and eventual dissipation of ocean
effect snow bands with the changing synoptic conditions.

Estimated time to complete: 1-2 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2003-05-29

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Description:
Polar lows are generally short-lived but intense events that occur over cold ocean waters, poleward of a baroclinic zone. The polar low in this case formed over the open waters of Ungava Bay, in northeastern Canada, on 2 December 2000. The case is presented as a series of challenging forecast questions followed by a more traditional case study presentation. Included in this exercise is a rich set of data products and access to background materials on polar low forecasting.

Objectives:
1. Recognize the synoptic scale precursors of polar lows
2. Recognize the low-level surface features that are conducive to the development of polar lows
3. Recognize the development of a polar low from observations. Identify polar lows using satellite imagery
4. Understand the limitations of model initialization and output for polar low forecasting
5. Apply understanding of polar low steering mechanisms to a tracking forecast

Estimated time to complete: 1-2 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2004-04-02

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Description:
POES 3: Case Studies contains two short case study examples that demonstrate different uses of polar satellite data. The first case example shows how AMSU microwave data can be used to supplement other datasets to improve precipitation forecasts. The second case example demonstrates the TRaP method for calculating rainfall from Hurricane Georges.

Objectives:
• State the advantages of using microwave data for precipitation forecasting
• Describe the method for comparing NWP forecasts with microwave moisture information
• Compare and contrast the information from GOES water vapor imagery with information from microwave TPW as it relates to Case 1.
• Describe the TRaP product

Estimated time to complete: 1-2 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 1999-12-10

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Description:
This interactive case exercise covers a 24-hour forecast period that
includes the challenge of precipitation type forecasting. The case
exercise provides an overview of precipitation type forecasting based on
model algorithms, partial thickness analysis, and the top-down method.

Objectives:
• Understand the limitations of NWP models in precipitation type forecasts.
• Apply partial thickness analysis for forecasting precipitation type.
• Apply the top-down Method for forecasting precipitation type.

Estimated time to complete: 27-90 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2005-09-27

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This module is not available on the Web. To order a CD, please see our contact information.

Description:
Satellite Meteorology: Case Studies Using GOES Imager Data is a continuation of the first module in the satellite meteorology series, Satellite Meteorology: Remote Sensing Using the New GOES Imager. This module includes a winter and summer severe storm case as well as a tutorial on tropical storms. It provides many opportunities to view and interpret GOES imager data and integrate those data with model, radar, and other data types. Additional material and exercises will be available on the COMET home page.

The subject matter experts for this module are Dr. James F. Purdom and Dr. Ray Zehr.

Estimated time to complete: 2-3 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 1997-01-01

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Description:
This exercise examines an event that took place in the 24 hour time period beginning at 18Z, Dec 31, 2000 in southern British Columbia, Canada and northern Washington/Idaho, United States. This is a companion piece to the COMET Webcast, Slantwise Convection: An Operational Approach.

Objectives:
• Apply techniques for assessing and forecasting conditional symmetric instability and associated slantwise convection

Estimated time to complete: 45 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2002-06-17

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Description:
This Webcast is a recreation of a presentation on slantwise convection given by Kent Johnson in February, 2002 in Boulder, Colorado. It focuses on assessing the release of conditional symmetric instability as slantwise convection. It provides an overview of the characteristics and theory of CSI, assessment of CSI and slantwise induced precipitation in complex terrain, and operational challenges to assessing CSI.

Objectives:
1. Show that the atmosphere can be intertially and gravitationally stable, but unstable to a slantwise displacement when near or at saturation.

2. Demonstrate the vertical-cross section approach in diagnosing the potential for conditional symmetric instability (CSI).

3. Examine ways to improve forecasts that involve a potential slantwise convection situation.

4. Examine the typical characteristics of CSI in complex terrain.

5. Apply a slantwise convection analysis to a real world situation.

Estimated time to complete: 40 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2002-06-17

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Description:
This module helps the student develop an understanding of the contribution of snowmelt in the hydrologic forecasting process. The module first explains the influences of wind, sun, terrain, and vegetation on snow water distribution and then discusses the evolution of snowpack characteristics. From there, the student will learn about energy exchanges between the snow and the atmosphere and how that affects how quickly and how completely snow will melt. Finally, an explanation is presented of water flow through snow and the fate of that water when it reaches the ground surface. The lesson will be highlighted with brief examples of actual snowmelt cases.

Objectives:
Describe the development and evolution of snowpack:
- Explain the influences of terrain, wind, vegetation, and temperature.
- Describe how sublimation affects snowpack.
- Describe the process of snow metamorphism.
- Explain SLR and SWE.
- Describe why and how snow energy exchanges are important.

Describe the processes leading up to and during melting:
- Explain the importance of latent heat exchange.
- Describe what is necessary for rapid melting.
- Explain the importance of rainfall on the snowmelt process.

Describe the fate of melt water from snow:
- Describe how water can move through the snowpack.
- Explain what happens when melt water reaches the ground surface.
- Discuss a situation that would result in rapid runoff from snowmelt.

Estimated time to complete: 60 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2007-02-02

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Description:
In this Webcast, Dr. Schultz outlines the subtle and often confusing issues surrounding conditional symmetric instability. Material is then presented to encourage the meteorological community to properly apply these concepts to diagnose actual regions of CSI and apply that knowledge to forecasting banded precipitation. Avenues for future research are also discussed.

This lesson is based on an article of the same name that appears in the Dec.1999 issue of the AMS journal, Monthly Weather Review. In response to feedback, a version of this Webcast that can be installed on your computer for local playback is also provided.

Objectives:
1. Point out pitfalls so that they don't continue to be perpetuated

2. Illustrate some deficiencies in our understanding of CSI

3. Recommend operational uses of CSI that are consistent with our current state of knowledge

4. Encourage future operational research explorations

Estimated time to complete: 30 min

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2000-01-07

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Description:
Lake and ocean effect processes can have a significant impact on snowfall amounts in many parts of North America, and can be very tricky to forecast. This short module is a collection of narrated reference material on many aspects of lake effect snow forecasting. It is divided into three main topics: Basic Ingredients of Lake/Ocean Snow, Banding Processes, and Satellite Detection. These materials are also available as the separate Supporting Topics within the case exercise module, Ocean Effect Snow: New England Snow Storm, 14 January 1999: http://meted.ucar.edu/norlat/snow/ocean_effect_case/.

Objectives:
• Identify the key conditions for the formation of lake or ocean effect snows events
• Identify the mesoscale factors that lead to the establishment of ocean effect snow bands.
• Describe how frictional and thermal convergence can impact lake effect snow production
• Recognize ocean effect snow bands from satellite and radar displays.

Estimated time to complete: 1 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2005-02-09

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Description:
This module presents an overview of the climatology, formation, evolution, detection, and forecasting of polar lows. The presentation has five sections: Disturbances in Cold Air Masses; Climatology of Cold Air Vortices and Polar Lows; Monitoring and Nowcasting of Polar Lows; Polar Lows and NWP; and Forecasting Process for Polar Lows. It also includes a printable forecasting checklist.

Objectives:
• Recognize the synoptic scale precursors of polar lows
• Recognize the low-level surface features that are conducive to the development of polar lows
• Recognize the development of a polar lows from observations.
• Identify polar lows using satellite imagery
• Understand the limitations of model initialization and output for polar low forecasting

Estimated time to complete: 1.5 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2004-04-02

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Description:
This module presents an overview of various aspects of precipitation
type forecasting. It includes sections on microphysics and the ice
crystal process, application of partial thickness analysis, application
of the top-down method, and an overview of model algorithms used for
precipitation type analysis.

Objectives:
• Explain the microphysics of snow crystal growth, the interaction of cloud water with
cloud ice, and the important roles of dendrites and aggregation.
• Apply microphysics knowledge to operational settings.
• Apply partial thickness analysis for forecasting precipitation type.
• Apply the top-down Method for forecasting precipitation type.
• Understand the limitations of NWP models in precipitation type forecasts.

Estimated time to complete: 30 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2005-09-27

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Description:
When the new grid-scale precipitation scheme was implemented in the Eta model on November 27, 2001, precipitation type became available as a forecast variable. This variable can be used to complement the diagnosed precipitation type based on forecasted vertical temperature and moisture profiles. In this case, the diagnosed precipitation type from the NCEP (a.k.a Baldwin/Schichtel) algorithm is compared to the predicted precipitation type in the experimental/parallel version of the 12-km Eta model for an early winter storm in the southern and eastern U.S.

Estimated time to complete: 40 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2003-03-03

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Description:
An examination of how the updated Eta-12 model, with its higher resolution, improved topography, and upgraded cloud and precipitation package, performed in forecasting the initiation and evolution of the first portion of the Buffalo, NY historic lake effect snow event (24-26 December 2001).

Estimated time to complete: 45 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2002-03-05

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Description:
This case discusses the failure of the Short-Range Ensemble Forecast (SREF) system to capture a significant snowfall over the interior northern Mid-Atlantic states and New England that occured on January 6-7, 2002. While this is a winter case, the lessons learned herein are applicable to use of the SREF in all seasons.

Estimated time to complete: 1 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2002-06-04

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Description:
Dans son oeuvre détaillée de 130 pages, Ivan Dubé du Service météorologique du Canada nous rappelle les processus physiques qui déterminent la densité de la neige, et élabore un nouvel algorithme qui permet la diagnose et la prévision améliorées de la densité de la neige. Ce travail est basé sur les données recueillies au Québec. Le document discute aussi les résultats d’un programme de vérification de l’algorithme, et se termine avec quelques cas pour illustrer son utilisation.

Estimated time to complete: 10 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2003-06-00

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Description:
Les cartes de TPE, produites au CMC deux fois par jour, sont disponibles au Web à l’adresse fournie dans ce document. Il s’y trouve aussi une liste de facteurs synoptiques destiné aux météorologues d’exploitation pour encadrer leur utilisation des cartes de TPE dans l’identification et la prévision des régions de l’ICS et de la convection penchée.

Estimated time to complete: 20 min

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2002-01-05

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Description:
This is the French version of this module.

This module discusses the current theories of atmospheric conditions associated with aircraft icing and applies the theories to the icing diagnosis and forecast process. The contribution of liquid water content, temperature, and droplet size parameters to icing are examined. Identification of icing type, icing severity, and the hazards associated with icing features are presented. Tools to help diagnose atmospheric processes that may be contributing to icing and the special case of supercooled large drop (SLD) icing are examined and applied in short exercises.

The use of graphics, animations, and interactive exercises in Forecasting Aviation Icing: Icing Type and Severity helps the forecaster to gain an understanding of icing processes, to identify icing hazards, and to apply diagnosis and forecast tools as aids to evaluate and anticipate potential aircraft icing threats.

The subject matter expert for this module is Dr. Marcia Politovich of NCAR/Research Applications Program.

This module is also available in English.

Objectives:
The goal of this training module is to help you improve your icing forecasts by

1. Becoming more familiar with the types, conditions, and hazards of aircraft icing.
2. Learning what factors determine icing type and severity, and how they interrelate.
3. Knowing what physical processes create favorable icing conditions.
4. Recognizing the types of mesoscale environments that generate such physical processes.
5. Learning some techniques to apply and patterns to look for when diagnosing data products for possible icing threats.

Performance Objectives

A. Aircraft Icing
1. Name and distinguish between the main types of in-flight aircraft icing; rank them in terms of potential hazard to aviation.
2. Describe the conditions under which the main types of in-flight aircraft icing form.
3. Name and distinguish between the four icing severity reporting categories used by pilots.

B. Icing Factors
1. Name the main factors that determine the type and severity of icing to expect in a given environment.
2. Identify ranges of values for liquid water content, temperature, and altitude that are most favorable to icing.
3. Describe the influence of droplet size on ice collection efficiency and accretion pattern.
4. Predict the most likely icing type and severity level to expect for given ranges of cloud liquid water content, temperature, and droplet size.

C. Icing Environments and Physical Processes
1. Describe the impact to icing of each of the six categories of water phase transitions.
2. Describe several of the most favorable synoptic and mesoscale environments for development of hazardous icing conditions:

• Three patterns that enhance cloud formation and hence icing potential
• Three environments that are especially conducive to supercooled large drop formation
• Two physical processes that support supercooled large drop formation
• Cloud-top conditions most favorable to supercooled large drop formation

D. Data Assessment
1. Assess the icing threat in various layers of skew T-log p diagrams.
2. Identify favorable areas and layers for supercooled large drop formation integrating:
• GOES 3.9 micron imagery
• Skew-T diagrams
• Profiler data
• WSR-88D reflectivity and velocity
• Surface precipitation observations

Estimated time to complete: 3-5 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2005-10-01

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Description:
Este módulo ayuda a comprender el papel del deshielo en el proceso de pronóstico hidrológico. El módulo comienza con una explicación de cómo los factores tales como el viento, el sol, la topografía y la vegetación influyen en la distribución del agua de deshielo y después presenta la evolución de las características de la capa de nieve. Esa base permite estudiar los intercambios energéticos entre la nieve y la atmósfera y cómo influyen en la rapidez y totalidad del derretimiento de la nieve. Finalmente, se explican el movimiento del agua por la nieve y su destino cuando alcanza la superficie del suelo. La lección incluye varios ejemplos breves de casos reales de deshielo.

Objectives:
Describir el desarrollo y la evolución de la capa de nieve:
* explicar los efectos del terreno, del viento, de la vegetación y de la temperatura;
* describir cómo la sublimación afecta la capa de nieve;
* describir el proceso de metamorfismo de la nieve;
* explicar los conceptos de relación nieve a líquido y equivalente en agua de la nieve;
* describir la importancia de los intercambios de energía que tienen lugar en la capa de nieve.

Describir los procesos hasta y durante el deshielo:
* explicar la importancia del intercambio de calor latente;
* describir las condiciones necesarias para el deshielo rápido;
* explicar la importancia de la lluvia para el proceso de deshielo de la nieve.

Describir el destino del agua del deshielo de la nieve:
* describir el movimiento del agua por una capa de nieve acumulada;
* explicar lo que ocurre cuando el agua de deshielo alcanza la superficie del suelo;
* describir una situación en que el deshielo produciría un episodio de escorrentía rápida.

Estimated time to complete: 1 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2007-08-29

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Description:
A menudo, la precipitación cae y se acumula en bandas discretas, con cantidades que varían considerablemente sobre distancias cortas. Este módulo examina varios mecanismos que producen precipitación en bandas de mesoescala, centrándose principalmente en los procesos que operan en los ciclones de latitudes medias. El módulo comienza con una descripción de los modelos de ciclogénesis noruego y de cinta transportadora. A continuación se examinan en detalle varios procesos de precipitación en bandas, incluidas la deformación/frontogénesis, las lenguas de aire cálido en altura (Trowal, o TROugh of Warm air ALoft), la unión de frentes, la inestabilidad condicional simétrica/convección oblicua y las circulaciones inducidas por fusión/evaporación. El módulo concluye con algunas discusiones sobre la representación de la precipitación en bandas por los modelos de PNT y la detección de la precipitación en bandas mediante sensores satelitales.

Estimated time to complete: 3 h

Includes audio: yes

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
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Last published on: 2007-09-28

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Description:
Este módulo bilingüe español-inglés presenta las teorías actuales sobre las condiciones atmosféricas asociadas con el engelamiento de aeronaves y aplica dichas teorías al proceso de diagnóstico y pronóstico de engelamiento. También examina el papel de factores tales como el contenido de agua líquida, la temperatura y el tamaño de las gotitas. Se presentan los aspectos de identificación de tipos de engelamiento, la gravedad del engelamiento y los peligros asociados con las características de engelamiento. También se estudian las herramientas que ayudan a diagnosticar los procesos atmosféricos que pueden contribuir al engelamiento y se examina y se aplica en breves ejercicios el caso especial de engelamiento por gotas grandes sobreenfriadas (GGS).

El uso de gráficos, animaciones y ejercicios interactivos ayuda a comprender los procesos de engelamiento, a identificar los peligros de engelamiento y a aplicar las herramientas de diagnóstico y de pronóstico para evaluar y pronosticar las posibles amenazas de engelamiento para las aeronaves. La experta a cargo de este módulo es la Dra. Marcia Politovich de NCAR/Research Applications Program. Este módulo también está disponible en una versión bilingüe inglés-francés.

El objetivo de este módulo de formación es ayudarle a mejorar sus pronósticos de engelamiento. Cuando termine de estudiarlo:

1. Conocerá mejor los tipos de engelamiento de aeronaves y las condiciones y los peligros con ellos relacionados.
2. Entenderá qué factores determinan el tipo y la gravedad del engelamiento, y la relación que existe entre ellos.
3. Sabrá qué procesos físicos crean condiciones favorables para el engelamiento.
4. Podrá reconocer los tipos de ambientes de mesoescala que producen estos tipos de procesos físicos.
5. Conocerá algunas técnicas prácticas y sabrá reconocer ciertos patrones al analizar los productos de datos para identificar las regiones de posible peligro de engelamiento.

Objectives:
Objetivos prácticos

A. Engelamiento de aeronaves
1. Nombrar y distinguir los principales tipos de engelamiento de aeronaves en vuelo, y clasificarlos en términos de peligro potencial para la aviación.
2. Describir las condiciones en las que se forman los principales tipos de engelamiento de aeronaves en vuelo.
3. Nombrar y distinguir las cuatro categorías de informe de gravedad de engelamiento empleadas por los pilotos.

B. Factores de engelamiento
1. Nombrar los factores principales que determinan el tipo y la gravedad del engelamiento que podemos esperar en un entorno dado.
2. Identificar los rangos de valores para contenido de agua líquida (CAL), temperatura y altitud que son más favorables para el engelamiento.
3. Describir el efecto del tamaño de la gotitas sobre la eficiencia de acumulación de las gotas y los patrones de acumulación del hielo.
4. Predecir el tipo de engelamiento más probable y el nivel de gravedad que se puede esperar para ciertos rangos de contenido de agua líquida, temperatura y tamaño de la gotitas.

C. Ambientes y procesos físicos que conducen al engelamiento
1. Describir el impacto de cada una de las seis categorías de transición de fase del agua sobre el engelamiento.
2. Describir varios de los ambientes sinópticos y de mesoescala más favorables para el desarrollo de condiciones de engelamiento peligrosas:
• Tres patrones que intensifican la formación de nubes y, por tanto, el potencial de engelamiento.
• Tres entornos particularmente propicios para la formación de gotas grandes sobreenfriadas (GGS).
• Dos procesos físicos que apoyan la formación de gotas grandes sobreenfriadas (GGS).
• Las condiciones en las cimas de las nubes más favorables para la formación de gotas grandes sobreenfriadas (GGS).

D. Evaluación de datos
1. Evaluar el peligro de engelamiento en varias capas en diagramas oblicuos T - log p.
2. Identificar áreas y capas favorables para la formación de gotas grandes sobreenfriadas integrando los siguientes materiales:
• imágenes de 3,9 micrómetros del GOES
• diagramas oblicuos T - log p
• datos del perfilador del viento
• datos de reflectividad y velocidad de radar WSR-88D
• observaciones de precipitación en la superficie

Estimated time to complete: 3-5 h

Includes audio: no

Required plug-ins:   Flash RealPlayer Java Adobe® Reader®
 * Plug-in information

Last published on: 2008-06-09

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