MetEd/NorLatMet: MetEd's Northern Latitude Meteorology Community

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

close

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

close

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

close

Description:
During this presentation, Dr. Brad Colman (NOAA/NWS) covers both the philosophical and methodological approaches to weather forecasting in general, with a special emphasis on challenges introduced in areas of complex terrain. The insightful comments made by the presenter regarding recommended approaches to applying conceptual models, mesoscale model output, and decision trees in the forecast process are useful to anyone who predicts the weather.

Objectives:
• Review the forecast process.
• Become aware of the challenges of forecasting in the diverse terrain of the Western U.S.
• Review the characteristics of mesoscale circulations.
• Describe the impact of complex terrain on simple geostrophic flow.
• Compare and contrast objective and subjective forecasting techniques.

Estimated time to complete: 35 min

Includes audio: yes

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

Last published on: 2003-12-22

close

Description:
The quick analysis of deformation zones provides an overview of system-relative atmospheric circulations. Since deformation is a primary factor in frontogenesis and frontolysis, understanding of these system-relative circulations is crucial to the diagnosis of atmospheric processes and weather prediction. This module is part of the series: "Dynamic Feature Identification: The Satellite Palette".

Objectives:
* Analyze the air masses and circulations
* Analyze the related paired and companion vorticity centers
* Analyze the related axis of maximum wind and wind maxima
* Analyze the location, orientation and shape of the deformation zone

Estimated time to complete: 75-90 min

Includes audio: no

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

Last published on: 2007-03-22

close

Description:
Following an analysis of the main features of a deformation zone, the diagnosis of temporal and spatial changes in these features can be used to deduce underlying meteorological processes and their progression. In turn, this knowledge can then be used in the forecast process to adjust the forecast accordingly. This module takes 35-45 minutes to complete. It is part of the series: "Dynamic Feature Identification: The Satellite Palette".

Objectives:
* Diagnose the relative intensities of each vorticity center associated with a deformation zone
* Predict the evolution of each associated vorticity center
* Predict the evolution of the deformation zone's location, orientation and shape
* Based on the predicted evolution of a deformation zone, identify areas of frontolysis and frontogenesis and trends in the weather

Estimated time to complete: 35-45 min

Includes audio: no

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

Last published on: 2007-11-05

close

Description:
The distribution of vorticity centres along an axis of maximum winds follows a fairly predictable pattern based on the characteristics of the flow. By diagnosing these characteristics, the meteorologist is able to quickly deduce the location and relative intensities of the associated vorticity centres as well as the relative sizes of the associated circulations. This information is summarized within the shape and orientation of the associated deformation zones. The deformation zones in turn reveal important details regarding feature motion and thermal advection and thus their diagnosis should be a critical part of the forecast process. This module takes 30-40 minutes to complete. It is part of the series: "Dynamic Feature Identification: The Satellite Palette".

Objectives:
* Compare the different characteristics of various flow patterns
* Locate the position and predict the relative intensities of vorticity centres along a flow
* Predict the position of the associated deformation zones based on the location and intensities of the vorticity centres

Estimated time to complete: 30-40 min

Includes audio: yes

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

Last published on: 2008-03-21

close

Description:
This exercise tracks Hurricane Michael as it moved into the Maritime region of the Canadian east coast in October, 2000. Analyze data and respond to questions focusing on forecasting the progression of the storm. This case exercise accompanies the Webcast, Hurricanes Canadian Style: Extratropical Transition.

Objectives:
• Distinguish between meteorological parameters favorable to tropical cyclone strengthening and weakening
• Identify meteorological parameters favorable for extratropical transition
• Apply the guidelines used for forecasting the motion of a tropical cyclone undergoing extratropical transition

Estimated time to complete: 30-45 min

Includes audio: yes

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

Last published on: 2002-06-06

close

Description:
This series addresses the use of satellite imagery and focuses attention on the identification of dynamic features using high-resolution satellite imagery with NWP verification. The series will eventually include more than 20 feature presentations on topics such as comma clouds, jet streaks, deformation zones, surface features, convection, and blocking.

Each feature presentation includes interactive identification exercises, analysis and diagnosis, conceptual models, and forecast implications.

Objectives:
• Analyze and diagnose dynamic features in satellite imagery
• Identify discrepancies between numerical model forecasts and atmospheric features
• Apply conceptual models to an atmospheric feature and correct for discrepancies between observed and numerical model analysis

Estimated time to complete: 20-90 min

Includes audio: no

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

Last published on: 2006-01-10

close

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

close

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

close

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

close

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

close

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

close

Description:
This Webcast is based on a presentation delivered by Jim Abraham of MSC at the Winter Weather Course in February 2001. The presentation discusses how, under the right synoptic conditions, hurricanes and tropical storms undergo a transition process to extratropical cyclones as they move into northern latitudes. During the transition process these "hybrid" systems can bring damaging weather conditions to Eastern Canada and the Northeastern States. It uses several case examples to demonstrate the process.

Objectives:
• Identify meteorological parameters favorable for tropical cyclone formation
• Identify meteorological parameters that inhibit hurricane intensification
• Describe the characteristics of a tropical cyclone prior to extra-tropical transition
• Describe the characteristics of transitioning tropical cyclones
• Detail the regions of a tropical cyclone and extratropical low that generate the greatest rainfall and winds

Estimated time to complete: 45 min

Includes audio: yes

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

Last published on: 2002-05-02

close

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

close

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

close

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

close