Description:
This webcast introduces the different marine forecast customers and discusses what forecast information they need to know and why they need to know it. A better understanding of the needs of the marine forecast customer will lead to better daily forecasts.

Objectives:
Objectives
1. Give marine forecasters a basic understanding of who the marine customers are and what their needs are.
2. Understand what is important to the marine customers and why.
3. Understand characteristics of specific water craft types.

Estimated time to complete: 90 min

Description:
This is the first in a series of new marine meteorology modules based on COMET’s old laser disk and CD-ROM modules on marine meteorology. This module is an introduction to waves and their associated characteristics. Several types of waves are presented, from the common wind wave to the rare tsunami wave. The basic physical, mathematical, and statistical traits of waves are discussed, along with how they change once waves become swell. This material serves as a building block to subsequent modules on wave generation, propagation, and dispersion.

Objectives:
After completing the module users will be able to:
- Recall the different wave types based on their different generation sources.
- Describe the physical characteristics of these different wave types, including anatomy and nomenclature
- Recall the mathematical expressions and equations that define physical characteristics
- Recall the statistical traits (i.e., wave spectrum and height
classifications) of waves.
- Describe the processes related to swell travel and dispersion.

Estimated time to complete: 1 h

Description:
This is the second in a series of training modules on marine wind and waves. The first module discussed wave types and characteristics and is a good primer to this next marine training topic. Wave Life Cycle I: Generation examines how wind creates waves and the inter-relationships between wind speed, wind duration, and fetch length during this process. These three factors are important to predicting wave height and what will limit wave growth. Additional topics include fully developed seas, observation sources, and various special wind events such as coastal jets and instability mixing in the marine boundary layer. While much of this instruction is at a basic level, all marine forecasters will find benefit in the more intermediate and advanced topics. These include the issue of dynamic or “trapped” fetch as well as the use of satellite-based observations of marine winds using the active microwave technique known as scatterometry. User interactions are included throughout the module and within the short case study. The next module in the series will look at propagation and dispersion as the waves leave the generation area.

Objectives:
After completing the module users will be able to:
- Describe how wind generates waves, including how wind speed, fetch length, and duration interact to affect the wave growth process.
- Use a wave nomogram to manually estimate wave height.
- Describe the remote sensing and numerical prediction tools that aid forecasting of wave generation.
- Describe fully developed seas.
- List in situ as well as remote sensing sources of wind observations and describe their capabilities.
- Recall some of the various special wind events such as coastal jets and instability mixing in the marine boundary layer that affect wave generation.
- Describe the issue of dynamic or "trapped" fetch.

Estimated time to complete: 60-90 min

Description:
The goal of the module is to enable a marine forecaster to manually predict how the wave height and period will change as the waves leave their generation area, become swell, and then propagate and disperse into the forecaster’s offshore coastal waters. While numerical wave prediction models can provide swell height and period forecasts, they are dependent on accurate wind forecasts by atmospheric prediction models. Therefore, manual skills in determining swell height and period are needed in order to cross-check or correct model predictions in cases of poor or unresolved model forecasts of winds. The module starts by discussing how swell propagate along great circle tracks and how these tracks will look different on various map projections. With this in mind the concept of developing a known “swell window” for a given location is introduced. Next, the module uses conceptual animations to demonstrate the effects of dispersion on the swell group as it propagates over a long distance. Also discussed are nonlinear processes, wave steepness, travel time, event duration, and opposing winds. Then the module explains how swell height changes due to angular spreading of wave energy and provides a simplified method to calculate this change. Finally, users are able to test their new understanding of these concepts through a short exercise where they are asked to determine swell height and period at multiple locations. User interactions are included throughout the module and within the short exercise. This is the third in a series of training modules on marine wind and waves. It follows the “Wave Types and Characteristics” and “Wave Generation” modules.

Objectives:
1.State the difference between seas and swell.
2.Recognize that waves propagate along great circle tracks and that these tracks look different on various 2-dimensional map projections.
3.Consider the effects of diffraction around barriers in forecasting swell heights.

4.Identify the effects of dispersion on a wave group, including:
a. waves become sorted by wave period
b. longer period waves outrun shorter period waves
c. swell height and steepness decrease
d. the wave group expands in space
e. the time it takes the entire wave group to pass a point increases

5.Explain how significant swell period can lengthen over time due to nonlinear interactions and dispersion, while individual swell period is conserved.

6.Given initial swell period, propagation distance, and fetch width, use a nomogram to forecast the change in significant swell period due to dispersion of a wave group.

7.Given initial or final swell period, propagation distance, and fetch width, use a swell travel time chart to forecast the time a swell to begin to impact a destination.

8.Using a swell travel time chart, forecast the length of time a wave group will affect a coastal area.

9.Given significant wave height for waves propagating in the central direction of a fetch area, forecast the decrease in significant wave height due to angular spreading for locations up to 70 degrees off the central direction of the wave group.

Estimated time to complete: 60 min

Description:
This module is intended for experienced forecasters moving from a land-based area to a coastal or Great Lakes region where both over-land and over-water forecast areas exist. This module highlights the differences between marine boundary layer and terrestrial boundary layer winds. The experienced forecaster is relatively familiar with the boundary layer over land and the associated implications for the wind field. Using this as a base, the module compares this known quantity with the lesser-known processes that occur in the marine boundary layer. Three major topics that influence marine boundary layer winds are discussed: stability within the boundary layer, isallobaric influence, and the effects of convection and tropical cyclones.

Objectives:
• Highlight the major differences between boundary-layer winds in the marine and over-land environments.
• Examine surface wind differences in stable and unstable boundary layers.
• Examine how the stability profile changes seasonally and diurnally.
• Assess the impact of isallobaric wind effects in a marine setting.
• Identify the main impacts of severe convection on marine winds.
• Recognize known model biases in predicting marine boundary layer winds and what situations require the forecaster to make adjustments.

Estimated time to complete: 2 h