Published on: 2019-10-30
Estimated time to complete: .50 - .75 h
Includes audio: no
Topic Area(s)
Numerical Modeling (NWP)
Winter Weather
Description:
Winter weather is one of the more challenging aspects of operational weather forecasting. Factors affecting the impact of winter storms include precipitation type, timing of precipitation onset and precipitation type changeovers, winds, visibility, temperature, and the temporal and spatial scales of high impact weather features such as mesoscale precipitation bands. The National Blend of Models version 3.2 incorporates a number of NWP model and ensemble forecast system (EFS) components. To make the probabilistic guidance more robust, deterministic components of the blend are combined with each ensemble member of the EFS to develop probabilistic winter guidance. This guidance helps the operational forecasters provide decision support to government officials, responding to winter weather events.
This lesson will help operational weather forecasters use NBM v3.2 winter weather guidance to assess risk and make forecasts for winter weather events.
Objectives:
Upon completion of this lesson, the learner should be able to:
- Identify at least two of the changes to the diagnosis of forecast winter weather elements in NBM v3.2
- Identify at least three probabilistic winter weather elements in NBM v3.2.
- Identify at least three deterministic winter weather elements in NBM v3.2.
- Demonstrate the appropriate use of NBM v3.2 probabilistic winter weather elements, through winter weather case examples.
Keywords
NBM, National Blend of Models, the Blend, winter weather, winter guidance, winter weather elements, precipitation type, blend techniques, probabilistic NWP, probabilistic products, probability of exceedance, snow, sleet, ice pellets, freezing rain, snow accumulation, ice accumulation, incident decision support services guidance, IDSS