Modifying NWP Output Course

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Description

The Modifying NWP course addresses how forecasters can assess NWP outputs and modify their forecasts. The five short video lessons present methods that can be used to compare observed weather and NWP output, along with ways to modify identified mismatches between NWP and observed weather in order to adjust for elements the models sometimes miss.

Prerequisites Include:

  • Satellite Feature Identification: Inferring Three Dimensions from Water Vapour Imagery
  • Satellite Feature Identification: Conveyor Belts
  • Deformation Zone Analysis
  • Vorticity Maxima and Comma Patterns
  • Vorticity Minima and Anticomma Patterns

Because there are no quizzes for these lessons, there is no completion certificate for this course. This is simply a suggested learning path through lessons with related and complementary topics.

Goals and Objectives

  • Assess relevant NWP output compared to surface observations.
    • Identify a possible process responsible for the mismatch.
  • Assess relevant NWP output compared to observed total-column integrations.
    • Interrogate mismatches with cross-sectional views and your 3D mental model.
    • Identify a possible process responsible for the mismatch.
  • Assess relevant NWP output compared to observed satellite imagery.
    • Identify a possible process responsible for the mismatch.
  • Define the different pieces of the PV equation.
  • Identify on a 1.5PVU height field what the likely contributors are to the PV height value.
  • Identify conveyor belts and vorticity centers from a 1.5PVU surface.
  • Identify the processes that are NOT included in the PV equation.
  • Identify the type of mismatch (spatial, temporal, magnitude, or existence) from potential vorticity overlays on water vapor imagery.
  • Based on the type of mismatch, adjust the PV surface and then the appropriate surface sensible weather variables based on process changes.
  • Know when to evaluate vertical cross sections of PV versus water vapor imagery.

Overview

This course is a 5-part series of short video lessons with interspersed exercises to encourage your active learning.  The following five lessons are included in this series.

Introduction to Modifying NWP Output

Surface observations are usually the first place we go when trying to find mismatches between observed weather and NWP output.  We'll talk in this lesson about appropriate methods for making those comparisons and build to a point where we will focus on bigger picture atmospheric processes.  

NWP Comparisons: Total Column Variables

Another way to try to find mismatches between observed weather and NWP output is by using total-column variables.  There are a few of them to choose from, and they make for a relatively simple comparison method for finding correctable mismatches.  In this lesson, we'll address appropriate methods for making these comparisons and build to a point where we will focus on bigger picture atmospheric processes.

Adjusting NWP: Direct comparison

If there were a way to make direct comparisons between satellite imagery and NWP output, that would appear to be the best possible way to find mismatches between the observed weather and NWP output.  In this lesson, we'll address possible methods for making direct comparisons, starting with pseudo or synthetic satellite imagery and building to a point where we focus on a relatively unused NWP output.

Introduction to PV

You've been introduced to Potential Vorticity (PV) as a concept or as a useful tool for NWP assessment, but what is PV really?  We'll dive into PV in this lesson and attempt to answer some of the more common questions about PV as a product.

PV Modification

You know what PV is, yet aren't quite sure how to modify it to make a better forecast.  In this short lesson, we will discuss how to modify the PV surface to match water vapour imagery and how those adjustments affect the surface sensible weather.

Course Outline

Additional Resources

Course Outline