INTELLIGENT USE OF THE AVN/MRF
Understanding the performance of an operational model is critical to being able to forecast the sensible weather
Why models have forecast problems
The way the physics are approximated can lead to model errors, for example
AVN/MRF APPROXIMATED PHYSICS
A NUMBER OF AVN/MRF PERFORMANCE CHARACTERISTICS HAVE CHANGED IN THE PAST YEAR.
LATEST AVN/MRF CHANGES
AVN/MRF Often Have Problems Handling Upslope Events
About 75% of the AVN Rainfall Over the OK Panhandle Was Grid-scale Precipitation (Not Convection).
Another Case: AVN Wraps Low Too Far North And West. Both Surface and 500 mb Lows Are Too Deep.
Aviation Model handling of 500 mb trough
BIAS COMPARISON OF 12-36 HR MRF AND EARLY ETA FORECASTS
The MRF and MRFX spin-up precipitation bombs and tropical systems erroneously at all time ranges.
MRF PRECIPITATION Convective - dashed Gridscale - solid green (inches -vs- time) BEFORE 7/21 AFTER 7/21
MRF RELATIVE HUMIDITY (pressure -vs- time) BEFORE 7/21 AFTER 7/21
MRF THETA-E (pressure -vs- time) BEFORE 7/21 AFTER 7/21
MRF PERFORMANCE FOR 3-5 DAY FORECASTS
MRF PERFORMACE FOR 3-5 DAY FORECASTS (CONT)
THE NGM AND AVN/MRF HAVE SERIOUS PROBLEMS WITH ARCTIC AIRMASSES
Why models have problems with arctic airmasses
LOWS TO THE LEE OF THE ROCKIES
Email: michael.eckert@noaa.gov
Home Page: www.hpc.ncep.noaa.gov/research/res2.html
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