1 / 11

PoP “We Want It But Don’t Get It”

PoP “We Want It But Don’t Get It”. Background Info. Lower 8 counties in Texas Complex terrain begins 70 miles west and southwest of Brownsville West, south, and southwest winds all downslope High RH in strong low level shear Model QPF and PoP almost always too generous

lyris
Download Presentation

PoP “We Want It But Don’t Get It”

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PoP“We Want It But Don’t Get It”

  2. Background Info • Lower 8 counties in Texas • Complex terrain begins 70 miles west and southwest of Brownsville • West, south, and southwest winds all downslope • High RH in strong low level shear • Model QPF and PoP almost always too generous • Model Thunder is often too agressive

  3. Cross Section of Deep South Texas

  4. Why ? • PW above 2 inches most likely to produce • Low level jet pumps up moisture but shreds/stretches convective column • Often results in light precipitation with streamer type showers • Thunder is also too generous in the models

  5. Is It a Best Practice? • Delete ALL model and SmartInit PoPs • 50% Modify the Wx grid and generate PoP • 50% Modify Pop and generate Wx • Still thinking of PoP as we used to and applying that to grids…then fragment into the required time blocks.

  6. Dangers • Unscientific – You bet! • Verification – Yeah right! • Accountability! • Meteorological Cancer – Well on the way!

  7. Population vs. Verification

  8. What Are We Searching For • A scientific or empirical formula tailored to our area. • Investigating the relationship between low level shear strength, PW and actual precip • Need to account for shear or a surrogate in GFE to get PoP more realistic.

  9. Conclusions • Meteorologists are proficient and comfortable, with current Zone type PoP • Sufficiently Vague for the “customers” • Basically making a mental transfer • Areal and Temporal Resolution, with verification will always be a problem.

More Related