Friday, May 21, 2010

Comparing Experimental QPF Outlooks with Hi-res model/radar data

As part of the 2010 HWT Spring Experiment (EFP), two new forecast components were added; Aviation and QPF. After analyzing various high-resolution (hi-res) models, outlooks were created for QPF expected to exceed 0.50 and 1 inch for two time periods (18-00 UTC and 00-06 UTC) for the Day 1 period. In the image below, you will see an example of one of these hi-res (WRF-HRRR) models 6-hour total precipitation overlayed with a "SLIGHT RISK" threat area for QPF exceeding 0.50 inch in the same 6-hour period. Each day during the Experiment, the morning forecast (threat area) was completed by 1530 UTC.

A screen capture of the latest composite reflectivity data is attached to show how the forecast is verifying to this point.

A "SLIGHT RISK" threat area is defined by 25 percent of the threat area expected to reach or exceed a specific amount (i.e. 0.50 inch).

David Nadler
Warning Coordination Meteorologist
NWS Huntsville AL