Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
429 AM EDT Tue Oct 03 2023
Valid 12Z Tue Oct 03 2023 - 12Z Wed Oct 04 2023
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE TEXAS COAST...
Southeasterly flow from the Gulf of Mexico will interact with a
coastal trough to produce showers and thunderstorms this afternoon
and early evening. Heavy rainfall is possible within the Slight
Risk area, between Houston and Corpus Christi this afternoon, when
instability will be at its peak (1000-15000J/Kg). There will be
plenty of moisture present, despite the lack of dynamic support,
with PWATs between 2-2.5" along the Texas coast. HREF neighborhood
exceedance probabilities of 2-5" are reasonably high at this time
so those were used as a proxy for this day 1 Slight Risk area.
...Great Plains and Upper Midwest...
A cold front moving across the Great Plains will act as a focus
for showers and thunderstorms today. Some locally heavy rain could
cause flash flooding, particularly over parts of eastern South
Dakota/Nebraska, but considering how dry the region is, that
threat is low for the most part. However, there's an increasing
signal for heavy rainfall to develop over portions of west Texas
south of Midland late this afternoon and evening. HREF exceedance
probabilities of over 2" are high for that area and there will be
substantial instability in place (1500-2000J/Kg) so an afternoon
upgrade may be necessary if upward trends continue.
The Day 2 outlook will be updated by 0830Z.
The Day 3 outlook will be updated by 0830Z.
Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt