Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1152 AM EDT Thu May 15 2025
Day 3
Valid 12Z Sat May 17 2025 - 12Z Sun May 18 2025

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM CENTRAL
TEXAS THROUGH NORTHERN ALABAMA AS WELL AS FOR PORTIONS OF THE
NORTHEAST...

...Texas to Alabama...

Another round of afternoon and evening thunderstorms is expected
from northeast Texas into northern Alabama Saturday and Saturday
night. Continued influx of Gulf moisture and instability on
southerly flow will clash with the cooler, dry air mass behind a
cold frontal passage over much of the Midwest on Friday. The storms
will form along this frontal interface. With that said, the forcing
in the upper levels should be greatly reduced over this region as
compared with previous days, as the upper forcing on Saturday will
be associated with a fast moving and weaker shortwave. This should
limit the coverage of storms. Once again however, recent heavy
rains in this area continue to keep the soils wet, and therefore
more prone to flash flooding. Should the forcing increase or amount
of moisture off the Gulf increase compared to current forecasts,
then it's possible a targeted Slight may eventually be needed,
with the DFW Metroplex area currently appearing to be at greatest
risk for an upgrade.

...Northeast...

Periods of heavy rain will move across the Northeast Saturday
afternoon ahead of a potent upper level low moving across the Great
Lakes. The storms will occur ahead of the upper low. There is some
uncertainty on storm coverage and intensity with moisture amounts
being limited in this area, but it is made up for by wetter than
average soils in this area of New England and New York. The
inherited Marginal Risk was trimmed out of most of Maine, as soils
there are drier than normal, which should allow any rainfall (which
should be less than an inch) to be absorbed by the dry soils.

The greatest flash flooding risk is likely in the Green and White
Mountains where terrain will worsen any potential flash flooding.

Wegman

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt