Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
852 PM EDT Sat Jul 5 2025
Day 2
Valid 12Z Sun Jul 06 2025 - 12Z Mon Jul 07 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
CENTRAL TEXAS AS WELL AS FOR PORTIONS OF THE CAROLINAS...

...2030Z Update...

...Central Texas...

In coordination with SJT/San Angelo, TX and FWD/Fort Worth, TX
forecast offices, a Slight Risk upgrade was introduced with this
update for portions of central Texas. While moisture amounts and
advection will both be waning by Sunday, especially as compared
with previous days, there will certainly still be enough moisture
and forcing to allow for a renewed round of slow-moving showers and
thunderstorms to affect this area. The biggest contributing factor
to the upgrade is the ongoing flooding and its associated impacts.
Thus, even lesser amounts of rain, as forecast on Sunday, will
have outsized impacts given the vulnerabilities in that area. The
storms should taper off by sunset across central Texas, ushering in
a prolonged period of much drier weather.

...Carolinas/TS Chantal...

With the guidance better handling TS Chantal and its track through
the Carolinas, and a bit stronger storm forecast to make landfall
in South Carolina tonight, by Sunday the storm will be rapidly
weakening. However, its associated rainfall and abundant moisture
will persist well inland from the landfall point. Most of the
guidance is in very good agreement on where the swath of heaviest
rainfall will occur on Sunday, namely from north-central South
Carolina through central North Carolina. For now...the consensus
keeps the rainfall shield just east of Charlotte, but may impact
Greensboro, and perhaps Raleigh and Winston-Salem. Forecast
rainfall has increased markedly, with the swath of rainfall now
featuring amounts exceeding 3 inches in 24 hours (of course local
rainfall amounts will be higher). Despite antecedent dry soil
conditions, the potential for very heavy rainfall with Chantal's
remnants are very likely overcome the initially dry soils in that
area, resulting in flash flooding. However, the dry antecedent
conditions should at least delay any flooding, and of course take a
little off the top of any flooding's severity. Thus, have
introduced a Slight Risk for north-central South Carolina and
portions of central North Carolina, with an area from Greensboro
south into northern South Carolina in a higher-end Slight Risk.

Any slowing of the storm or a better signal for heavy rainfall over
a bigger urban center would require a targeted Moderate Risk
upgrade with future updates.

...Central Gulf Coast...

Widely scattered showers and thunderstorms across southern
Louisiana will have ample Gulf moisture to feed upon Sunday
afternoon. With the potential for any of those storms moving over a
sensitive urban area such as New Orleans or Baton Rouge, a Marginal
Risk was introduced with this update.

Wegman


Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt