Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
433 PM EDT Tue Mar 25 2025
Day 1
Valid 1831Z Tue Mar 25 2025 - 12Z Wed Mar 26 2025

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF NORTHEAST TEXAS INTO SOUTHERN OKLAHOMA AND SOUTHEAST FLORIDA...

...Florida...

Introduced a focused Marginal Risk area mainly in the urban corridor
along the southeast Florida coast from this afternoon into early
evening. Radar has shown an evolution similar to the 12Z run of the
HREF with convection expanding north and eastward along the
urbanized I-95 corridor...and at least enough of a signal in the 1-
and 2-inch per hour probabilities to warrant a Marginal Risk area.
Refer to Mesoscale Precipitation Discussion 0083 for further
details.

Bann

...Texas/Oklahoma...

Convection is expected to develop by 06z tonight across portions of
southern OK near and just north of a stationary front. Southerly
flow should advect enough moisture northward to generate upwards
of 1000-2000 j/kg of CAPE with a base just above the boundary
layer. This elevated convection will track off to the southeast,
generally parallel to the low level convergence axis...which
supports some training potential. The 3km NAM is the wettest model,
but we have seen elevated convective setups like this verify
towards the higher end of the model spread, and the 3km NAM has
performed decently at these events in the past. So while it depicts
a lower probability outcome based on all available guidance, and a
swath of 1-3" is most likely, can not rule out a localized swath
of 3-6" of rain across portions of northeast TX into southern OK
late tonight into Wednesday morning.

Overall the flash flood risk at any location is low given the dry
antecedent conditions and narrow nature of any heavy rainfall
swath. However intense rainfall rates and some training could allow
for a localized flash flood threat to evolve, particularly if the
heavy rain overlaps any more sensitive urban or low lying area. We
opted to introduce a focused Marginal risk area to account for this
isolated potential.

Chenard


Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt