718
AGUS74 KWCO 011551 CCA
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL...CORRECTED
NWS National Water Center - Tuscaloosa AL
10:15 AM CDT TUE JUL 1 2025

.Synopsis...
Flooding possible through midweek in Florida... Flash flooding possible
through this week in the Southwest into the Southern Plains... Localized
flash and urban flooding possible in the Mid-Atlantic into the Northeast...

.Florida...
Periods of heavy rainfall may generate isolated flash and urban flooding
impacts along the I-10 corridor in FL through midweek. For most of the
state, current soil moisture values are near normal to slightly elevated at
50 -65% relative soil moisture, (0 - 10cm NASA SPoRT) and streamflow
values are near to below normal for this time of year (USGS), which
suggests infiltration capacity initially. The exception to this is the FL
Big Bend region, where wetter soils of greater than 85% relative soil
moisture (0-10cm, NASA SPoRT) are in place following recent rainfall, which
indicates slightly greater hydrologic sensitivity to rainfall. As of now,
the primary threat is urban flooding given the dense urban infrastructure
along the I-10 corridor. Both the GFS and NBM-forced NWM are indicating
little to no responses, as the heaviest QPF remains off of the coast. Most
flooding impacts should be from isolated convection.

.Southwest into the Southern Plains...
Sporadic convection due to abundant moisture and remnants of Tropical Storm
Barry, may lead to multiple rounds of heavy showers and flooding through
day 6 (Sun). In far western TX, the NWM is showing some isolated rapid
onset probability signals and recent rainfall in the area has elevated
pockets of soil moisture to near 90% (0-10cm, NASA SPoRT) suggesting some
threat of flash flooding. Additionally, heavier precipitation totals are
possible over the Sacramento Mountains in NM, which could lead to flash and
arroyo flooding through the week. Ponding of water in low lying areas may
be a concern. In general, recently burned areas will be particularly
vulnerable to flash flooding.

.Mid-Atlantic into the Northeast...
A progressive front embedded with convection may introduce the threat of
localized flash flooding through day 1 and possibly into day 2 (Tue - Wed).
Soils in the region are saturated at 50 - 70% relative soil moisture
(0-10cm, NASA SPoRT) suggesting there is some infiltration capacity
available. However, the NWM is showing rapid onset flooding probability
(ROF) signals ranging between 25 - 75% in areas such as Washington D.C.,
MD, northern VA, southern PA, and even eastern OH. Over the past 24 hours
there have been areas, such as Lancaster, PA, who have
received 5"+ of rain. There is a chance these storms could stall which
would lead to heavy downpours. Steep terrain in the foothills of the
Appalachian mountains and urban areas are particularly vulnerable to the
threat of prolonged and heavy showers.

//DLeisure

$$