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AGUS74 KWCO 031512
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT THU JUL 3 2025

.Synopsis...
Periods of heavy rain are expected across Florida into the Carolinas
through the weekend, causing isolated flash and urban flooding... Isolated
flooding potential across the Southwest into the Southern Plains through
Thursday... Renewed flood potential increasing for the Northern Plains...

.Florida into the Carolinas...
Periods of heavy rainfall will likely produce isolated flash and urban
flooding impacts along the I-10 and I-75 corridors in FL through at least
day 2 (Fri) and potentially into the weekend. Flooding impacts should be
mostly constrained to urban areas. QPF over the state has significantly
decreased, resulting in both GFS and NWM-forced NWM signals to become
almost non-existent over the state and decreasing confidence of small
stream flooding outside of channelized urban basins. Convection most likely
moves up the southeast coast this weekend bringing the potential for flash
and urban flooding. The area that is most vulnerable to flooding would be
near the SC/NC border onto the east-central North Carolina coastal plains
as soils are nearing saturation (NASA SPoRT 0 - 10 cm).

.Southwest into the Southern Plains...
Training convection over southeastern Oklahoma this morning into early this
afternoon will bring the potential for flooding over the region. NASA SPoRT
suggests that area top layer soils may have some capacity for infiltration
with 0 - 10 cm generally between 50 - 60%, however streams are generally
above normal. Heavy rainfall this morning over south-central parts of the
state have quickly saturated soils, indicating that even though there
mitigating factors to the east, soils still may quickly become overwhelmed
resulting in flash flooding and overland flow into already elevated streams.

Remnant tropical moisture and areas of convection will continue to produce
multiple rounds of heavy rainfall, and potentially isolated flooding today
across AZ, NM, and west TX. Heavy rainfall rates in the terrain across the
region will introduce the typical flash and arroyo flooding threat, as well
as potential flooding impacts across recently burned areas. In western TX
in the Big Bend to Odessa to San Angelo area, the NWM is showing isolated
potential for rapid onset flooding in this region that has elevated soil
moisture (70 - 90% 0 - 10cm RSM, NASA SPoRT) suggesting a locally increased
threat of flash flooding through this evening. Though convection should
generally be isolated, high-res models seem to be underperforming,
especially just east of the Rio Grande, which is most likely resulting in
the NWM underperforming.

.Northern Plains...
Rainfall returns to the region on days 2 - 3 (Fri - Sat), potentially
introducing a new and renewed flood threat to eastern NE, IA, and southern
MN by this weekend. Rainfall amounts are generally pretty low (1.5"
totals) however much of the region has been wet recently, with streamflows
still above normal across the aforementioned regions and multiple rivers
still in flood across southern MN from last weeks rainfall. The NBM and
GFS-forced NWM are showing potential for river rises across southern MN
through eastern NE by the end of this week, however much of the signal is
coming from a system in the middle of next week, with which there is very
low confidence.

//GKendrick

$$