341
AGUS74 KWCO 241517
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT SUN AUG 24 2025

.Synopsis...
Potential for flooding across the Central and Southern Plains... Flash and
urban flooding possible in eastern North Carolina... Localized flash and
urban flooding expected across the Southwest and the Intermountain West...
Heavy rainfall forecast in Alaska...

.Central and Southern Plains...
A wet weather pattern bringing daily rounds of rainfall through the
forecast period will increase the potential for flooding impacts. Rainfall
totals of up to 7" are possible over the next 7 days (WPC), but confidence
is low regarding which areas may see hydrologic responses due to
uncertainties in the placement and magnitude of the heaviest QPF each day.
Antecedent conditions are not favorable for the formation of efficient
runoff processes, with dry topsoils (5 - 30% RSM, 0 - 10 cm, NASA SPoRT)
and streamflows running generally near mean annual flows (USGS). The level
of the flood threat is contingent on if and where the rainfall overlaps
from day to day. Currently, hydrologic models are not picking up on much of
a flood signal across the region. HEFS river ensembles are showing no
response at the 30% probability threshold, and only have minor to moderate
flooding occurring in the 10% threshold. Similarly Southern Region QPF
ensembles only have a small selection of gages actually reaching flood
status at the 5% threshold. The region will have to be monitored closely as
the week progresses as the high 7-day QPF total should elicit some concern
for flood potential, but beyond scattered urban flooding impacts, the
flooding will likely only materialize towards the end of the 7-day period.

.Southwest and the Intermountain West...
Daily monsoonal showers will continue into next week across the region,
with localized flash and urban flooding possible. While widespread flooding
is not expected, rapid rises on small streams in steep terrain with shallow
soils, as well as in arroyos, slot canyons, and normally dry washes, remain
possible where heavy rainfall occurs. Debris flows are also possible near
recently burned areas.

.North Carolina...
Isolated flash and urban flooding is possible through today along the North
Carolina coast, with the Outer Banks being the area most likely to see
heavy rainfall-induced flood responses. Most of the heavier QPF looks to
remain off of the coast, but should storm training set up, flooding impacts
cannot be ruled out.

.Alaska...
Multiple rounds of heavy rain are forecast across western and interior AK
through early next week, with rainfall totals exceeding 3" across the
Middle Kuskokwim, Yukon, Koyukuk, and Kobuk river basins. While neither
widespread river flooding nor impactful small stream flooding are expected
at this time, sharp rises are likely on tributaries to these basins this
weekend, with mainstem rivers responding early next week. High snow levels
may add runoff from glacier melt, and additional rain later in the week
could keep water levels elevated.

//Bliss



$$