961
AGUS74 KWCO 041523
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
915 AM CST WED DEC 4 2024

.Synopsis...
River ice related flooding potential continues for portions of Alaska and
the Northern Plains and Upper Midwest... Wet period for East Texas through
portions of the Lower Mississippi Valley... Heavy lake effect snow expected
for the Northeast...

.Discussion...

.Alaska...
Across the central and southern Panhandle, periods of moderate to heavy
rain and snowmelt will continue through today and may elicit river rises,
especially along small streams and rivers across Ketchikan, Metlakatia and
Prince of Wales.

.East Texas through portions of the Lower Mississippi Valley and the
Southeast...
Periods of rain are expected today through day 7 (Tue) from far southeast
TX through LA into MS and portions of the Southeast, which could produce
isolated flooding impacts. Heaviest rainfall will occur on day 5 in much of
LA and portions of eastern TX. Soil conditions are dry across these regions
(NASA SPoRT) with normal to below normal streamflows (USGS), which will
mitigate most of the hydrologic response this week. However, much rainfall
early on could moisten soils enough to see isolated hydrologic responses
across portions of LA and eastern TX. Guidance from the National Water
Model (NWM) Medium Range Forecast (MRF) shows very isolated small stream
rises across central LA into central MS, with most peak flows on smaller
headwaters not expected until days 5 - 8 (Sun - Wed).

.Northern Plains and Upper Midwest...
Intermittent periods of arctic air are expected across much of the region
throughout the week, leading to rapid stream and river ice development
across the region, particularly across the Dakotas, MN, and WI.This area
will need to be closely monitored for potential freeze up ice jams.

Northeast...
Heavy lake effect snow is expected for portions of northeast OH, northwest
PA and NY through the end of the week with the greatest snow amounts found
across areas of higher terrain. Warmer temperatures, increased winds, and
the possibility of rainfall early next week may produce snowmelt and runoff
through the region. Both the NBM and GFS forced versions of the NWM suggest
high flows are possible through the area in that time frame, however there
is still uncertainty in the forecast regarding all of the above mentioned
factors. Interests in this region will need to monitor forecasts through
the next several days for potential impacts.

//TMK





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