211
AGUS74 KWCO 281530
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT THU AUG 28 2025

.Synopsis...
Flash, urban, and riverine flooding is possible across the Central Plains
into the Southeast... Isolated flash and urban flooding expected across the
Southwest into the Southern Plains... River rises/potential flooding in
Alaska...

.Central Plains into the Southeast...
Showers and thunderstorms will continue this morning across portions of
southern KS into the portions of the western and southern Ozarks which may
bring additional flash and urban flooding impacts, along with rapid rises
on streams and rivers. Soils are wet from overnight rainfall (0 - 10cm RSM,
NASA SPoRT) and flows are above normal (USGS) which suggests efficient
overland flow is possible into already swollen streams and rivers.
Furthermore, basins with complex terrain may also be more susceptible to
flash and urban flooding due to increased runoff. Isolated minor river
flooding is ongoing and forecast in portions of south KS and northern OK.
The National Water Model Short Range Forecast is hinting at some isolated
50% probabilities of rapid onset flooding generally concentrated in the
Ozarks. These rises are forecast to peak in flow over the course of the
next 4 - 8 hours with the mainstem rivers following thereafter through the
end of the week as high flows are routed out of the tributaries.

The forecast heavy rainfall will continue into this weekend and begin to
sag south and east into portions of MS, LA, and AL which may cause some
instances of isolated flash and urban flooding. Soils and streams are much
less conducive to hydrologic impacts as drier conditions and below normal
flows prevail across much of the region. High rainfall rates and training
thunderstorms are likely going to be the primary driver for flooding
impacts. River ensemble guidance is suggesting isolated rises to minor
should not be ruled out, but will be highly dependent on the training
rainfall mentioned above.

.Southwest into the Southern Plains...
Monsoonal moisture continues to threaten the area with instances of
isolated flash and urban flooding, particularly over recently burned areas.
Rainfall forecasts for the next 3 days suggest the majority of the forecast
QPF will be in the TX and OK Panhandles and gradually sinking south before
another potential push into the NM by late next week. Confidence in the
exact placement and magnitude is low late in the period due to the timing.
The rainfall totals are broadly 1 - 3" with some embedded higher totals,
which combined with recently burned areas may cause debris flows and
subsequent flash flooding.

.Alaska...
A period of wet and unsettled weather is expected to continue across much
of the state, with the heaviest rainfall totals in the south and west of
Fairbanks, through the end of the week. River rises and subsequent flooding
are ongoing across portions of the Upper Koyukuk River basin following
recent rainfall over the past several days. Sharp river rises are possible
across the remainder of the Koyukuk and Kobuk basins. Additional rainfall
impacting south-central AK may generate sharp rises and subsequent flooding
along streams and rivers across the Kenai Peninsula, across the Prince
William Sound, and along the Yentna, Susitna and Skwentna rivers over the
next 72 hours.

//JAC

$$