312
AGUS74 KWCO 061520
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT MON OCT 6 2025

.Synopsis...
Potential for isolated flash and urban flooding continues for portions of
the Florida Peninsula...  Heavy rainfall potential across the Four Corners
and Southwest late this week...Ongoing coastal flooding in Western
Alaska...Potential for isolated flash and urban flooding in the Lower
Mississippi and Ohio Valley

.Florida Peninsula...
The Florida Peninsula will remain vulnerable to flooding impacts for at
least the next week. Rainfall associated with a persistent easterly flow
will continue to fall on this primed landscape, leading to a continued
threat of urban, small stream, and coastal flooding through tonight. This
is a classic compound flooding event, where multiple factors are working
together to enhance the risk. The first is, consistent rainfall has already
elevated soil moisture across the peninsula, leaving little capacity for
the ground to absorb new rain. Also, unusually high astronomical tides,
known as King Tides, are raising coastal water levels. This slows or even
prevents freshwater drainage from rivers and canals into the ocean, causing
water to back up inland. Finally, many streams, particularly in southern
Florida, are already running high, further reducing the efficiency of the
drainage network.

Additional rainfall on days 4 - 5 (Thu - Fri) has the potential to bring a
new round of flash and urban flooding to the area. Due to the spread in
rainfall forecasts, there is a considerable amount of uncertainty in the
exact placement of flood impacts, if any.

.Four Corners and Southwest...
Later this week, daily rounds of moderate to locally heavy rainfall are
expected to begin on day 4 (Thu) across this region. While forecast
confidence remains low for the exact location of impacts due to model
spread, rainfall forecasts on day 6-7 focus the heaviest rainfall over the
Mogollon Rim of AZ and into the mountains of SW NM. Impacts at this time
are mainly expected to be flash, urban, and arroyo flooding. Any burn scars
in the region will remain a threat with the potential for flash flooding
and debris flows.

Western Alaska...
A coastal flood event is developing across portions of western Alaska, with
moderate to major coastal flooding expected. This event will be prolonged
through day 4 (Thu) by a system bringing high winds, locally heavy
rainfall, and storm surge. As the associated precipitation moves further
inland, it could exacerbate inland freshwater flooding on coastal rivers.

Lower Mississippi and Ohio Valley...
For days 1 - 2 (Mon - Tue), there is a threat of isolated flash and urban
flooding, with the Memphis and Nashville TN as well as Louisville, KY metro
areas being at risk for urban flash flooding. The overall flood threat
across this region is low, as soil moisture values are extremely low with
streamflows running near their seasonal normal (low) values. Due to the dry
soil moisture values, a river flood event is not expected.

//Leisure

$$