964
AGUS74 KWCO 161550 RRA
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT MON JUN 16 2025

.Synopsis...
Small stream and flash flood potential continues for the Mid Atlantic into
the Upper Ohio Valley, Lower Ohio Valley, and Central Plains and Upper
Midwest... Snowmelt runoff concerns across Northern Alaska... Ongoing river
flooding in East Texas into Louisiana...

.Mid Atlantic into the Upper Ohio Valley...
Flash flooding is possible through day 2 (Tue) especially across eastern NC
through southcentral VA into WV due to multiple rounds of heavy rainfall
falling in basins that have already seen totals of 1 - 4"+ over the last 72
hours (MRMS). Confidence is low in the exact placement and magnitude of
flooding impacts due to the convective nature of the rainfall, but the more
hydrologically vulnerable areas include Greenville/Rocky Mount, NC where 4
- 6" have fallen in the last 24 hours alone, as well as the more complex
terrain of western VA into WV. The National Water Model (NWM) SRF supports
the potential for locally significant flooding with pockets of annual
exceedance probabilities (AEPs) in the 50 - 10% range scattered across the
region. Unsurprisingly given the recent rainfall, eastern NC is showing
high potential for extensive flooding with a swath of AEPs in the 20 - 10%
range near the aforementioned Greenville/Rocky Mount area.
Rapid-onset-flooding (ROF) probability signals are sparse, but isolated
basins in eastern NC and along the VA/WV border are showing 25 - 50% ROF
probabilities, slightly increasing confidence in the potential for flooding
in these areas. Recent runs of the HRRR have also been lighting up streams
in the vicinity of John H. Kerr Reservoir and this area will continue to be
watched as the system develops.

.Lower Ohio Valley...
Heavy rainfall totals of 2"+ (WPC) are expected across southeast MO into IL
and KY through today and bring the potential for isolated flash, urban, and
small stream flooding. Soil moistures are elevated across the region (NWM
soil moisture analysis) and streams are running at or above mean annual
flows (USGS), suggesting that antecedent conditions are vulnerable enough
that persisting heavy rain/storm training could lead to localized
significant flooding impacts. The NWM SRF supports the localized flood
threat with scattered pockets of stream reaches exceeding the 20 - 4% AEP
thresholds.

.Central Plains and Upper Midwest...
Heavy rainfall (1 - 2"+, WPC) is expected across eastern NE/KS into MO and
IA on day 2 (Tue) and brings with it the potential for isolated flash
flooding impacts. The QPF has continued to shift southward and is no longer
expected to overlap the more hydrologically vulnerable parts of southern
MN. That being said, northern IA has received rainfall totals of 1 - 3"
over the last 72 hours (RFC QPE) and isolated flash and small stream
flooding impacts from this next round of rainfall cannot be ruled out.
Outside of northern IA, the flooding threat is mitigated by drier soils
(NWM soil moisture analysis) and streamflows near or below normal (USGS),
but urban and nuisance flooding remains possible should persistent heavy
rainfall materialize.

.East Texas into Lousiana...
Minor and moderate river flooding is ongoing across the area, and major
flooding is ongoing in the Trinity and Neches basins. Recent rainfall has
caused renewed rises on some rivers delaying the recession of floodwaters.
Most rivers will be in recession by the end of the week.

.Northern Alaska...
Flooding along North Slope rivers is possible through mid week. An above
average late season snowpack combined with temperatures rising into the 60s
and 70s is expected to cause a rapid snowmelt. With ice intact on larger
rivers, ice jams could result from the snowmelt entering the rivers and
lead to sudden rises and flooding. High flows or flooding could lead to
bank erosion that could threaten nearby roads and impact access to
airstrips and low lying infrastructure. River levels are likely to crest
through early this week.

//Bliss



$$