FOUS30 KWBC 190824
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
324 AM EST Thu Feb 19 2026

Day 1
Valid 12Z Thu Feb 19 2026 - 12Z Fri Feb 20 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS SOUTHERN
CALIFORNIA AND PORTIONS OF THE OHIO VALLEY INTO THE CENTRAL APPALACHIANS...

...Southern California...
A strong mid-level shortwave will bring an increase in rainfall to
southern CA this morning into the afternoon. This is a quick moving
system that will not have a lot of moisture to work with. Plenty 
of cold air aloft though, which will allow for upwards of a couple
hundred J/kg of CAPE and some localized heavier rainfall rates. 
The quick cell motions and limited moisture will keep rainfall 
totals generally under 1", possibly as high as ~1.5" in favored 
upslope areas. Hourly rainfall should peak in the 0.25"-0.5" range,
although very localized amounts over 0.5" are probable. Overall, 
we would not expect these totals or rates to result in a 
significant flood risk. Given high soil moisture from rainfall 
earlier this week, this additional rainfall could be enough to 
result in localized minor flood impacts.

...OH valley into central Appalachians...
Multiple rounds of showers and embedded thunderstorms may result in
a localized flood risk today into tonight across portions of
eastern KY, southern OH and into WV and southwest PA. WAA this
morning into this afternoon will result in an uptick in convection
across this corridor, with the cold frontal passage tonight accompanied
by additional showers and thunderstorms. By late tonight much of 
this region could be looking at 1-2" of rainfall, with localized 
totals potentially getting into the 2-3" range. 

The 06z HRRR and 00z Gem Reg are in good agreement on this 
axis of heavier rainfall, with the 00z ECMWF and AIFS in the same 
ballpark as well. Not really sure why the 00z ARW, ARW2, 3km NAM 
are so sparse with convection and light with rainfall totals. Their
evolution is not supported by the favorable mesoscale and large 
scale pattern, and so prefer leaning towards the wetter non- ncep 
guidance and recent HRRR runs. Based on forecast instability and 
recent HRRR output, hourly rainfall could locally approach and 
exceed 1" across this corridor both with the WAA convection and 
cold frontal activity. NASA SPoRT soil moisture analysis shows 
above average soil saturation across this region as well. So, 
while not expecting widespread or significant flood impacts, the 
combination of total rainfall locally exceeding 2", hourly rainfall
approaching 1", and high soil saturation...suggests that at least 
some minor runoff concerns could evolve today into tonight.

An axis of stronger convection may materialize farther northwest 
of the Marginal risk across portions of IL/IN/OH. While heavier 
short term rates are likely here, the current expectation is that 
activity will be more progressive and thus the higher rates more 
short lived. Soil conditions are also considerably drier across 
this corridor, and so we will not include this region in the 
Marginal risk for now. 

Chenard


Day 2
Valid 12Z Fri Feb 20 2026 - 12Z Sat Feb 21 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Chenard


Day 3
Valid 12Z Sat Feb 21 2026 - 12Z Sun Feb 22 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Chenard
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