Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
324 AM EST Fri Nov 21 2025

Day 1
Valid 12Z Fri Nov 21 2025 - 12Z Sat Nov 22 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF 
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA...

Showers and thunderstorms are expected across southern California,
southern Nevada and southwest Arizona as lobes of vorticity rotate
to the east of the low offshore. Instability appears to be on the
weak side which will likely be a limiting factor, however some 
brief heavier rates are still possible from short training segments
within the deep layer southerly flow. A Slight Risk for excessive
rainfall remains in effect for southern California and southwest
Arizona and a Marginal Risk spans from the California coast to
south-central Arizona.

For the Missouri/Ohio/Tennessee Valleys there will be an elevated
threat for locally excessive rainfall. During this period a steady
stream of above average moisture will be transported northward and
encounter an east-west boundary. Isolated areas of moderate to 
heavy rainfall that leads to spotty problems from run-off can be
expected. However...the flow aloft becomes increasingly flat and 
confluent during the day which will reduce the risk of any 
excessive rainfall. A Marginal Risk area was maintained from
eastern Kansas to West Virginia/western Virginia/western North
Carolina.

Campbell


Day 2
Valid 12Z Sat Nov 22 2025 - 12Z Sun Nov 23 2025

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

Campbell


Day 3
Valid 12Z Sun Nov 23 2025 - 12Z Mon Nov 24 2025

...There is a Slight Risk for excessive rainfall in the Southern 
Plains...

The low pressure system that brought heavy rainfall for the West
Coast during the Day 1 period will be exiting into the Southern
Plains and the warm, moist air will support scattered to widespread
heavy rainfall. There is an increasing signal that this setup could
be a significant event, especially for north-central portions of 
Texas and into southern Oklahoma where a couple of solutions are 
suggesting a narrow swath of 4 to 6 inches possible. A Slight Risk
for excessive rainfall is in effect for for much of north-
central/northeast Texas and south/east Oklahoma. A broader Marginal
Risk spans from the Big Bend vicinity to southwest Missouri and
western Arkansas. This part of the country will continue to be
monitored for a possible upgrade to a Moderate with future updates.

Campbell


Day 1 threat area: https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Day 2 threat area: https://www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Day 3 threat area: https://www.wpc.ncep.noaa.gov/qpf/99epoints.txt