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FOUS30 KWBC 241556
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1156 AM EDT Sat May 24 2025

Day 1
Valid 16Z Sat May 24 2025 - 12Z Sun May 25 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE OZARKS AND
MID-SOUTH...

...South-Central Plains through Mid-South into the Southeast...

16Z Update...
Organized mesoscale systems continuing this morning over eastern
OK, central AR and some activity over northern MS/AL. This activity
is waning with IR satellite imagery depicting warming trends.

There is general agreement among 12Z CAMs for afternoon
redevelopment over southeast KS/northeast OK over the Plains and
propagating southeast over eastern OK, southeast MO and much of AR
which all saw heavy rain over the past day (except for northwest AR
which was largely avoided). These storms should once again produce
heavy rainfall rates, per 12Z HREF with probabilities for 3 inches
in three hours and RAP guidance renewing 1.75 inch PW on the
continued southerly flow from the Gulf. Extra caution should be
given through the greater Ozarks region given this holiday weekend
with greater activity in and around flash flood prone areas.

Frontal convergence farther east through northern GA will allow
scattered heavy development where the Marginal Risk was expanded
through.


...Central High Plains...

Moist low level easterly flow maintains PWs of 0.75 to 1 inch (2+
standard deviations above normal), which along with mid-level
energy and right entrance region jet forcing, will continue to
support storm development with locally heavy rainfall over the High
Plains with afternoon development east from the Laramie Mountains
and Front Range. Slow storm motions could allow local rainfall of
2 to 3 inches. The Marginal Risk was expanded over western Neb and
southeast WY with some shrinking along the I-25 corridor in CO.

Jackson

Day 2
Valid 12Z Sun May 25 2025 - 12Z Mon May 26 2025

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FROM
FAR SOUTHEASTERN KANSAS AND NORTHEASTERN OKLAHOMA INTO THE
OZARKS...

...Southern and central Plains through the Ozarks into the
Tennessee Valley...

Storms developing Saturday night and early Sunday may remain
ongoing through the early part of the period across the Ozark
region. These storms are expected to move east and weaken early in
the period. However, there remains a strong signal for
redevelopment during the evening and overnight hours along a
lingering boundary extending from Oklahoma through the Ozarks.
Enhanced low level convergence will support pooling moisture,
fueling heavy rainfall rates with some potential for training as
this moisture interacts with a series of mid level shortwaves.
Meanwhile, strengthening southerly winds ahead of an amplified
trough moving across the Southwest will support deepening moisture
along the western extent of the front and an increasing threat for
heavy rainfall back across southwestern Oklahoma into northwestern
Texas. Some of this activity may also reach the Ozark region by the
end of the period. With these repeating events expected to push
rain totals into the 4-6 inch range in some spots, a Moderate Risk
centered over northeastern Oklahoma into the Ozarks was maintained.

While the better organized and heaviest amounts are expected to
center near the Ozarks, there is the potential for localized heavy
amounts, producing isolated flash flooding concerns, to spread
further east along the boundary through the Tennessee Valley and
into areas as far east as the southern Appalachians.

....Central Rockies/High Plains...
Moisture and forcing will remain favorable for additional rounds
of showers and thunderstorms, capable of producing heavy rainfall
rates. While widespread heavy totals are not expected, models do
show a notable signal for locally heavy amounts, which may raise
isolated flash flooding concerns over eastern Wyoming into western
South Dakota and the Nebraska Panhandle, as well as over portions
of northeastern Colorado.

Pereira

Day 3
Valid 12Z Mon May 26 2025 - 12Z Tue May 27 2025

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF THE
SOUTHERN PLAINS TO THE TENNESSEE VALLEY...

While some additional heavy rains are possible across the Ozarks,
the greater threat is expected to shift further south as an upper
trough moves from the Southwest into the Plains. This will push the
front and deeper moisture further south and east. Deep, moist
southwesterly flow, with energy aloft, will support an axis for
storms to develop from eastern Texas and southeastern Oklahoma to
the Tennessee Valley. The overnight models showed enough spread to
encourage maintaining just a Slight Risk for now. However, some of
the guidance, including the GFS, UKMET, and CMCreg, are producing
amounts suggesting an upgrade may be required in a future issuance.

Pereira

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