Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1124 AM EDT Sun May 10 2026

Day 1
Valid 16Z Sun May 10 2026 - 12Z Mon May 11 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
CENTRAL AND NORTH TEXAS...

...16Z Update...

The Slight Risk area was expanded a bit with this update, mostly
towards the south but also to include the rest of the DFW
Metroplex. Clusters of storms are expected to develop this
afternoon, likely as a continuation of the showers and storms
ongoing currently over Oklahoma, but developing further south into
Texas. Much of the convective activity is expected to congeal south
and west of the Metroplex, but urban concerns and some expected
development over the Metroplex still heighten the flash flooding
risk into the lower-end Slight category. Meanwhile, while
convection will be more numerous and strong further south and west,
less urban development may help to mitigate the flash flooding
threat a bit. By late evening, around 03Z/10pm CDT or so, the
convection is expected to have organized into a mostly single line
of storms that will progressively shift southeast towards the Gulf.
This should greatly mitigate the flash flooding threat by that
point and beyond. Thus, the flash flooding threat is greatest in
the late afternoon and evening while the storms are still
organizing and therefore have more chaotic and slow forward
motions.

Wegman

...Previous Discussion...

The overall forecast philosophy for the new Day 1 period remains
largely consistent with the previous thinking, though an upgrade to
a Slight Risk has been introduced for portions of Central and
North Texas. While some uncertainty remains regarding the exact
evolution of the convective elements, a growing signal for higher-
end rainfall totals is becoming evident in the latest guidance.

Totals of 2-4 inches are increasingly likely across portions of
Central and North Texas by the late afternoon and evening,
supported by a moist, unstable airmass and strong ascent. Deepening
moisture is expected to pool along a composite surface boundary,
with PWs climbing to around 1.5 inches near the intersection of the
cold front and dryline. This moisture is expected to interact with
strong low level convergence and increasing upper level divergence
as a shortwave trough moves east, generating numerous storms
capable of producing heavy rainfall rates.

Further raising the concern for heavy amounts and potential flash
flooding will be cell training. Storms developing along the
boundary and ahead of the approaching wave may track over some
areas repeatedly, leading to localized excessive totals. Both the
HREF and RRFS indicate the potential for this setup, showing their
highest probabilities for QPF exceeding 2 inches extending from
parts of Central into North Texas, including southern sections of
the DFW Metro. Therefore, the Slight Risk was introduced to reflect
increasing confidence for scattered flash floods within this area.

Elsewhere, the Marginal Risk was expanded a bit, but remains
centered across much of the same region, reflecting the potential
for convective storms and heavy rainfall rates, though with less
organization or lower confidence in the potential for heavy
accumulations in comparison to the upgraded Slight Risk area.

Pereira

Day 2
Valid 12Z Mon May 11 2026 - 12Z Tue May 12 2026

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

Pereira

Day 3
Valid 12Z Tue May 12 2026 - 12Z Wed May 13 2026

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

Pereira

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