Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1141 AM EDT Mon Jun 22 2026
Day 2
Valid 12Z Tue Jun 23 2026 - 12Z Wed Jun 24 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL IN EFFECT OVER
PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS TO LOWER MISSISSIPPI
VALLEY...

...Central and Southern Plains to Lower Mississippi Valley...

The morning period on Tuesday will be one to monitor as lingering
heavy convection across the ArkLaTex to the I-20 corridor could
enhance flash flood prospects early on in the forecast, a lingering
potential that would carry out of the D1 period. Multiple CAMs and
even the ML are suggesting heavy rains would carry over from the
overnight period into early Tuesday morning with prob fields just
north of the DFW metro actually quite impressive for >3" of
additional rainfall in the 12z Tue to 00z Wed window, running
between 30-60%. This would easily lend to flash flooding
capabilities in the urban corridor, even some of the larger towns
surrounding due to the prominent urban sprawl in place. This is
certainly a period to watch as the evolution from the previous
period will dictate the threat in the D2. For now, a SLGT risk was
added to encompass the area of greatest concern for the front half
of the period.

As we head into the afternoon and evening hours, the mid and upper
pattern across the Western and Central U.S. will setup into a
persistent northwesterly flow regime with multiple shortwave
ejections out of the Rockies allowing for a maturation of
thunderstorms over the High Plains during peak diurnal instability.
From there, organization of thunderstorms are likely to occur as
they migrate downstream and mature with sufficient mid-level shear
presence to maintain any thunderstorm complex generation. This is a
relatively classic MCS pattern for this time of the year with heavy
rain prospects likely to occur from the Front Range down through
KS/OK, eventually migrating into the Lower Mississippi Valley by
the end of the forecast period. Totals on D2 are consistent
within the means with 1-2" rainfall coverage encompassing a large
portion of the Central High Plains down through OK. This puts
emphasis on heavy rainfall over the western half of KS into OK for
the period with a chance for locally 3+ inches in some of the
hardest hit locations. These areas will have already been subject
to heavy rainfall in recent periods, so grounds could still be
somewhat saturated and more susceptible to flash flooding upfront.
Given the consistent signal and ensemble QPF forecast, a SLGT risk
was added across the above area with the heaviest rainfall likely
to occur over western KS into northern OK.

...Southeast Virginia...

Shortwave ejecting out of the Tennessee Valley will make headway
into the southern Mid Atlantic with several pieces of guidance
indicating a small focused area of heavy rainfall across the
Hampton Roads area of southeast Virginia. The approach of the
shortwave trough is aiding in development of a surface low off the
VA Capes leading to a narrow corridor of enhanced convergence
across the Tidewater during the period Tuesday morning. CAMs are
generally aggressive with local maxima between 2-3" across the
Tidewater, an area more prone to flash flooding due to urbanization
factors present. HREF neighborhood probabilities for >2" are up
between 50-70% across the area, a threshold that would be
sufficient for flash flood potential, especially when you combine
the rate factors of 1-2"/hr most likely in the strongest cell
cores given the suitable environment in place. Considering the
probabilities and the expectation for locally heavy rainfall, a
small MRGL risk was added over southeast VA to account for the
threat.

Kleebauer


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