Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Sun Jun 14 2026
Day 1
Valid 12Z Sun Jun 14 2026 - 12Z Mon Jun 15 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR THE SOUTHERN
PLAINS AS WELL AS FOR NORTHERN NEW ENGLAND...

...Southern Plains...

Today will likely be the calmest of the next 3 days across Texas,
which isn't saying much as it will still be plenty active. A very
slow moving cold front will sink south across Oklahoma and Arkansas
today. Ahead of the front, an impressively moisture-laden air mass
is in place over not just Texas, but much of the Gulf Coast. Across
eastern Texas, an ongoing MCS across Oklahoma and Arkansas
delineating the leading edge of the aforementioned cold front will
continue to drift south and weaken through the morning hours, which
is typical behavior for MCSs once the sun comes up. While the MCS
will have some forward speed to it, the availability of plentiful
moisture, with PWATs to 2 inches will continue to support heavy
rainfall with the strongest cells. The remnants of the MCS will
likely impact the Metroplex in the mid-to-late morning.

Meanwhile, plentiful southerly flow off the Gulf into southeast
Texas will lead to widespread but largely disorganized shower and
thunderstorm activity from the Houston and San Antonio metros
north. The plentiful moisture will still be available, so anywhere
where cell mergers or localized training features develop,
localized flash flooding will be possible today. Any urban areas
will only increase the flash flooding potential, though there's
considerable uncertainty whether any of the biggest cities in Texas
will be directly impacted.

Across west Texas and the Hill Country, afternoon and evening
thunderstorms will impact those areas, with portions of west Texas
recently hard hit from heavy rains at a higher threat for
additional flash flooding. A higher-end Slight has been issued for
this region. For the Hill Country, the main flooding threat will be
tonight, as an MCS develops due to plentiful merging thunderstorms
and a southward push of the cold front in that region. The storms
will run into increasing resistance tonight in the form of a
strengthening LLJ, which should slow down the forward speed of the
storms as the traverse the Hill Country. Due to the flashy nature
of the terrain in the Hill Country, the higher-end Slight was also
introduced for this region as well. Back into New Mexico,
afternoon and evening storms could interact with both the terrain
features in the area, such as the Sacramento Mountains, urban El
Paso, and any burn scars in the area.

...Northern New England...

A Slight Risk upgrade was introduced with this update in
coordination with BTV/Burlington, VT and CAR/Caribou, ME forecast
offices. The same cold front that will be impacting the Southern
Plains will have a much easier time pushing eastward, as a large
upper level low over Canada pushes frequent shortwave disturbances
east across the northeastern U.S. Despite the progressive nature of
the front, a surge of moisture will rapidly advect north into New
England ahead of the front, aided by increasing upper level support
as a strong shortwave becomes more negatively tilted with time as
it rounds the southeastern periphery of the upper level low. The
moisture surge will also increase the instability, with MUCAPE
values around 1,000 J/kg expected on average, and values up to
2,000 in some areas, including southeastern VT. The plume of
moisture and instability will support numerous fast-moving
thunderstorms training northeastward along the Canadian border. The
training storms will impact recently hard hit areas of northern New
England, where soils are wetter than normal going into this event.
While there's some question as to how strong the storms will get,
the likelihood they will train along and south of the plume of
greatest rainfall is high. The storms will train over northern New
England for several hours before the cold front sweeps across from
west to east tonight. Topographic effects could locally increase
rainfall rates, as well as worsen any possible flash flooding.
This further supports the Slight Risk upgrade for the area.

...Elsewhere...

The Marginal Risk for the Mid-Atlantic and the east coast of
Florida are largely the same. For the Mid-Atlantic afternoon and
evening storms feeding on the same moisture plume that will advance
into New England could lead to localized instances of flash
flooding, especially in urban areas along the I-95 corridor, though
the severe threat appears greater.

On the east coast of Florida, sea breeze interactions with the
abundant moisture over the state should allow for a renewed
development of afternoon and evening thunderstorms today. The
storms will be nearly stationary, so mergers will pose the greatest
threat for more prolonged periods of heavy rain, though all strong
cells will be capable of localized heavy rain.

Wegman


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