National Short Range Forecast Discussion
Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
416 PM EDT Tue Jun 22 2021
Valid 00Z Wed Jun 23 2021 - 00Z Fri Jun 25 2021
...A Slight Risk of excessive rainfall extending from the southern
Mid-Atlantic to the Central Gulf Coast will remain in effect overnight...
...Severe thunderstorms will be possible this over the Central Plains and
the Middle Mississippi Valley through Thursday...
...A Critical Risk of fire weather conditions has been issued for portions
of the Central Great Basin...
A long, slow moving frontal boundary traversing the coastline from the
Northeast to Gulf Coast and into the Southern Plains will be the focal
point for heavy rainfall for much of the short-range period. High moisture
values ahead of the front mixing with a destabilized atmosphere will
likely result in the development of showers and thunderstorms with high
rain rates that could produce isolated to scattered flash flooding. At
present, a Slight Risk of excessive rainfall has been issued by the
Weather Prediction Center from the Mid-Atlantic to the central Gulf Coast
and will remain in effect through Wednesday morning. While the northern
half of the frontal boundary is forecast to propagate offshore by
Wednesday morning, the southern portion over the Southeast and Gulf Coast
is expected to stall and linger. With the front sitting in place
convection will continue to focus over these regions, extending the risk
of isolated flash flooding for some areas through Thursday morning.
Elsewhere, showers and thunderstorms are forecast to develop along a weak
quasi-stationary front extending from the Central Plains to the Middle
Mississippi Valley. Due to the potential for some of these storms to
become severe and capable of producing large hail and gusty winds, the
Storm Prediction Center has issued a Slight Risk of severe thunderstorms
for portions of Iowa and eastern Nebraska through Wednesday morning.
Isolated flash flooding associated with these storms will also be a
By Wednesday evening, a cold front diving south through central Canada
will reach the Northern Plains and Upper Midwest, triggering showers and
thunderstorms throughout the regions. Similarly to the previous day,
damaging winds and large hail could be produced by these thunderstorms if
they were to become severe. As such, the Storm Prediction Center has
issued a Slight Risk of severe thunderstorms for much of Nebraska, with
Marginal Risks issued for portions of the Central Plains and Upper
Midwest. Heavy rainfall associated with these storms will also create a
risk for scattered flash flooding.
Out West warm, dry, and windy surface conditions in the Central Great
Basin and Southwest will create favorable conditions for fire weather,
with a Critical Risk area encompassing much of central/southern Utah,
eastern Nevada, and northwestern Arizona. Additionally, dry thunderstorms
with isolated lightning strikes will be possible over the Northern Great
Basin where dry fuels are present, creating another risk area for fire
weather. With these conditions in place, Red Flag Warnings are currently
in effect for portions of the Southwest, Great Basin, and Central Rockies.
To the south, a plume of moisture surging into the Southwest and Southern
California will interact with upper-level energy to trigger showers and
thunderstorms over the regions Wednesday morning before spreading into
parts of the Great Basin and the Central/Southern Rockies overnight.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php