769 
FXUS01 KWBC 270436
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
1235 AM EDT Sat Jun 27 2026

Valid 12Z Sat Jun 27 2026 - 12Z Mon Jun 29 2026

...Flooding threat across portions of the Plains and Ohio Valley
into Mid-Atlantic on Saturday...

...Scattered to widespread severe thunderstorms across portions of
the northern Plains and Ohio Valley into the Mid-Atlantic...

...Critical to Extremely Critical fire weather conditions continue
over portions of the Intermountain West/Four Corners into the
weekend...

...Heat begins to build over the South into Saturday before a more
widespread expansion into the Plains on Sunday as a dangerous
central to eastern U.S. heat wave begins...


A broad upper trough digging across the western U.S. will continue
to promote unsettled weather through the weekend, while
strengthening southerly flow downstream will support multiple
rounds of convection across the Plains into the Mid-Atlantic. At
the surface, a frontal boundary extending from the central Plains
into the Ohio/Tennessee Valley and Mid-Atlantic will remain the
primary focus for widespread showers and thunderstorms on
Saturday. Repeated rounds of convection along the boundary will
maintain a threat for excessive rainfall, with scattered to
numerous instances of flash flooding possible from portions of
Mid-Mississippi Valley into the Mid-Atlantic. Additionally, with
sufficient moisture and instability, the Storm Prediction Center
has highlighted the Mid-Mississippi Valley into the Mid-Atlantic
for a severe thunderstorm threat for Saturday, with a risk for
hail and gusty winds. The strongest storms will be near the
Mid-Atlantic coast, where instability will be the highest and
shortwave impulses will reinforce strong gusty winds over the
area. On Sunday, the upper-level ridge begins to build and the the
frontal boundary over the central Plains lifts into the Upper
Midwest, while the front over Ohio Valley into the Mid-Atlantic
becomes semi-stationary. This will aide in the continuation of
showers and thunderstorms along the boundary.

Over the northern High Plains into the Upper Midwest, a
strengthening lee cyclone and associated cold front will bring
locally heavy rainfall as the frontal boundary slowly moves
eastward. Increasing instability and stronger deep-layer shear
ahead of the advancing western trough will support organized
severe thunderstorms across the northern Plains on Saturday before
shifting into the Upper Midwest on Sunday. SPC has highlighted
portions of the northern High Plains with a Enhanced Risk of
severe thudnerstorms for Saturday with a Slight Risk over portions
of North Dakota and the Upper Midwest on Sunday. Additionally,
large hail, damaging winds, and a few tornadoes may be possible
with the strongest storms. With the rich Gulf moisture moving
northward into the Plains and interacting with unstable air, heavy
rainfall rates may develop and will bring a risk for excessive
rainfall across portions of the Northern Plains on Saturday. On
Sunday, the flood threat develops over the Upper Midwest, as the
system moves east, while a shortwave energy reinforces showers and
thunderstorms over portions of the Northern Plains/Rockies.

In regard to temperatures, the amplifying upper trough across
western U.S. will bring cooler than normal temperatures along with
widespread showers from the Pacific Northwest through the northern
Rockies. Highs will drop between 20-35 degrees below normal across
much of western U.S. through the weekend. Farther east and south,
the expanding upper ridge will allow hot and humid conditions to
overspread across the Southern Plains, Lower Mississippi Valley,
and Southeast. On Sunday, much of central U.S. and the Southeast
will see Moderate to Major HeatRisk conditions, as a late June to
early July heat wave begins to build across the area. This level
of heat and humidity may bring health impacts to anyone without
adequate hydration and cooling. 

Dangerous fire conditions continue over portions of the Great
Basin and Four Corners as gusty southwesterly winds, dry airmass,
and poor overnight recovery brings a Extremely Critical Risk of
fire weather (level 3/3) on Saturday. Dry fuels will facilitate
the rapid spread of fires/wildfires of any new ignitions. Critical
fire weather conditions continue into Sunday as strong winds and
dry conditions persist.


Oudit


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php




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