Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
407 PM EDT Fri Mar 24 2023

Valid 00Z Sat Mar 25 2023 - 00Z Mon Mar 27 2023

...Flash flooding and severe weather threats across the Lower
Mississippi/Tennessee/Ohio Valleys tonight...

...Showers and thunderstorms for the East Coast, snow and a wintry mix for
the Midwest and Interior Northeast/New England this weekend...
 
...Unsettled weather and chilly temperatures with locally heavy mountain
snowfall to continue across the West...

Widespread showers and thunderstorms are forecast to continue/redevelop
along a quasi-stationary front through the Ohio Valley, as well as
southward ahead of a cold front pushing through the Lower Mississippi
Valley on today. Anomalously high moisture will continue to spread
northward from the Gulf of Mexico and pool along this quasi-stationary
boundary, helping to fuel heavy rain producing storms. There is a Moderate
Risk (level 3/4) of Excessive Rainfall in effect from northern Arkansas
northeastward into the Lower Ohio Valley overlapping a region where
repeated rounds of storms are forecast to produce additional rainfall
between 1-2 inches, locally higher, and lead to the risk of scattered to
widespread instances of flash flooding. In addition, very buoyant air with
moderate to strong CAPE values as well as strong low-level and upper-level
shear will lead to the risk for widespread severe weather. The Storm
Prediction Center has issued a Moderate Risk (level 3/5) for a regional
outbreak of severe thunderstorms over the Lower Mississippi Valley with
hail, strong winds, and tornadoes, some strong, all anticipated. To the
west, strong, gusty winds behind the advancing cold front and very dry
conditions have also prompted a Critical Risk of Fire Weather from the
Storm Prediction Center over portions of the Southern High Plains through
Saturday. Showers and thunderstorms return to the Southeast/central Gulf
Coast on Sunday but the risks for excessive rainfall and severe
thunderstorms remain marginal.

The low pressure system associated with the active weather today will
continue to deepen/better organize as it shifts northward towards the
Great Lakes on Saturday. Widespread showers and thunderstorms are forecast
to continue ahead of a northward moving warm front and trailing cold front
shifting eastward towards the East Coast overnight into early Saturday
afternoon. The increased forward motion of the frontal system should keep
storms from lingering over the same areas too long, significantly reducing
forecast rain amounts compared to areas farther west, with the highest
totals of 0.5-1 inch expected through the Mid-Atlantic. In addition to the
rain, wrap-around precipitation in the colder air to the north and west of
the surface low track will lead to snow for portions of the Great Lakes
and the Interior Northeast/New England. Some moderate to heavy snowfall
totals of 4-8+ inches are possible from southeastern Wisconsin into
northern Michigan on Saturday, with 3-6 inches expected for higher
elevations and regions close to the Canadian border in the Interior
Northeast/New England. A wintry mix including a light glaze of freezing
rain is also possible across the Lower Peninsula of Michigan and portions
of the northern Appalachians.

Temperatures ahead of the advancing front will be above average from
southern/eastern Texas into the Southeast and southern Mid-Atlantic, with
highs in the 70s and 80s forecast. Temperate highs in the upper 40s and
low 50s over New England today will drop into the 30s and low 40s
Saturday. Highs over the Great Lakes will be in the 40s today with 30s for
Saturday, and a similar drop is forecast over portions of the Northern
Plains with 30s and 40s today dipping into the 20s for some locations
Saturday. Highs will moderate a bit further south over the Central Plains
and Middle Mississippi Valley from the 40s and low 50s today into the
mid-50s for many locations Saturday.

Mean upper-level troughing and energetic flow over a couple frontal
systems pushing through the West will keep precipitation chances up and
temperatures well below average across northern and central portions of
the region. Heavy snow totals over a foot are forecast for the Cascades as
well as for mountain ranges in the Northern Rockies and southward into the
eastern Great Basin, with more moderate snowfall for the ranges of the
Central Rockies. Accumulations are expected to remain light for lower
elevations. Some light accumulating snow is also expected into the
adjacent Central High Plains. High temperatures will be chilly Saturday
and Sunday, with 30s for the Great Basin and northern/central Rockies, 40s
for the Pacific Northwest and Southern Rockies, 50s for northern/central
California, and 60s to low 70s for southern California and the Desert
Southwest. Some locations across the Great Basin will see highs near or at
record low maximum temperatures for the date.

Kebede/Putnam


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