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

Valid 12Z Fri Mar 24 2023 - 12Z Sun Mar 26 2023

...Flash flooding and severe weather threat spreads into the Lower
Mississippi/Tennessee/Ohio Valleys Friday...

...Showers and thunderstorms for the East Coast, snow and a wintry mix for
the Midwest and Interior Northeast/New England heading into the 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 frontal boundary through the Ohio Valley and
southward ahead of a cold front pushing through the Lower Mississippi
Valley on Friday. 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 areal average rainfall
totals between 2-4 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 Friday and Saturday.

The low pressure system associated with the active weather Friday 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 during the day Friday and
continue 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 further 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 the northern Lower
Peninsula of 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. Some near record-tying/breaking highs
in the upper 80s are forecast over North Carolina Friday. Temperate highs
in the upper 40s and low 50s over New England Friday will drop into the
30s and low 40s Saturday. Highs over the Great Lakes will be in the 40s
Friday with 30s for Saturday, and a similar drop is forecast over portions
of the Northern Plains with 30s and 40s Friday 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
Friday 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 potions 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.

Putnam


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