972
ACUS48 KWNS 110851
SWOD48
SPC AC 110849

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0349 AM CDT Tue Mar 11 2025

Valid 141200Z - 191200Z

...DISCUSSION...
...Days 4-6/Fri-Sun - Mid/Lower MS Valley to the Southeast and
Mid-Atlantic...

An intense spring storm system will deliver a multi-day severe
weather episode to portions of the central and eastern U.S.
beginning Friday and continuing through the weekend. All severe
thunderstorm hazards are expected, including widespread damaging
winds, tornadoes (some strong), and large hail.

On Friday, an anomalously intense upper cyclone is forecast to
deepen as it tracks northeast across the southern/central Plains to
the Upper Midwest. An intense jet streak (greater than 100 kt at 500
mb) will overspread the Ozarks and Mid-MS Valley during the
afternoon into the overnight hours. Likewise, a low-level jet will
intensify Friday night to 65+ kt. As intense surface cyclogenesis
occurs, southerly low-level flow will transport modest moisture as
far north as eastern IA, southeast MN and southern WI. Deeper
boundary-layer moisture will remain focused southward from the
Mid-South toward the Lower MS Valley/central Gulf coast.
Nevertheless, strongly forced convection within intense deep-layer
flow will pose a widespread risk for severe (potentially significant
severe) thunderstorm winds and tornadoes from late afternoon into
the overnight hours across a large area centered on the Mid/Lower MS
Valley vicinity.

On Saturday, the upper cyclone over the Upper Midwest will lift
northeast into Ontario, but a larger-scale upper trough will remain
over the Plains. The Plains trough will intensify and spread east
toward the MS/OH Valleys. This will maintain the eastward
progression of a strongly forced line of convection from the Ohio
Valley south/southwest into the Deep South/central Gulf coast
vicinity through Saturday night. Portions of the Deep South into GA
may see multiple rounds of severe convection with a mix of both
supercell and QLCS storm modes potentially moving across the region,
posing a concern for damaging tornadoes and swaths of severe winds.

On Sunday, the system will continue to shift east, with a moist
airmass and strong deep-layer flow continuing to support a line of
convection producing damaging winds into the Carolinas and
Mid-Atlantic vicinity.

Outlook areas will continue to be refined over the coming days as
key features become better resolved.

..Leitman.. 03/11/2025