SPC Mar 16, 2025 1630 UTC Day 1 Convective Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1128 AM CDT Sun Mar 16 2025

Valid 161630Z - 171200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
FAR EASTERN OHIO INTO NORTHERN WEST VIRGINIA...FAR WESTERN
MARYLAND...AND WESTERN PENNSYLVANIA...

...SUMMARY...
Scattered damaging wind swaths and a few tornadoes will be the
primary threats this afternoon and evening across parts of the Ohio
Valley into the Mid-Atlantic and Southeast.

...Ohio Valley into the Mid-Atlantic...
A highly amplified upper trough over the MS Valley this morning will
advance eastward over much of the eastern CONUS today. An embedded
100+ kt southwesterly mid-level jet and associated large-scale
ascent will overspread the upper OH Valley and western Mid-Atlantic
regions through this evening. The primary surface low over eastern
Lower MI will develop northeastward into Ontario and Quebec through
the day, while an attendant cold front sweeps eastward across the OH
Valley/Mid-Atlantic through the period. Recent visible satellite
imagery shows some clearing ahead of the synoptic cold front in
eastern OH and western PA. Although low-level moisture will be
somewhat limited, with surface dewpoints generally in the mid to
upper 50s, cool mid-level temperatures will overspread the narrow
warm sector this afternoon. This, combined with daytime heating,
will support a narrow zone of up to 250-500 J/kg of MLCAPE just
ahead of the cold front and/or pre-frontal trough, which should be
sufficient for surface-based convection.

Bands of low-topped thunderstorms have developed both along and just
ahead of the cold front. This activity will move quickly
east-northeastward across WV, western/central PA, and parts of NY
through the day. With strong low/mid-level flow already in place per
area VWPs, this line should pose a threat for mainly scattered
damaging winds, with peak gusts perhaps reaching up to 60-70 mph.
There will also be rather strong low-level shear in place, which may
support some threat for a few tornadoes embedded within the line,
especially if low-level flow can remain backed more to a
southeasterly component. The northeastward extent of this severe
wind and tornado risk into the Mid-Atlantic and NY remains unclear,
as persistent cloud cover will inhibit daytime heating to some
extent. Still, most guidance shows one or more lines persisting
through the afternoon and evening while posing some wind threat.
Severe probabilities have been adjusted northeastward across parts
of the Mid-Atlantic to account for latest observational and guidance
trends.

...Southeast/Carolinas...
The southern portion of the highly amplified upper trough will
continue eastward across the lower MS Valley and Southeast today, as
an intense southerly low-level jet shifts east across north FL and
the Carolinas through this evening. Ongoing pre-frontal convection
has mostly weakened late this morning/early afternoon, with a couple
of stronger cells persisting over southeast GA and north FL where
greater low-level moisture and instability is present. Adequately
enlarged low-level hodographs within a gradually destabilizing
airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker
instability over the coastal Carolinas) should continue to support
organized convection through the afternoon and evening, before
activity eventually moves offshore. Broken line segments (mainly
Carolinas) and some supercells (mainly southeast GA and north FL)
will pose a threat for scattered damaging winds (peak gusts up to
55-70 mph) and a few tornadoes.

..Gleason/Squitieri.. 03/16/2025

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