Apr 11, 2024 1630 UTC Day 1 Convective Outlook
Updated: Thu Apr 11 16:36:06 UTC 2024 (20240411 1630Z Day 1 shapefile | 20240411 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20240411 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 22,441 3,049,176 Canton, OH...Charleston, WV...Huntington, WV...Parkersburg, WV...Massillon, OH...
SLIGHT 121,124 26,622,327 Jacksonville, FL...Columbus, OH...Cleveland, OH...Tampa, FL...Pittsburgh, PA...
MARGINAL 208,375 38,989,075 Baltimore, MD...Charlotte, NC...Washington, DC...Virginia Beach, VA...Raleigh, NC...
Probabilistic Tornado Graphic
20240411 1630 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
10 % 22,534 3,054,448 Canton, OH...Charleston, WV...Huntington, WV...Parkersburg, WV...Massillon, OH...
5 % 75,347 16,448,339 Jacksonville, FL...Tampa, FL...Pittsburgh, PA...St. Petersburg, FL...Akron, OH...
2 % 220,930 43,481,707 Columbus, OH...Baltimore, MD...Charlotte, NC...Washington, DC...Cleveland, OH...
Probabilistic Damaging Wind Graphic
20240411 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 16,050 1,616,360 Charleston, WV...Huntington, WV...Parkersburg, WV...Wheeling, WV...Athens, OH...
15 % 125,376 27,763,293 Jacksonville, FL...Columbus, OH...Cleveland, OH...Tampa, FL...Pittsburgh, PA...
5 % 210,056 39,225,243 Baltimore, MD...Charlotte, NC...Washington, DC...Virginia Beach, VA...Raleigh, NC...
Probabilistic Large Hail Graphic
20240411 1630 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 75,530 15,887,747 Columbus, OH...Cleveland, OH...Pittsburgh, PA...Cincinnati, OH...Lexington-Fayette, KY...
   SPC AC 111636

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1136 AM CDT Thu Apr 11 2024

   Valid 111630Z - 121200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
   WV...EASTERN OH...SOUTHWEST PA...FAR NORTHEAST KY...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS FL...

   ...SUMMARY...
   Severe thunderstorms with a few tornadoes, scattered damaging winds,
   and isolated severe hail are possible across the upper Ohio River
   Valley and parts of the Appalachians this afternoon into tonight.
   Scattered damaging winds and a couple of tornadoes remain possible
   this afternoon across the northern and central Florida Peninsula.

   ...Upper Ohio River Valley...
   Some forecast uncertainty persists in the short term regarding the
   magnitude of today's severe risk, largely attributable to persistent
   cloud cover, scattered warm sector showers/thunderstorms, with a
   broken overcast still prevailing at midday, even with a
   northeastward-expanding dry slot per water vapor imagery. While
   there are thermodynamic uncertainties and potential limitations,
   will continue to defer to favorable aspects of strengthening 1-2 km
   southerly winds and the steady deepening phase of the surface
   cyclone across the Ohio Valley. It generally appears that the
   currently depicted risks areas still largely reflect the relatively
   highest probability corridor for severe storms across the upper Ohio
   River Valley and Allegheny Plateau vicinity.

   Weak instability coupled with some enlargement of the hodograph can
   regionally support an environment in which discrete cells and
   semi-discrete clusters evolve into supercells. A few tornadoes are
   possible if stronger updrafts/supercells manage to develop, in
   addition to an accompanying threat for damaging gusts and perhaps
   isolated marginally severe hail.

   ...Mid-Atlantic States and Carolinas...
   A less focused and less certain severe risk appears to exist across
   the region. Cloud cover remains prevalent at midday coincident with
   low-level upslope flow, although some clearing is noted early this
   afternoon across the southern Appalachians vicinity. Where modest
   destabilization does occur this afternoon, long hodographs would
   conditionally support storm organization with any robust updrafts.
   Isolated to widely scattered strong to severe storms capable of a
   threat for damaging gusts and a couple of tornadoes are possible,
   particularly near the mountains/Blue Ridge, with a lower
   probability/lesser anticipated storm coverage expected farther east
   over the coastal plain/Delmarva.

   ...Florida...
   A broken band of thunderstorms will continue to move inland this
   afternoon across the western and northern Florida Peninsula. Ahead
   of this convection, warming boundary temperatures with dewpoints
   around 70F, beneath a likely lingering of capping aloft and weak
   mid-level lapse rates (12z observed sounding from Tampa Bay), is
   supporting MLCAPE of 750-1250 J/kg. Strong/veering wind profiles
   will support severe storms including some embedded supercells and
   locally intense clusters capable of tornado/damaging wind risks
   through at least mid-afternoon, with storm intensity/organization
   expected to gradually diminish into late afternoon and early
   evening.

   ..Guyer/Squitieri.. 04/11/2024

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