Nov 15, 2020 0600 UTC Day 1 Convective Outlook
Updated: Sun Nov 15 05:58:50 UTC 2020 (20201115 1200Z Day 1 shapefile | 20201115 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20201115 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 54,535 39,915,983 New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Newark, NJ...
Probabilistic Tornado Graphic
20201115 1200 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
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20201115 1200 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
5 % 54,458 39,889,547 New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Newark, NJ...
Probabilistic Large Hail Graphic
20201115 1200 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
No Risk Areas Forecast
   SPC AC 150558

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1158 PM CST Sat Nov 14 2020

   Valid 151200Z - 161200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE CENTRAL APPALACHIANS AND MID-ATLANTIC...

   ...SUMMARY...
   Thunderstorms associated with strong wind gusts will be possible
   this afternoon and evening across parts of the central Appalachians
   and Mid-Atlantic.

   ...Central Appalachians/Mid-Atlantic...
   An upper-level trough will move quickly east-northeastward across
   the southern Great Lakes region today. The system will become
   negatively tilted as a band of strong large-scale ascent moves into
   the central Appalachians. At the surface, a cold front will advance
   eastward into the central Appalachians with a pre-frontal trough
   developing ahead of the front. Thunderstorms will likely be ongoing
   along the pre-frontal trough at the start of the period across the
   Ohio and Tennessee Valleys. This line will move quickly eastward
   into the central Appalachians by midday. Ahead of the line, a
   corridor of maximized low-level moisture will exist with surface
   dewpoints mainly in the 50s F. This will be enough for weak
   destabilization ahead of the line. By afternoon, RAP forecast
   soundings have peak instability reaching the 200 to 400 J/kg range.
   This combined with extreme deep-layer shear of 100 to 110 kt and 40
   to 50 kt winds just above the surface, should enable a fine line to
   develop. The fine line is expected to quickly move across the
   Appalachian crest eastward into the foothills and coastal areas
   during the late afternoon and early evening. Isolated damaging wind
   gusts will be possible with this line of storms. A marginal risk has
   been introduced in this outlook for much of Pennsylvania, Maryland
   and northern Virginia extending eastward to the Mid-Atlantic coast.

   ..Broyles/Squitieri.. 11/15/2020

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z