Nov 4, 2017 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat Nov 4 07:30:31 UTC 2017 (20171104 0730Z Day 3 shapefile | 20171104 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0730 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Graphic
20171104 0730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 040730

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0230 AM CDT Sat Nov 04 2017

   Valid 061200Z - 071200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Thunderstorms may occur along a cold front from parts of southern
   New England and the Mid-Atlantic into the Tennessee/Ohio Valleys,
   Mid-South, and Ozarks on Monday. Severe thunderstorms appear
   unlikely.

   ...Synopsis and Discussion...
   Strong westerly winds at mid/upper levels should remain over much of
   the CONUS on Monday with a split flow pattern forecast to continue.
   A positively tilted upper trough should progress eastward across
   Canada and the northern Rockies through the period. At the surface,
   a cold front will move quickly eastward across New England and the
   Mid-Atlantic by Monday evening. This front will make slower
   southward progress over the OH/TN Valleys and Mid-South as it
   becomes increasingly parallel to westerly flow aloft.

   Thunderstorms may be ongoing at the start of the period along the
   cold front from parts of NY into PA and the eastern OH Valley.
   Instability is forecast to remain very weak across southern New
   England and the Mid-Atlantic Monday afternoon owing to poor
   mid-level lapse rates and only modest diurnal heating. Even though
   mid/upper-level flow will be strong across these regions along/ahead
   of the cold front, buoyancy should remain too weak to support an
   appreciable severe thunderstorm threat.

   Farther south across the TN Valley and Mid-South, low-level moisture
   should be comparatively greater, with surface dewpoints generally in
   the mid to upper 60s to the south of the cold front. Still,
   large-scale forcing should remain nebulous across this region
   through Monday afternoon, and the potential for additional
   thunderstorm formation along the front seems relatively low. A
   modestly strengthening southwesterly low-level jet may eventually
   encourage some convective development by Monday evening/night. But,
   this activity may occur behind the cold front and be mainly
   elevated. The potential for organized severe thunderstorms across
   the Mid-South/TN Valley and vicinity appears too low/conditional for
   any severe probabilities at this time.

   ..Gleason.. 11/04/2017

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z