Nov 4, 2021 1300 UTC Day 1 Convective Outlook
Updated: Thu Nov 4 12:44:27 UTC 2021 (20211104 1300Z Day 1 shapefile | 20211104 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20211104 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Tornado Graphic
20211104 1300 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
20211104 1300 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
No Risk Areas Forecast
Probabilistic Large Hail Graphic
20211104 1300 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 041244

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0744 AM CDT Thu Nov 04 2021

   Valid 041300Z - 051200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Severe thunderstorms are unlikely across the U.S. today.

   ...Synopsis/Discussion...
   In a progressive mid/upper-level pattern, broadly cyclonic flow is
   evident around troughing that extends from eastern Canada across the
   Upper Great Lakes to deep south TX and northeastern MX.  The
   southwestern portion of that troughing is a basal southern-stream
   shortwave perturbation quite evident in moisture-channel imagery
   over northeastern MX and the lower Rio Grande Valley -- convectively
   augmented by a prior/overnight MCS now located over the extreme
   western Gulf.  The trough should move eastward to the north-central/
   west-central Gulf by the end of the period.  Assorted small
   perturbations/vorticity maxima are possible in the downstream
   southwest flow aloft, from the central Gulf across FL.

   A wavy surface frontal zone was analyzed at 11Z under and ahead of
   the trough aloft, from northeastern MX across the northwestern Gulf
   (south and east of BRO), north-central/northeastern Gulf, central
   FL, to a low over Atlantic waters southeast of eastern NC.  Isolated
   to scattered thunderstorms are possible episodically and mainly this
   afternoon south of the front across the southern FL Peninsula, then
   area-wide overnight on both sides of the boundary.  Given the
   presence of roughly 35-40 kt effective-shear magnitudes in forecast
   soundings this afternoon over south FL, a few organized multicells
   are possible, with strong downdraft gusts.  At this time,
   unconditional severe potential appears too isolated and low to
   warrant a categorical outlook.

   Elsewhere, a strong shortwave trough is apparent just offshore from
   the pacific Northwest.  This feature should deamplify gradually as
   it eject east-northeastward to northeastward today, reaching western
   MT and central ID by 00Z.  The trough then should reach eastern MT
   and southwestern SK by 12Z.  Isolated thunder may occur today over
   parts of the northern Rockies and interior Northwest, associated
   with frontal and post-frontal/large-scale lift preceding the Pacific
   perturbation.

   ..Edwards.. 11/04/2021

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