Nov 10, 2020 1630 UTC Day 1 Convective Outlook
Updated: Tue Nov 10 16:15:40 UTC 2020 (20201110 1630Z Day 1 shapefile | 20201110 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20201110 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 66,222 15,769,498 Chicago, IL...Milwaukee, WI...Madison, WI...Aurora, IL...Rockford, IL...
MARGINAL 134,526 19,293,407 Jacksonville, FL...Indianapolis, IN...St. Louis, MO...Fort Wayne, IN...Orlando, FL...
Probabilistic Tornado Graphic
20201110 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
5 % 39,768 8,605,188 Milwaukee, WI...Madison, WI...Aurora, IL...Rockford, IL...Naperville, IL...
2 % 87,370 15,178,017 Chicago, IL...St. Louis, MO...Grand Rapids, MI...Joliet, IL...Springfield, IL...
Probabilistic Damaging Wind Graphic
20201110 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
15 % 66,887 15,920,117 Chicago, IL...Milwaukee, WI...Madison, WI...Aurora, IL...Rockford, IL...
5 % 134,035 19,165,538 Jacksonville, FL...Indianapolis, IN...St. Louis, MO...Fort Wayne, IN...Orlando, FL...
Probabilistic Large Hail Graphic
20201110 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
No Risk Areas Forecast
   SPC AC 101615

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1015 AM CST Tue Nov 10 2020

   Valid 101630Z - 111200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   NORTHEAST MISSOURI...EASTERN IOWA...NORTHERN ILLINOIS...AND
   SOUTHEAST WISCONSIN...

   ...SUMMARY...
   Thunderstorms capable of producing damaging to severe winds and a
   few tornadoes are possible this afternoon and evening from parts of
   Missouri northeastward into portions of Iowa, Illinois, and
   Wisconsin.

   ...Mid MS Valley...
   Water vapor loop shows a strong shortwave trough and associated
   mid-level speed max rotating across the central Plains into MO/IA. 
   This feature will result in strong surface cyclogenesis as a surface
   low deepens along a cold front extending from northern MO into WI. 
   The corridor along and just east of the low/front will be the area
   of concern for strong/severe thunderstorms today.

   Thunderstorms are ongoing this morning along the front over MO. 
   Convection is expected to intensify and build northward toward the
   surface low by early afternoon.  CAM solutions indicate that the
   bowing convective structures will not be substantially undercut by
   the front, suggesting the activity will remain primarily
   surface-based.  This supports a risk of damaging wind gusts in the
   stronger cores.  Forecast soundings show strengthening low-level
   shear across the threat area through the afternoon as the deepening
   low helps to back/enhance near-surface winds.  This could promote
   the development of a few semi-discrete supercells along the line,
   posing a risk of a few tornadoes.

   The activity will track northeastward across Lake MI this evening
   and eventually into northern Lower MI.  Thermodynamic parameters
   will be rather weak over this area, but there is some potential for
   a lingering risk of locally strong/damaging wind gusts.  

   ...FL...
   Relatively strong deep southeasterly flow is present today across
   the FL peninsula.  A moist and moderately unstable air mass is also
   in place across the region, with broken sunshine this afternoon
   helping to steepen low-level lapse rates.  Local VAD profiles show 
   25-35 knot winds in the 0-3km layer.  Most CAM solutions show
   relatively fast-moving thunderstorms affecting the region, posing a
   risk of locally gusty/damaging wind gusts.

   ..Hart/Cook.. 11/10/2020

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