Sep 19, 2017 1730 UTC Day 2 Convective Outlook
Updated: Tue Sep 19 17:01:49 UTC 2017 (20170919 1730Z Day 2 shapefile | 20170919 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170919 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 121,565 11,789,546 Milwaukee, WI...Kansas City, MO...Madison, WI...Overland Park, KS...Rockford, IL...
Probabilistic Graphic
20170919 1730 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 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 121,827 11,532,210 Milwaukee, WI...Kansas City, MO...Madison, WI...Overland Park, KS...Rockford, IL...
   SPC AC 191701

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1201 PM CDT Tue Sep 19 2017

   Valid 201200Z - 211200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE U.P. OF
   MI TO NORTHEAST KS...

   ...SUMMARY...
   A few severe storms are possible from northeastern Kansas
   northeastward to the Upper Peninsula of Michigan Wednesday afternoon
   and evening.

   ...Discussion...

   Strong short-wave trough is expected to eject across the upper Red
   River Valley as a 500mb speed max translates across eastern ND
   toward the international border region of northern MN. Height falls
   will focus across this region early in the period before shifting
   into northwest ON where large-scale forcing for ascent should
   encourage convection along/ahead of cold front.

   In the wake of the short-wave, surface pressures will rise across
   the plains which will drive a surface front to a position from
   western WI, southwest into central KS by early afternoon. Strong
   capping along this boundary should inhibit thunderstorm development
   until later in the day when boundary-layer heating should weaken CIN
   such that parcels, assisted by frontal ascent, are capable of
   reaching their LFC. While large-scale ascent will focus across
   Canada, it appears strong, potentially severe, thunderstorms will
   develop along the wind shift within a sheared environment supportive
   of sustaining organized updrafts. Large hail and damaging winds are
   the primary threats with line segments/clusters that should mature
   during the late afternoon/early evening. This activity should linger
   into the overnight hours across this Mid-Mississippi Valley as the
   front stalls and convection is aided by a veered LLJ into northern
   MO.

   A few strong storms could evolve along the dry line across the
   southern Plains but overall the severe threat appears too limited to
   warrant 5% severe probs at this time.

   ..Darrow.. 09/19/2017

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z