Jul 26, 2021 1730 UTC Day 2 Convective Outlook
Updated: Mon Jul 26 17:30:52 UTC 2021 (20210726 1730Z Day 2 shapefile | 20210726 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20210726 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 21,058 3,431,161 Minneapolis, MN...St. Paul, MN...Rochester, MN...Bloomington, MN...Plymouth, MN...
MARGINAL 143,364 22,888,741 Boston, MA...Buffalo, NY...Madison, WI...Rochester, NY...Providence, RI...
Probabilistic Tornado Graphic
20210726 1730 UTC Day 2 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 2 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20210726 1730 UTC Day 2 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 2 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 164,002 26,318,794 Boston, MA...Minneapolis, MN...Buffalo, NY...St. Paul, MN...Madison, WI...
Probabilistic Large Hail Graphic
20210726 1730 UTC Day 2 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 2 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 21,058 3,431,161 Minneapolis, MN...St. Paul, MN...Rochester, MN...Bloomington, MN...Plymouth, MN...
5 % 72,233 3,551,004 Madison, WI...Sioux Falls, SD...Brooklyn Park, MN...Eau Claire, WI...Coon Rapids, MN...
   SPC AC 261730

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1230 PM CDT Mon Jul 26 2021

   Valid 271200Z - 281200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTHERN
   MINNESOTA...WEST-CENTRAL WISCONSIN...

   ...SUMMARY...
   Isolated thunderstorms are possible late Tuesday across the upper
   Mississippi Valley.  A conditional risk for large hail and damaging
   gusts will accompany the stronger storms.  Strong to locally severe
   gusts will be possible mainly Tuesday afternoon and evening for
   parts of the Northeast.

   ...Synopsis...
   A mid-level anticyclone will be centered over the central High
   Plains on Tuesday while a mid-level low will reside over central
   Quebec.  A belt of strong northwesterly mid-level flow will extend
   from south-central Canada into the upper Great Lakes and into the
   Northeast.  Model guidance indicates a disturbance will move from
   the western Great Lakes eastward into NY during the day.  

   ...Upper MS Valley...
   A reservoir of low-level moisture will reside over the region
   Tuesday to the south of a residual frontal zone draped
   northwest-southeast.  The airmass is forecast to become very
   unstable by late afternoon as a cap weakens due to strong heating. 
   However, the lack of appreciable large-scale forcing for ascent will
   likely limit convective coverage with a weak cap remaining through
   the early evening.  However, weak 850 mb theta-e advection near the
   boundary may aid in isolated storm development by early evening in a
   corridor from eastern SD to central WI.  Strong shear/large CAPE
   would conditionally support a hail risk with any sustained storm.  

   ...Northeast...
   Broad cyclonic mid-level flow will encompass the Northeast to the
   south of a primary disturbance over Canada.  Models show strong
   westerly mid-level flow moving through the base of the large-scale
   trough.  Strong heating through midday and into the afternoon will
   result in steepened low-level lapse rates.  The arrival of the
   aforementioned disturbance into the lower Great Lakes by mid
   afternoon will probably aid in storm development across NY with
   activity spreading/developing east into southern New England.  As a
   few clusters develop during peak heating, a gradual intensification
   is expected as storms move through an environment characterized with
   upper 50-lower 60s surface dewpoints.  Strong to locally severe
   gusts capable of damaging gusts are possible with the stronger
   clusters before this activity weakens during the evening as it
   approaches the coast.

   ..Smith.. 07/26/2021

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

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