Jun 26, 2025 0600 UTC Day 1 Convective Outlook
Updated: Thu Jun 26 06:31:29 UTC 2025 (20250626 1200Z Day 1 shapefile | 20250626 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20250626 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 16,396 766,502 Waterloo, IA...Dubuque, IA...Cedar Falls, IA...Mason City, IA...Platteville, WI...
MARGINAL 853,883 127,038,860 Chicago, IL...Philadelphia, PA...Detroit, MI...Columbus, OH...Baltimore, MD...
Probabilistic Tornado Graphic
20250626 1200 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 % 16,689 824,827 Waterloo, IA...Dubuque, IA...Cedar Falls, IA...Mason City, IA...Platteville, WI...
2 % 12,943 1,104,239 Madison, WI...Janesville, WI...Ames, IA...La Crosse, WI...Fort Dodge, IA...
Probabilistic Damaging Wind Graphic
20250626 1200 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 % 16,322 754,915 Waterloo, IA...Cedar Falls, IA...Mason City, IA...Platteville, WI...Waverly, IA...
5 % 854,748 127,018,873 Chicago, IL...Philadelphia, PA...Detroit, MI...Columbus, OH...Baltimore, MD...
Probabilistic Large Hail Graphic
20250626 1200 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
5 % 205,024 40,519,346 Baltimore, MD...Charlotte, NC...Washington, DC...Virginia Beach, VA...Atlanta, GA...
   SPC AC 260631

   Day 1 Convective Outlook RESENT 1
   NWS Storm Prediction Center Norman OK
   0131 AM CDT Thu Jun 26 2025

   Valid 261200Z - 271200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
   ACROSS NORTHERN IOWA AND SOUTHERN WISCONSIN...

   ...SUMMARY...
   A few tornadoes and isolated wind damage will be possible this
   afternoon from northern Iowa into southwest Wisconsin.  Isolated
   wind damage will be possible across a broad area of the eastern
   Plains, Ohio Valley, Mid-Atlantic, the Southeast and Montana.

   ...Northern IA/southwest WI area this afternoon...
   A weak midlevel trough over NE, enhanced by overnight convection,
   will progress east-northeastward over IA during the afternoon, along
   with an associated/weak wave along a surface baroclinic zone. 
   Modest enhancement to vertical shear along the baroclinic zone, and
   MLCAPE near or above 2500 J/kg will support the potential for a band
   of storms along and ahead of the front this afternoon.  The
   initial/more discrete storms could be supercells with the potential
   to produce a few tornadoes, in addition to isolated wind damage and
   marginally severe hail.  Convection will likely grow upscale into a
   line by late afternoon, and the severe threat will begin to diminish
   by late evening.

   ...Southeast today...
   Around the southeast periphery of a weakening midlevel high over KY,
   a midlevel low will drift slowly west-northwestward over FL and
   weaken gradually through tonight.  Widespread convection is still
   ongoing from late Wednesday evening across AL/GA, with relatively
   widespread convective overturning and associated outflow.  Remnant
   outflows and differential heating zones will play a role in
   additional thunderstorm development later this afternoon, though
   regional reductions in surface temperatures/moisture from yesterday
   will make the environment less favorable for widespread damaging
   downbursts compared to Wednesday.  Given the mesoscale complexity of
   the pattern and reductions in lapse rates/buoyancy, will hold off on
   adding any SLGT risk/15% wind areas in this outlook.  However, some
   part of GA/AL/MS may need to be reconsidered in later updates. 

   ...OH Valley into the Mid-Atlantic this afternoon...
   Scattered thunderstorms are expected again this afternoon in
   association with daytime heating, residual boundaries from prior
   convection, and terrain circulations.  Though vertical shear will be
   weak, steepening low-level lapse rates and precipitation loading
   could support isolated wind damage with downbursts from mid
   afternoon into the evening.

   ...Western OK to northeast KS this afternoon/evening...
   Scattered thunderstorm development is expected this afternoon along
   and ahead of weak front across KS, and farther to the south into the
   strongly heated airmass and east edge of the midlevel moisture plume
   now across west TX.  Vertical shear will be weak through this
   corridor, but thermodynamic profiles will favor strong downdrafts
   and the potential for isolated strong-severe outflow gusts for a few
   hours this afternoon/evening.

   ...MT this afternoon/evening...
   A subtle midlevel trough and associated/diffuse front will move
   across the northern Rockies this afternoon into tonight.  Deep
   mixing and inverted-V profiles will favor some potential for
   strong-severe outflow gusts with scattered high-based thunderstorms
   along and ahead of the diffuse front this afternoon into this
   evening.

   ..Thompson/Moore.. 06/26/2025

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z