Storm Prediction Center - Day 1 Outlook

Data From the SPC

Day 1 Graphical Outlook

Definition: The probability values represent the chance of severe weather occurring within 25 miles of any point, which is approximately the size of a major metropolitan area.

Day 1 & 2: The outlook contains individual severe probabilities for tornadoes, wind, and hail.
Day 3: Due to greater uncertainty, the outlook only forecasts the combined probability of all three types of severe weather.

Context: Probabilities for severe thunderstorm wind and hail are typically higher than for tornadoes because they are more common. A 15% probability for a tornado means significantly above normal odds of a tornado nearby, which should be taken seriously, even though the number seems low.

Note: The peak daily tornado probabilities in the most tornado prone portions of the country (Plains and Southeast) are slightly above 2%. Therefore, most days with any tornado probabilities are well above climatology.


SPC Category Descriptions (Click image to enlarge)



Issue Times

Day 2 Outlook

Day 1 Outlook Discussion

SPC AC 110550

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1250 AM CDT Sun Oct 11 2026

   Valid 111200Z - 121200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   NORTH CAROLINA AND VIRGINIA...

   ...SUMMARY...
   Thunderstorms capable of producing isolated severe wind gusts and a
   tornado or two will be possible today across parts of the
   Mid-Atlantic. Additional storms with isolated severe gusts will be
   possible in parts of the Desert Southwest and Four Corners region.

   ...Mid-Atlantic...
   The remnants of Isaias will move through the southern Appalachians
   and Mid-Atlantic today. At the surface, a moist airmass will advect
   northeastward across North Carolina and eastern Virginia, where
   dewpoints will increase into the 70s F. MLCAPE is forecast to peak
   in the 1000 to 1500 J/kg range over parts of the Mid-Atlantic by
   afternoon. Scattered thunderstorms will develop in the Carolina
   Piedmont this morning and move northeastward into the lower
   elevations of eastern North Carolina and south-central Virginia
   early this afternoon. RAP forecast soundings from near Raleigh
   northward to west of Richmond around midday have long curved
   hodographs, with 0-3 km storm-relative helicity in the 200 to 225
   m2/s2 range. This will support a tornado threat with supercells that
   remain discrete. The tornado threat should persist into the evening
   as the stronger storms move toward the Mid-Atlantic coast.

   ...Desert Southwest/Four Corners...
   A mid-level shortwave trough will move northeastward today from the
   Desert Southwest into the Four Corners region. At the surface, an
   axis of low-level moisture will be in place from southwestern
   Arizona extending northeastward toward the Four Corners. Weak
   instability will develop along this southwest-to-northeast corridor
   as surface temperature warm. Large-scale ascent associated with the
   shortwave trough will support scattered thunderstorm development
   this afternoon. Forecast soundings from western Arizona into
   southeast Utah this afternoon have strong unidirectional winds from
   the south-southwest in the low to mid-levels. The resultant strong
   deep-layer shear could support a marginal wind-damage threat.

   ..Broyles/Chalmers.. 10/11/2026

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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

Issued by the Weather Prediction Center