Current SPC Activity Chart

See Current Severe US Wx Maps

SPC Activity Chart
Hazard Mon (12/08) Tue (12/09) Wed (12/10) Thu (12/11) Fri (12/12) Sat (12/13) Sun (12/14) Mon (12/15)
Severe No Severe No Thunder No Thunder No Area No Area No Area No Area No Area
Fire No Critical No Critical No Area No Area No Area No Area No Area No Area

Forecast Discussion - Convective Outlook

   SPC AC 081603

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1003 AM CST Mon Dec 08 2025

   Valid 081630Z - 091200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Severe thunderstorms are not expected through tonight.

   ...Synopsis and Discussion...
   A progressive upper pattern will persist today with a pair of
   shortwave troughs, one currently moving towards the central
   Appalachians and the other moving towards the Four Corners and
   central Rockies, continuing eastward/southeastward as another pair
   of shortwave troughs drop into the northern Plains and Upper
   Midwest. At the surface, high pressure will continue to shift
   eastward/southeastward over more of the eastern CONUS while a low,
   currently in the western Atlantic off the SC coast, progresses
   northeastward. 

   A cold front extends southwestward from the western Atlantic surface
   low through central FL, which is the only area across the entire
   CONUS with any notable low-level moisture. Dewpoints over south FL
   preceding this front are currently in the low 70s, and mesoanalysis
   indicates modest buoyancy over the region. Convergence along the
   front will be modest and much of the large-scale ascent will be
   displaced north and east of this region, but isolated showers and
   thunderstorms are still expected this afternoon and evening.
   Moderate deep-layer vertical shear is in place, and there is a
   very-low-probability risk for a damaging gust or two. However,  
   limited updraft depth and/or persistence should mitigate the overall
   severe potential.

   ..Mosier/Leitman.. 12/08/2025

    

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z

        
   SPC AC 080501

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1101 PM CST Sun Dec 07 2025

   Valid 091200Z - 101200Z

   ...NO THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   The risk for thunderstorms appears negligible across the U.S Tuesday
   through Tuesday night.

   ...Discussion...
   While a blocking high to the north of the Aleutians may undergo at
   least some short-lived suppression, models indicate that a
   downstream high may become a bit more prominent across the southern
   mid- to subtropical latitudes of the eastern Pacific during this
   period.  As this occurs, a belt of strong anticyclonic flow is
   likely to be maintained across much of the eastern mid-latitude
   Pacific through the northern U.S. intermountain region and Rockies. 

   One of a number of short wave perturbations progressing through this
   jet is forecast to emerge and contribute to amplifying mid-level
   troughing as it digs across the northern Great Plains through Upper
   Midwest, accompanied by a rapidly migrating surface cyclone into the
   upper Great Lakes by late Tuesday night.  It appears that this will
   be trailed by a gradually consolidating and increasingly significant
   surface cold intrusion.

   A notable preceding surface front may remain a focus for
   thunderstorm development near and south-southeast of the Florida
   Straits Tuesday into Tuesday night.  The trailing flank of this
   front is forecast to weaken across the southwestern Gulf Basin, and
   some Gulf boundary-layer modification may commence to the north. 
   However, this is likely to remain rather modest, and an initial
   low-level offshore flow across the Gulf Coast, veering to an
   increasing westerly component by Tuesday night, will tend to inhibit
   inland moistening.

   ..Kerr.. 12/08/2025

   WUUS02 PTSDY2 

   

        
   SPC AC 080727

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0127 AM CST Mon Dec 08 2025

   Valid 101200Z - 111200Z

   ...NO THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   The risk for thunderstorms appears negligible across the U.S.
   Wednesday through Wednesday night.

   ...Discussion...
   Models indicate that an increasingly prominent high may build once
   again across and north of the Aleutians vicinity, but it appears
   that there will be little change to the downstream flow across the
   mid-latitude eastern Pacific into western North America, through at
   least this period.  Downstream, there is substantive spread in the
   model output concerning the subsequent evolution of short wave
   troughing initially digging across the Midwest at the outset of the
   period, and another notable perturbation digging toward the Great
   Lakes region, after emerging from the southern Hudson Bay vicinity. 
   Regardless, larger-scale mid/upper troughing to the east of the
   Rockies will be reinforced, and related surface developments are not
   likely to promote a southerly return flow off the Gulf Basin, where
   boundary-layer modification in the wake of the prior front will only
   be gradually underway.

   ..Kerr.. 12/08/2025

   WUUS03 PTSDY3 

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1930Z