Current SPC Activity Chart

See Current Severe US Wx Maps

SPC Activity Chart
Hazard Fri (03/29) Sat (03/30) Sun (03/31) Mon (04/01) Tue (04/02) Wed (04/03) Thu (04/04) Fri (04/05)
Severe Marginal No Severe No Area Severe Severe No Area No Area No Area
Fire Critical Critical Critical No Area No Area No Area No Area No Area

Forecast Discussion - Convective Outlook

   SPC AC 290532

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1232 AM CDT Fri Mar 29 2024

   Valid 291200Z - 301200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF THE MIDWEST...

   ...SUMMARY...
   Marginally severe hail is possible with storms over portions of the
   Midwest Friday night.

   ...Midwest...

   Upper ridge is forecast to shift east across the MS Valley today as
   a short-wave trough currently located over the lower CO River valley
   advances into the central Plains by 30/00z. This feature will then
   shift east, inducing weak height falls over the upper Midwest,
   before progressing to near 87W longitude by the end of the period.
   Latest model guidance suggests a LLJ will strengthen across the
   central Plains early, then shift downstream into IL by 06z, in
   response to the approaching short wave. While moisture is initially
   quite scant across this region, there is reason to believe PW values
   may increase to near one inch later this evening, with mean mixing
   ratios expected near 8 g/kg.

   Moisture is beginning to advance north across TX early this morning,
   as evidenced by 50F surface dew points now approaching the DFW
   Metroplex. While absolute moisture content will remain seasonally
   low with this return event, 500mb temperatures will remain cold
   (-20C) north of the midlevel jet. Forecast soundings suggest
   elevated parcels will become weakly inhibited by mid evening, and
   scattered convection should develop ahead of the short wave within
   the warm advection zone. While the magnitude of instability will
   remain a bit weak, steep midlevel lapse rates are expected to
   support robust updrafts, the strongest of which could generate
   marginally severe hail. Convection should initiate over eastern IA
   then spread into northern IL/southern WI during the late
   evening/overnight hours.

   ..Darrow/Bentley.. 03/29/2024

    

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

        
   SPC AC 290559

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1259 AM CDT Fri Mar 29 2024

   Valid 301200Z - 311200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   A severe threat is not expected to develop across the continental
   U.S. on Saturday and Saturday night.

   ...DISCUSSION...
   Anticyclonic mid-level flow is forecast across much of the central
   and eastern U.S. on Saturday. Thunderstorms will be possible during
   the day into the evening from the Mid Mississippi Valley into the
   upper Ohio Valley, as a subtle shortwave trough moves eastward.
   Thunderstorms will also be possible across parts of California and
   Nevada, along the eastern edge of an upper-level system moving
   south-southeastward, offshore and parallel to the California coast.
   A severe threat is not expected to develop in any of these areas on
   Saturday and Saturday night.

   ..Broyles.. 03/29/2024

   WUUS02 PTSDY2 

   

        
   SPC AC 280726

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0226 AM CDT Thu Mar 28 2024

   Valid 301200Z - 311200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Organized severe thunderstorms are not forecast on Saturday.

   ...Synopsis and Discussion...
   A deep, closed upper low initially off the coast of central CA
   should move slowly southward along/near the southern CA Coast on
   Saturday. Cold mid-level temperatures and strong forcing for ascent
   associated with an enhanced mid/upper-level jet should support weak
   instability, and the potential for isolated lighting flashes with
   any low-topped convection that can develop from parts of central
   into southern CA. Organized severe thunderstorms appear unlikely
   across this region given the meager MUCAPE forecast.

   Isolated thunderstorms may occur Saturday over parts of the southern
   Great Lakes/OH Valley, as a low-amplitude shortwave trough moves
   east-southeastward across these areas. A weak surface low is also
   forecast to develop eastward over this region in tandem with the
   shortwave trough. Limited low-level moisture, with surface dewpoints
   generally in the low 50s, should temper how much instability can
   develop through Saturday afternoon given the presence of modest to
   poor mid-level lapse rates. This will likely hinder the overall
   severe threat across the OH Valley, even though deep-layer shear
   conditionally supports the potential for organized convection.

   Finally, occasional lightning flashes may occur with elevated
   convection that develops late Saturday night into early Sunday
   morning across parts of NE into southwestern IA and northern MO.
   Low-level moisture is expected to gradually return northward across
   the southern/central Plains through the day, and this area will be
   on northern fringe of this process. Strong forcing associated with a
   southerly low-level jet may provide sufficient lift for parcels to
   reach their LFC. Still, forecast MUCAPE appears too weak to support
   a meaningful hail threat through the end of the period (early Sunday
   morning).

   ..Gleason.. 03/28/2024

   WUUS03 PTSDY3 

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z