Aug 4, 2015 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Tue Aug 4 06:47:07 UTC 2015 (20150804 0730Z Day 3 shapefile | 20150804 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0730 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 139,977 8,127,617 Memphis, TN...Birmingham, AL...Little Rock, AR...Huntsville, AL...Sioux Falls, SD...
Probabilistic Graphic
20150804 0730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 140,135 8,152,561 Memphis, TN...Birmingham, AL...Little Rock, AR...Huntsville, AL...Sioux Falls, SD...
   SPC AC 040647

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0147 AM CDT TUE AUG 04 2015

   VALID 061200Z - 071200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS OVER PORTIONS OF THE MID SOUTH
   FROM ERN AR TO NRN AL...

   ...THERE IS A MRGL RISK OF SVR TSTMS OVER PORTIONS OF THE NRN PLAINS
   FROM ERN SD INTO MN/IA...

   ...SUMMARY...
   ISOLATED STRONG THUNDERSTORMS WILL BE MOST LIKELY FROM PORTIONS OF
   LOWER-MIDDLE MISSISSIPPI RIVER VALLEY EAST TO THE CENTRAL
   APPALACHIANS AND MID-ATLANTIC ON THURSDAY. ANOTHER AREA WITH THE
   LIKELIHOOD FOR ISOLATED STRONG STORMS WILL BE ACROSS THE NORTHERN
   PLAINS AND UPPER MISSISSIPPI VALLEY.

   ...OVERVIEW...
   WLY/NWLY MIDLEVEL FLOW AOB 40KT WILL EXIST FROM THE NRN HIGH PLAINS
   ESEWD ACROSS THE MIDDLE MS VALLEY AND EAST TO MID-ATLANTIC COAST. A
   FEW DISTURBANCES ARE FORECAST TO BE EMBEDDED WITHIN THIS BELT OF
   WEAK TO MODEST FLOW. THE STRONGEST OF THESE WILL BE A SHORTWAVE
   TROUGH EJECTING EAST ACROSS MT DURING THE DAY. DOWNSTREAM FROM THIS
   STRONGER IMPULSE...AN ELONGATED SHORTWAVE TROUGH...PARTLY RESULTING
   FROM A NUMBER OF MCV MERGERS...WILL MOVE EAST ACROSS THE CNTRL TO
   NRN PLAINS FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING. ANOTHER
   MCV/SHORTWAVE IMPULSE OVER THE MID/LOWER MS VALLEY WILL SPREAD EAST
   TO THE TN VALLEY DURING THE DAY. GENERALLY WEAK FORCING FOR ASCENT
   WITH THESE DISTURBANCES WILL COMBINE WITH DIURNAL DESTABILIZATION TO
   PROMOTE STRONG TO ISOLATED SEVERE WEATHER DURING THURSDAY AFTERNOON
   AND EVENING.

   ...MID SOUTH...
   EXPECT STRONG DESTABILIZATION TO OCCUR ALONG THE SWRN FLANK OF
   DECAYING MCS FROM ERN AR TO ADJACENT AREAS OF NRN MS DURING THE
   MORNING/EARLY AFTERNOON. STRONG CAPPING PERSISTING ACROSS THESE
   AREAS MAY PROHIBIT MORE WIDESPREAD STORM DEVELOPMENT. HOWEVER...
   DEGREE OF INSTABILITY IN THE PRESENCE OF PERSISTENT AND FOCUSED LOW
   LEVEL CONVERGENCE...IN COMBINATION WITH MODEST TO LOCALLY STRONG
   SPEED/DIRECTIONAL SHEAR...SUGGEST AT LEAST A MARGINAL AND
   CONDITIONAL RISK OF SEVERE STORMS.

   ...NRN/CNTRL PLAINS...
   WARM ADVECTION AND INCREASING DEEP-LAYER FORCING FOR ASCENT WILL
   DEVELOP ACROSS THESE AREAS THROUGH THE PERIOD AS A LEADING/WEAK
   SHORTWAVE TROUGH MOVES EAST AND IS QUICKLY FOLLOWED BY A STRONGER
   IMPULSE SPREADING EAST FROM MT THROUGH THURSDAY NIGHT. STRONG
   DESTABILIZATION SHOULD OCCUR ON THE FLANK OF RESIDUAL MCS
   OUTFLOW/DEVELOPING WARM FRONT FROM ERN SD INTO MN DURING THE DAY.
   LIFT ACROSS THE REGION WILL THEN INCREASE INTO THE EVENING AS THE
   NEXT SYSTEM MOVES EAST AND HEIGHT FALLS INDUCE SURFACE WAVE
   DEVELOPMENT ON THE FRONT ACROSS ERN SD. SEVERE WEATHER RISK SHOULD
   EVOLVE AND PERSIST INTO THE EVENING GIVEN THE DEVELOPING SURFACE LOW
   AND STRENGTHENING FLOW/SHEAR ACROSS THE REGION.

   ..CARBIN.. 08/04/2015

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