May 25, 2006 1300 UTC Day 1 Convective Outlook
Updated: Thu May 25 16:36:18 UTC 2006
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Public Severe Weather Outlook

The SPC is forecasting an outbreak of severe thunderstorms today and tonight across portions of the United States. This is an extremely dangerous situation. Please read the latest public statement about this event.

Categorical Graphic
20060525 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20060525 1300 UTC Day 1 Tornado Probabilities Graphic
Probabilistic Damaging Wind Graphic
20060525 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Probabilistic Large Hail Graphic
20060525 1300 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 251250
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0750 AM CDT THU MAY 25 2006
   
   VALID 251300Z - 261200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF
   IND...OH...IL...AND KY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID ATL CST THROUGH
   THE TN VLY TO OZARKS/SRN PLNS...
   
   ...SYNOPSIS...
   WI UPR LOW SHOULD CONTINUE ESE THROUGH EARLY FRIDAY AS 60+ KT MID
   LEVEL JET STREAK AND ASSOCIATED MID LEVEL DRY PUNCH NOW OVER SRN
   IA/WRN IL...PER WV AND VWP DATA...SWEEP E/SE INTO SRN IND/NRN KY BY
   THIS EVENING.  COUPLED WITH PERSISTENT INFLUX OF INCREASINGLY MOIST
   BOUNDARY LAYER FLOW FROM MO/AR AND THE LWR TN VLY...STAGE APPEARS
   SET FOR A SIGNIFICANT SEVERE WEATHER EPISODE THIS AFTERNOON INTO
   TONIGHT OVER PARTS OF THE OH VLY.  A MORE LIMITED SEVERE THREAT MAY
   EXTEND E ACROSS THE CNTRL/SRN APLCNS TO THE VA CST.  LATER IN THE
   PERIOD...STRONG TO SEVERE STORMS MAY DEVELOP W INTO THE OZARKS AND 
   KANSAS.
   
   COLD FRONT NOW EXTENDING FROM CNTRL WI SWD INTO NRN IL AND THEN SW
   INTO CNTRL KS SHOULD ACCELERATE SE TODAY AS MID/UPR LEVEL JET STREAK
   REDEVELOPS ESEWD.  BY EARLY AFTERNOON...FRONT SHOULD EXTEND FROM WRN
   LOWER MI AND INTO SW MO.  THE TRAILING WRN PART OF THE BOUNDARY
   SHOULD BECOME STATIONARY OVER SRN KS.  FARTHER E...MODERATE/DEEP WLY
   FLOW AND SURFACE HEATING SHOULD PROMOTE N/EWD REDEVELOPMENT OF
   DIFFUSE WARM FRONT INTO ERN OH/NRN WV AND ERN VA/SRN MD BY LATE IN
   THE DAY.
   
   ...OH VLY...
   SEVERAL BANDS OF TSTMS EXPECTED TO DEVELOP IN BROAD ZONE OF
   CONFLUENT/MOIST WSWLY LOWER TROPOSPHERIC FLOW ALONG AND AHEAD OF
   MI/IL COLD FRONT THIS AFTERNOON INTO TONIGHT AS SURFACE HEATING AND
   LARGE SCALE ASCENT IN EXIT REGION OF APPROACHING JET STREAK FURTHER
   DESTABILIZE REGION.  WITH MLCAPE LIKELY TO RANGE FROM 1500 TO 3000
   J/KG AND 50 KT WSWLY 700 MB FLOW PRESENT TO ENHANCE TROPOSPHERIC
   SHEAR...SUSTAINED SUPERCELLS APPEAR LIKELY OVER IND/WRN OH/SRN
   MI...AND PERHAPS SE IL/WRN KY. MEAN LOW LEVEL WSWLY FLOW SUGGESTS
   THAT CONVERGENCE WILL NOT BE PARTICULARLY STRONG ALONG FRONT. 
   COUPLED WITH EXISTING W/E BREADTH OF WARM SECTOR...POTENTIAL WILL
   THEREFORE EXIST FOR A FEW LONG-LIVED DISCRETE STORMS AND STRONG
   TORNADOES...ESPECIALLY IN IND/WRN OH.
   
   PERSISTENCE/DEGREE OF FORCING FOR ASCENT...AND WIDESPREAD NATURE OF
   INSTABILITY FIELD...SUGGEST THAT STORMS WILL MERGE INTO MORE OR LESS
   SOLID LINES BY THIS EVENING.  THE MAIN SEVERE THREATS SHOULD
   TRANSITION TO WIND/HAIL AS THE MCSS CONTINUE E/SE INTO PA/WV CNTRL
   KY BY MID TO LATE EVENING.
   
   ...TN VLY...
   TWO AREAS OF TSTMS LEFTOVER FROM YESTERDAY'S ACTIVITY CONTINUE ATTM
   OVER SRN KY/NRN TN.  THIS ACTIVITY IS BEING FED BY A WEAKER BRANCH
   OF THE SAME WSWLY LLJ EXPECTED TO CONTRIBUTE TO THE OH VLY STORMS. 
   GIVEN CLEAR SKIES S OF THE STORMS...EXPECTED PERSISTENCE OF WLY LOW
   LEVEL/UPSLOPE FLOW...POTENTIAL WILL EXIST FOR DIURNAL
   REINTENSIFICATION OF THESE STORMS ACROSS THE TN VLY/SRN APLCNS 
   LATER TODAY.  THE MAIN THREATS SHOULD BE DAMAGING WIND/HAIL FROM
   FORWARD-PROPAGATING/BOWING LINE SEGMENTS.
   
   ...VA/NRN NC...
   LOW LEVEL MOISTURE WILL CONTINUE TO SPREAD NWD OVER THE NC/VA
   PIEDMONT AND CSTL PLN TODAY AS LEE TROUGH SETS UP E OF THE SRN/CNTRL
   APLCNS.  AT THE SAME TIME...SURFACE HEATING AND WLY FLOW ALOFT
   SHOULD ALLOW A SEGMENT OF SYNOPTIC SCALE WARM FRONT NOW IN THE OH
   VLY REFORM N INTO CNTRL/ERN VA.  SURFACE HEATING ALONG THIS
   FEATURE...ALONG WITH ARRIVAL OF ENHANCED LOW LEVEL MOISTURE...MAY
   SUPPORT STORM DEVELOPMENT OVER PARTS OF NC/VA LATER TODAY.  STORMS
   MAY ALSO REDEVELOP E ACROSS THE MTNS FROM ACTIVITY NOW IN ERN KY. 
   SUFFICIENT DEEP SWLY SHEAR AWAY FROM BOUNDARY WILL BE PRESENT TO
   SUPPORT ORGANIZED STORMS WITH STRONG WINDS/POSSIBLE HAIL.  IN
   ADDITION...A CONDITIONAL THREAT MAY SLOW DEVELOP FOR A TORNADO OR
   TWO LATE IN THE DAY IN ZONE OF ENHANCED LOW LEVEL SHEAR IN SE VA.
   
   ...SRN HI PLNS...
   TERRAIN-DRIVEN UPSLOPE CIRCULATIONS AND SUBTLE IMPULSES ALOFT
   EXPECTED TO SUPPORT WIDELY SCATTERED LATE AFTERNOON/EVENING STORMS
   IN STRONGLY HEATED/WEAKLY SHEARED ENVIRONMENT OVER THE SRN HI PLNS. 
   LARGE T/TD SPREADS OF 30-35 DEGREES F WILL FOSTER MICROBURSTS...BUT
   SUFFICIENT MOISTURE MAY ALSO BECOME INVOLVED IN STORM UPDRAFTS TO
   YIELD LARGE HAIL.
   
   ...KS/OZARKS TONIGHT/EARLY FRIDAY...
   ELEVATED STORMS WITH LARGE HAIL MAY DEVELOP LATE TONIGHT/EARLY
   FRIDAY ACROSS PARTS OF KS/MO AND NRN AR...IN ZONE OF INCREASING WAA
   ASSOCIATED WITH NOCTURNALLY-STRENGTHENED MOIST LLJ.
   
   ..CORFIDI/MEAD/JEWELL.. 05/25/2006
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z