Jun 1, 2013 0100 UTC Day 1 Convective Outlook
Updated: Sat Jun 1 00:46:36 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe weather outbreak possible over parts of the southern plains to the ozark plateau late this afternoon into tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20130601 0100 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130601 0100 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20130601 0100 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
20130601 0100 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 24,398 3,063,139 Oklahoma City, OK...Tulsa, OK...Springfield, MO...Norman, OK...Broken Arrow, OK...
SLIGHT 239,111 28,188,992 Chicago, IL...Indianapolis, IN...Detroit, MI...St. Louis, MO...Toledo, OH...
   SPC AC 010042

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0742 PM CDT FRI MAY 31 2013

   VALID 010100Z - 011200Z

   ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS CENTRAL TO NERN
   OK...EXTREME SERN KS...SWRN MO...EXTREME NWRN AR...

   ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM SRN OK TO SRN
   LOWER MI AND NWRN OH...

   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS UPPER MS VALLEY TO
   WRN/NRN WI AND WRN UPPER MI...

   ...SYNOPSIS...
   MID-UPPER LEVEL CYCLONE CENTERED OVER NERN SD IS FCST TO PERSIST AS
   WELL-DEFINED VORTICITY MAX...BUT DEAMPLIFY INTO
   HIGH-AMPLITUDE/OPEN-WAVE TROUGH OVER MN BY AROUND 12Z.  TROUGH WILL
   EXTEND SWWD ACROSS CENTRAL PLAINS TO NERN NM/TX PANHANDLE REGION BY
   THEN.  AS THIS OCCURS...UPPER JET MAX IS EXPECTED TO STRENGTHEN FROM
   IA NEWD ACROSS LM TO NRN ONT...WHILE SWRN LIMB OF SAME JET CORE
   WEAKENS OVER SRN HIGH PLAINS.  AMONG NUMEROUS...MOSTLY SUBTLE AND
   SMALL PERTURBATIONS ARE EMBEDDED WITHIN ASSOCIATED FLOW FIELD...MOST
   PRONOUNCED BEING SHORTWAVE OVER ERN CO AND MCV OVER OH.  OH FEATURE
   WILL MOVE NEWD...PRECEDED BY CONVECTION WITH MRGL WIND/HAIL THREAT
   FOR 2-3 MORE HOURS.  DCVA RELATED TO APCHG CENTRAL HIGH-PLAINS
   TROUGH MAY AID IN PERSISTING CONVECTIVE POTENTIAL OVERNIGHT IN SRN
   PLAINS/OZARKS.

   AT SFC...PRIMARY CYCLONE WAS CENTERED OVER SERN ND AND SHOULD
   CLOSELY FOLLOW MID-UPPER VORTICITY MAX INTO MN OVERNIGHT.  SFC COLD
   FRONT SHOULD CONTINUE TO MOVE EWD ACROSS UPPER MS VALLEY REGION...IA
   AND NRN MO OVERNIGHT...AND SLOWLY SEWD OVER PORTIONS WRN MO...SERN
   KS...AND NRN/WRN OK.  DOUBLE DRYLINE STRUCTURE WAS ANALYZED AT 23Z
   WITH INITIAL BOUNDARY EXTENDING FROM SECONDARY LOW OVER SWRN OK SWWD
   BETWEEN SNK-SWW AND INTO TX BIG BEND REGION.  SECONDARY DRYLINE WAS
   EVIDENT ON MESONET DATA AND RADAR REFLECTIVITY ALONG WRN EDGE OF
   UPPER 60S/70S F DEW POINT AIR MASS FROM E OF HBR SWD TO NEAR RPH. 
   THESE FEATURES SHOULD RETREAT/CONSOLIDATE THROUGH REMAINDER
   EVENING...MERGING WITH SFC FRONTAL ZONE OVER SWRN OK.

   ...SRN PLAINS TO MID MS VALLEY REGION AND IL...
   SUBSTANTIAL SVR EVENT IS UNDERWAY OVER THIS CORRIDOR WITH MULTIPLE
   TORNADIC OR POTENTIALLY TORNADIC TSTMS FROM SWRN MO TO CENTRAL OK. 
   THIS INCLUDES SUPERCELL CLUSTER MOVING THROUGH OKC METRO AREA WITH
   HISTORY OF MULTIPLE-VORTEX TORNADO PRODUCTION.  BACKED SFC WINDS AND
   RELATED ENLARGEMENT OF LOW-LEVEL HODOGRAPHS ARE NOW WELL UNDERWAY
   AND SHOULD CONTINUE FOR A FEW MORE HOURS...LEADING TO EFFECTIVE SRH
   300-400 J/KG THAT COULD REACH 500 J/KG WHILE INFLOW PARCELS STILL
   ARE SFC-BASED.  REF WWS 260...262...263...265...AND RELATED
   MESOSCALE DISCUSSIONS FOR LATEST UPDATED DETAILS OVER THIS CORRIDOR.


   THIS EVENING THROUGH OVERNIGHT...MCS WITH CONCENTRATED DAMAGING-WIND
   POTENTIAL IS EXPECTED TO EVOLVE FROM CENTRAL OK TO SRN MO AND MOVE
   EWD ACROSS NERN OK...SRN MO AND SRN IL.  EMBEDDED SUPERCELLS AND
   LEWP/BOW FEATURES STILL WILL POSE TORNADO POTENTIAL AS WELL THROUGH
   MUCH OF OVERNIGHT HOURS.  EFFECTIVE INFLOW PARCELS SHOULD REMAIN AT
   OR NEARLY SFC-BASED WELL INTO TONIGHT SINCE DIABATIC STABILIZATION
   OF VERY HIGH-THETAE INFLOW LAYER WILL BE SLOW/GRADUAL. 
   MEANWHILE...MLCAPE 2500-4500 J/KG WILL PERSIST THROUGH EVENING.

   ...UPPER MS VALLEY...WI...LS...UPPER MI...
   BKN BANDS OF TSTMS ALONG/AHEAD OF SFC COLD FRONT WILL MOVE INTO AIR
   MASS CHARACTERIZED BY 500-1000 J/KG MLCAPE AND INCREASING EFFECTIVE
   SHEAR WITH SEWD EXTENT.  HAIL HAS BEEN AND WILL REMAIN PRIMARY SVR
   THREAT FROM HERE ON...THOUGH SOME ORTHOGONAL COMPONENT OF FLOW ALOFT
   WITH RESPECT TO CONVECTIVE ALIGNMENT ALSO IS EVIDENT IN SUPPORT OF
   GUST THREAT.  REF WW 261 AND LATEST MESOSCALE DISCUSSIONS FOR
   NEAR-TERM GUIDANCE ACROSS THIS AREA.  OVERALL SVR HAZARD SHOULD
   DIMINISH AFTER ABOUT 04Z.

   ...NRN INDIANA...
   SMALL BUT SVR COMPLEX OF TSTMS SHOULD PROCEED ENEWD ACROSS NRN
   INDIANA WITH POTENTIAL FOR DAMAGING GUSTS AND ISOLATED/MRGLLY SVR
   HAIL.  ALTHOUGH DEEP SHEAR IS BEING LIMITED BY LACK OF STG MID-UPPER
   WINDS...FORWARD PROPAGATION AND PRECIP-LOADING EFFECTS WILL
   CONTRIBUTE TO GUST THREAT WITH THIS ACTIVITY.  REF WW 264 AND
   ASSOCIATED MESOSCALE DISCUSSIONS FOR MORE DETAILED SHORT-TERM
   GUIDANCE.

   ..EDWARDS.. 06/01/2013

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z