Feb 5, 2008 1630 UTC Day 1 Convective Outlook
Updated: Tue Feb 5 16:44:10 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the parts of the mid south this afternoon and tonight....   Please read the latest public statement about this event.

Categorical Graphic
20080205 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080205 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080205 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080205 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 051616
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1016 AM CST TUE FEB 05 2008
   
   VALID 051630Z - 061200Z
   
   ...THERE IS A HIGH RISK OF SVR TSTMS LARGE PART OF AR...PARTS OF NRN
   MS...WRN TN...WRN KY...AND A SMALL PART OF SRN IL AND SERN MO......
   
   ...THERE IS A MDT RISK OF SVR TSTMS SURROUNDING THE HIGH RISK BUT
   EXTENDING ENEWD INTO THE OH RIVER VALLEY AND TOWARD THE TN RIVER
   VALLEY......
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE SRN PLAINS
   ENEWD INTO THE OH/TN RIVER VALLEYS AND CENTRAL GULF STATES......
   
   OVERALL SYNOPTIC SETUP WILL BECOME QUITE FAVORABLE FOR AN OUTBREAK
   OF SEVERE THUNDERSTORMS AND TORNADOES...INCLUDING LONG-LIVED
   TORNADIC SUPERCELLS...CENTERED ON THE MID SOUTH THIS AFTERNOON AND
   EVENING.  MAXIMUM SEVERE THREAT AREA WILL SHIFT EWD ACROSS MS RIVER
   INTO WRN TN VALLEY AND NRN GULF STATES TONIGHT.
   
   ...SYNOPSIS...
   DEEP UPPER LEVEL TROUGH AND ASSOCIATED EXTREME MID AND UPPER LEVEL
   WIND FIELDS /H5 JET MAX IN EXCESS OF 90 KT...130+ KT AT H25/ WILL
   SUSTAIN AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE SRN PLAINS
   INTO THE GULF COAST STATES/OH RIVER VALLEYS THROUGH THE PERIOD.
   WIDESPREAD...ELEVATED THUNDERSTORMS CONTINUE TO INCREASE  THIS
   MORNING ASSOCIATED WITH EJECTING LOWER AMPLITUDE WAVE FROM NRN TX
   ACROSS OK.  ADDITIONAL WIDESPREAD THUNDERSTORMS CONTINUE TO
   BACKBUILD/PERSIST WITHIN BROAD REGION OF LOW LEVEL WAA AND ENHANCED
   ASCENT NEAR SURFACE COLD FRONT PUSHING SLOWLY SWD OVER THE OH RIVER
   VALLEY.
   
   SURFACE LOW IS DEVELOPING RED RIVER AREA OF SRN OK/NRN TX AND IS
   FORECAST TO DEEPEN FURTHER AS IT LIFTS NEWD ALONG SURFACE FRONT INTO
   NRN AR BY LATE TODAY AND INTO SRN IND LATER TONIGHT.  AS UPPER
   SYSTEM EJECTS EWD...DRY LINE/N-S SURFACE TROUGH WILL BEGIN TO SURGE
   EWD ACROSS CENTRAL/ERN  TX AND SHIFT STEADILY EAST ACROSS THE
   LOWER/MID MS RIVER VALLEYS TONIGHT. MEANWHILE...SURFACE FRONT
   TRAILING FAST MOVING SHORTWAVE TROUGH NOW MOVING ACROSS THE UPPER
   MIDWEST IS EXPECTED TO STALL AND THEN LIFT NWD SLIGHTLY LATE TONIGHT
   AS A WARM FRONT IN RESPONSE TO DEEPENING SURFACE LOW ACROSS THE
   LOWER OH RIVER VALLEY.  NET RESULT WILL BE PERSISTENT MOISTENING
   WITHIN BROAD WARM SECTOR FROM ERN TX INTO THE TN VALLEY THROUGH THE
   PERIOD...WITH SURFACE DEW POINTS AOA 60F EXTENDING AS FAR NORTH AS
   THE OH RIVER VALLEY.
   
   ...LOWER OH/MID MS RIVER VALLEY ENEWD INTO KY/MID OH RIVER VALLEY...
   
   
   EARLY DAY ACTIVITY WILL CONTINUE TO POSE AN ISOLATED RISK OF SEVERE
   WITHIN WEAK INSTABILITY AND SMALL CAP FROM PORTIONS OF SERN MO INTO
   NRN KY/SWRN OH.  SHEAR WILL REMAIN MORE THAN ADEQUATE FOR
   SUPERCELLS...AND TORNADO THREAT MAY INCREASE THROUGH THE EARLY
   AFTERNOON. AS SURFACE LOW DEEPENS AND MOVES ENEWD ACROSS SRN MO THIS
   EVENING AND THE STRONG MID/UPPER JET MAX ROTATES NEWD ACROSS AR
   FORECAST SOUNDINGS INDICATE EXTREME SHEAR AND EFFECTIVE INFLOW
   TAPPING LOW/MID 60F SURFACE DEW POINTS.
   
   WITH SURFACE BOUNDARIES EXPECTED TO REMAIN VICINITY OF SERN MO TO
   SRN OH THERE WILL BE A STRONG FOCUS FOR SURFACE BASED SUPERCELLS TO
   DEVELOP THRU THE EVENING.  HAVE EXTENDED THE HIGH RISK NEWD INTO WRN
   KY/SRN IL FOR THE CONCERN OF LONG LIVED TORNADIC SUPERCELLS VICINITY
   BOUNDARY. IN ADDITION A STRONGLY FORCED SQUALL LINE IS EXPECTED TO
   DEVELOP AHEAD OF THE DEEPENING SURFACE LOW WITH POTENTIAL FOR
   SIGNIFICANT WIND DAMAGE THIS EVENING EWD INTO LOWER OH VALLEY.
   
   
   ...MID SOUTH INTO THE CENTRAL GULF COAST STATES...
   
   EXPECT ISOLATED SEVERE THUNDERSTORMS...INITIALLY ELEVATED...WILL
   PERSIST AS THEY SPREAD ENEWD AHEAD OF WEAKENING IMPULSES IN
   SUBTROPICAL JET STREAM. ACTIVITY SHOULD BECOME INCREASINGLY
   SURFACE-BASED BY EARLY THIS AFTERNOON WITHIN EXTREME SHEAR AND VERY
   MOIST BOUNDARY LAYER INCREASING RISK OF ISOLATED TORNADOES/DAMAGING
   WINDS.  12Z SOUNDING FROM LZK AND MODIFIED OUN SOUNDING INDICATE
   MLCIN IS RELATIVELY WEAK ALREADY.  ONCE CAPPING BREAKS FROM ERN OK
   INTO NRN HALF OF AR/FAR SRN MO WITH THIS INITIAL WAVE...SEVERE
   THREAT SHOULD RAMP UP QUICKLY.
   
   APPEARS SRN/ERN AR INTO FAR NRN LA/WRN TN/NWRN MS WILL REMAIN
   RELATIVELY FREE OF MOIST CONVECTION THROUGH THE EARLY AFTERNOON...AS
   EARLY DAY ACTIVITY SHIFTS NEWD ACROSS THE OZARK PLATEAU/MO.
   THUS...AS MAIN IMPULSE AND ASSOCIATED SURFACE FRONT SPREAD EWD LATE
   TODAY...ROBUST THUNDERSTORM DEVELOPMENT SHOULD ENSUE WITHIN MLCAPE
   AROUND 1000 J/KG AND WEAK CIN.  EXTREME SHEAR WITH SFC-1 KM SRH IN
   EXCESS OF 300 M2/S2 SUGGESTS STORMS WILL RAPIDLY DEVELOP ROTATION
   AND AN ATTENDANT TORNADO THREAT ONCE THEY ROOT INTO DEEPLY MOIST
   BOUNDARY LAYER.  ANY TORNADIC SUPERCELLS COULD PRODUCE A LONG-LIVED
   SIGNIFICANT TORNADO IN THIS ENVIRONMENT.  STORMS MAY TEND TO EVOLVE
   INTO A BROKEN SQUALL LINE LATE THIS EVENING AS FRONT INTERACTS WITH
   RICH GULF MOISTURE AND MOVES ACROSS THE GULF COAST STATES OVERNIGHT.
   DAMAGING WIND THREAT COULD ALSO BECOME WIDESPREAD GIVEN EXTREME
   WIND FIELDS JUST OFF THE SURFACE...ALTHOUGH THREAT FOR A SIGNIFICANT
   TORNADO WILL CONTINUE OVERNIGHT WITH LEWP AND PRE-SQUALL LINE
   DEVELOPMENT.
   
   ..HALES.. 02/05/2008
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z