Jan 30, 2013 0100 UTC Day 1 Convective Outlook
Updated: Wed Jan 30 00:57:32 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms with widespread damaging winds and several tornadoes expected over parts of the lower ohio valley...mid south...and lower mississippi valley through tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20130130 0100 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130130 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
20130130 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
20130130 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.
   SPC AC 300053
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0653 PM CST TUE JAN 29 2013
   
   VALID 300100Z - 301200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF FAR NE TX...NRN
   LA...AR...NW MS...WRN TN...SE MO...SRN IL...FAR SW IND AND WRN KY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
   PLAINS....ARKLATEX....LOWER TO MID MS VALLEY AND OH VALLEY...
   
   ...LOWER TO MID MS VALLEY...
   THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH MOVING
   EWD INTO THE SRN PLAINS. AN 80 TO 100 KT MID-LEVEL JET IS CURRENTLY
   EJECTING NEWD ACROSS THE SRN PLAINS. THIS ALONG WITH A STRENGTHENING
   LOW-LEVEL JET WILL ENABLE DEEP LAYER SHEAR TO CONTINUE TO INCREASE
   ACROSS THE LOWER TO MID MS VALLEY THIS EVENING. THE STRENGTHENING
   SHEAR COMBINED WITH INCREASING LIFT ASSOCIATED WITH A BAND OF STRONG
   LARGE-SCALE ASCENT WILL HELP A SQUALL-LINE TO CONTINUE TO ORGANIZE.
   MODEL FORECASTS STRONGLY INTENSIFY THE LINE LATE THIS EVENING
   DRIVING A NEARLY CONTINUOUS LINEAR MCS ACROSS THE LOWER TO MID MS
   VALLEY AND INTO THE TN VALLEY DURING THE OVERNIGHT PERIOD. AS THE
   SQUALL-LINE MOVES EWD ACROSS THE MODERATE RISK AREA...A WIDESPREAD
   SEVERE THREAT WILL EXIST AND SEVERAL SIGNIFICANT EVENTS APPEAR
   LIKELY.
   
   OBJECTIVE ANALYSIS CURRENTLY SHOWS A POCKET OF MODERATE INSTABILITY
   EXTENDING FROM NE TX NEWD INTO CNTRL AR WHERE THE LITTLE ROCK 00Z
   SOUNDING SHOWS MUCAPE AROUND 1100 J/KG. THIS INSTABILITY WAS
   CO-LOCATED WITH A POCKET OF MID 60S F SFC DEWPOINTS WHICH SHOULD
   CONTINUE TO ADVECT NEWD ACROSS THE MODERATE RISK AREA. THE LITTLE
   ROCK SOUNDING ALSO SHOWS 70 KT OF DEEP LAYER SHEAR WHICH COMBINED
   WITH THE INSTABILITY SHOULD EASILY SUPPORT SUPERCELL DEVELOPMENT.
   CURRENT RADAR TRENDS SHOW MULTIPLE DISCRETE CELLS DEVELOPING JUST TO
   THE WEST OF LITTLE ROCK. AS THESE CELLS MOVE ACROSS CNTRL AND ERN AR
   AND INTO THE CORE OF THE LOW-LEVEL JET...SHEAR WILL BE FAVORABLE FOR
   SUPERCELLS AND TORNADOES. AT LITTLE ROCK...0-3 KM STORM RELATIVE
   HELICITIES OF 500 TO 600 M2/S2 AND LCL HEIGHTS BELOW 700 METERS
   SHOULD BE SUFFICIENT FOR STRONG TORNADOES ESPECIALLY WITH DISCRETE
   CELLS THAT REMAIN AHEAD OF THE SQUALL-LINE. 50 TO 60 KT OF FLOW AT 1
   TO 2 KM SHOULD ALSO MAKE CONDITIONS FAVORABLE FOR WIDESPREAD WIND
   DAMAGE AS THE SQUALL-LINE CONTINUES TO ORGANIZE. THE WIND DAMAGE AND
   TORNADO THREAT IS EXPECTED TO CONTINUE INTO WCNTRL TN...ECNTRL MS
   AND WRN AL AFTER MIDNIGHT WITH A SEVERE THREAT POSSIBLE THROUGH MUCH
   OF THE OVERNIGHT PERIOD.
   
   ...OH VALLEY...
   A SQUALL-LINE IS CURRENTLY ONGOING FROM ECNTRL IL SWWD ACROSS SE MO
   LOCATED IN THE EXIT REGION OF A PRONOUNCED 70 TO 80 KT MID-LEVEL
   JET. AS THIS JET EJECTS NEWD ACROSS THE OH VALLEY THIS
   EVENING...DEEP LAYER SHEAR WILL CONTINUE TO STRENGTHEN. THIS
   COMBINED WITH STRONG LARGE-SCALE ASCENT SHOULD ENABLE THE
   SQUALL-LINE TO ORGANIZE WITH THE LINE MOVING EWD ACROSS IND AND WRN
   KY LATE THIS EVENING. INCREASING LOW-LEVEL MOISTURE AND INSTABILITY
   COMBINED WITH VERY STRONG FLOW JUST ABOVE THE SFC...SHOULD ENABLE
   THE SQUALL-LINE TO BECOME AN EFFICIENT WIND DAMAGE PRODUCER. AS SFC
   DEWPOINTS GRADUALLY INCREASE INTO THE LOWER 60S F ACROSS PARTS OF
   THE OH VALLEY...A TORNADO THREAT WILL ALSO BE POSSIBLE ESPECIALLY
   WITH ROTATING CELLS EMBEDDED IN THE LINE.
   
   ..BROYLES.. 01/30/2013
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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