Jan 30, 2013 1300 UTC Day 1 Convective Outlook
Updated: Wed Jan 30 12:46:34 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20130130 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20130130 1300 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 1300 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 1300 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 301242
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0642 AM CST WED JAN 30 2013
   
   VALID 301300Z - 311200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER OH VALLEY SWD TO
   THE CNTRL GULF COAST AND EWD TO THE MIDDLE AND SERN ATLANTIC
   COAST...
   
   ...SYNOPSIS...
   
   AN INTENSE UPPER-LEVEL TROUGH OVER THE GREAT PLAINS WILL ASSUME AN
   INCREASING NEGATIVE TILT WHILE PROGRESSING RAPIDLY NEWD INTO THE
   NERN U.S. BY THURSDAY MORNING.  THIS SYSTEM IS COMPRISED OF A LEAD
   VORTICITY MAXIMUM OVER THE LOWER MO VALLEY WHICH WILL MOVE NEWD INTO
   THE UPPER GREAT LAKES TODAY IN ADVANCE OF A MORE SUBSTANTIAL
   VORTICITY MAXIMUM TRANSLATING THROUGH THE MID/LOWER MS VALLEYS INTO
   THE APPALACHIANS BY TONIGHT.  THIS LATTER FEATURE WILL BE ATTENDED
   BY A 100-130 KT MIDLEVEL JET STREAK AND 12-HR HEIGHT FALLS AT 500 MB
   EXCEEDING 250-300 M.
   
   AT THE SURFACE...LOW PRESSURE OVER CNTRL IL WILL UNDERGO DEEPENING
   WHILE DEVELOPING NEWD THROUGH LOWER MI INTO SWRN ONTARIO.  AT THE
   SAME TIME...A COLD FRONT TRAILING SWWD FROM THIS LOW PRESSURE WILL
   OVERTAKE A DOWNSTREAM PACIFIC FRONT OR PRE-FRONTAL TROUGH WITH THE
   COMPOSITE BOUNDARY SWEEPING EWD TO OFF THE MID AND SERN ATLANTIC
   COASTS BY 31/12Z.
   
   ...UPPER OH VALLEY SWD TO THE CNTRL GULF COAST AND EWD TO THE MIDDLE
   AND SERN ATLANTIC COAST...
   
   AN EXTENSIVE QLCS EXTENDING FROM CNTRL OH SSWWD TO SERN PARTS OF
   MS/LA AS OF 12Z IS WELL-RESOLVED BY THE LATEST CONVECTION-ALLOWING
   MODEL GUIDANCE -- NAMELY THE ARW CORES.  THESE DATA SUGGEST THAT THE
   NRN EXTENT OF THE SQUALL LINE MAY WEAKEN TEMPORARILY WHILE MOVING
   THROUGH THE APPALACHIANS BEFORE INTENSIFYING OVER THE PIEDMONT LATE
   THIS AFTERNOON INTO EVENING.  INSTABILITY WILL REMAIN QUITE
   LIMITED...RESULTING IN SHALLOW CONVECTIVE TOWERS WITH LITTLE OR NO
   LIGHTNING ACTIVITY.  NONETHELESS...THE INTENSE HEIGHT FALLS/FORCING
   FOR ASCENT AND 60-70 KT FLOW JUST OFF THE GROUND /SEE THE 12Z ILN
   SOUNDING/ WILL BE SUPPORTIVE OF CORRIDORS OF WIND DAMAGE AND PERHAPS
   A FEW TORNADOES WITH EMBEDDED LEWP STRUCTURES.
   
   OVER THE GULF COAST STATES...MULTIPLE BANDS OF MORE DISCRETE
   STORMS...INCLUDING SUPERCELLS...HAVE RECENTLY DEVELOPED ACROSS AL
   WITHIN A CONFLUENT LOW-LEVEL FLOW REGIME DOWNSTREAM FROM THE PRIMARY
   QLCS.  THE 12Z BHM SOUNDING SHOWED THE PRESENCE OF A MOIST AND
   RATHER DEEP BOUNDARY LAYER...YIELDING MLCAPE OF AROUND 1000 J/KG. 
   WHEN COUPLED WITH EFFECTIVE BULK SHEAR OF 60 KT AND EFFECTIVE SRH
   VALUES OF 300-350 M2/S2...THE CORRIDOR OVER CNTRL/ERN AL INTO WRN GA
   WILL HAVE A HEIGHTENED RISK FOR TORNADOES IN ASSOCIATION WITH ANY
   LONGER-LIVED SUPERCELLS THAT PERSIST AHEAD OF THE QLCS. 
   OTHERWISE...THE POTENTIAL FOR CORRIDORS OF WIND DAMAGE WILL EXIST
   WITH THE QLCS AS IT ADVANCES RAPIDLY EWD ACROSS THE SRN APPALACHIANS
   AND ERN GULF STATES TODAY...TO OFF THE SERN ATLANTIC COAST LATER
   TONIGHT.
   
   ..MEAD/ROGERS.. 01/30/2013
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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