Apr 10, 2013 1730 UTC Day 2 Convective Outlook
Updated: Wed Apr 10 17:32:48 UTC 2013
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20130410 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20130410 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 342,094 49,388,540 Indianapolis, IN...Columbus, OH...Charlotte, NC...Nashville, TN...Louisville, KY...
   SPC AC 101730
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1230 PM CDT WED APR 10 2013
   
   VALID 111200Z - 121200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THU AND THU NIGHT ACROSS THE
   LOWER OHIO/TENNESSEE VALLEYS AND CENTRAL/EASTERN GULF STATES INTO
   THE CAROLINAS...
   
   ...SYNOPSIS...
   TO THE SOUTH OF A PROMINENT HIGHER LATITUDE BLOCK...MODELS SUGGEST
   THAT UPPER TROUGHING ENCOMPASSING MUCH OF THE INTERIOR OF THE U.S.
   WILL PERSIST...BUT CYCLONIC FLOW MAY BEGIN TO BECOME LESS AMPLIFIED
   DURING THIS FORECAST PERIOD.  ONLY A SLOW EASTWARD PROGRESSION OF A
   MID-LEVEL CLOSED LOW FROM THE MID MISSOURI VALLEY INTO THE UPPER
   MIDWEST IS FORECAST THURSDAY AND THURSDAY NIGHT.  BUT...A
   SIGNIFICANT SHORT WAVE IMPULSE...NOW DIGGING INTO THE BASE OF LARGER
   SCALE TROUGHING ACROSS THE NORTHERN MEXICAN PLATEAU...APPEARS LIKELY
   TO ACCELERATE EAST NORTHEAST OF THE LOWER RIO GRANDE VALLEY THROUGH
   THE CENTRAL/SOUTHERN APPALACHIANS/MID ATLANTIC REGION BY 12Z FRIDAY.
    UNCERTAINTY LINGERS CONCERNING TIMING...BUT THE MOST RAPID
   ACCELERATION MAY OCCUR EAST OF THE LOWER MISSISSIPPI VALLEY THURSDAY
   EVENING INTO THE OVERNIGHT HOURS.  AS THIS OCCURS...INCREASED
   COUPLING OF AN ASSOCIATED 500 MB JET STREAK WITH A STRENGTHENING 850
   MB SPEED MAXIMUM APPEARS PROBABLE ACROSS THE EASTERN GULF STATES
   INTO THE CAROLINAS...ACCOMPANIED BY SECONDARY FRONTAL WAVE
   DEVELOPMENT ACROSS SOUTHEASTERN MISSISSIPPI AND CENTRAL ALABAMA INTO
   THE LEE OF THE SOUTHERN APPALACHIANS.
   
   MODELS ALSO SUGGEST THAT THERE WILL BE CONTINUED SLOW DEEPENING OF
   THE PRIMARY SURFACE CYCLONE ACROSS SOUTHERN PORTIONS OF THE GREAT
   LAKES REGION...WEST OF THE APPALACHIANS.  THE TRAILING COLD FRONT IS
   EXPECTED TO ADVANCE EAST OF THE MISSISSIPPI VALLEY...INTO THE
   VICINITY OF THE APPALACHIANS BY THE END OF THE PERIOD...AS A
   SIGNIFICANT PRECEDING INTRUSION OF COLD AIR IS SLOW TO MODIFY ACROSS
   THE LOWER GREAT LAKES REGION AND MUCH OF THE NORTHEAST.
   
   ...LWR OH/TN VALLEYS AND CNTRL/ERN GULF STATES INTO CAROLINAS...
   DEEP LAYER SHEAR IS EXPECTED TO BECOME MORE THAN SUFFICIENT FOR
   SEVERE STORMS WITHIN THE WARM ENVIRONMENT ENCOMPASSING A LARGE
   PORTION OF THE EASTERN U.S...AHEAD OF THE FRONT ADVANCING EAST OF
   THE MISSISSIPPI VALLEY...AND SOUTH OF THE STALLING FRONT ACROSS THE
   UPPER OHIO VALLEY AND MID ATLANTIC COAST REGION.  AND SOME ASPECTS
   OF THE EVOLVING LARGE SCALE PATTERN APPEAR FAVORABLE FOR A MORE
   SIGNIFICANT SEVERE WEATHER OUTBREAK THAN INDICATED BY THE CURRENT
   CATEGORICAL AND PROBABILISTIC OUTLOOKS.  HOWEVER...ONE PROMINENT
   POTENTIAL LIMITING FACTOR EVIDENT IN MODEL FORECASTS IS THE
   CONTINUING PRESENCE OF DRIER POCKETS WITHIN THE WARM SECTOR INTO THE
   DAY THURSDAY...PARTICULARLY IN THE BOUNDARY LAYER...EAST OF THE
   CENTRAL APPALACHIANS...AND ACROSS THE CUMBERLAND PLATEAU SOUTHWARD
   INTO EASTERN GULF COASTAL AREAS.  WHILE THIS MAY MODIFY SOME ON
   SOUTHERLY LOW-LEVEL FLOW...RICHER BOUNDARY LAYER MOISTURE
   CHARACTERIZED BY UPPER 60S/70S DEW POINTS IS NOT EXPECTED INLAND OF
   IMMEDIATE GULF COASTAL AREAS DURING THIS PERIOD.
   
   EARLY PERIOD PRE-FRONTAL CONVECTION AND ASSOCIATED CLOUD COVER
   PROVIDE ADDITIONAL UNCERTAINTY CONCERNING DESTABILIZATION...
   PARTICULARLY ACROSS THE LOWER OHIO/TENNESSEE VALLEYS.  HOWEVER... AT
   LEAST A NARROW NORTH/SOUTH CORRIDOR OF WEAK TO MODERATE BOUNDARY
   LAYER BASED DESTABILIZATION APPEARS PROBABLE DURING THE PEAK
   AFTERNOON HEATING.  IN THE PRESENCE OF WIND PROFILES...WHICH
   FORECAST SOUNDINGS SUGGESTS COULD EXHIBIT PRONOUNCED LOW-LEVEL
   HODOGRAPH SIZE AND CLOCKWISE CURVATURE...STRONG/SEVERE STORMS APPEAR
   PROBABLE...INCLUDING THE RISK FOR AT LEAST A FEW DISCRETE SUPERCELLS
   CAPABLE OF PRODUCING TORNADOES AND LARGE HAIL.
   
   FARTHER SOUTH...PROBABILITIES FOR THE EVOLUTION OF AN ORGANIZED
   SEVERE MESOSCALE CONVECTIVE SYSTEM APPEAR HIGHER AS FORCING/SHEAR
   INCREASES IN ASSOCIATION WITH THE ACCELERATING SHORT WAVE IMPULSE
   ...ACROSS ALABAMA/GEORGIA BY EARLY THURSDAY EVENING.  THIS MAY BE
   ACCOMPANIED BY A MORE SUBSTANTIVE/WIDESPREAD DAMAGING WIND THREAT. 
   TORNADOES AND LARGE HAIL WILL ALSO BE POSSIBLE WITH THIS ACTIVITY.
   
   ..KERR.. 04/10/2013
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z