Dec 22, 2013 0100 UTC Day 1 Convective Outlook
Updated: Sun Dec 22 00:49:47 UTC 2013 (20131222 0100Z Day 1 shapefile | 20131222 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...widespread severe thunderstorms expected over parts of the lower mississippi to ohio valleys this afternoon and tonight....   Please read the latest public statement about this event.  View What is a Watch? clip.

Categorical Graphic
20131222 0100 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20131222 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
20131222 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
20131222 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 49,024 5,352,409 Nashville, TN...Louisville, KY...Clarksville, TN...Murfreesboro, TN...Jackson, TN...
SLIGHT 157,798 19,480,107 Columbus, OH...New Orleans, LA...Lexington, KY...Cincinnati, OH...Birmingham, AL...
   SPC AC 220045

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0645 PM CST SAT DEC 21 2013

   VALID 220100Z - 221200Z

   ...THERE IS A MDT RISK OF SVR TSTMS FOR NRN MS...NWRN
   AL...WRN/MIDDLE TN...WRN/CNTRL KY...FAR SRN IND...

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL GULF COAST TO
   THE OH VALLEY...

   ...CNTRL GULF COAST TO OH VALLEY...
   WAVY QUASI-STATIONARY FRONT REMAINS ACROSS CNTRL OH S/SWWD TO SWRN
   LA. TWO DISTINCT SURFACE CYCLONES HAVE PERSISTED ALONG THIS
   BOUNDARY...ONE ALONG THE KY/SWRN IND BORDER AND THE OTHER NEAR THE
   AR/TN BORDER. THE MOST INTENSE LEWP/BOW STRUCTURES WITHIN AN
   EXTENSIVE QLCS WERE LOCATED INVOF THESE CYCLONES AND WILL LIKELY
   POSE THE GREATEST RISK FOR SEVERE. THE NRN CYCLONE SHOULD BECOME
   DOMINANT AS THE SHORTWAVE TROUGH CENTERED OVER OK  PROGRESSES NEWD
   TOWARDS THE MID-MS VALLEY. AS THIS OCCURS...THESE LEWP/BOWS WILL
   LIKELY RACE NEWD TOWARDS THE TN AND CNTRL OH VALLEYS. ALTHOUGH
   BUOYANCY IS ONLY AROUND 500-1000 J/KG PER 00Z JAN/BNA/BMX
   RAOBS...PRESENCE OF LOWER TO MIDDLE 60S SURFACE DEW POINTS AMIDST
   EXTREME LOW-LEVEL SHEAR WILL POSE A CONTINUED RISK FOR SCATTERED TO
   NUMEROUS DAMAGING WINDS ALONG WITH A FEW EMBEDDED TORNADOES
   /POSSIBLY STRONG/ THROUGH THE EVENING. INCREASINGLY NEUTRAL LAPSE
   RATES WITH NRN EXTENT SHOULD EVENTUALLY LEAD TO WEAKENING OF THE
   QLCS ACROSS THE CNTRL/UPPER OH VALLEY OVERNIGHT. 

   TOWARDS THE CNTRL GULF COAST...THE LACK OF SUBSTANTIAL MID-LEVEL
   HEIGHT FALLS OWING TO THE TRACK OF THE SHORTWAVE TROUGH SHOULD
   RESULT IN GRADUALLY WEAKENING LOWER-LEVEL FLOW. BUT WITH THE
   PRESENCE OF UPPER 60S TO LOWER 70S SURFACE DEW POINTS...CONVERGENCE
   ALONG THE FRONT/QLCS MAY MAINTAIN A CONVECTIVE BAND PUSHING E/NEWD
   OVERNIGHT WITH MORE ISOLATED RISKS FOR DAMAGING WINDS AND A TORNADO
   OR TWO.

   ..GRAMS.. 12/22/2013

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