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Day 4-8 Severe Weather Outlook Issued on Nov 14, 2013
Updated: Thu Nov 14 10:01:03 UTC 2013
Day 4-8 Severe Weather Outlook Graphics Issued on Nov 14, 2013
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
D4 236,207 37,092,047 Indianapolis, IN...Columbus, OH...Detroit, MI...Memphis, TN...Nashville, TN...
D4Sun, Nov 17, 2013 - Mon, Nov 18, 2013 D7Wed, Nov 20, 2013 - Thu, Nov 21, 2013
D5Mon, Nov 18, 2013 - Tue, Nov 19, 2013 D8Thu, Nov 21, 2013 - Fri, Nov 22, 2013
D6Tue, Nov 19, 2013 - Wed, Nov 20, 2013 (All days are valid from 12 UTC - 12 UTC the following day)
Note: A severe weather area depicted in the Day 4-8 period indicates a 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears highly unlikely during the entire period (e.g. less than a 30% probability for a regional severe storm area across the CONUS through the entire Day 4-8 period).
 Forecast Discussion

   ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 141000
   SPC AC 141000

   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0400 AM CST THU NOV 14 2013

   VALID 171200Z - 221200Z

   ...DISCUSSION...
   SOME UNCERTAINTY LINGERS...BUT TRENDS IN THE MEDIUM RANGE FORECAST
   GUIDANCE ARE INCREASINGLY SUGGESTIVE OF THE DEVELOPMENT OF AN
   ENVIRONMENT SUPPORTIVE OF AN OUTBREAK OF SEVERE THUNDERSTORMS ACROSS
   PARTS OF THE MIDDLE MISSISSIPPI VALLEY EASTWARD THROUGH MUCH OF THE
   OHIO VALLEY ON SUNDAY.  MOST GUIDANCE NOW APPEARS GENERALLY FASTER
   WITH THE CONTINUED EASTWARD PROGRESSION OF A STRONG SHORT WAVE
   TROUGH...FROM THE CENTRAL PLAINS EARLY SUNDAY TO THE LOWER GREAT
   LAKES/UPPER OHIO VALLEY/CENTRAL APPALACHIANS REGION BY LATE SUNDAY
   NIGHT.  MOST MODELS ARE NOW SUGGESTIVE THAT THIS WILL BE ACCOMPANIED
   BY STRONG SURFACE CYCLOGENESIS...WITH MOST RAPID SURFACE PRESSURE
   FALLS ACROSS PARTS OF THE GREAT LAKES REGION AND OHIO VALLEY LATE
   SUNDAY AFTERNOON INTO SUNDAY NIGHT.  

   A 90+ KT 500 MB JET STREAK NOSING THROUGH THE OHIO VALLEY...COUPLED
   WITH STRENGTHENING SOUTHERLY WARM SECTOR 850 MB FLOW...PERHAPS IN
   EXCESS OF 70 KTS ACROSS PARTS OF THE OHIO VALLEY INTO THE LOWER
   GREAT LAKES...WILL CONTRIBUTE TO VERY STRONG DEEP LAYER WIND FIELDS
   AND SHEAR.  IT ALSO APPEARS INCREASINGLY PROBABLE THAT THIS WILL
   COINCIDE WITH AN INFLUX OF SEASONABLY HIGH MOISTURE CONTENT AT LEAST
   AS FAR NORTH AND EAST AS THE LOWER OHIO VALLEY...CONTRIBUTING TO
   SUFFICIENT CAPE FOR VIGOROUS STORM DEVELOPMENT.  SUPERCELLS WITH A
   RISK FOR TORNADOES WILL BE POSSIBLE...PARTICULARLY IN EARLY STAGES
   OF CONVECTIVE DEVELOPMENT...PERHAPS AS EARLY AS MID DAY ACROSS PARTS
   OF THE MIDDLE MISSISSIPPI INTO LOWER OHIO VALLEY VALLEY.

   EVENTUALLY...THOUGH...ACTIVITY PROBABLY WILL EVOLVE INTO A SQUALL
   LINE WITH DAMAGING STRAIGHT-LINE WINDS BECOMING THE MOST PROMINENT
   SEVERE THREAT.  IT MAY NOT BE OUT OF THE QUESTION THAT THIS COULD
   PROGRESS INTO PARTS OF THE MID ATLANTIC SEABOARD AND NORTHEAST LATE
   SUNDAY NIGHT INTO MONDAY...BUT THIS IS STILL TOO UNCERTAIN TO
   DELINEATE A REGIONAL SEVERE RISK AREA EAST OF THAT CURRENTLY
   DEPICTED.  THEREAFTER...CONVECTIVE POTENTIAL THROUGH THE REMAINDER
   OF THE PERIOD APPEARS LOW.

   ..KERR.. 11/14/2013

   CLICK TO GET WUUS48 PTSD48 PRODUCT
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Page last modified: November 14, 2013
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