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< Day 3 Outlook    
Day 4-8 Severe Weather Outlook Issued on Jun 18, 2013
Updated: Tue Jun 18 08:35:04 UTC 2013
D4-8 D4 D5 D6 D7 D8
 Population  Cities/Towns  CWAs  Interstates  Counties  FEMA Regions

Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4Fri, Jun 21, 2013 - Sat, Jun 22, 2013 D7Mon, Jun 24, 2013 - Tue, Jun 25, 2013
D5Sat, Jun 22, 2013 - Sun, Jun 23, 2013 D8Tue, Jun 25, 2013 - Wed, Jun 26, 2013
D6Sun, Jun 23, 2013 - Mon, Jun 24, 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 180833
   SPC AC 180833

   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0333 AM CDT TUE JUN 18 2013

   VALID 211200Z - 261200Z

   ...DISCUSSION...
   ...NRN PLAINS TO THE UPPER GREAT LAKES...
   A SEVERAL DAY PERIOD OF ORGANIZED SEVERE TSTMS MAY PERSIST INTO
   EARLY NEXT WEEK. HOWEVER...SYNOPTIC/MESOSCALE PREDICTABILITY BREAKS
   DOWN ON D3 AND LINGERS INTO THE MEDIUM-RANGE RENDERING LOW
   CONFIDENCE FOR HIGHLIGHTING ANY INDIVIDUAL DAY WITH HIGH-END SEVERE
   PROBABILITIES.

   ON THE LARGE-SCALE...THERE IS BROAD CONSISTENCY AMONG ECMWF/GFS/CMC
   DETERMINISTIC RUNS ALONG WITH ENSEMBLE MEANS THAT THE UPPER-LEVEL
   TROUGH OVER THE NORTHWEST WILL EITHER DAMPEN OR EJECT NEWD INTO
   S-CNTRL CANADA. IN THE WAKE OF THIS...A PRIMARILY ZONAL FLOW REGIME
   SHOULD DEVELOP AROUND D6/SUN WITH A BELT OF MODERATE TO STRONG
   MID-LEVEL WLYS PERSISTING ALONG THE NRN TIER OF STATES.
   TIMING/EVOLUTION DIFFERENCES HAMPER THE HANDLING OF SHORTWAVE
   IMPULSES AND HOW THEY MODULATE TSTM ACTIVITY ALONG THE LINGERING
   PRESENCE OF A QUASI-STATIONARY FRONT. BUT WITH A STRONG TO EXTREMELY
   UNSTABLE AIR MASS REMAINING S OF THE BOUNDARY OWING TO A PRONOUNCED
   EML...DAILY BOUTS OF ORGANIZED MESOSCALE SEVERE EVENTS APPEAR
   POSSIBLE.

   ..GRAMS.. 06/18/2013

   CLICK TO GET WUUS48 PTSD48 PRODUCT


To retrieve previous Day 4-8 convective outlooks, enter the date YYYYMMDD (e.g., 20050310 for March 10, 2005.)
Data available since March 8, 2005.
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Page last modified: June 18, 2013
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