Day 4-8 Severe Weather Outlook Issued on Jul 10, 2014
Updated: Thu Jul 10 09:18:03 UTC 2014
Severe Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
D6
128,451
60,387,637
New York, NY...Philadelphia, PA...Baltimore, MD...Boston, MA...Washington, DC...
D4
Sun, Jul 13, 2014 - Mon, Jul 14, 2014
D7
Wed, Jul 16, 2014 - Thu, Jul 17, 2014
D5
Mon, Jul 14, 2014 - Tue, Jul 15, 2014
D8
Thu, Jul 17, 2014 - Fri, Jul 18, 2014
D6
Tue, Jul 15, 2014 - Wed, Jul 16, 2014
(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 100916
SPC AC 100916
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0416 AM CDT THU JUL 10 2014
VALID 131200Z - 181200Z
...DISCUSSION...
MODELS HAVE REMAINED CONSISTENT...INDICATING UPPER PATTERN WILL
UNDERGO AMPLIFICATION IN THE 4-8 PERIOD. A BLOCKING PATTERN AND
SYNOPTIC UPPER TROUGH WILL BECOME ESTABLISHED OVER THE ERN U.S. BY
DAYS 5-6. COLD FRONT WILL GRADUALLY DEVELOP SEWD WITHIN THIS REGIME
WITH THE MOIST WARM SECTOR BECOMING CONFINED TO THE SRN THIRD OF THE
COUNTRY BY DAY 7.
DAY 4-5 /SUNDAY-MONDAY/ SOUTH OF COLD FRONT AND WITHIN AMPLIFYING
UPPER FLOW REGIME...A SEVERE THREAT SHOULD EXIST FROM THE MIDWEST
INTO THE OH VALLEY REGION DAY 4 AND THE OH VALLEY AND NERN U.S. DAY
5 WITH SOME SEVERE POTENTIAL ALSO LINGERING OVER THE CNTRL PLAINS.
LOCATION OF THE MORE SUBSTANTIAL SEVERE THREAT AREAS ON THESE DAYS
WILL BE MODULATED BY ANTECEDENT CONVECTION AND POSSIBLE MCS
DEVELOPMENT WHICH LOWERS OVERALL PREDICTABILITY REGARDING THE
PLACEMENT OF A 30% OR GREATER SEVERE RISK AREA AT THIS TIME.
DAY 6 /TUESDAY/ A MORE SUBSTANTIAL SEVERE THREAT MAY DEVELOP FROM
THE MID-ATLANTIC INTO THE NERN STATES AS A STRONG VORTICITY MAXIMUM
ROTATES THROUGH BASE OF UPPER TROUGH ACCOMPANIED BY STRONG WIND
PROFILES AND INTERACTS WITH THE MOIST BOUNDARY LAYER LIKELY TO BE IN
PLACE.
..DIAL.. 07/10/2014
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