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Day 4-8 Severe Weather Outlook Issued on Dec 22, 2012 |
Updated: Sat Dec 22 09:59:03 UTC 2012 |
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D4 | Tue, Dec 25, 2012 - Wed, Dec 26, 2012 |
D7 | Fri, Dec 28, 2012 - Sat, Dec 29, 2012 |
D5 | Wed, Dec 26, 2012 - Thu, Dec 27, 2012 |
D8 | Sat, Dec 29, 2012 - Sun, Dec 30, 2012 |
D6 | Thu, Dec 27, 2012 - Fri, Dec 28, 2012 |
(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.
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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.
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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).
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ZCZC SPCSWOD48 ALL
ACUS48 KWNS 220958
SPC AC 220958
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0358 AM CST SAT DEC 22 2012
VALID 251200Z - 301200Z
...DISCUSSION...
THE MEDIUM RANGE MODELS MOVE A PROGRESSIVE UPPER-LEVEL TROUGH
QUICKLY ESEWD ACROSS THE ROCKIES MONDAY NIGHT AND INTO THE SRN
PLAINS ON TUESDAY/DAY 4. STRONG LARGE-SCALE ASCENT AND MOISTURE
RETURN AHEAD OF THE SYSTEM WILL ALLOW SCATTERED TO NUMEROUS
THUNDERSTORMS TO DEVELOP ACROSS THE TX COASTAL PLAINS AND IN THE
LOWER MS VALLEY FROM LATE MONDAY NIGHT INTO TUESDAY. AS THE EXIT
REGION OF A POWERFUL MID-LEVEL JET NOSES INTO THE LOWER MS
VALLEY...SEVERE STORMS WILL BE POSSIBLE DUE TO STRONG DEEP LAYER
SHEAR AND WIDESPREAD ASCENT. THE PROGRESSIVE NATURE OF THE SYSTEM
MAY ENABLE A SQUALL-LINE TO ORGANIZE AND QUICKLY MOVE EWD ACROSS THE
LOWER MS VALLEY ON TUESDAY AND INTO THE CNTRL GULF COAST STATES. IT
APPEARS THAT A SUBSTANTIAL SEVERE WEATHER THREAT WILL BE POSSIBLE ON
TUESDAY AND TUESDAY NIGHT ACROSS A BROAD CORRIDOR FROM SE TX
EXTENDING ENEWD ACROSS LA...MS ...AL AND INTO THE FL PANHANDLE.
AS THIS SYSTEM CONTINUES TO MOVE ENEWD INTO THE CAROLINAS ON
WEDNESDAY/DAY 5...A SEVERE THREAT WILL CONTINUE TO BE POSSIBLE. AN
ENHANCED SEVERE THREAT COULD OCCUR IF A LINEAR MCS OR A CLUSTER OF
SEVERE STORMS MOVES INTO THE REGION FROM THE WEST LATE TUESDAY
NIGHT. AT THIS POINT...WILL NOT ISSUE AN OUTLOOK AREA FOR THE
CAROLINAS UNTIL CONFIDENCE IS A BIT GREATER CONCERNING THE TIMING OF
THE UPPER-LEVEL TROUGH. BY LATE IN THE DAY 4 TO 8 PERIOD...THE
MODELS MOVE ANOTHER UPPER-LEVEL TROUGH INTO THE CNTRL U.S. THIS
COULD BE FAVORABLE FOR STRONG THUNDERSTORMS IN THE LOWER TO MID MS
VALLEY AGAIN ON FRIDAY/DAY 7 BUT MUCH UNCERTAINTY EXISTS AT THIS
RANGE.
..BROYLES.. 12/22/2012
CLICK TO GET WUUS48 PTSD48 PRODUCT
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