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Day 4-8 Convective Outlook Issued on Apr 19, 2011
Updated: Tue Apr 19 09:00:04 UTC 2011
| D4 | Fri, Apr 22, 2011 - Sat, Apr 23, 2011 |
D7 | Mon, Apr 25, 2011 - Tue, Apr 26, 2011 |
| D5 | Sat, Apr 23, 2011 - Sun, Apr 24, 2011 |
D8 | Tue, Apr 26, 2011 - Wed, Apr 27, 2011 |
| D6 | Sun, Apr 24, 2011 - Mon, Apr 25, 2011 |
(All days are valid from 12 UTC - 12 UTC) |
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).
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 190859
SPC AC 190859
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT TUE APR 19 2011
VALID 221200Z - 271200Z
...DISCUSSION...
A RELATIVELY LOW AMPLITUDE/FAST MOVING BELT OF WEST-SOUTHWESTERLY
MID/UPPER FLOW IS EXPECTED TO INITIALLY PREVAIL...WITH GREATER
PATTERN AMPLIFICATION POSSIBLE INTO THE WEEKEND/EARLY NEXT WEEK VIA
A WESTERN STATES TROUGH AS PER 00Z ECMWF/GEFS/UKMET GUIDANCE. WHILE
SEVERE WEATHER THREATS WILL UNDOUBTEDLY EXIST DURING THE
PERIOD...CONFIDENCE IN THE DELINEATION OF SPECIFIC 30 PERCENT
CALIBER SEVERE RISK AREAS IS CURRENTLY LIMITED OWING TO UNCERTAINTY
REGARDING SHORTWAVE-TYPE FEATURES.
ON DAY 4/FRIDAY...THE 00Z DETERMINISTIC GFS/GEFS CONTINUE TO EXHIBIT
GREATER AMPLIFICATION OF AN UPPER MIDWEST/MO VALLEY SHORTWAVE TROUGH
WITH SOMEWHAT STRONGER SURFACE CYCLOGENESIS AS COMPARED TO THE 00Z
ECMWF/UKMET. THIS HAS RAMIFICATIONS ON THE MAGNITUDE/SPATIAL EXTENT
OF THE SEVERE RISK...ALTHOUGH AT LEAST A CATEGORICAL SLIGHT
RISK-TYPE SCENARIO SEEMS PROBABLE. SEVERE TSTMS CAN BE EXPECTED
WITHIN A CORRIDOR FROM THE SOUTH-CENTRAL PLAINS...AND MORE SO...THE
OZARKS AND MIDDLE MS/LOWER OH RIVER VALLEYS WITHIN A RELATIVELY
MOIST AIRMASS ALONG/AHEAD OF A COLD FRONT.
AS PREVIOUSLY MENTIONED...THE CONSENSUS OF MEDIUM RANGE GUIDANCE
WOULD IMPLY THE EVOLUTION OF A MORE SUBSTANTIAL WESTERN STATES
TROUGH BY LATE THIS WEEKEND. FROM DAY 5/SATURDAY INTO DAYS 6/7
SUNDAY/MONDAY...THE SOUTHERN PLAINS /NEAR AND EAST OF A
DRYLINE/...TO PERHAPS THE OZARKS/MIDDLE MS VALLEY ALONG A REMNANT
FRONTAL ZONE...WILL BE A FOCUS FOR SEVERE TSTM POTENTIAL EACH DAY.
BUT AGAIN...SPECIFIC PREDICTABILITY/CONFIDENCE IS LIMITED IN THAT
TIME FRAME.
..GUYER.. 04/19/2011
CLICK TO GET WUUS48 PTSD48 PRODUCT
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