Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS48 KWNS 290901
SWOD48
SPC AC 290859

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0359 AM CDT SUN MAR 29 2015

VALID 011200Z - 061200Z

...DISCUSSION...
AT LEAST LOW PROBABILITIES EXIST FOR ORGANIZED SEVERE STORMS ON
D4-6/WED-FRI ACROSS PARTS OF THE CNTRL STATES...WITH HIGHEST
CONFIDENCE CENTERED ON D5/THU IN THE OZARK PLATEAU AREA. GUIDANCE
CONTINUES TO PROG A VIGOROUS SHORTWAVE TROUGH MOVING E ALONG THE
INTERNATIONAL BORDER OVER THE NRN GREAT PLAINS AND UPPER MIDWEST ON
D4...WITH AN UPSTREAM LOWER-LATITUDE IMPULSE SHIFTING E ACROSS THE
WEST ON D5. OVERALL RUN-TO-RUN CONTINUITY WITH THIS LATTER FEATURE
REMAINS POOR WITH A FAST-MOVING ZONAL UPPER JET BISECTING MUCH OF
THE CONUS.

AN AREA OF SEVERE STORMS IS POSSIBLE OVER PARTS OF THE UPPER MIDWEST
TO THE LOWER MO VALLEY ON D4 ALONG A FAST-MOVING COLD FRONT SWEEPING
E FROM A CYCLONE PROBABLY LOCATED OVER THE SRN CANADIAN PRAIRIES.
GREATEST UNCERTAINTY IN THIS TIME FRAME IS THE DEGREE OF POLEWARD
MOISTURE TRANSPORT ALONG WITH PHASING OF A COMPACT MID-LEVEL JET
STREAK OVER A PROBABLE NARROW WARM SECTOR.

ON D5...AS THE FRONT IMPINGES ON THE BROADER AND MORE UNSTABLE WARM
SECTOR FROM THE SRN GREAT PLAINS TO MID-SOUTH...STRENGTHENING
MID-LEVEL WLYS DOWNSTREAM OF THE WRN CONUS TROUGH SHOULD YIELD A
FAVORABLE ENVIRONMENT FOR ORGANIZED STORMS. CAPPING MAY BE ROBUST
OVER MUCH OF THE WARM SECTOR GIVEN PREVAILING SWLYS AT 700 MB WITH
CONVECTION LIKELY FORCED ALONG THE FRONT AND SRN GREAT PLAINS
DRYLINE. BY D6...LOWER PREDICTABILITY WITH SPATIOTEMPORAL DETAILS OF
THE FRONT AND ITS POTENTIAL INCREASED SEPARATION FROM A STRONG
MID/UPPER-LEVEL JET RENDERS LOW CONFIDENCE IN DELINEATING AN AREA
THIS OUTLOOK.

..GRAMS.. 03/29/2015



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