Severe Storm Outlook Narrative (AC)
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000
ACUS48 KWNS 230852
SWOD48
SPC AC 230851

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0351 AM CDT WED APR 23 2014

VALID 261200Z - 011200Z

...DISCUSSION...
..SIGNIFICANT MULTI-DAY SEVERE EVENT EXPECTED ACROSS PORTIONS OF THE
CENTRAL AND SOUTHERN PLAINS SATURDAY AND SUNDAY AND ACROSS THE MS
VALLEY AND MID SOUTH ON MONDAY...STRONG TORNADOES ARE POSSIBLE...

MEDIUM RANGE FORECAST CONTINUES TO BE HEAVILY WEIGHTED TOWARD THE
ECMWF DUE TO RUN-TO-RUN CONSISTENCY REGARDING THE 500MB EVOLUTION OF
WRN U.S. TROUGH.  CONCERNS REGARDING POLAR FRONT UNDERCUTTING STRONG
SWLY FLOW ALOFT HAVE ABATED THIS MORNING.  LATEST GUIDANCE DEEPENS
LEE CYCLONE OVER SERN CO SATURDAY AFTERNOON WITH SUBSEQUENT MOVEMENT
INTO WRN KS ON SUNDAY.  INTENSE 500MB SPEED MAX APPROACHING 90KT
SHOULD ROUND THE BASE OF THE TROUGH ALONG THE AZ/MEXICAN BORDER THEN
EJECT INTO SWRN KS EARLY SUNDAY.  AS A RESULT SFC LOW IS NOT
EXPECTED TO ADVANCE APPRECIABLY EWD UNTIL LATER MONDAY AS SECONDARY
MID-LEVEL SPEED MAX DEVELOPS FROM NORTH TX INTO THE LOWER OH RIVER
VALLEY.

MODERATE TO EXTREME INSTABILITY SHOULD DEVELOP EAST OF THE DRYLINE
SATURDAY AFTERNOON ALONG ERN PLUME OF STEEP LAPSE RATES.  STRONGLY
DIFLUENT FLOW ALOFT SHOULD ENCOURAGE VIGOROUS SUPERCELL DEVELOPMENT
FROM PORTIONS OF WCNTRL TX...NWD INTO KS.  VERY LARGE HAIL AND
TORNADOES CAN BE EXPECTED WITH THIS ACTIVITY.

IT/S NOT ENTIRELY CLEAR HOW FAR EAST THE DRYLINE WILL MIX SUNDAY AS
LOWEST PRESSURES WILL REMAIN FOCUSED ACROSS THE HIGH PLAINS OF WRN
KS.  MODELS MIX DRYLINE EAST OF I-35 CORRIDOR ACROSS OK BY 18Z
SUNDAY BUT THE DAY5 FORECAST WILL ACCOUNT FOR DRYLINE NOT MIXING
ACROSS THE PLAINS AS FAST AS MODELS CURRENTLY DEPICT.  AS A
RESULT...SUBSTANTIAL MID-LEVEL FLOW SHOULD OVERSPREAD THE
MOIST/BUOYANT WARM SECTOR AND ANOTHER DIURNALLY-INITIATED ROUND OF
POTENTIALLY TORNADIC SUPERCELLS COULD EVOLVE.

LATER MONDAY IT APPEARS THE SFC FRONT/DRYLINE SHOULD ADVANCE INTO
THE MS VALLEY.  SCATTERED-NUMEROUS SUPERCELLS SHOULD EVOLVE AHEAD OF
THE FRONT FROM LA...NWD INTO MO AND POSSIBLY AS FAR EAST AS MIDDLE
TN.  TORNADOES AND LARGE HAIL REMAIN POSSIBLE WITH WARM-SECTOR
CONVECTION.

..DARROW.. 04/23/2014



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