Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS01 KWNS 170546
SWODY1
SPC AC 170544

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1244 AM CDT THU APR 17 2014

VALID 171200Z - 181200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
A COUPLE OF STRONG STORMS ARE POSSIBLE TODAY ACROSS PARTS OF THE
SOUTHERN AND CENTRAL FLORIDA PENINSULA...PERHAPS APPROACHING OR
BRIEFLY EXCEEDING SEVERE LIMITS.

...SYNOPSIS...
IN THE WAKE OF THE SIGNIFICANT EARLY WEEK COLD INTRUSION TO THE LEE
OF THE ROCKIES...WHICH IMPACTED A LARGE PORTION OF THE GULF OF
MEXICO...CONVECTIVE POTENTIAL ACROSS MUCH OF THE U.S. APPEARS LIKELY
TO REMAIN SEASONABLY LOW THROUGH THIS FORECAST PERIOD.  WHILE THE
MID/UPPER PATTERN HAS TRENDED MORE ZONAL...STRONGER FLOW EMERGING
FROM THE MID LATITUDE PACIFIC SPLITS INTO A COUPLE OF BELTS
EXTENDING ACROSS THE PACIFIC COAST THROUGH THE ATLANTIC SEABOARD.

INTERACTION BETWEEN THE SOUTHERN OF THESE TWO STREAMS WITH ANOTHER
BELT OF WESTERLIES EMERGING FROM THE SUBTROPICAL EASTERN PACIFIC MAY
CONTRIBUTE TO THE EVOLUTION OF A COUPLE OF MORE SUBSTANTIVE  SHORT
WAVE TROUGHS ACROSS THE SOUTHERN TIER OF THE U.S. TODAY INTO
TONIGHT.  ONE OF THESE APPEARS LIKELY TO TAKE SHAPE ACROSS THE GULF
COAST STATES AND GULF OF MEXICO BY LATE TONIGHT.  ASSOCIATED FORCING
FOR UPWARD VERTICAL MOTION...COUPLED WITH GULF BOUNDARY LAYER
MOISTENING WITHIN A BROADENING REMNANT BAROCLINIC ZONE...MAY
CONTRIBUTE TO CONSIDERABLE THUNDERSTORM ACTIVITY...MAINLY OVER PARTS
OF THE CENTRAL AND EASTERN GULF OF MEXICO.  THE MOST VIGOROUS
CONVECTION PROBABLY WILL REMAIN CONFINED TO THE SOUTH CENTRAL GULF
OF MEXICO...BUT WEAK CONVECTION WITH EMBEDDED THUNDERSTORMS MAY
IMPACT GULF COASTAL AREAS FROM SOUTHEAST LOUISIANA THROUGH THE
FLORIDA PANHANDLE LATE TONIGHT.

...FLORIDA PENINSULA...
WHILE HIGHEST THUNDERSTORM PROBABILITIES ARE EXPECTED TO GENERALLY
BE CONFINED TO THE GULF OF MEXICO...A GRADUAL INCREASE IN
PRECIPITABLE WATER APPEARS LIKELY ACROSS THE PENINSULA THROUGH THE
PERIOD.  AND MODEL OUTPUT CONTINUES TO SUGGEST THAT THIS COULD
CONTRIBUTE TO SCATTERED THUNDERSTORM ACTIVITY DURING THE DAYTIME
HOURS.  MID/UPPER FORCING FOR CONVECTIVE DEVELOPMENT IS
WEAK/UNCLEAR...BUT LIFT ALONG DEVELOPING SEA BREEZES...PARTICULARLY
ACROSS INTERIOR OR WESTERN PORTIONS OF THE SOUTHERN PENINSULA...IS
EXPECTED TO PROVIDE THE PRIMARY FOCUS ANY ACTIVITY.  THERE REMAINS
CONSIDERABLE UNCERTAINTY AMONG THE MODEL DATA CONCERNING THE EXTENT
OF THE BOUNDARY LAYER HEATING AND DESTABILIZATION THAT WILL OCCUR
TODAY.  HOWEVER...A RESIDUAL COOL MID-LEVEL ENVIRONMENT AND AT LEAST
MODESTLY STRONG CLOUD BEARING LAYER SHEAR MAY BE ENOUGH TO ENHANCE
ONE OR TWO STORMS... PROVIDING SOME POTENTIAL FOR MARGINALLY SEVERE
WIND OR HAIL.

..KERR/MOSIER.. 04/17/2014



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