Severe Storm Outlook Narrative (AC)
Issued by NWS

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350
ACUS02 KWNS 141727
SWODY2
SPC AC 141726

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CST SUN FEB 14 2016

VALID 151200Z - 161200Z

...THERE IS A SLGT RISK OF SVR TSTMS MONDAY AFTERNOON ACROSS PARTS
OF SOUTHEASTERN MISSISSIPPI INTO SOUTHWESTERN ALABAMA AND ADJACENT
GULF COASTAL AREAS....

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
CENTRAL AND EASTERN GULF COAST REGION...

...THERE IS A MRGL RISK OF SVR TSTMS LATE MONDAY NIGHT NEAR COASTAL
SOUTH CAROLINA...

...SUMMARY...
THUNDERSTORMS MAY IMPACT PORTIONS OF THE CENTRAL INTO EASTERN GULF
COAST MONDAY...AND COASTAL SOUTH CAROLINA LATE MONDAY NIGHT...WITH
SOME RISK FOR SEVERE WEATHER.

...SYNOPSIS...
LARGE-SCALE UPPER RIDGING STILL BUILDING OVER THE EASTERN
PACIFIC...AND GRADUALLY DEVELOPING INLAND OF THE PACIFIC
COAST...APPEARS LIKELY TO REMAIN PROMINENT THROUGH THIS FORECAST
PERIOD.  THE EVOLUTION OF DOWNSTREAM TROUGHING ACROSS THE CENTRAL
INTO EASTERN U.S. IS MORE UNCERTAIN...HOWEVER.  SIZABLE SPREAD IS
EVIDENT AMONG THE MODELS...AND WITHIN THE MODEL ENSEMBLE OUTPUT
/PARTICULARLY THE NCEP SREF/...CONCERNING AT LEAST A COUPLE OF SHORT
WAVE PERTURBATIONS EMERGING FROM A STRONG JET STREAK ROUNDING THE
CREST OF THE RIDGE...BEFORE DIGGING TO THE LEE OF THE ROCKIES.

ONE IMPULSE...ALREADY IN THE PROCESS OF DIGGING TO THE LEE OF THE
NORTHERN ROCKIES...APPEARS LIKELY TO REACH THE CENTRAL PLAINS BY 12Z
MONDAY.  THEREAFTER...THE DEGREE TO WHICH IT CONTINUES DIGGING
TOWARD THE CENTRAL/EASTERN GULF COAST REGION BEFORE TURNING
EASTWARD...VERSUS DIGGING INTO THE OZARK PLATEAU BEFORE TURNING INTO
THE OHIO/TENNESSEE VALLEYS...REMAINS UNCLEAR.

IN LOWER LEVELS THIS MAY HAVE CONSIDERABLE IMPACT ON POTENTIAL
SURFACE CYCLOGENESIS ACROSS THE SOUTHEAST...AND THE EXTENT OF
LOW-LEVEL MOISTURE RETURN OFF THE GULF OF MEXICO...AS WELL AS THE
WESTERN ATLANTIC.  REGARDLESS...EVEN OVER PORTIONS OF THE WESTERN
AND CENTRAL GULF OF MEXICO THAT HAVE NOT BEEN IMPACTED BY THE BRUNT
OF THE MOST RECENT COLD INTRUSION...CONSIDERABLE BOUNDARY LAYER
MODIFICATION NEEDS TO OCCUR TO SUPPORT A SUBSTANTIVE RETURN FLOW
MOISTURE.  FURTHERMORE...EVEN THE NAM...WHICH MAY BE AMONG THE MOST
AGGRESSIVE WITH THE UPPER IMPULSE DIGGING INTO THE GULF COAST
REGION...INDICATES ONLY MODEST SURFACE FRONTAL WAVE DEVELOPMENT
ACROSS NORTHERN PORTIONS OF THE GULF STATES INTO THE LEE OF THE
SOUTHERN APPALACHIANS DURING THIS PERIOD.

...SOUTHEASTERN U.S...
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST WEAK BOUNDARY LAYER
DESTABILIZATION IS AT LEAST POSSIBLE INLAND OF CENTRAL GULF COASTAL
AREAS BY MIDDAY MONDAY...AND PERHAPS SOUTH CAROLINA COASTAL AREAS
LATE MONDAY NIGHT.  ACROSS THE CENTRAL GULF COAST REGION...THIS MAY
COINCIDE WITH FORCING FOR LARGE-SCALE ASCENT ASSOCIATED WITH WARM
ADVECTION...IN THE PRESENCE OF AT LEAST MARGINALLY SUFFICIENT
STRENGTHENING OF DEEP LAYER FLOW AND SHEAR TO SUPPORT ORGANIZED
THUNDERSTORM DEVELOPMENT...INCLUDING SUPERCELLS.  ALTHOUGH THE
EXTENT OF THE SEVERE WEATHER POTENTIAL IS UNCERTAIN...IT STILL SEEMS
MOST PROBABLE THAT IT WILL BE MAXIMIZED ACROSS PARTS OF SOUTHEASTERN
MISSISSIPPI INTO SOUTHWESTERN ALABAMA...AND ADJACENT COASTAL
AREAS...MONDAY AFTERNOON.

..KERR.. 02/14/2016

$$



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