Severe Weather Threat for Saturday 2/21/15

[Wxradar 30623]

Well as of now, there is a marginal risk by the SPC for the north eastern Texas, Northern Louisiana, and Southern Arkansas area.

 

 

 

 

 

 

SPC AC 201730

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST FRI FEB 20 2015

VALID 211200Z - 221200Z

...THERE IS A MRGL RISK OF SVR TSTMS FROM NERN TX THROUGH A PORTION
OF THE LOWER MS VALLEY...

...SUMMARY...
A FEW STRONG TO SEVERE THUNDERSTORMS REMAIN POSSIBLE SATURDAY
AFTERNOON AND EVENING FROM NORTHEASTERN TEXAS...SOUTHERN
ARKANSAS...NORTHERN LOUISIANA...INTO NORTHERN AND CENTRAL
MISSISSIPPI. THE PRIMARY THREAT APPEARS TO BE STRONG TO MARGINALLY
SEVERE WIND GUSTS...BUT A BRIEF TORNADO OR TWO CANNOT BE RULED OUT.

...SYNOPSIS...

BROAD UPPER TROUGH WILL DOMINATE THE SYNOPTIC PATTERN ON SATURDAY. A
SHORTWAVE TROUGH NOW MOVING TOWARD THE CNTRL ROCKIES SHOULD REACH
THE MIDDLE MS VALLEY EARLY SATURDAY AND CONTINUE THROUGH THE OH
VALLEY DURING THE DAY. THIS FEATURE WILL PROVIDE IMPETUS FOR A COLD
FRONT TO CONTINUE THROUGH ERN TX AND THE LOWER MS VALLEY. FARTHER
SOUTH A WEAKER...LOW AMPLITUDE SRN STREAM IMPULSE WILL MOVE THROUGH
TX INTO LA AND MS.

...EXTREME NERN TX THROUGH THE LOWER MS VALLEY REGION...

NEAR SFC WINDS HAVE VEERED TO SLY OVER THE WRN GULF WHERE THE
BOUNDARY LAYER IS UNDERGOING MODIFICATION WITH DEWPOINTS APPROACHING
60F. AS THE ERN U.S. SFC RIDGE ADVANCES EWD...A SSWLY LLJ IS
FORECAST TO INTENSIFY FROM NERN TX THROUGH LA...AR AND WRN TN. THIS
FEATURE WILL ADVECT PARTIALLY MODIFIED GULF AIR NEWD RESULTING IN
DESTABILIZATION THROUGH THE PRE-FRONTAL WARM SECTOR. MODEST
MID-LEVEL LAPSE RATES AND WIDESPREAD CLOUDS SHOULD LIMIT MLCAPE TO
AOB 500 J/KG. STORMS ARE EXPECTED TO INCREASE ALONG THE SEWD
ADVANCING COLD FRONT...LIKELY EVOLVING INTO PREDOMINANT LINEAR
MODES. THIS ACTIVITY WILL BE EMBEDDED WITHIN STRONG EFFECTIVE SHEAR
SUPPORTIVE OF ORGANIZED STORMS INCLUDING BOWING SEGMENTS AND
EMBEDDED MESOCYCLONES. GIVEN THE EXPECTED MODE AND LIMITED
INSTABILITY...PRIMARY THREAT SHOULD REMAIN ISOLATED STRONG TO
DAMAGING WIND GUSTS. WILL MAINTAIN A MARGINAL RISK THIS UPDATE DUE
TO POTENTIAL LIMITING FACTORS ASSOCIATED WITH THE EXPECTED MARGINAL

THERMODYNAMIC ENVIRONMENT...BUT CONTINUE TO MONITOR FOR A POSSIBLE
SLIGHT RISK IN THE DAY 1 OUTLOOKS.