[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 111725
SWODY2
SPC AC 111724

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1124 AM CST SAT MAR 11 2006

VALID 121200Z - 131200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF
TX...OK...LA...AR...MS...TN...MO...IA...IL...KY AND TN...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS...LOWER MS VALLEY...TN VALLEY...UPPER OH
VALLEY AND UPPER MIDWEST...

...MS VALLEY/SRN PLAINS...
A BROAD UPPER-LEVEL TROUGH WILL CONTINUE IN PLACE ACROSS THE WRN
U.S. WITH SOUTHWEST FLOW PRESENT ACROSS THE GREAT PLAINS AND MS
VALLEY TONIGHT INTO SUNDAY. A 100 KT MID-LEVEL JET IS FORECAST TO
MOVE INTO THE PLAINS STATES SUNDAY AND SUNDAY NIGHT. SHORTWAVE
ACTIVITY EMBEDDED IN THE BROAD SOUTHWEST FLOW REGIME WILL CAUSE
LARGE-SCALE ASCENT TO INCREASE ACROSS THE REGION BY AFTERNOON. THIS
COMBINED WITH A BROAD WARM SECTOR WILL PROVIDE THE INGREDIENTS
NECESSARY FOR A WIDESPREAD SEVERE WEATHER THREAT SUNDAY AND SUNDAY
NIGHT.

MODEL FORECASTS ARE RELATIVELY CONSISTENT...INITIATING WIDESPREAD
THUNDERSTORM ACTIVITY ALONG THE WRN EDGE OF THE LOW-LEVEL MOISTURE 
GRADIENT SUNDAY AFTERNOON. INITIATION WOULD MOST LIKELY OCCUR WHERE
SFC HEATING IS MAXIMIZED WITH SEVERAL STORM CLUSTERS DEVELOPING NEAR
A SFC LOW ACROSS NRN MO EXTENDING SSWWD ACROSS WRN...ERN OK AND NE
TX NEAR A DRYLINE. AS THE STORMS MOVE EWD INTO THE STRONGER
LOW-LEVEL FLOW AND GREATER INSTABILITY...SEVERAL MCS CLUSTERS SHOULD
ORGANIZE AND TRACK EWD ACROSS THE MODERATE RISK AREA.

FORECAST SOUNDINGS ACROSS THE REGION FROM 21Z TO 03Z SUNDAY
AFTERNOON AND EVENING SHOW 0-6 KM SHEAR VALUES RANGING FROM AROUND
60 KT ACROSS THE ARKLATEX TO ABOUT 80 KT IN THE LOWER OH VALLEY.
CONSIDERING MODERATE INSTABILITY IS FORECAST ACROSS A BROAD WARM
SECTOR...THE ENVIRONMENT APPEARS FAVORABLE FOR SUPERCELLS ACROSS THE
ENTIRE REGION. SUPERCELLS WILL BE THE MOST LIKELY MODE WHERE STORMS
REMAIN DISCRETE WITH BOW ECHOES AND MULTICELL STORMS LIKELY IN STORM
CLUSTERS OF LINEAR ORIENTATION. LOW-LEVEL SHEAR PROFILES APPEAR
FAVORABLE FOR TORNADOES WITH THE GREATEST TORNADO THREAT LIKELY IN
AREAS WHERE THE INSTABILITY IS MAXIMIZED. THE STRONG VERTICAL SHEAR
AND STEEP MID-LEVEL LAPSE RATES WILL BE FAVORABLE FOR LARGE HAIL
WITH VERY LARGE HAIL POSSIBLE WITH THE STRONGER SUPERCELL STORMS IN
THE LATE AFTERNOON AND EARLY EVENING. WIND DAMAGE WILL BE LIKELY
ESPECIALLY AS STORM CLUSTERS ORGANIZE INTO LINES DURING THE EVENING
HOURS. A LARGE LINEAR MCS SHOULD DEVELOP AND CONTINUE EWD ACROSS THE
MS RIVER AND UPPER OH VALLEY. ALTHOUGH STORM INTENSITY SHOULD
GRADUALLY DECREASE OVERNIGHT...AT LEAST AN ISOLATED SEVERE WEATHER
THREAT SHOULD CONTINUE LATE SUNDAY NIGHT DUE TO THE BROAD WARM
SECTOR IN PLACE.

...CNTRL PLAINS...
BROAD SOUTHWEST FLOW WILL BE IN PLACE ACROSS THE PLAINS STATES AS A
SFC LOW ORGANIZES ALONG A FRONTAL BOUNDARY FROM NRN MO EXTENDING WWD
ACROSS SRN NEB AND NRN KS LATE SUNDAY AFTERNOON. LOW-LEVEL
CONVERGENCE ALONG THE BOUNDARY SHOULD RESULT IN SCATTERED
THUNDERSTORM INITIATION AS SFC TEMPS WARM DURING THE DAY. SUPERCELLS
WILL BE POSSIBLE DUE TO THE STRONG VERTICAL SHEAR IN PLACE. ALTHOUGH
INSTABILITY IS FORECAST TO BE RELATIVELY WEAK...FORECAST SOUNDINGS
SHOW STEEP MID-LEVEL LAPSE RATES. AS A RESULT...A FEW OF THE STORMS
COULD PRODUCE LARGE HAIL AND/OR WIND DAMAGE DURING THE LATE
AFTERNOON OR EARLY EVENING HOURS WITH THE SEVERE WEATHER THREAT
LIKELY DECREASING DURING THE EVENING ON SUNDAY DUE TO DECREASING
INSTABILITY.

..BROYLES.. 03/11/2006