SPC AC 021649
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1049 AM CST SUN MAR 02 2008
VALID 031200Z - 041200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS SRN AR AND MUCH OF LA AND
MS...
...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN OK/ERN TX EWD INTO
THE TN VALLEY AND CNTRL GULF STATES...
--WIDESPREAD SEVERE WEATHER IS EXPECTED ACROSS THE LOWER MS VALLEY
MONDAY AND MONDAY NIGHT WITH THE POTENTIAL FOR DAMAGING WINDS AND A
FEW SIGNIFICANT TORNADOES.--
...SYNOPSIS...
DYNAMIC MIDLEVEL TROUGH CENTERED OVER THE SRN HIGH PLAINS MONDAY
MORNING WILL UNDERGO INTENSIFICATION AND ASSUME AN INCREASING
NEGATIVE TILT AS ATTENDANT JET STREAK ROUNDS THE TROUGH
BASE...CONTRIBUTING TO SUBSTANTIAL HEIGHT FALLS EWD ACROSS THE SRN
PLAINS INTO THE LOWER MS VALLEY. IN THE LOW LEVELS...ATTENDANT
SURFACE LOW WILL LIKEWISE DEEPEN WHILE DEVELOPING NEWD THROUGH THE
ARKLATEX AND MS DELTA REGIONS AND EVENTUALLY INTO WRN OR MIDDLE TN
BY TUESDAY MORNING. A WARM FRONT INITIALLY FROM W-CNTRL AR TO THE
CNTRL GULF COAST WILL CONCURRENTLY LIFT NEWD AHEAD OF THE DEEPENING
LOW WHILE TRAILING COLD FRONT PUSHES EWD/SEWD THROUGH ERN TX AND THE
LOWER MS VALLEY.
...SRN LOW PLAINS EWD THROUGH THE LOWER MS AND TN VALLEYS...
STRONG TO POTENTIALLY SEVERE TSTMS /LIKELY ORGANIZED INTO A LINEAR
CONVECTIVE SYSTEM/ ARE EXPECTED TO BE IN PROGRESS MONDAY MORNING
ALONG COLD FRONT FROM THE OZARK PLATEAU REGION SWWD INTO CNTRL TX.
STORMS SHOULD INCREASE IN BOTH COVERAGE AND INTENSITY THROUGH THE
DAY ALONG AND AHEAD OF COLD FRONT WITH ACTIVITY RAPIDLY
MOVING/DEVELOPING EWD/NEWD ACROSS THE LOWER MS VALLEY AND EVENTUALLY
INTO THE TN VALLEY AND CNTRL GULF STATES MONDAY NIGHT INTO TUESDAY
MORNING.
PRE-FRONTAL AIR MASS WILL DESTABILIZE THROUGH THE PERIOD OWING
LARGELY TO A MOISTENING BOUNDARY LAYER WITH DEWPOINTS INCREASING
THROUGH THE 60S FROM THE SABINE RIVER VALLEY EWD ACROSS MUCH OF THE
LOWER MS VALLEY INTO THE CNTRL/ERN GULF STATES. THE STRONGEST
INSTABILITY IS FORECAST ACROSS SERN TX...LA AND CNTRL/SRN MS WHERE
RICHER BOUNDARY LAYER MOISTURE WILL COMBINE WITH DIABATIC HEATING TO
SUPPORT MLCAPES OF 1000-1500 J/KG. INSTABILITY WILL TEND TO
DECREASE WITH NWD AND EWD EXTENT ACROSS THE REGION.
VERTICAL SHEAR WILL BE QUITE STRONG /MOST NOTABLY ALONG THE
MIGRATORY LLJ AXIS/ WHERE EFFECTIVE BULK SHEAR AND SRH VALUES SHOULD
EXCEED 45-50 KT AND 300-400 M2/S2 RESPECTIVELY. THUS POTENTIAL WILL
EXIST FOR SUPERCELLS /SOME LONG-LIVED/ EMBEDDED WITHIN LARGER-SCALE
QLCS AND/OR IN ADVANCE OF MAIN CONVECTIVE SYSTEM WITH A THREAT OF
SIGNIFICANT TORNADOES ALONG WITH HAIL. CORRIDORS OF DAMAGING WIND
ALSO APPEAR LIKELY /NAMELY WITH ANY LARGER-SCALE BOWS/ GIVEN
STRONG...AMBIENT WIND FIELDS AND RESULTANT FAST STORM MOTIONS.
..MEAD.. 03/02/2008
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NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0800Z
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