New SPC Day 2 MDT SRN AL/WRN FL
Posted: Tue Apr 05, 2005 1:13 pm
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SPC AC 051736
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1236 PM CDT TUE APR 05 2005
VALID 061200Z - 071200Z
THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 WNW
BVE 30 ESE MCB 30 NNW LUL 35 NNW MEI 25 WSW TCL 25 ENE 0A8 35 WNW
AUO 20 ENE TOI 10 WSW DHN 10 SE PFN.
THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SE
7R4 10 NE TXK 25 S UMN 20 NW TBN 40 SW BLV 10 NW HOP 45 ENE RMG 15 N
MCN 35 NNE MGR 25 S TLH.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 NNE GLS 35 N HOU
30 NNW CLL 15 NNW ACT MWL 35 WNW CSM 40 NNW GAG 15 N DDC 50 ENE HLC
35 E BKX 10 WSW BRD 20 NE ELO ...CONT... 15 NNW ART 35 NNE UCA 15
WNW ALB 20 WNW BAF BID ...CONT... 25 SSE NEL 15 W CXY 25 NE PKB 20
SE HTS 15 NNE HSS 15 E CAE 40 SE CTY.
...THERE IS A MDT RISK OF SVR TSTMS OVER EXTREME SOUTHEAST
LOUISIANA...SRN MISSISSIPPI/ALABAMA...AND THE WESTERN FLORIDA
PANHANDLE...
...THERE IS A SLGT RISK OF SVR TSTMS AROUND THE MDT RISK AREA FROM
LA/AR AND SRN MO TO WRN/MIDDLE TN....AND WRN GA...
...POTENTIAL EXISTS FOR WIDESPREAD SEVERE THUNDERSTORMS FROM THE
MISSISSIPPI DELTA REGION EAST ACROSS SOUTHERN ALABAMA AND THE
WESTERN FLORIDA PANHANDLE ON WEDNESDAY...
...SYNOPSIS...
HIGHLY AMPLIFIED AND PROGRESSIVE/ACTIVE FLOW REGIME WILL EXIST
ACROSS THE CONUS THROUGH WEDNESDAY. RISING HEIGHTS ACROSS THE
ROCKIES AND HIGH PLAINS IN RESPONSE TO VERY STRONG UPSTREAM TROUGH
APPROACHING THE PACIFIC NORTHWEST WILL ACT TO DISLODGE THE DEEP
CYCLONE NOW DEVELOPING INTO THE SRN PLAINS. DUE TO THE HIGHLY
AMPLIFIED NATURE OF THE SRN PLAINS SYSTEM...ASSOCIATED WARM FRONT
WILL EXTEND WELL NORTH OF THE PARENT CIRCULATION...AND WILL BE
SITUATED FROM THE GREAT LAKES TO THE NORTHEAST. HEIGHT FALLS
ASSOCIATED WITH A NRN STREAM SHORT WAVE TROUGH WILL INDUCE A WEAK
SFC WAVE/LOW ALONG THE FRONTAL ZONE OVER THE ERN GREAT LAKES BY
WEDNESDAY EVENING.
MAIN FEATURE OF INTEREST FOR SEVERE STORMS WILL BE THE DEEP CYCLONE
TRACKING ESEWD FROM OK TO THE LWR MS VLY DURING THE DAY/EVENING.
WITH 50-70KT MID LEVEL FLOW WRAPPING AROUND THE BASE OF MID LEVEL
LOW OVER THE NWRN GULF COAST REGION...STRONG CONFLUENT LOW LEVEL
FLOW FROM OFF THE NRN GULF IS EXPECTED TO MAINTAIN MOIST INFLOW TO
AN ADVANCING SEVERE LINEAR MCS FROM THE LWR MS VLY/DELTA REGION EAST
ACROSS THE DEEP SOUTH ON WEDNESDAY.
...MS DELTA TO WRN FL PNHDL...
THERE IS GOOD AGREEMENT AMONG A SUITE OF SHORT RANGE GUIDANCE THAT
STRONG FORCING FOR ASCENT WITHIN EXIT REGION OF MID/UPPER LEVEL
JET...COUPLED WITH MODEST LOW LEVEL MOISTURE FLUX AND WARM AIR
ADVECTION...WILL CONTRIBUTE TO A PREFRONTAL SQUALL LINE ARCING FROM
ERN AR ACROSS PARTS OF LA/MS BY EARLY WEDNESDAY MORNING.
INITIALLY...UPSTREAM AIR MASS AHEAD OF THE SQUALL LINE WILL ONLY BE
MARGINALLY UNSTABLE GIVEN CURRENT RESIDUAL CP AIR MASS OVER THE
REGION. HOWEVER...HEIGHT FALLS ASSOCIATED WITH THE APPROACHING
MID/UPPER LEVEL SYSTEM...AND STRONG THETA-E ADVECTION OVER THE NRN
GULF...ARE EXPECTED TO RESULT IN SUFFICIENT INSTABILITY TO MAINTAIN
VIGOROUS UPDRAFTS IN A STRONGLY SHEARED FLOW REGIME. GREATEST
OPPORTUNITY FOR STRONGER DESTABILIZATION SHOULD OCCUR CLOSE TO THE
GULF COAST WHERE MID 60S F SFC DEWPOINTS WILL SPREAD INLAND...AND A
FEW HOURS OF MARGINAL HEATING SHOULD OCCUR AHEAD OF THE STRONGEST
FORCING ASSOCIATED WITH THE SQUALL LINE.
LINEAR STORM MODE AND WIDESPREAD DAMAGING WINDS APPEAR MOST LIKELY
GIVEN THE POTENTIAL FOR AN EXISTING SQUALL LINE MOVING INTO THE
REGION FROM THE WEST. MODEL SOUNDINGS ARE SUGGESTING THAT ACTIVITY
WILL BE MOVING INTO A REGION OF HIGHER STORM RELATIVE HELICITY
ACROSS EXTREME SERN LA AND SRN MS DURING THE MORNING. THESE HIGHER
SRH VALUES ARE PARTLY DUE TO SLIGHTLY BACKED BOUNDARY LAYER FLOW
AHEAD OF THE SQUALL LINE...AND LOW LEVEL FLOW OF 50KT AOB 850MB.
GIVEN THIS PRONOUNCED LOW LEVEL SHEAR...SUPERCELLS EMBEDDED WITHIN
THE LINE...OR DEVELOPING AHEAD OF LINE WITHIN RECOVERING WARM
SECTOR...WILL HAVE THE POTENTIAL TO PRODUCE A FEW TORNADOES.
..CARBIN.. 04/05/2005