[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 130536
SWODY1
SPC AC 130535

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1135 PM CST SAT FEB 12 2005

VALID 131200Z - 141200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 E
PSX VCT 25 WSW CLL 30 SW TXK 10 S TBN 25 NNW MDH 30 E PAH 35 NNW TCL
30 WSW SEM 15 SSW CEW.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 WNW DRT 40 N JCT
MWL 30 N MLC 20 E JLN 40 NNE SZL 20 N UIN 15 N BMI 15 SE LAF 10 NE
BWG 35 ENE HSV 30 S AUO 25 NE AQQ.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 SE CRP 60 WNW MFE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 NNE CTB 20 ENE GTF
15 NE BTM 30 E S80 30 ENE ALW 25 WSW YKM 30 NW HQM.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/WRN GULF COAST
NWD INTO THE LOWER OH/MS VLYS...

...SYNOPSIS...
A PAIR OF WELL-DEFINED SHORTWAVE TROUGHS WILL TRANSLATE THROUGH THE
SRN PLAINS AND INTO THE MS VLY/MIDWEST SUNDAY AND SUNDAY NIGHT. 
LEAD IMPULSE WILL MOVE FROM OK TO IL BY SUNDAY NIGHT WHILE A
SECONDARY IMPULSE DIGS SEWD ACROSS TX TOWARD THE WRN/CNTRL GULF
STATES.  

AT THE SURFACE...LOW OVER SWRN KS WILL MOVE INTO WRN MO BY 18Z
SUNDAY AND THEN TURN NEWD TOWARD CHICAGO BY 06Z MONDAY.  A TRAILING
COLD FRONT/PRE-FRONTAL TROUGH S OF THE LOW WILL MOVE FROM THE SRN
PLAINS SUNDAY MORNING...TO THE OZARKS AND E TX SUNDAY AFTERNOON AND
THE MS VLY AND WRN GULF BASIN SUNDAY NIGHT.  

...OZARKS/MID-SOUTH...
WARM CONVEYOR SHOWERS/CLOUDS ARE LIKELY TO MOVE INTO THE OH/TN VLYS
EARLY SUNDAY WITH A DRY SLOT...NOW OBSERVED OVER OK...MOVING EWD
INTO THE OZARKS/MID-SOUTH BY SUNDAY AFTERNOON. THE LOW-LEVELS IN
THE WARM SECTOR WILL GRADUALLY MOISTEN...WITH SURFACE DEW POINTS
INTO THE LOWER-MID 50S AS FAR N AS SRN MO.  MID-LEVEL LAPSE RATES
SHOULD STEEPEN AS COLD POCKET ALOFT ASSOCIATED WITH THE TROUGH MOVES
ACROSS THE REGION.  BUT...NAM FORECAST SOUNDINGS ARE PROBABLY TOO
UNSTABLE OWING TO SHALLOW CONVECTIVE SCHEME...WITH NAM-KF FORECAST
SOUNDINGS PROBABLY MORE REPRESENTATIVE WITH SBCAPES AOB 1000 J/KG.

AS SRN PERIPHERY OF THE LEAD WAVE SKIRTS THE WARM SECTOR SUNDAY
AFTERNOON...ALL MODELS AGREE THAT TSTMS WILL INITIATE FROM SCNTRL MO
INTO AR BY 21Z.  STORMS WILL PROBABLY BE SLOW TO MATURE GIVEN
RELATIVELY WEAK THERMAL BUOYANCY AND WIDESPREAD SEVERE TSTMS ARE NOT
EXPECTED.  HOWEVER...LOW-LEVEL SHEAR WILL REMAIN STRONG WITH
EFFECTIVE SRH AOA 200 M2/S2 AND 0-6KM SHEAR OF 35+ KTS THROUGH
EVENING.  THIS COULD SUPPORT SUPERCELLS WITH LARGE HAIL AND DAMAGING
WINDS...ESPECIALLY IF INSTABILITY IS STRONGER THAN FORECAST. A
TORNADO OR TWO COULD ALSO OCCUR... MAINLY WHERE LOW-LEVEL SHEAR WILL
BE THE STRONGEST...NAMELY ACROSS SCNTRL/SERN MO INTO NRN/CNTRL AR
DURING THE MID-LATE AFTERNOON. 

ACTIVITY WILL MOVE ENEWD TOWARD THE LOWER OH AND TN VLYS SUNDAY
NIGHT...BUT WILL WEAKEN AS THE LOW-LEVEL JET AND UPPER SYSTEM BECOME
REMOVED FROM THE THETA-E AXIS.

...CNTRL/WRN GULF COASTAL AREA...
A NARROW CORRIDOR OF MODIFIED GULF MOISTURE /SURFACE DEW POINTS NEAR
60F/ CONTINUES TO ADVECT NWD INTO ERN TX AND SRN LA.  AS THE
SECONDARY SHORTWAVE TROUGH APPROACHES...COMBINATION OF LARGE SCALE
ASCENT AND STEEPENING MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO SOME
DESTABILIZATION.  MOISTURE RETURN IS NOT OF HIGH QUALITY...SO
THERMAL BUOYANCY IS APT TO REMAIN WEAK...AOB 1000 J/KG AND WILL
LIKELY LIMIT THE OVERALL SEVERE POTENTIAL.  NONETHELESS...GIVEN
STRONG VERTICAL SHEAR AND PRESENCE OF DEEP UVV...POTENTIAL FOR A FEW
ORGANIZED TSTMS WILL EXIST WITH LARGE HAIL AND DAMAGING WINDS.
THOUGH THE STRONGER LOW-LEVEL SHEAR/LLJ BEGINS TO TRANSLATE NWD
EARLY IN THE DAY...A TORNADO CANNOT BE RULED OUT ACROSS THE UPPER TX
COAST AND SRN LA SUNDAY.  

INSTABILITY GRADIENT WILL BE RATHER STRONG EAST OF THE MS RVR WHERE
LOW-LEVEL TRAJECTORIES FAVOR A MORE STABLE AIR MASS.  THUS...TSTMS
THAT MOVE EWD ACROSS THE LOWER MS VLY SUNDAY NIGHT WILL LIKELY
WEAKEN.

..RACY.. 02/13/2005

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.