[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 160529
SWODY1
SPC AC 160528

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1228 AM CDT MON OCT 16 2006

VALID 161200Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO PARTS OF
AR/MS AND WESTERN AL...

LARGE UPPER LOW CURRENTLY OVER EASTERN AZ/WESTERN NM IS FORECAST TO
BECOME AN OPEN WAVE AND PROPAGATE RAPIDLY NORTHEASTWARD ACROSS TX
AND INTO THE MID MS VALLEY BY LATE MONDAY NIGHT.  MEANWHILE...VERY
STRONG SOUTHERLY LOW LEVEL JET /50-80 KNOTS/ WILL DEVELOP FROM LA
INTO MO/IL.  THIS WILL RESULT IN A ZONE OF KINEMATIC FIELDS VERY
FAVORABLE FOR SEVERE THUNDERSTORMS ON MONDAY FROM EAST TX INTO THE
CENTRAL GULF COAST STATES.  THE MAIN FORECAST PROBLEM WILL BE THE
EVOLUTION OF LOW LEVEL MOISTURE/INSTABILITY AND THE POTENTIAL FOR
SURFACE-BASED STORMS.

...ARKLATEX REGION INTO CENTRAL GULF COAST STATES...
CURRENTLY RADAR/SATELLITE IMAGERY SHOWS LARGE TROPICAL-LIKE MCS
ALONG THE UPPER TX GULF COAST. SEVERAL SUPERCELLS ARE EMBEDDED WITH
THIS ACTIVITY...WHICH WILL MOVE ONSHORE BEFORE DAYBREAK.  FORECAST
SOUNDINGS ACROSS THIS AREA SHOW RAPIDLY STRENGTHENING LOW LEVEL
WINDS ACROSS EAST TX AND MUCH OF LA /3KM SR-HELICITY VALUES OF
400-1000 M2/S2 CO-LOCATED WITH DEWPOINTS AOA 70F/...SUGGESTING THAT
THREAT FOR ISOLATED TORNADOES AND GUSTY/DAMAGING WINDS WILL ONLY
INCREASE THROUGH THE DAY AS MCS MOVES NORTHWARD TOWARD THE MEM AREA.
 LACK OF STRONG INSTABILITY AND ONLY MARGINAL MID LEVEL LAPSE RATES
SUGGEST THAT AREAL COVERAGE OF SEVERE STORMS WILL BE RATHER LOW. 
HOWEVER...STRENGTH OF WIND FIELDS...TROPICAL AIRMASS...AND
APPROACHING UPPER TROUGH INDICATE THE POTENTIAL FOR A FEW TORNADOES
DESPITE WEAK INSTABILITY.  EXTENT OF THREAT WILL ALSO BE MODULATED
BY HOW FAR NORTHEAST THE RICH MOISTURE WILL MAKE IT INTO AR/TN/MS. 
THIS AREA WILL BE MONITORED DURING LATER UPDATES FOR THE POTENTIAL
OF GREATER DESTABILIZATION AND A POSSIBLE UPGRADE. 

...CENTRAL-NORTHEAST TX...
SOME DAYTIME HEATING WILL BE POSSIBLE ALONG WEST EDGE OF PLUME OF
DEEP CLOUDS/MOISTURE...ALLOWING AIR MASS TO BECOME MODERATELY
UNSTABLE OVER PARTS OF CENTRAL TX.  COOLING TEMPERATURES ALOFT AND
STEEPENING LAPSE RATES WILL PROMOTE SCATTERED THUNDERSTORM
DEVELOPMENT BY MID AFTERNOON ROUGHLY ALONG A DRT-ACT AXIS.  DEEP
LAYER EFFECTIVE SHEAR IN THIS REGION WILL SUPPORT SUPERCELL STORMS
CAPABLE OF LARGE HAIL AND DAMAGING WINDS.  ACTIVITY IS EXPECTED TO
SPREAD EAST-NORTHEASTWARD DURING THE EVENING...PROVIDING PARTS OF
NORTHEAST TX WITH ANOTHER ROUND OF STRONG/SEVERE STORMS.

..HART/GUYER.. 10/16/2006