[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 290609
SWODY2
SPC AC 290608

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1208 AM CST MON NOV 29 2004

VALID 301200Z - 011200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 SW
GLS HOU POE MLU UOX MSL BHM 35 WNW AUO DHN 35 SSE CEW.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 SSE DRT ACT HRO
TBN MTO DAY ZZV 10 NNW EKN 20 WNW RDU 10 NW AGS MGR 25 SSE TLH.

...THERE IS A SLGT RISK OF SVR TSTMS TUESDAY/TUESDAY NIGHT ACROSS
PORTIONS OF THE CENTRAL AND EASTERN GULF STATES....

LATEST WATER VAPOR IMAGERY INDICATES BROAD CLOSED LOW CONTINUES TO
EVOLVE IN SOUTHERN BRANCH OF THE WESTERLIES...ACROSS THE SOUTHERN
PLATEAU/ROCKIES...MUCH AS FORECAST BY MODELS THE PAST SEVERAL DAYS. 
WITH FAIRLY VIGOROUS UPSTREAM SHORT WAVE ALREADY DIGGING INTO THE
BRITISH COLUMBIA/PACIFIC NORTHWEST COAST...LEAD SYSTEM DOES NOT
APPEAR LIKELY TO REMAIN OVER THE FOUR CORNERS STATES LONG.

STRENGTH AND RATE AT WHICH CLOSED/LOW TROUGH ACCELERATES EAST
NORTHEAST OF THE SOUTHERN ROCKIES HAS BEEN A CONSIDERABLE SOURCE OF
UNCERTAINTY IN RECENT MODEL RUNS.  UPSTREAM SHORT WAVE WILL BE
SLOWED AND WEAKENED AS IT PROGRESSES INLAND THROUGH FAIRLY SHARP
UPPER RIDGE...BUT LATEST ETA/GFS RUNS NOW ARE RATHER SIMILAR IN
SUGGESTING DOWNSTREAM SYSTEM WILL LIFT INTO THE SOUTH CENTRAL HIGH
PLAINS LATE MONDAY INTO EARLY TUESDAY. TROUGH IS FORECAST TO
PROGRESS EASTWARD THROUGH THE REMAINDER OF THE SOUTH CENTRAL PLAINS
DURING THE DAY TUESDAY...BEFORE UPSTREAM SOUTHERN BRANCH TROUGH...IN
CONJUNCTION WITH A MORE PROGRESSIVE NORTHERN BRANCH SHORT
WAVE...FORCE EASTWARD ACCELERATION INTO THE LOWER OHIO VALLEY
TUESDAY NIGHT.

IN RESPONSE TO EVOLVING UPPER PATTERN...SURFACE LOW IS EXPECTED TO
FORM/DEEPEN ON NORTHERN END OF INVERTED SURFACE TROUGH...EXTENDING
FROM CENTRAL GULF COASTAL AREAS INTO THE TENNESSEE VALLEY...BEFORE
MIGRATING NORTHEASTWARD TOWARD THE UPPER OHIO VALLEY.  DESPITE
INLAND EVOLUTION OF SURFACE LOW...SUBSTANTIAL SURFACE WARM SECTOR
DOES NOT APPEAR LIKELY TO DEVELOP...PRIMARILY DUE TO CONTINUING
INFLUENCE OF BROAD SURFACE RIDGE SHIFTING OFF THE ATLANTIC COAST.

...GULF COAST STATES...
AT LEAST A NARROW TONGUE OF SURFACE-BASED DESTABILIZATION IS
EXPECTED IN ASSOCIATION WITH MOISTURE RETURN AHEAD OF SURFACE COLD
FRONT...WHICH SHOULD BEGIN TO ADVANCE EAST OF THE LOWER MISSISSIPPI
VALLEY AND WESTERN GULF COASTAL AREAS BY MID DAY TUESDAY.  MID-LEVEL
LAPSE RATES WILL REMAIN WEAK DUE TO POSITIVE TILT ORIENTATION OF
UPSTREAM SHORT WAVE TROUGH...BUT WEAK HEATING OF AIR MASS WITH 60F+
DEW POINTS WILL CONTRIBUTE TO AT LEAST WEAK CONDITIONAL INSTABILITY.


MODELS HAVE GENERALLY BEEN CONSISTENT IN SUGGESTING VERY STRONG
/100+ KT AT 500 MB/ SOUTHWESTERLY MID-LEVEL JET STREAK WILL SHIFT
EASTWARD AHEAD OF UPPER TROUGH AXIS.  THIS WILL CONTRIBUTE TO
STRENGTHENING SHEAR AND FLOW FIELDS ACROSS MUCH OF THE GULF
STATES...INCLUDING WARM SECTOR...WHERE MEAN DEEP LAYER ENVIRONMENTAL
SPEEDS MAY EXCEED 40 KT.  THUS...DESPITE WEAK
INSTABILITY...POTENTIAL FOR DAMAGING WINDS WILL BE ENHANCED BY
STRONGER CONVECTION...WHICH WILL AID DOWNWARD TRANSFER OF HIGHER
MOMENTUM TO THE SURFACE.

NARROW PRE-FRONTAL SQUALL LINE APPEARS POSSIBLE...MAINLY DURING THE
AFTERNOON/EARLY EVENING ACROSS PARTS OF SOUTHEAST LOUISIANA/
SOUTHERN MISSISSIPPI AND WESTERN ALABAMA.  AS STRONGER FORCING
DEVELOPS NORTHEAST OF GULF COASTAL AREAS LATER IN THE EVENING...
CONVECTIVE LINE SHOULD WEAKEN. HOWEVER...MORE ISOLATED CELLS MAY
EVENTUALLY DEVELOP IN CONFLUENT BAND NEAR LOW-LEVEL JET
AXIS...SHIFTING EASTWARD INTO EASTERN GULF COASTAL AREAS OVERNIGHT. 
SHEAR PROFILES LIKELY WILL REMAIN STRONG ENOUGH NEAR COASTAL
AREAS...WHERE INLAND ADVECTION OF MOIST BUOYANT BOUNDARY LAYER WILL
PERSIST...TO SUPPORT RISK FOR SUPERCELLS AND TORNADOES OVERNIGHT.

..KERR.. 11/29/2004

...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.