[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 210042
SWODY1
SPC AC 210041

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0641 PM CST SAT NOV 20 2004

VALID 210100Z - 211200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 S
VCT 25 N NIR 55 ESE AUS 25 NW HOU 25 S BPT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SSE P07 15 NW FST
45 E ROW 25 SE AMA 15 W LBL DDC P28 25 W OKC ADM PRX 10 SW ELD GWO
BHM ATL 40 ENE MCN AYS VLD 30 SE TLH.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 NNW SVC 55 WNW SAD
GBN 50 NW GBN 10 SE IGM 35 SW BCE 25 SSW CNY 30 SW MTJ 35 E DRO 35
ENE 4SL 15 S SAF 40 WNW ONM 80 NNW SVC.

...THERE IS A SLGT RISK OF SVR TSTMS THIS EVENING ALONG THE
MID/UPPER TEXAS COAST....

STRONG MID/UPPER JET...DIGGING AROUND NORTHEASTERN PACIFIC RIDGE
INTO BROAD WESTERN/CENTRAL U.S. TROUGH...WILL CONTINUE SOUTHWARD
FROM THE LEE OF THE CASCADES THROUGH THE VICINITY OF THE SIERRA
NEVADA TONIGHT.  AS THIS OCCURS...CLOSED LOW...NOW EVOLVING OVER THE
GREAT BASIN...WILL GRADUALLY DEVELOP SOUTH/SOUTHWESTWARD THROUGH THE
REMAINDER OF THE FORECAST PERIOD.  MEANWHILE..AS SIGNIFICANT
NORTHERN BRANCH SHORT WAVE PROGRESSES SLOWLY EASTWARD ACROSS THE
UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES REGION...WEST
SOUTHWESTERLY MID/UPPER FLOW REGIME WILL CONTINUE TO STRENGTHEN IN
BROAD SWATH ACROSS THE SOUTHEASTERN TWO-THIRDS OF THE NATION.

....SOUTHERN PLAINS/GULF COASTAL AREAS...
WHILE LOW-LEVEL FRONTAL ZONE ASSOCIATED WITH LEAD UPPER SYSTEM
ADVANCES SOUTHEASTWARD THROUGH THE OHIO VALLEY...FRONT WILL STALL
ACROSS THE RED RIVER VALLEY AND TEXAS SOUTH PLAINS.  PRIOR COOL
SURGE WILL CONTINUE TO WEAKEN OVER THE SOUTHEAST STATES...WITH AIR
MASS CONTINUING TO MOISTEN/WARM OVER THE MUCH OF THE GULF OF MEXICO
AND GULF COASTAL AREAS.  EVAPORATIVE COOLING OF CONVECTIVE
PRECIPITATION IN DRY BOUNDARY LAYER HAS SLOWED INLAND PROGRESSION OF
COASTAL FRONT ACROSS SOUTH CENTRAL TEXAS/THE UPPER TEXAS AND
LOUISIANA COASTS AND THE FLORIDA PANHANDLE.  HOWEVER...WEAK SURFACE
BASED DESTABILIZATION IS EXPECTED OVERNIGHT FARTHER INLAND ACROSS
THE CENTRAL GULF COAST STATES...IN ASSOCIATION WITH CONTINUED WEAK
SOUTHERLY LOW-LEVEL FLOW.  THIS WILL OCCUR AS DE-AMPLIFYING IMPULSE
EMBEDDED WITHIN WEST SOUTHWESTERLY UPPER FLOW REGIME PROGRESSES OUT
OF TEXAS.

UPPER FEATURE APPEARS TO BE PROVIDING FORCING FOR ONGOING CONVECTIVE
DEVELOPMENT FROM WESTERN OKLAHOMA INTO EASTERN/SOUTHEAST TEXAS. 
WHILE SOME MARGINALLY SEVERE HAIL WILL REMAIN POSSIBLE INTO THE
EVENING ACROSS PARTS OF WESTERN OKLAHOMA AND NORTHWEST/NORTH CENTRAL
TEXAS...NORTH OF CYCLONIC UPPER JET AXIS...PRIMARY SEVERE THREAT
SHOULD REMAIN FOCUSED ON COASTAL FRONT NEAR THE MID/UPPER TEXAS
COAST.

DESPITE WEAK MID-LEVEL LAPSE RATES BENEATH SUBTROPICAL MOIST
PLUME...BOUNDARY LAYER DEW POINTS AROUND 70F ALONG TEXAS COASTAL
AREAS ARE CONTRIBUTING TO MIXED LAYER CAPE TO 2000 J/KG.  THIS IS
SUPPORTING VIGOROUS UPDRAFTS IN FAVORABLY SHEARED ENVIRONMENT FOR
SUPERCELLS...AND ONGOING ACTIVITY NORTH OF VICTORIA WILL PERSIST AT
LEAST ANOTHER FEW HOURS...SPREADING ALONG FRONT INTO AREAS
NEAR/SOUTH OF HOUSTON LATER THIS EVENING.  WITH SOUTHERLY LOW-LEVEL
JET ONLY ON THE ORDER OF 25 KT...LOW-LEVEL SHEAR PROFILES ARE
SOMEWHAT MARGINAL...BUT STILL MAY BE SUFFICIENT FOR AN ISOLATED
TORNADO OR DAMAGING WIND GUST.

LOW-LEVEL JET IS NOT PROGGED TO STRENGTHEN SIGNIFICANTLY AS IT VEERS
AND SHIFTS NORTHEASTWARD INTO THE CENTRAL GULF STATES OVERNIGHT. 
THUS...WHILE STRONGER CONVECTION WILL TEND TO DEVELOP INTO THIS
REGION...SEVERE THREAT APPEARS EVEN MORE MARGINAL THAN ALONG THE
TEXAS COAST.

...SOUTHERN PLATEAU...
STRONG FORCING FOR UPWARD VERTICAL MOTION/MID-LEVEL COOLING WILL
CONTRIBUTE TO SUFFICIENT DESTABILIZATION TO MAINTAIN SCATTERED
THUNDERSTORM ACTIVITY OVERNIGHT ACROSS MUCH OF NORTHERN ARIZONA AND
THE FOUR CORNERS REGION.

..KERR.. 11/21/2004

...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.