[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 031259
SWODY1
SPC AC 031257

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0657 AM CST MON JAN 03 2005

VALID 031300Z - 041200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SSW SFO NID GCN
ABQ CAO RSL STJ BMI 10 E FWA 20 NNE FKL LBE CRW 40 SSW LOZ UOX 35
NNE MLU 30 S SHV 50 SW LFK 45 NNW NIR 40 WNW COT DRT.

...NO SVR TSTM AREAS FORECAST...

PHASING OF IMPULSES IN SOUTHERN BRANCH OF POLAR WESTERLIES AND
SUBTROPICAL WESTERLIES APPEARS TO HAVE OCCURRED OFF THE SOUTHERN
CALIFORNIA/NORTHERN BAJA COAST.  STRONG DIGGING JET IS EVIDENT IN
LATEST WATER VAPOR IMAGERY ACROSS THIS REGION...AND ASSOCIATED COLD
CLOSED LOW CONTINUES TO DEVELOP SOUTHWARD NEAR THE CALIFORNIA COAST.
MODELS STILL SUGGEST THIS FEATURE WILL BOTTOM OUT IN BASE OF BROAD
UPPER TROUGH DURING THIS FORECAST PERIOD...BUT SEEM A BIT SLOWER
WITH EASTWARD/INLAND PROGRESSION ACROSS SOUTHERN CALIFORNIA INTO
SOUTHERN PLATEAU.

MODELS SUGGEST LITTLE CHANGE TO DOWNSTREAM LARGE-SCALE PATTERN
THROUGH TONIGHT...WITH NEXT IN SERIES OF SUBTROPICAL SHORT WAVE
TROUGHS PROGGED TO LIFT OUT OF THE LOWER LATITUDE EASTERN PACIFIC. 
DOWNSTREAM IMPULSES CONTINUE TO WEAKEN IN CONFLUENT MID/UPPER FLOW
REGIME...BETWEEN EASTERN CANADIAN POLAR LOW AND SUBTROPICAL RIDGE
OVER THE GULF OF MEXICO.  MOST SIGNIFICANT OF THESE FEATURES IS
CURRENTLY SPREADING INTO THE LOWER MISSOURI VALLEY...WITH ASSOCIATED
UPWARD VERTICAL MOTION FIELD STILL STRONG ENOUGH TO SUPPORT BROAD
AREA OF PRECIPITATION. THOUGH THUNDERSTORM ACTIVITY HAS BEGUN TO
DIMINISH AS SYSTEM WEAKENS...MOIST AND CONDITIONALLY UNSTABLE
THERMODYNAMIC ENVIRONMENT WILL MAINTAIN AT LEAST LOW RISK FOR
THUNDERSTORMS EASTWARD NEAR STALLED BAROCLINIC ZONE THROUGH THE OHIO
VALLEY.

NEXT INFLUX OF MID/HIGH LEVEL MOISTURE OFF THE LOWER LATITUDE
EASTERN PACIFIC IS ALREADY OVERSPREADING THE NORTHERN MEXICAN
PLATEAU AND THE SOUTHERN HIGH PLAINS.  THIS IS OCCURRING AS RETURN
FLOW OF LOW-LEVEL MOISTURE OFF THE GULF OF MEXICO CONTINUES AROUND
SOUTHERN/WESTERN PERIPHERY OF LARGE SURFACE RIDGE OFF THE ATLANTIC
COAST. CONVECTION IS EXPECTED TO INCREASE ONCE AGAIN LATER TODAY/
TONIGHT...WITH ANOTHER BROAD PRECIPITATION SHIELD LIKELY TO DEVELOP
FROM PARTS OF THE CENTRAL/SOUTHERN PLAINS INTO THE MIDDLE
MISSISSIPPI VALLEY.

...SRN HIGH PLAINS INTO THE OZARKS...
MODELS INDICATE TIGHTER THERMAL GRADIENT...ASSOCIATED WITH LEADING
EDGE OF INTRUSION OF MODIFIED ARCTIC AIR...WILL GENERALLY LINGER
ACROSS NORTHERN OKLAHOMA AND SOUTH CENTRAL MISSOURI TODAY.  ZONE OF
STEEPER ISENTROPIC ASCENT WILL PROVIDE ONE FOCUS FOR THUNDERSTORM
ACTIVITY AS NEXT SUBTROPICAL SHORT WAVE LIFTS INTO THE SOUTH CENTRAL
STATES.

THIS FEATURE APPEARS LIKELY TO TAKE A MORE WESTWARD TRACK THAN PRIOR
SUBTROPICAL SYSTEM...AS UPSTREAM CLOSED LOW BOTTOMS OUT AND BEGINS
TO TURN TOWARD THE SOUTHWEST STATES.  STRONGEST MID/UPPER FORCING IS
EXPECTED TO SPREAD ACROSS EASTERN NEW MEXICO AND WEST TEXAS
BY/SHORTLY AFTER 04/00Z...AND SHOULD PROVIDE ANOTHER FOCUS
CONVECTIVE DEVELOPMENT.

THOUGH RELATIVELY WARM MID-LEVEL AIR WILL CONTINUE TO MINIMIZE LAPSE
RATES FARTHER EAST...STEEPER LAPSE RATES IN CLOSER PROXIMITY TO THE
SOUTHERN ROCKIES WILL SUPPORT SOMEWHAT BETTER RISK OF VIGOROUS DEEP
CONVECTION TODAY.  IN CONJUNCTION WITH DAYTIME HEATING...MOIST
UPSLOPE FLOW IS EXPECTED TO CONTRIBUTE TO MIXED LAYER CAPE OF 500 TO
1000 J/KG IN CORRIDOR ACROSS THE SOUTHERN HIGH PLAINS. THIS WILL BE
SURFACE-BASED SOUTH OF FRONT...FROM EAST CENTRAL/SOUTHEAST NEW
MEXICO INTO THE TEXAS SOUTH PLAINS...WHERE A COUPLE OF STORMS COULD
PRODUCE GUSTY WINDS/HAIL APPROACHING OR BRIEFLY EXCEEDING SEVERE
LIMITS.  HAIL WILL BE PRIMARY THREAT IN ACTIVITY DEVELOPING
NORTHEASTWARD ALONG STRENGTHENING LOW-LEVEL JET INTO PARTS OF
WESTERN OKLAHOMA DURING THE EVENING HOURS.

...SOUTHWESTERN STATES...
EXIT REGION OF MID/UPPER JET WILL NOSE ACROSS SOUTHERN CALIFORNIA 
COASTAL AREAS INTO THE LOWER COLORADO VALLEY LATE THIS AFTERNOON AND
TONIGHT.  STRONG COOLING ALOFT SHOULD CONTRIBUTE TO SUFFICIENT
DESTABILIZATION FOR INLAND DEVELOPMENT OF THUNDERSTORM ACTIVITY. 
THERMODYNAMIC PROFILES SHOULD BECOME SUPPORTIVE OF SMALL HAIL IN
MORE VIGOROUS CELLS.  STRONGEST INSTABILITY APPEARS LIKELY ALONG
SOUTHERN CALIFORNIA COASTAL AREAS NEAR SAN DIEGO...WHERE SHEAR
PROFILES COULD ALSO SUPPORT AN ISOLATED SUPERCELL.

..KERR.. 01/03/2005

...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.