[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 210608
SWODY1
SPC AC 210605

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1205 AM CST MON FEB 21 2005

VALID 211200Z - 221200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 S UKI 30 SSW RBL
40 ESE RBL 55 WNW BIH 35 NNW NID 65 SSW LAS 30 E IGM 30 WNW PHX 60
SSW GBN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 ESE JAX 45 WNW CTY
...CONT... 10 WNW BVE LCH 20 NNE PSX 25 WNW VCT 30 SE SAT 35 WSW AUS
65 SW TYR 35 ESE PRX 35 ENE FSM 35 SW JLN 30 NNW SGF 45 ESE VIH 15
WNW EVV 20 E SDF 30 NNE HTS 50 WSW EKN 10 NW SHD 25 SSW DCA 15 ENE
SBY.

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
SPLIT FLOW PATTERN ALOFT IS FORECAST ACROSS THE HALF OF THE CONUS
THIS PERIOD...WITH STRONG VORT MAX INITIALLY OVER OK / SRN KS
FORECAST TO MOVE RAPIDLY ENEWD BUT WEAKEN AS IT MOVES THROUGH
CONFLUENT FLOW.  MEANWHILE UPPER LOW MOVES SEWD ALONG THE CA COAST
THROUGH THE PERIOD.  

AT THE SURFACE...COLD FRONT IS FORECAST TO EXTEND INITIALLY FROM THE
LOWER GREAT LAKES WSWWD ALONG THE OH VALLEY INTO OK.  WHILE NRN
PORTION OF THIS BOUNDARY SHOULD MOVE RAPIDLY EWD AND OFF THE
MID-ATLANTIC COAST BY AFTERNOON AHEAD OF UPPER VORT MAX...THE REST
OF THE ROUGHLY W-E FRONTAL ZONE WILL MOVE SLOWLY SWD WITH TIME.  BY
LATE IN THE PERIOD...FRONT SHOULD EXTEND FROM THE CAROLINAS WWD
ACROSS NRN PORTIONS OF THE GULF COAST STATES AND INTO NRN / CENTRAL
TX.

...UPPER TX COAST / E TX ENEWD ACROSS THE LOWER MS / TN VALLEYS...
COLD FRONT IS FORECAST ACROSS NRN PORTIONS OF THIS REGION -- FROM
ROUGHLY THE RED RIVER VALLEY INTO THE TN VALLEY -- AT THE START OF
THE PERIOD.  THUNDERSTORMS WILL LIKELY BE ONGOING ALONG THIS FRONTAL
ZONE...FROM PARTS OF AR EWD ACROSS THE TN VALLEY...WITH A FEW STORMS
POSSIBLY SEVERE.  HOWEVER...WITH FRONT FORECAST TO MAKE LITTLE SWD
PROGRESS WITH TIME...WIDESPREAD PRECIPITATION INVOF FRONTAL ZONE /
AHEAD OF UPPER VORT MAX SHOULD LIMIT POTENTIAL FOR HEATING /
DESTABILIZATION DURING THE DAY.  THEREFORE...EXPECT THAT THREAT FOR
HAIL / LOCALLY DAMAGING WINDS SHOULD REMAIN LIMITED THROUGH THE
PERIOD ACROSS THIS PART OF THE REGION. 

FARTHER S -- FROM E TX ACROSS THE GULF COAST STATES... SLY COMPONENT
OF LOW-LEVEL FLOW WILL ADVECT MID 60S DEWPOINTS NWD ACROSS MUCH OF
THIS REGION CONTRIBUTING TO THE DEVELOPMENT OF 1000 TO 2000 J/KG
MEAN-LAYER CAPE DURING THE AFTERNOON.  HOWEVER... MINIMAL LOW-LEVEL
CONVERGENCE ANTICIPATED S OF SURFACE FRONT AND FORECAST LACK OF ANY
SIGNIFICANT FEATURE ALOFT SUGGEST THAT WIDESPREAD / ORGANIZED
CONVECTIVE DEVELOPMENT WILL BE UNLIKELY.  

NONETHELESS...DEGREE OF MOISTURE / INSTABILITY WILL LIKELY SUPPORT
SCATTERED CONVECTIVE DEVELOPMENT ALONG MESOSCALE LOW-LEVEL
BOUNDARIES.  WITH STRENGTH OF UPPER FLOW / DEEP SHEAR SUPPORTIVE OF
STORM ORGANIZATION...A FEW SEVERE STORMS WILL LIKELY EVOLVE WITHIN
THIS REGION.  OVERALL COVERAGE OF POSSIBLE SEVERE WEATHER SHOULD
REMAIN LIMITED HOWEVER...SO WILL MAINTAIN ONLY LOW-PROBABILITY
SEVERE THREAT OVER THE ENTIRE AREA.

...SRN CA...
LARGE UPPER LOW IS FORECAST TO MOVE SEWD ALONG THE CA COAST THIS
PERIOD...WITH MODERATELY-STRONG / DIFFLUENT SWLY FLOW ALOFT FORECAST
ACROSS SRN CA DURING THE AFTERNOON WITHIN SERN QUADRANT OF THE LOW. 


THOUGH DESTABILIZATION SHOULD REMAIN LIMITED...LOW-LEVEL CONVERGENCE
/ UPSLOPE FLOW COMBINED WITH UPPER DIFFLUENCE WILL BE SUPPORTIVE OF
THUNDERSTORMS -- PARTICULARLY ACROSS COASTAL PORTIONS OF SRN CA
DURING THE AFTERNOON.  DEEP-LAYER SHEAR SHOULD BE SUFFICIENT FOR
SEVERE STORMS...WITH THE MAIN QUESTION ATTM BEING POTENTIAL FOR
DESTABILIZATION WITHIN WHAT COULD BE AN AREA OF WIDESPREAD CLOUDS /
PRECIPITATION.

WILL MAINTAIN A LOW-PROBABILITY THREAT FOR HAIL / DAMAGING WINDS AND
PERHAPS A TORNADO OR TWO...WITH UPGRADE TO SLIGHT RISK POSSIBLE IN
LATER FORECASTS ONCE EVOLUTION OF AIRMASS BECOMES MORE CLEAR.

FURTHER N...HAVE ADDED A LOW-PROBABILITY HAIL THREAT INTO THE
CENTRAL VALLEY...AS IT APPEARS THAT DRY SLOT MAY OVERSPREAD THIS
REGION ALLOWING SOME HEATING / DESTABILIZATION.  THOUGH SHEAR SHOULD
REMAIN MUCH WEAKER ACROSS THIS AREA...COLD TEMPERATURES ALOFT WOULD
SUPPORT A MARGINAL HAIL THREAT SHOULD SUFFICIENT INSTABILITY
DEVELOP.

..GOSS.. 02/21/2005

...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.