SPC AC 301956
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0156 PM CST THU DEC 30 2010
VALID 302000Z - 311200Z
...NO SVR TSTM AREAS FORECAST...
...ERN KS...
VIGOROUS SHORTWAVE TROUGH...CURRENTLY MOVING ESEWD THROUGH THE FOUR
CORNERS REGION PER WATER VAPOR IMAGERY...WILL TRACK ACROSS THE SRN
ROCKIES WITH A PORTION OF THIS FEATURE REACHING WRN/SWRN KS BY 12Z
FRIDAY. 30-50 METER HEIGHT FALLS PER 12 HR AT 500 MB ARE EXPECTED
LATE TONIGHT ACROSS ERN KS WITH THE APPROACH OF THIS SYSTEM. 18Z
SURFACE ANALYSIS SHOWED A 987 MB CYCLONE OVER FAR NWRN IA ATTENDANT
TO A LEAD SHORTWAVE TROUGH...WITH A COLD FRONT TRAILING SWWD INTO
SWRN KS TO A SECOND LOW PRESSURE AREA IN SERN CO. THE CO LOW WILL
DEVELOP EWD ALONG THE OK/KS BORDER THIS FORECAST PERIOD AS THE COLD
FRONT ADVANCES ESEWD.
A FARTHER WNWWD EXPANSION OF THE GENERAL TSTM LINE WILL BE INCLUDED
IN THIS CONVECTIVE OUTLOOK TO INCLUDE THE REST OF ERN KS...WITH THIS
WWD TREND ALREADY INDICATED IN THE PREVIOUS ISSUANCE OF THIS
OUTLOOK. 15Z SREF/18Z RUC CONCUR THIS WNWWD EXPANSION AS FORECAST
SOUNDINGS SHOW STRONG LOW LEVEL WAA TONIGHT BENEATH STEEP MIDLEVEL
LAPSE RATES RESULTING IN ELEVATED MUCAPE OF 200-400 J/KG. HEIGHT
FALLS/FORCING FOR ASCENT SPREADING INTO CENTRAL/ERN KS LATE
TONIGHT/EARLY FRIDAY SHOULD SUPPORT ELEVATED TSTM DEVELOPMENT AFTER
31/09Z.
...ELSEWHERE...
REST OF THE FORECAST REMAINS ON TRACK WITH NO CHANGES REQUIRED.
..PETERS.. 12/30/2010
.PREV DISCUSSION... /ISSUED 1006 AM CST THU DEC 30 2010/
INTENSE DEEPENING CONTINUES WITH DEVELOPING COLD WRN TROUGH.
POWERFUL MID/UPPER JET ROTATES AROUND BASE OF TROUGH AND INTO SRN HI
PLAINS TONIGHT IN CONCERT WITH SHORT WAVE NOW SRN UT/NRN AZ MOVING
INTO CENTRAL HIGH PLAINS.
SOUTHERLY LOW LEVEL WINDS WILL CONTINUE TO DRAW GULF MOISTURE
NORTHWARD...WITH LOWER 60S DEWPOINTS EXPECTED ACROSS MUCH OF EAST
TX/EASTERN OK/LA/AR BY THIS EVENING. DESPITE THE IMPROVING
THERMODYNAMIC ENVIRONMENT FOR ORGANIZED/SEVERE STORMS...THE SOUTHERN
PLAINS WILL BE BETWEEN UPPER TROUGHS THIS EVENING AND MUCH OF
TONIGHT. IN ADDITION WARM SECTOR EXPECTED TO REMAIN CAPPED UNTIL
STRONG ASCENT WITH APPROACHING S/WV TROUGH AND JET MAX WILL SPREAD
ACROSS SRN PLAINS INTO LOWER MO VALLEY TOWARD 12Z FRI.
STRONG LOW LEVEL AND DEEP LAYER VERTICAL SHEAR POSES A MARGINAL RISK
OF SUPERCELL DEVELOPMENT ONCE STORMS ARE ABLE TO DEVELOP OVERNIGHT
FROM THE ARKLATEX REGION NWD.
LATE TONIGHT /AFTER 09Z/...LARGE SCALE FORCING WILL BEGIN TO
INCREASE DRAMATICALLY ACROSS OK/KS INTO LWR MO VALLEY WITH SOME
POTENTIAL FOR A FORCED-LINE OF CONVECTION DEVELOPING AHEAD OF THE
COLD FRONT OVER ERN KS/NRN OK. THIS COULD INCREASE POTENTIAL FOR
DAMAGING WINDS TOWARD THE END OF FORECAST PERIOD.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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