DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 211956
SWODY1
SPC AC 211954

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0154 PM CST WED NOV 21 2012

VALID 212000Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

...DISCUSSION...

THREAT FOR THUNDERSTORMS ALONG THE PACIFIC NW COAST WILL GRADUALLY
DIMINISH AS THE UPPER THERMAL TROUGH MOVES INLAND. OTHERWISE...A FEW
LIGHTNING STRIKES REMAIN POSSIBLE OVER THE NRN ROCKIES WITH
CONVECTION DEVELOPING IN ASSOCIATION WITH OROGRAPHIC ASCENT AND
MIGRATORY VORTICITY MAXIMA WITHIN PLUME OF 7-7.5 C/KM MID LEVEL
LAPSE RATES. HOWEVER...WEAK INSTABILITY SUGGESTS COVERAGE SHOULD
REMAIN AOB 10%.

ELSEWHERE...PRIMARY AREA OF THUNDERSTORM DEVELOPMENT THIS EVENING
WILL EXIST ACROSS SERN NM AND SWRN TX.

..DIAL.. 11/21/2012

.PREV DISCUSSION... /ISSUED 1001 AM CST WED NOV 21 2012/

...FAR W TX...SRN NM...
A SHORTWAVE IMPULSE NEAR BAJA CALIFORNIA WILL CONTINUE TO TRACK
TOWARD THE NE THROUGH THE PERIOD. THUNDERSTORMS AHEAD OF THE IMPULSE
HAVE BEEN ONGOING ACROSS NRN MEXICO THIS MORNING. ISOLATED TO WIDELY
SCATTERED THUNDERSTORM ACTIVITY IS EXPECTED TO SPREAD E/NE INTO SRN
NM/FAR W TX WHERE LOW LEVEL MOISTURE IS INCREASING ON S/SELY LOW
LEVEL FLOW. STEEP MID LEVEL LAPSE RATES AND VERTICALLY VEERING WIND
PROFILES MAY ALLOW FOR SOME LOOSELY ORGANIZED STORM STRUCTURES BUT
MODEST SFC HEATING AND DEWPOINTS ONLY CLIMBING INTO THE MID 40S WILL
LIMIT INSTABILITY TO LESS THAN 500 J/KG.

...WRN WA/ORE...PORTIONS OF ERN WA/CNTRL ID...FAR W-CNTRL MT...
AN UPPER TROUGH OVER THE PAC NW WILL CONTINUE MOVING EWD ACROSS THE
NRN ROCKIES THROUGH 12Z/THU. SEVERAL IMPULSES ROTATING THROUGH THE
TROUGH WERE PROVIDING FOCUS FOR ISOLATED THUNDERSTORM ACTIVITY WEST
OF THE CASCADES AND ACROSS HIGHER TERRAIN IN ERN WA/CNTRL ID. STEEP
LAPSE RATES BELOW 700 MB AND COLD TEMPERATURES ALOFT WILL ALLOW FOR
ISOLATED THUNDER TO CONTINUE IN MOIST/WEAKLY UNSTABLE UPSLOPE
ENVIRONMENT AHEAD OF THE TROUGH. ACTIVITY SHOULD END AROUND 00Z
TONIGHT AS MIDLEVEL HEIGHTS QUICKLY INCREASE WITH TROUGH PASSAGE.

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.