DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 011238
SWODY1
SPC AC 011236

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0636 AM CST SUN DEC 01 2013

VALID 011300Z - 021200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
BROADLY/GENTLY CYCLONIC FLOW PATTERN IS FCST TO CONTINUE OVER MOST
OF CONUS. GREATEST PERTURBATION WILL BE HEIGHT FALLS AND TIGHTENING
HEIGHT/THERMAL GRADIENTS OVER NWRN STATES...IN ADVANCE OF STG
SHORTWAVE TROUGH NOW EVIDENT IN MOISTURE CHANNEL IMAGERY INVOF BC
COAST. WEAKER/POSITIVELY TILTED TROUGH -- NOW LOCATED OVER 4-CORNERS
REGION -- IS EXPECTED TO MOVE ESEWD TO OK AND NW TX BY THIS
EVENING...THEN WEAKEN AND ACCELERATE EWD TO SRN APPALACHIANS BY END
OF PERIOD. NRN-STREAM MID-UPPER LEVEL TROUGH WAS LOCATED OVER
PORTIONS LOWER MI AND ERN UPPER MI...FCST TO MOVE EWD ACROSS NRN
APPALACHIANS THROUGH TONIGHT.

11Z SFC CHART SHOWED WEAK FRONTAL-WAVE LOW LOCATED OVER
LH...ASSOCIATED WITH NRN-STREAM SHORTWAVE ALOFT. COLD FRONT WAS
DRAWN FROM THERE SWWD ACROSS NRN KS...BECOMING WARM FRONT OVER WRN
NEB AND WRN SD. WARM FRONT WILL STRENGTHEN WHILE EXTENDING SEWD
FROM DEEPENING CYCLONE OVER BC/AB BORDER...WHILE COLD FRONT WEAKENS
AND BECOMES QUASISTATIONARY OVER INDIANA...IL AND MO.

...ARKLATEX...MID-SOUTH...
AHEAD OF APCHG SHORTWAVE...LOW-LEVEL WAA WILL CONTINUE AND
STRENGTHEN SOMEWHAT IN SW-NE ALIGNED BELT S OF SFC FRONT...FROM E TX
ACROSS TN VALLEY AND SRN APPALACHIANS. TIME SERIES OF FCST
SOUNDINGS IN WAA ZONE INDICATE TWO FAVORABLE PROCESSES AT
WORK...ULTIMATELY JUXTAPOSING VERTICALLY TO YIELD AT LEAST MRGLLY
FAVORABLE/DEEP BUOYANCY FOR THUNDER AFTER DARK...
1. INCREASING THETAE IN 800-900 MB LAYER RELATED TO MOIST
ADVECTION/TRANSPORT...AND
2. WEAK LARGE-SCALE DCVA/UVV AND HEIGHT FALLS PRECEDING PERTURBATION
NOW OVER 4 CORNERS...SUBTLY STEEPENING MIDLEVEL LAPSE RATES AND
SLOWLY MUTING THERMAL WARM NOSE AROUND 700 MB.

ACCORDINGLY...FCST SOUNDINGS AND PLANAR SREF/SPECTRAL/NAM GUIDANCE
SUGGEST AREA OF DECREASINGLY INHIBITED...250-700 J/KG ELEVATED
MUCAPE DEVELOPING THIS EVENING OVER ARKLATEX AND SHIFTING/SPREADING
EWD ACROSS LOWER MS RIVER VALLEY OVERNIGHT. STREAKY/EPISODIC
THUNDER THEREFORE IS POSSIBLE OVER THIS REGION.

..EDWARDS/GARNER.. 12/01/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.