012

ACUS01 KWNS 211300

SWODY1

SPC AC 211257



DAY 1 CONVECTIVE OUTLOOK  

NWS STORM PREDICTION CENTER NORMAN OK

0657 AM CST FRI NOV 21 2008



VALID 211300Z - 221200Z



...NO SVR TSTM AREAS FORECAST...



...SYNOPSIS...

DEEP BUT PROGRESSIVE TROUGH WILL CONTINUE E FROM THE OH VLY TO OFF

THE MID ATLANTIC CST THIS PERIOD AS UPSTREAM DISTURBANCE NOW OVER MT

AMPLIFIES SE INTO THE LWR MO VLY.  DRY AND/OR COOL AIR WILL PREVAIL

AT LWR LVLS ACROSS MOST OF THE CONUS.



...GRT LKS...

CONVECTION WILL CONTINUE OVER THE WARMER WATERS OF THE GRT LKS

TODAY...WITH THE DEEPEST ACTIVITY SHIFTING TO LKS HURON...ERIE

AND ONTARIO AS UPR SYSTEM CONTINUES EWD.  FORECAST SOUNDINGS SHOW

SIGNIFICANT LWR TROPOSPHERIC COOLING OVER THE NEXT 24 HR BEFORE

PROFILES BEGIN TO WARM...WITH THE STEEPEST SFC-3KM LAPSE RATES OVER 

WRN PORTIONS OF LAKE ERIE.  WEAKLY CYCLONIC WNW FLOW MAY SUPPORT A

FEW STRONGER UPDRAFTS AND POSSIBLE EMBEDDED LIGHTNING WITHIN SNOW

SQUALLS.



...PAC NW...

FAIRLY VIGOROUS TROUGH NOW NEARING 140W WILL APPROACH THE WA CST

TONIGHT AND CONTINUE ENE INTO SRN BC/AB EARLY SATURDAY.  THE 

GREATEST COOLING ALOFT WILL REMAIN JUST N OF THE INTERNATIONAL

BORDER...WHERE 5OO MB TEMPS WILL BE AOB MINUS 30C.  WITH THE

STEEPEST LAPSE RATES JUST CLIPPING THE NW TIP OF WA...EXPECT THAT

MOST OF ANY ASSOCIATED LIGHTNING WILL REMAIN N OF THE BORDER.



..CORFIDI/JEWELL.. 11/21/2008