FXUS65 KBOU 022128
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
230 PM MST WED DEC 02 2009

.SHORT TERM...FOR TNGT...SOME LIGHT SNOW MAY LINGER NEAR THE 
FOOTHILLS AND PALMER DIVIDE THIS EVENING WITH WEAK UPSLOPE COMPONENT 
IN PLACE.  MDT TO STG NLY FLOW ALOFT WITH ANOTHER DISTURBANCE 
DROPPING OUT OF THE NORTH BRINGS ANOTHER SURGE OF CANADIEN AIR INTO 
THE CWFA.  SPATIAL CROSS-SECTIONS SHOW SOME WEAK UPSLOPE DEVELOPING 
WITH ENOUGH MSTR FOR SOME MORE LIGHT SNOW.  NOT MUCH WITH JUST SOME 
WEAK QG ASCENT PRESENT BLO 700 MB.  IN ANY EVENT...WL BUMP POPS UP 
TO LIKELY FOR AREAS IN AND NEAR THE FRONT RANGE FOOTHILLS AND PALMER 
DIVIDE FOR LATE TNGT AND THURSDAY MORNING.  WL MNTN MINIMAL 
ACCUMULATIONS OF 1-2 INCHES IN THE FOOTHILLS...AN INCH OR LESS IN 
THE URBAN CORRIDOR...ENOUGH TO COVER THE ICY SPOTS FOR THE MORNING 
COMMUTE.  BY THURSDAY AFTN...SNOW WL DIMINISH AS THE UPSLOPE WEAKENS 
WITH INCRG VSBYS AND CIGS.  

.LONG TERM...A NORTH-NORTHWEST FLOW ALOFT WILL BE OVER THE REGION 
THURSDAY NIGHT AND FRIDAY AS A LARGE UPPER LEVEL TROUGH SPINS OVER 
THE GREAT LAKES. MAY SEE SOME LIGHT SNOW LINGER INTO THURSDAY 
EVENING OVER THE FAVORED UPSLOPE AREAS SOUTH AND WEST OF DENVER AND 
INTO THE FOOTHILLS. LOW LEVEL FLOW WILL SWITCH WESTERLY AROUND 
MIDNIGHT BRINGING AN END TO ANY UPSLOPE SNOW THAT IS LINGERING. 
FRIDAY WILL BE SLIGHTLY WARMER BUT REMAIN COOL WITH THE SNOW ON THE 
GROUND AND A RELATIVELY COOL AIRMASS IN PLACE. 

A STRONG UPPER LEVEL TROUGH DROPPING SOUTH INTO THE NORTHERN ROCKIES 
WILL INDUCE A WEAK RIDGE OVER THE CENTRAL ROCKIES ON SATURDAY. 
TEMPERATURES WILL CLIMB ABOVE FREEZING SATURDAY UNDER A WESTERLY 
FLOW ALOFT. THE UPPER LEVEL TROUGH WILL DRIVE A COLD FRONT THROUGH 
EASTERN COLORADO SATURDAY NIGHT AS THE TROUGH PARKS OVER THE 
NORTHWEST QUARTER OF THE U.S. WILL SEE A GOOD CHANCE FOR SNOW SUNDAY 
FOR THE FOOTHILLS AND URBAN CORRIDOR AS A PIECE OF ENERGY FROM THE 
TROUGH MOVES OVER THE REGION IN A WESTERLY FLOW ALOFT. ALSO ADDING 
TO THE SNOW...A NORTHEASTERLY LOW LEVEL FLOW WILL CREATE UPSLOPE 
CONDITIONS. THE UPSLOPE FLOW AND SNOW WILL DECREASE SUNDAY NIGHT.

THE WESTERLY FLOW ALOFT WILL PERSIST INTO NEXT WEEK. THIS WILL BRING 
A CHANCE FOR SNOW TO THE MOUNTAINS...ESPECIALLY COME MONDAY AND 
MONDAY NIGHT WHEN A DISTURBANCE EMBEDDED IN THE FLOW MOVES OVER THE 
AREA. THIS SYSTEM MAY ALSO DROP LIGHT SNOW OVER LOWER ELEVATIONS. 
THE COOL AIR WILL REMAIN IN PLACE THROUGH AT LEAST TUESDAY...KEEPING 
TEMPERATURES BELOW NORMAL. COLD AIR MAY EXIT THE AREA BY MID WEEK 
BRINGING NEAR NORMAL TEMPERATURES BACK TO THE AREA.

&&

.AVIATION...WL KEEP JUST VCSH IN THE TAFS THROUGH 08Z...WITH NO 
RESTRICTIONS TO CIGS/VSBYS THRU THAT TIME.  ANOTHER SURGE OF CANDIAN 
AIR IS EXPECTED TO MOVE THROUGH DENVER AREA AFTER 08Z.  CLOUDS AND 
CIGS WILL LOWER AS SOME LIGHT SNOW REDEVELOPS.  MAIN WINDOW FOR 
LIGHT SNOW WL BE FM 11Z-17Z THURSDAY MORNING.  COULD SEE OCNL IFR 
CONDITIONS DEVELOP IN THIS WINDOW...WITH SNOW ACCUMULATIONS OF 
AROUND ONE HALF INCH OR LESS.  IMPROVING CONDITIONS ARE EXPECTED 
AFTER 18Z AS UPSLOPE WEAKENS AND COLD...DRY AMS SETTLES INTO PLACE. 
&&

.BOU WATCHES/WARNINGS/ADVISORIES...NONE. 

$$

COOPER/MEIER