FXUS65 KBOU 302126
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
225 PM MST MON NOV 30 2009

.SHORT TERM...CLEAR SKIES AND A VERY DRY AIRMASS TONIGHT. A LITTLE 
INCREASE IN WINDS ALOFT SHOULD SURFACE ON THE HIGHER RIDGES AND EAST 
SLOPES KEEPING TEMPERATURES UP THERE...OTHERWISE IT WILL NOT BE MUCH 
WARMER THAN LAST NIGHT. LOWERED FORECAST TEMPS A LITTLE...ESPECIALLY 
IN THE MOUNTAIN VALLEYS.

COLD FRONT LOOKS A LITTLE FASTER AND SHOULD MOVE THROUGH AROUND 
MIDDAY. WE SHOULD SEE DECENT COOLING DURING THE AFTERNOON. WHILE 
WINDS WILL NOT BE REAL STRONG...THERE WILL BE ENOUGH TO ACCENTUATE 
THE FEEL OF THE COLDER AIR. HOURLY TEMP GRIDS WILL SHOW A MIDDAY 
HIGH IN THE 40S WITH TEMPERATURES DOWN TO AROUND 30 BY THE END OF 
THE AFTERNOON. INCOMING AIR IS NOT SATURATED...SO IT WILL TAKE A 
WHILE FOR THE CLOUD DECK TO DEVELOP. I WILL SHOW SOME INCREASE IN 
CLOUDS FROM THE NORTHWEST BUT JUST A 10 PERCENT CHANCE OF SNOW IN 
THE HIGH MOUNTAINS DURING THE LATE AFTERNOON...SAVING MOST OF THE 
CLOUD DEVELOPMENT FOR THE EVENING.

.LONG TERM...ON TUESDAY NIGHT...THE UPPER LEVEL TROUGH IS PROGGED TO 
PASS ACROSS NORTHERN COLORADO.  THE MDLS INDICATE WEAK TO MDT QG 
ASCENT ASSOCIATED WITH THE UPSLOPE FM THE SFC TO 700 MB...WITH WEAK 
QG ASCENT AOA 700 MB.  MOST OF THIS STICKS AROUND TUESDAY NIGHT THEN 
GRADUALLY WEAKENS AND SHIFTS TO THE SOUTHEAST ON WEDNESDAY.  NAM12 
SPATIAL CROSS-SECTIONS INDICATE DCRG MSTR AS THE NERLY BOUNDARY LYR 
WINDS TRANSITION TO MORE OF A NNWLY COMPONENT.  WL UP POPS TO LIKELY 
FOR TUESDAY NIGHT....BUT WL KEEP ACCUMULATIONS ON THE LIGHT SIDE.  
WL GO WITH 1-4 INCHES IN THE FOOTHILLS...WITH 1-3 INCHES ALG THE 
URBAN CORRIDOR.  MUCH COLD AMS IS PROGGED FOR WEDNESDAY AND THURSDAY 
WITH AFTN TEMPERATURES GENERALLY IN THE 20S SO DROPPED THOSE AS 
WELL.  A DRIER NORTHERLY FLOW WL BE OVER CO WITH A RIDGE ALONG THE 
WEST COAST AND A CLOSED LOW WOUND UP OVER THE UPPER MIDWEST/GREAT 
LAKES REGION...WITH AN UPPER LEVEL RIDGE OVER CO ON FRIDAY.  THE 
COMMON DENOMINATOR THROUGH THE PERIOD APPEARS TO BE COLD 
TEMPERATURES. PLENTY OF INCONSISTENCY HOWEVER ABOUT THE NEXT 
POSSIBLE TROF ON SATURDAY.  THE OPERATIONAL GFS INDICATES A TROF 
WILL DROP OUT OF CANADA INTO ACRS NRN CO SATURDAY AND SATURDAY 
NIGHT...WHILE THE ECMWF STILL INDICATES A RIDGE ALONG THE WRN CO 
BORDER.  WITH AN UNSETTLED AND UNCERTAIN FCST WL LEAVE THE POPS 
RELATIVELY UNCHANGED.  WL MAKE ONLY MINOR ADJUSTMENT TO THE POP 
GRIDS INCRG THEM FM A 10 TO 20 POP ALG THE FRONT RANGE/PALMER 
DIVIDE FOR SATURDAY AND SATURDAY NIGHT.  
&&

.AVIATION...A COLD FRONT WILL PASS THROUGH DENVER AROUND 18Z TUESDAY 
FOLLOWED BY NORTH TO NORTHEAST WINDS GUSTING TO AROUND 20 KNOTS. 
CLOUD DEVELOPMENT WILL BE SLOW BEHIND THE FRONT. THERE IS A CHANCE 
OF INSTRUMENT APPROACHES BEING NEEDED IN THE LATE AFTERNOON...BUT 
MORE LIKELY THIS WILL WAIT UNTIL EVENING. LIGHT SNOW IS LIKELY 
TUESDAY NIGHT.

&&

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

$$

GIMMESTAD/COOPER