FXUS65 KBOU 101044
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
340 AM MST THU DEC 10 2009

.SHORT TERM...A STRONG WLY FLOW IS EXPECTED TO CONTINUE TODAY AS A 
UPPER LEVEL JET CONTINUES OVER CO.  THERE IS SOME LINGERING MSTR IN 
THE MTNS THIS MORNING...BUT MDT QG DESCENT AND INCREASING STABILITY 
SHOULD SQUASH ANY LINGERING SNOW SHOWERS BY THIS AFTN.  MAIN CONCERN 
THIS MORNING HAS BEEN THE GUSTY WINDS THAT DEVELOPED ALONG THE FRONT 
RANGE.  GUSTY WINDS COUPLED WITH THE LIGHT GRAINY SNOW WE RECEIVED 
COULD PRODUCE SOME PROBLEMS WITH BLOWING SNOW THIS MORNING.  HIGHWAY 
93 BETWEEN GOLDEN AND BOULDER AND HIGHWAY 287 FM FORT COLLINS TO THE 
WYOMING BORDER COULD BE THE PRIMARY TROUBLE SPOTS.  THE COMBINATION 
OF SUBSIDENCE ALOFT AND THE PRESENCE OF A DEVELOPING SFC LEE TROF 
HAS RESULTED IN A TIGHTENING SFC PRESSURE GRADIENT AND STRONG WINDS 
ALONG THE FRONT RANGE THIS MORNING.  SPATIAL CROSS-SECTIONS SHOW THE 
STRONGEST WINDS WILL BE BETWEEN 09Z AND 15Z THIS MORNING...THEN THE 
WINDS ARE PROGGED TO GRADUALLY WEAKEN.  I WENT AHD AND ISSUED A 
WINTER WEATHER ADVSY FOR BLOWING SNOW FOR ZONES 35..36..38 AND 39 
UNTIL 18Z THIS MORNING.  BY THIS AFTERNOON THE STRONGER WINDS SHOULD 
RETREAT TO THE MOUNTAINS AND HIGHER FOOTHILLS LOCATIONS.  STLT THIS 
MORNING INDICATING MODERATING TEMPERATURES IN THE VICINITY OF THE 
STRONGEST WINDS.  AREAS NEAR THE FOOTHILLS ARE IN THE TEENS IN THE 
WINDIER AREAS WHILE GREELEY IS AT 9 BELOW ZERO AND DIA IS NEAR 
ZERO.  TEMPERATURES WILL RECOVER TODAY BUT AREAS EAST OF THE LEE 
TROF LIKE GREELEY WILL BE SLOER TO RECOVER. NORTHERN AND EASTERN 
PORTIONS OF THE DENVER METRO AREA MAY REMAIN COLD AS WELL VS THE 
REST OF THE METRO AREA.   TNGT THE FLOW ALOFT IS PROGGED TO WEAKEN 
SOMEWHAT AS THE JETSTREAM SHIFTS TO THE EAST AND A RIDGE OF HIGH 
PRESSURE MOVES IN FROM THE WEST.  GUSTY WINDS MAY AGAIN REDEVELOP 
ALONG THE FRONT RANGE BUT SHOULD NOT BE A STRONG AS THIS MORNING.   

.LONG TERM...NORTHWEST FLOW ALOFT WILL BECOME WESTERLY FRIDAY AND IT 
WILL REMAIN GENERALLY OUT OF THE WEST THROUGH THE WEEKEND AND 
THROUGH THE MIDDLE PART OF NEXT WEEK. THIS PATTERN WILL RESULT IN 
WARMER CONDITIONS FOR THE AREA. THERE WILL BE A COUPLE OF 
DISTURBANCE EMBEDDED IN THE WESTERLY FLOW BRINGING A CHANCE OF SNOW 
TO THE MOUNTAINS. BECAUSE OF THE WESTERLY FLOW MOST OF THE SNOW WILL 
BE ALONG AND WEST OF THE CONTINENTAL DIVIDE. NO WELL ORGANIZED 
SYSTEMS ANTICIPATED SO THE SNOW FALL AMOUNTS WILL BE ON THE LIGHT 
SIDE...ESPECIALLY BECAUSE THE WESTERLY FLOW DOES NOT PRODUCE A LOT 
OF OROGRAPHIC SNOW. AREAS EAST OF THE DIVIDE ARE EXPECTED TO STAY 
DRY THROUGH THE MIDDLE PART OF NEXT WEEK DUE TO THE DOWNSLOPE FLOW. 
MODELS HINTING AT A WEAK PUSH FROM THE NORTHWEST MONDAY THAT WILL 
COOL TEMPERATURES SOME. CAN'T RULE OUT THE POSSIBILITY OF LIGHT SNOW 
MONDAY IF WINDS TURN NORTHERLY...WILL HAVE 10 POPS FOR THIS SYSTEM 
BUT EXPECT THINGS TO BE DRY. WESTERLY FLOW ALOFT WEAKENS MID NEXT 
WEEK AS AN UPPER LEVEL RIDGE DEVELOPS. THIS WILL LIKELY END ANY 
THREAT OF SNOW FOR THE MOUNTAINS.

&&

.AVIATION...VFR CONDITIONS EXPECTED TODAY AND TONIGHT.  DEVELOPING 
LEE TROF HAS CAUSED THE AIRMASS AT D.I.A. TO OSCILLATE SIGNIFICANTLY 
THIS MORNING.  SUSPECT SELY WINDS WILL REMAIN IN PLACE AS A LEE TROF 
DEVELOPS ALONG THE FRONT RANGE.  AS A RESULT...AREAS NORTH AND EAST 
OF DENVER (INCLUDING D.I.A.) MAY REMAIN STUCK IN THE COLDER AIRMASS 
TODAY WHILE DOWNSLOPE NEAR THE FOOTHILLS SHOULD MODIFY TEMPERATURES 
AT BJC AND APA.  GUSTY WLY WINDS MAY CONTINUE AT BJC THROUGH 17Z 
THAN DCRS THIS AFTN. 

&&

.BOU WATCHES/WARNINGS/ADVISORIES...WIND CHILL WARNING THROUGH       
9 AM THIS MORNING FOR THE MOUNTAINS...ZONES 31..33 AND 34.  WINTER 
WEATHER ADVISORY FOR AREAS IN AND NEAR THE FRONT RANGE FOOTHILLS 
UNTIL 11 AM THIS MORNING...ZONES 35..36..38 AND 39.

$$
COOPER/MEIER