FXUS65 KBOU 091121
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
410 AM MST WED DEC 9 2009

.SHORT TERM...COLD TEMPERATURES THE MAIN STORY TODAY AS MOST 
LOCATIONS ARE HAVING THEIR COLDEST MORNING OF THE YEAR. RECORD LOW 
OF -16 AT DIA WHILE MOST OF THE CITY HAS BEEN IN THE -5 TO -10 
RANGE. STRETCHING THE DEFINITION...BUT I WILL ISSUE A WIND CHILL 
ADVISORY FOR THIS MORNING AS EVEN THE SLIGHT DRAINAGE WIND OVER THE 
EASTERN SUBURBS IS PUSHING THE WIND CHILL DOWN TO -30. MORE SERIOUS 
CONDITIONS IN THE HIGHER MOUNTAINS AS STRONG WEST WINDS ALOFT WILL 
CONTINUE. WINDS HAVE BEEN GUSTING IN THE 40 TO 60 MPH RANGE ALONG 
THE CREST OF THE DIVIDE...WITH TEMPERATURES AROUND -15. THE VALLEYS 
ARE WARMER WITH NOT MUCH WIND...BUT THE ZONE BETWEEN 10 THOUSAND 
FEET AND TIMBERLINE SHOULD HAVE ENOUGH WIND TO HAVE DANGEROUS WIND 
CHILLS. SO I AM ISSUING THE RARE WIND CHILL WARNING FOR THE HIGH 
MOUNTAIN ZONES THROUGH THURSDAY MORNING WHEN TEMPERATURES SHOULD BE 
WARMING. I TRIMMED HIGHS A LITTLE EVERYWHERE...A BIT MORE ON THE 
NORTH AND EAST SIDE OF DENVER AS THE COLD AIR SHOULD HOLD ON THERE 
WITH LIGHT WINDS TODAY. CUT LOWS AGAIN TONIGHT AS THERE IS NOT MUCH 
WARMING...IT SHOULD BE A BIT WARMER THAN THIS MORNING BUT THE ONLY 
AREAS WITH BIG CHANGES SHOULD BE ALONG THE FOOTHILLS WHERE THERE 
WILL BE SOME DRAINAGE WIND TONIGHT. WILL PLAY THE WINDS SPREADING 
DOWN THE EAST SLOPES WITH TIME...JUST A GRADUAL EROSION OF THE 
INVERSION FROM ABOVE. SOME CLOUDS AND LIGHT SNOW LINGER ON THE 
DIVIDE...BUT VERY SHALLOW MOISTURE. THAT MAY BE REINFORCED AS A 
SHORTWAVE PASSES TO THE NORTH THIS AFTERNOON...THEN IT SHOULD DRY 
FURTHER TONIGHT.

.LONG TERM...FOR THURSDAY...MAIN CONCERN WILL BE STRONG WINDS AND 
COLD WIND CHILLS IN THE HIGH COUNTRY.  SPATIAL CROSS-SECTIONS STILL 
INDICATE A STRONG CROSS-MOUNTAIN WIND COMPONENT OF 50 KTS THROUGH 
THURSDAY MORNING...GRADUALLY WEAKENING IN THE AFTN.  WILL ALLOW THE 
WIND CHILL WARNING ISSUED BY THE SHORT TERM GUY TO CARRY OVER INTO 
THURSDAY MORNING FOR ZONES 31..33 AND 34.  ALTHOUGH ANY LINGERING 
SNOW SHOULD BE A DONE DEAL BY 18Z THURSDAY...AREAS OF BLOWING SNOW 
WILL CONTINUE OVER THE HIGHER MOUNTAIN PASSES.  AS FOR THE NORTHEAST 
PLAINS...TEMPERATURES START TO MODIFY SOMEWHAT BUT IN A SCROOGE LIKE 
MANNER (BURRR HUMBUG) ESPECIALLY IN THE GREELEY...STERLING 
LOCATIONS.  BETTER WARMUP WILL OCCUR ON FRIDAY AND SATURDAY. 
ADJUSTMENTS TO THE GRIDS INVOLVED DROPPING THE TEMPERATURES IN THE 
MOUNTAINS VALLEYS AND A FEW PLAINS LOCATIONS THURSDAY NIGHT BY A FEW 
DEGREES.  OTHERWISE LEFT MUCH OF THE EXTENDED UNTOUCHED.  ZONAL FLOW 
WILL BE IN PLACE BY THE END OF THE WEEK...A SOME WEAK EMBEDDED 
DISTURBANCES SLIPPING ACROSS THE STATE...THE FIRST OF WHICH WILL BE 
LATE FRIDAY NIGHT/SATURDAY MORNING...WITH THE MAIN TROF AXIS NOT 
EXPECTED UNTIL SOMETIME MONDAY.  PRIMARY RECIPIENT OF ANY SNOW  
WILL BE IN THE HIGH COUNTRY...WHILE THE PLAINS SHOULD STAY DRY.    

&&

.AVIATION...VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...WIND CHILL WARNING THROUGH 
      THURSDAY MORNING MOUNTAINS...ZONES 31..33 AND 34.
     WIND CHILL ADVISORY UNTIL 9 AM DENVER METRO AREA...ZONES
      39 AND 40.

$$
GIMMESTAD/COOPER