FXUS65 KBOU 091218 CCA
AFDBOU

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

CORRECTED RECORD LOW AT DENVER TODAY IS -20

.SHORT TERM...COLD TEMPERATURES THE MAIN STORY TODAY AS MOST 
LOCATIONS ARE HAVING THEIR COLDEST MORNING OF THE YEAR. NEAR RECORD 
LOW OF -17 AT DIA AS OF 5 AM 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