FXUS65 KBOU 092102
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
200 PM MST WED DEC 09 2009

.SHORT TERM...MAIN CONCERN OVER THE NEXT 24 HOURS WILL BE HIGH WIND 
POTENTIAL FOR THE MOUNTAINS AND EAST SLOPES AND HOW MUCH WIND 
REFLECTION WILL OCCUR ON THE PLAINS. ALREADY SOME STRONGER WINDS 
HAVE MIXED DOWN ON THE ADJACENT PLAINS AS A MIDDLE LEVEL SPEED MAX 
PASSED OVER...WHICH SHOWED UP WELL IN THE RUC CROSS SECTIONS. THERE 
IS A WEAK UPPER LEVEL WAVE OVER THE NORTHERN ROCKIES WHICH WILL MOVE 
ACROSS OUR NORTHERN MOUNTIANS TONIGHT WITH INCREASING MOISTURE THIS 
EVENING. MOISTURE DEPTH STILL NOT THAT DEEP BUT WITH STRONG 
OROGRAPHICS...MAY BE ABLE TO SQUEEZE OUT 1-2 INCHES OF SNOW. BEHIND 
THE WAVE...STRONGER SUBSIDENCE KICKS IN AFTER MIDNIGHT AS SHOWN IN 
THE QG VERTICAL VELOCITY FIELDS. CROSS SECTIONS SHOW WINDS 
INCREASING AGAIN OVER THE EAST SLOPES WITH CROSS BARRIER COMPONENT 
OF 50-60KT. GIVEN THE STRONG SHEARED ENVIORNMENT WITH A JET 
OVERHEAD...AN AMLIFIED MOUNTAIN WAVE IS NOT LIKELY AND THE STRONGEST 
WINDS SHOULD BE CONFINED TO THE HIGHER EAST SLOPES. SURFACE GRADIENT 
ALSO TIGHTENS UP OVERNIGHT BUT GENERALLY UNDER 10 MB ACROSS THE 
STATE. ABOVE PARAMETERS FAIRLY MARGINAL FOR A WIDESPREAD WIND EVENT 
SO WON'T ISSUE ANY HIGH WIND WARNING. WON'T BE SUPRISED THOUGH IF WE 
RECEIVE A COUPLE OF HI WINDS AROUND 70KT. THERE IS AN ONGOING WIND 
CHILL WARNING FOR THE MOUNTAINS AND WILL KEEP THAT GOING THROUGH TNT 
IN COMBINATION WITH THE STRONG WINDS AND COLD TEMPERATURES REMAINING 
BELOW ZERO ABOVE TIMBERLINE. WILL ALSO ADD SOME BLOWING SNOW TO THE 
WEATHER GRIDS FOR THE FOOTHILLS AS THERE SHOULD STILL BE AREAS OF 
BLOWING SNOW OVER EXPOSED AREAS.   

.LONG TERM...COLD AND BRISK NORTHWEST FLOW ALOFT WILL CONTINUE OVER 
THE AREA THURSDAY NIGHT...GRADUALLY GIVING WAY TO MORE ZONAL 
CONDITIONS BY FRIDAY NIGHT.  THE MODELS SHOW A DEVELOPING WAVE 
PASSING BY EARLY ON SATURDAY WITH A MORE SUBSTANTIAL ONE PROGGED TO 
AFFECT THE STATE LATER SATURDAY AND EARLY SUNDAY.  WITH THE LACK OF 
ANY SIGNIFICANT UPSLOPE...PRECIPITATION FROM THESE SYSTEMS WILL MOST 
LIKELY BE CONFINED TO THE HIGH COUNTRY WHERE PRETTY DECENT SNOW MAY 
FALL WITH THE SECOND WAVE SATURDAY NIGHT INTO SUNDAY.  MODERATE TO 
STRONG WEST TO NORTHWEST WINDS IN THE MOUNTAINS WILL ALSO BE RATHER 
PERSISTENT THROUGH MUCH OF THE PERIOD...OCCASIONALLY MAKING THEIR 
WAY IN TO THE FOOTHILLS AND PLAINS LOCALES CLOSE TO THE FOOTHILLS.  
TEMPERATURES WILL MAKE A GRADUAL CLIMB UPWARDS TOWARDS NORMAL 
THROUGH THE REST OF THE WEEK AND MAY ACTUALLY STAY THERE INTO EARLY 
NEXT WEEK.  

&&

.AVIATION...VFR CONDITIONS EXPECTED THROUGH TONIGHT. GENERAL 
DRAINAGE WINDS EXPECTED AT DEN/APA TNT BUT EXPECT ANOTHER PUFF OF 
WEST WINDS AT BJC LATER TNT AS SFC GRADIENT INCREASES BEHIND THE 
WAVE. GUSTS UP TO 30KT POSSIBLE AT BJC BETWEEN 06Z-16Z.  

&&

.BOU WATCHES/WARNINGS/ADVISORIES...WIND CHILL WARNING THROUGH       
THURSDAY MORNING MOUNTAINS...ZONES 31..33 AND 34.      

$$
SWE/ET