RSS FeedsIssued by NWS Denver/Boulder, CO
000 FXUS65 KBOU 230942 AFDBOU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 242 AM MST MON NOV 23 2009 .SHORT TERM...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA THRU MIDDAY WITH SOME DECENT QG ASCENT IN THE MID LVLS. THIS SYSTEM IS ALREADY PRODUCING SNOW IN THE MTNS AND WILL CONTINUE TO DO SO THROUGH THE LATE MORNING HOURS. MAIN HEADACHE FOR TODAY IS OVER NERN CO. A COLD FRONT WILL MOVE ACROSS NERN CO LATER THIS MORNING WITH NNW LOW LEVEL FLOW. AS THIS FNT MOVES ACROSS AND COMBINES WITH PASSAGE UPPER LEVEL TROUGH AND QG ASCENT COULD SEE A BRIEF PERIOD OF ENHANCED SNOW SHOWER ACTIVITY OVER THE PLAINS WHICH COULD DROP A QUICK INCH OF SNOW IN A FEW SPOTS FROM MID MORNING THRU THE EARLY AFTN HOURS. LATEST RUC KEEPS MOST OF THIS PCPN EAST IF THE I-25 URBAN CORRIDOR HOWEVER IF LOW LEVEL WINDS BRIEFLY BECOME MORE NNE FOR AN HOUR OR TWO THAT COULD LEAD TO SOME SNOW FROM DENVER SOUTH TO THE PALMER DIVIDE. THUS WILL MENTION CHC POPS FOR THRU 18Z FOR ALL OF NERN CO AND MENTION SOME MINOR ACCUMULATIONS. BY THIS AFTN THE SYSTEM IS FCST TO MOVE RAPIDLY SE AND INTENSIFY OVER SWRN NE/NWRN KS. THUS COULD SEE SOME LINGERING SNOW OVER THE FAR NERN CORNER THRU LATE AFTN WITH DRYING CONDITIONS ALONG THE FRONT RANGE AS NWLY DOWNSLOPE LOW LEVEL FLOW OCCURS. IN THE MTNS MOISTURE IS FCST TO LINGER THRU THE AFTN HOURS AND WITH NWLY FLOW IN PLACE MAY STILL SEE SOME LIGHT OROGRAPHIC SNOWS. TEMPERATURES WILL BE QUITE A BIT COLDER BEHIND THE FRONT WITH HIGHS MAINLY IN THE UPPER 30S TO LOWER 40S ACROSS NERN CO. FOR TONIGHT THE UPPER LEVEL TROUGH WILL MOVE AWAY FROM THE AREA WITH DRIER AIR SPREADING ACROSS THE ENTIRE AREA. HOWEVER COULD STILL SEE A FEW LINGERING -SHSN IN THE MTNS AND OVER THE FAR NERN CORNER EARLY THIS EVENING BEFORE PCPN ENDS. .LONG TERM...WEAK RIDGING ALOFT WILL MOVE OVER COLORADO ON TUESDAY WITH DRY AND WARMER CONDITIONS. THE NEXT DISTURBANCE WILL DIVE INTO THE CENTRAL PLAINS ON WEDNESDAY AND BRUSH THE FAR NORTHEAST PLAINS OF COLORADO. THE GFS PRESENTS A BIT MORE MSTR AND EVEN SOME LIGHT QPF OVER THE FAR PLAINS WHERE THE NAM IS DRIER. WILL ADD A 10 POP OVER THE FAR NERN CO ZONES FROM LATE TUE NIGHT AND WED AM. BROAD...LARGE SCALE RIDGING BUILDS ACROSS THE STATE ON THURSDAY AND FRIDAY WITH DRY CONDITIONS AND WARMING TEMPS. FOR THE WEEKEND TIME PERIOD...THE NEXT UPPER LEVEL DISTURBANCE MOVES ACROSS COLORADO BUT THERE IS STILL A LOT OF UNCERTAINTY WITHIN THE LONG RANGE MODELS. THE EUROPEAN MODEL DIGS MORE ENERGY INTO THE DESERT SOUTWEST WHILE THE GFS STILL SHOWING A WIDE VARIETY OF SOLUTIONS AMONGST ITS ENSEMBLE MEMBERS. DESPITE THE UNCERTAINTY WILL ADD AT LEAST A SLIGHT CHC FOR THE MTNS AND COOLER TEMPS FOR ENTIRE CWA. && .AVIATION...TRICKY FCST FOR THE MID MORNING HOURS AS PASSAGE OF COLD FRONT AND UPPER LEVEL TROUGH COULD PRODUCE A 1-2 HOUR WINDOW OF STEADIER SNOW BETWEEN 14Z-16Z WHICH COULD BRIEFLY PRODUCE UP TO AN INCH OF SNOW ALONG WITH LOW CEILINGS AND VISIBILITIES IF PCPN DOES DVLP. THIS SYSTEM WILL MOVE ACROSS RATHER QUICKLY SO CONDITIONS SHOULD IMPROVE BY 17Z I WOULD THINK. WINDS WITH THE FRONT WILL BE OUT OF THE NNW IN THE 15-20 MPH RANGE WITH A FEW GUSTS TO 25 MPH POSSIBLE. BY EARLY THIS EVENING WINDS WILL QUICKLY DIMINISH WITH WINDS BECOMING DRAINAGE AFTER 03Z. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. $$ RPK/SWE
