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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS65 KBOU 121013
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
313 AM MST THU DEC 12 2013

.SHORT TERM...
-- Changed Discussion --
DRY WNW FLOW ALOFT WILL BE OVER THE AREA TODAY THRU
TONIGHT. MAIN CONCERN FOR TODAY WILL BE HIGHS OVER NERN CO. SNOW
COVER STILL EXISTS OVER ERN LARIMER INTO CENTRAL WELD AND OVER THE
PALMER DIVIDE. OVERALL LOW LEVEL WINDS FIELDS WILL BE LIGHT SO
THERE WILL NOT BE MUCH OF A DOWNSLOPE COMPONENT OVER THE PLAINS
ALTHOUGH THERE WILL BE PLENTY OF SUN. SO THE BIG QUESTION IS WILL
THE LOW LEVEL INVERSIONS BE BKN OR NOT AS THERE WILL BE 5 TO 6
DEGREES C OF WARMING JUST ABV THE SFC.

THE NAM AND GFS PRETTY MUCH SHOW NO INVERSIONS ANYWHERE WITH
READINGS IN THE 40S ACROSS THE PLAINS WITH HIGHS IN THE LOWER 50S
AROUND DENVER.  MEANWHILE THE HRRR AND TO SOME EXTENT THE RAP SHOW
INVERSIONS NOT BREAKING IN THE SNOW COVERED AREAS AS READINGS HOLD
IN THE 30S.  IN ADDITION THE HRRR SHOWS QUITE A CONTRAST OVER THE
DENVER METRO AREA WITH READINGS NEAR 50 OVER THE SRN SUBURBS WHILE
IN NRN AREAS HIGHS STAY IN THE 35 TO 40 RANGE.  THERE MAY END UP
BEING A WK DENVER CYCLONE WHICH ALLOWS FOR NLY SFC FLOW OVER THE NRN
SUBURBS THAT ALLOWS FOR SOME OF THE COOLER SFC TEMPS OVER WELD
COUNTY TO MOVE SOUTH SO CAN NOT COMPLETELY IGNORE WHAT THE HRRR
SHOWS. FOR NOW WILL KEEP READINGS COOLER THAN GUIDANCE FROM NORTH
OF DENVER TO FORT COLLINS TO GREELEY AND TOWARDS LIMON. FURTHER
SOUTH WILL HAVE HIGHS IN THE 45 TO 50 DEGREE RANGE AND OVER THE
FAR NERN CORNER.


.LONG TERM...MODELS HAVE A COUPLE WEAK UPPER TROUGHS TO MOVE
ACROSS THE CWA. BOTH WITH SLIGHTLY COOLER AIMASSES. THE FIRST ON
FRIDAY MORNING...THEN ANOTHER FRIDAY NIGHT LATE/EARLY SATURDAY
MORNING. BY SATURDAY AFTERNOON AND NIGHT...FAIRLY STRONG
NORTHERLY FLOW ALOFT IS PROGGED. THERE IS WEAK UPWARD SYNOPTIC
SCALE ENERGY PROGGED FOR THE CWA FRIDAY INTO FRIDAY NIGHT...THEN
ALL DOWNWARD MOTION SATURDAY AND SATURDAY NIGHT. THE LOW LEVEL
WINDS ARE PROGGED TO GO TO UPSLOPE FRIDAY AFTERNOON AND EVENING.
MORE NORMAL DIURNAL PATTERNS ARE PROGGED FOR SATURDAY. FOR
MOISTURE...IN INCREASES SOMEWHAT FRIDAY...WITH THE BEST FRIDAY
EVENING OVER THE MOUNTAINS. MOISTURE DRIES OUT LATE FRIDAY
NIGHT...AND THERE ISN`T MUCH SATURDAY OR SATURDAY NIGHT. THE QPF
FIELDS SHOW A TINY AMOUNT OF MEASURABLE SNOWFALL OVER THE HIGH
MOUNTAINS FRIDAY EVENING...BUT ONLY ON THE GFS. WILL KEEP POPS IN
FRIDAY NIGHT...MOSTLY OVER JUST THE HIGH MOUNTAINS. FOR
TEMPERATURES...FRIDAY`S HIGHS ARE 2-4 C COOLER THAN TODAY`S.
SATURDAY`S ARE SIMILAR TO FRIDAY`S. FOR THE LATER DAYS...SUNDAY
THROUGH WEDNESDAY...MODELS KEEP MODERATE NORTHWESTERLY FLOW ALOFT
FOR THE CWA SUNDAY AND MONDAY. ON TUESDAY AND WEDNESDAY IT IS
WEST-NORTHWESTERLY AND INCREASES IN SPEED....ESPECIALLY ON THE
GFS. THE GFS BRINGS A JET MAXIMUM OVER THE CWA...THE ECMWF KEEPS
IT WELL NORTH AND NORTHEAST. MOISTURE IS LACKING ALL FOUR DAYS.
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
VFR TODAY AND TONIGHT. WINDS WILL BE LIGHT SLY THIS
MORNING AND MORE SSW AFTER SUNRISE. FOR THIS AFTN THERE MAY BE A
WK DENVER CYCLONE WITH WINDS BECOME MORE NNE AFTER 20Z. BY 00Z
WINDS MAY BECOME MORE ESE AND THEN BACK TO DRAINAGE BY 02Z.
-- End Changed Discussion --


&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...RPK
LONG TERM....RJK
AVIATION...RPK