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000
FXUS65 KBOU 100413
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
913 PM MST MON DEC 9 2013

.UPDATE...


&&

.SHORT TERM...GUSTY WINDS CONTINUE IN/BASE OF THE FOOTHILLS THIS
EVENING BUT THERE HAS BEEN A DECREASING TREND DURING THE PAST 2
HOURS. STRONGEST SUBSIDENCE HAS MOVED AWAY WHICH HELPED TO
ENHANCE THE STRONGER WINDS EARLIER THIS EVENING. CROSS SECTIONS
SHOWING STRONGEST WINDS WILL RECEED INTO THE HIGHER FOOTHILLS
OVERNIGHT. STILL COULD BE SOME GUSTY WINDS IN THE 40-60 MPH RANGE
BUT STILL DON`T THINK IT WILL BE A WIDESPREAD HIGH WIND EVENT.
WITH THESE UPDATES HAVE INCREASED WINDS AND TRENDS FOR THE REST OF
TONIGHT AND FOR HIGHER WINDS IN THE MOUNTAINS ON TUESDAY. SURFACE
GRADIENT WILL RELAX TUESDAY AFTERNOON AS WEAK FRONT WILL DIMINISH
THE GRADIENT ACROSS THE STATE.

.AVIATION...STILL QUITE WINDY AT BJC AND WILL EXTEND THE STRONG
WEST WINDS THROUGH ABOUT 08Z AND THEN DECREASE A BIT. WINDS AT DEN
WILL CONTINUE TO DECREAE AND SHIFT MORE SOUTHWEST OVERNIGHT THOUGH
THERE COULD BE AN OCCASIONAL PUFF OF WEST WINDS DURING THE NIGHT.
WEAK SURFACE FRONT WILLL MOVE ACROSS TERMINALS LATE TUE AFTERNOON
AS WINDS SHIFT NORTH AND NORTHEAST.

&&

.PREV DISCUSSION... /ISSUED 625 PM MST MON DEC 9 2013/

UPDATE...

SHORT TERM...STRONG AND GUSTY WINDS HAVE DEVELOPED IN THE LOWER
AND BASE OF FOOTHILLS WITH A FEW LOCALIZED HIGH WIND GUSTS BETWEEN
GOLDEN AND BOULDER. MOST OTHER AREAS ARE MUCH LOWER...GENERALLY IN
THE 30-50 MPH RANGE. BEING SO LOCALIZED WILL NOT ISSUE A HIGH WIND
WARNING FOR NOW. GOOD MOUNTAIN WAVE SET UP AS 00Z DENVER SOUNDING
SHOWED STRONG INVERSION AT 700MB WHILE SURFACE GRADIENT AROUND
12MB ACROSS THE STATE. QG FIELDS ALSO SHOWING VERY STRONG
SUBSIDENCE AS RAP SHOWED +50 ON THE QG VERTICAL VELOCITY FIELDS
AT 500MB. WILL WATCH THIS CLOSELY THIS EVENING IN CASE
OBSERVATIONS SHOW THE STRONGER WINDS BECOME MORE WIDESPREAD.

AVIATION...GUSTY WEST WINDS HAVE NOW SURFACED AT KDEN AND HAVE
ADDED STRONGER WINDS AT THE TERMINAL UNTIL 03Z. EXPECT GUSTY WINDS
TO CONTINUE AT BJC IN THE 25-40KT RANGE. WINDS WILL GRADUALLY
DECREASE IN BOTH LOCATIONS LATER THIS EVENING.

PREV DISCUSSION... /ISSUED 338 PM MST MON DEC 9 2013/

SHORT TERM...SUBSIDENCE BEHIND THIS MORNING`S WEAK TROUGH
COMBINED WITH INCREASING PRESSURE GRADIENT FROM GJT TO DEN AND
MIXING TO PRODUCE GUSTY WINDS ACROSS MOUNTAINS AS WELL AS IN AND
NEAR FOOTHILLS. LATEST RAP ANALYSIS SHOWING THE MAIN BATCH OF
SUBSIDENCE NOW MOVING OVERHEAD. MOST GUSTS WERE AROUND 40
MPH...THOUGH THERE WERE GUSTS AROUND 55 MPH IN WIND PRONE AREAS IN
THE FOOTHILLS OF NORTHERN JEFFERSON COUNTY. WINDS WERE LESS
FURTHER AWAY FROM THE FOOTHILLS. THE GUSTY WINDS WERE PRODUCING
SOME BLOWING SNOW...CONFINED TO OPEN AREAS. THE GUSTY WINDS WILL
PERSIST INTO THE EVENING THEN RETREAT INTO THE HIGHER FOOTHILLS BY
MIDNIGHT AS MIXING AND SUBSIDENCE WEAKENS. BUT THESE WINDS SHOULD
ALSO STRENGTHEN AS CROSS MOUNTAIN FLOW INCREASES TO AROUND 40 KTS.
THIS COULD RESULT IN GUSTS AROUND 65 MPH IN WIND PRONE AREAS. NOT
EXPECTING THE GUSTS REACHING HIGH WIND CRITERIA OF 75 MPH AT THIS
TIME. SOME BLOWING SNOW WILL BE POSSIBLE...ESPECIALLY IN OPEN
AREAS. A BIT OF MOISTURE STILL TRAPPED ACROSS THE MOUNTAIN AND
THERE MAY BE A FEW LIGHT SNOW SHOWERS OR FLURRIES. OVERNIGHT
TEMPERATURES EXPECTED TO FALL INTO THE SINGLE DIGITS ACROSS THE
PLAINS WITH BELOW ZERO READINGS IN THE HIGH COUNTRY AND LOW LYING
AREAS NEAR LIMON AND GREELEY. TEMPERATURES TO BE WARMER IN AND
NEAR FOOTHILLS DUE TO THE DOWNSLOPE WINDS. ON TUESDAY...NORTHWEST
FLOW ALOFT TO PREVAIL. THERE WILL BE SOME WARMING DUE TO UPPER
LEVEL RIDGE BUILDING ACROSS THE GREAT BASIN AND DOWNSLOPE WINDS
ALONG FOOTHILLS. TEMPERATURES ACROSS THE PLAINS TO WARM INTO THE
LOWER 30S...WITH UPPER 20S IN THE LOW LYING AREAS. MOUNTAIN AREAS
SHOULD WARM INTO THE TEENS BUT GUSTY WINDS WILL KEEP WIND CHILL
READINGS BELOW ZERO. GUIDANCE VALUES STILL A BIT OPTIMISTIC WITH
THE WARMUP. SOME MOISTURE AND WEAK LIFT MOVES INTO THE NORTHERN
MOUNTAINS...ENOUGH FOR A SLIGHT CHANCE OF LIGHT SNOW. ANY
ACCUMULATIONS TO BE MINIMAL.

LONG TERM...WEATHER THE NEXT WEEK WILL BE DOMINATED BY A RIDGE
OVER COLORADO. WEAK RIPPLES COMING NORTH OF US IN WESTERLY FLOW
AND A WEAK LOW PASSING WELL SOUTH OF US. ALL OF THESE THINGS
CONTINUE TO GET WEAKER WITH SUBSEQUENT MODEL RUNS AND SHOULD NOT
HAVE MUCH EFFECT ON OUR WEATHER. THERE WILL BE A CHANCE OF LIGHT
SNOW IN THE MOUNTAINS WITH THE TAIL END OF THE NORTHERN SHORT
WAVES...AND WEAK SURGES OF COOL AIR FROM THE NORTH AS WELL. THESE
WILL COME ABOUT FRIDAY AND AGAIN ON SUNDAY OR MONDAY...BRINGING
A LITTLE COOLING...OR DELAYING THE WARMING...EACH DAY. BY THE END
OF THE WEEK THE AIR ALOFT WILL BE QUITE WARM...BUT THE LOW LEVELS
WILL LAG BEHIND. ALL OF THIS IS WELL COVERED IN THE CURRENT
FORECAST AND THE MODEL CONSENSUS LOOKS GOOD.

AVIATION...WESTERLY WINDS HAVE PUSHED ACROSS THE AREA
AIRPORTS WITH GUSTS AROUND 35 KTS AT KBJC. WINDS MUCH LESS AT KDEN
AND KAPA...AROUND 12 KTS. WINDS AT KDEN AND KAPA WILL TRANSITION
TO DRAINAGE BY 02Z...REMAINING WESTERLY AT KBJC. SOME GUSTS COULD
AGAIN REACH 35 KTS AT KBJC OVERNIGHT. ON TUESDAY...WINDS WILL
WEAKEN AND BECOME NORTHWEST BY 17Z...SPEEDS AROUND 8 KTS. VFR TO
CONTINUE WITH UNLIMITED CEILINGS.

&&

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

$$

SHORT TERM...ENTREKIN
LONG TERM....GIMMESTAD
AVIATION...ENTREKIN