Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 181719
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1019 AM MST TUE NOV 18 2014

.UPDATE...
ISSUED AT 1019 AM MST TUE NOV 18 2014

NO CHANGES TO THE FORECAST NECESSARY AT THIS TIME. WINDS OVER THE
MOUNTAINS HAVE DECREASED SOME FROM EARLIER THIS MORNING...BUT WE
ARE WAITING FOR THE NEXT UPPER LEVEL JET TO MOVE OVER THE AREA
OVER THE NEXT FEW HOURS. SHOULD SEE THE WINDS INCREASE THORUGH THE
AFTERNOON AS THE MOUNTAIN WAVE AMPLIFIES WITH THE APPROACH OF THE
UPPER JET. THE GUSTY WINDS IN THE FOOTHILLS WILL BE THE MAIN STORY
INTO THIS EVENING. HIGH CLOUDS ARE ALSO BEGINNING TO INCREASE AS
UPPER LEVEL MOISTURE ASSOCIATED WITH THE APPROACHING JET MOVES IN
FROM THE NORTH.

UPDATE ISSUED AT 541 AM MST TUE NOV 18 2014

UPGRADED THE HIGH WIND WATCH TO A WARNING IN THE FOOTHILLS AND
WILL START THE WARNING NOW...GIVEN WINDS ALREADY HAVE GUSTED UP
AROUND 60 MPH WEST OF BOULDER. WINDS WILL FLUCTUATE THIS AM WHERE
SOME TIME PERIODS WILL HAVE LIGHTER WINDS FOLLOWED BY MUCH
STRONGER WINDS . AT THE MOMENT THERE IS A BIT OF A LULL WITH
WINDS MAINLY UNDER 50 MPH.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 330 AM MST TUE NOV 18 2014

MAIN CONCERN TODAY AND TONIGHT IS WITH THE HIGH WIND POTENTIAL IN
THE FRONT RANGE FOOTHILLS. OBSERVATIONS ALREADY SHOWING A SLOW
INCREASE IN THE WINDS OVERNIGHT WITH GUSTS IN THE 40-60 MPH
RANGE. HIGHEST GUST SO FAR WAS 60 MPH AT WONDERVU OVER COAL CREEK
CANYON. EXPECT THESE WINDS TO INCREASE EVEN FURTHER THIS AM AND
AFTERNOON WITH INCREASING STABILITY AND STRONG DEVELOPING STABLE
LAYER AROUND 700MB. THIS ALREADY EVIDENT FROM RADIOMETRIC SOUNDING
AT BOULDER AT 09Z. IN ADDITION...POTENTIAL FOR A NARROW WINDOW OF
A MEAN STATE CRITICAL LAYER THIS MORNING AS MID LEVEL FLOW BECOMES
MORE NORTHERLY.  4KM WRF SHOWING GUSTS NEARING 90 MPH AT SEVERAL
POINTS IN WESTERN BOULDER CO TODAY AND THIS EVENING. NAM CROSS
SECTIONS INDICATE STRONGEST CROSS BARRIER FLOW FROM 18Z-03Z TNT
WITH FLOW OF 40-55KT. THIS EVENT STILL SEEMS BORDERLINE BUT DO
EXPECT WINDS TO REACH HIGH WIND CRITERIA IN WIND PRONE AREAS BUT
CERTAINLY NOT WIDESPREAD. WILL GO AHEAD AND UPGRADE THE WATCH TO
A WARNING BUT MAY START THE WARNING AS EARLY AS 15Z CONSIDERING
THE INCREASING WINDS ALREADY OCCURRING.

GIVEN THE INCREASING DOWNSLOPE WINDS EXPECT TEMPERATURES TO BE
MUCH WARMER TODAY...ESPECIALLY IN LOCATIONS IN AND NEAR THE
FOOTHILLS AND ADJACENT PLAINS. MAIN CHANGE TO FORECASTS WAS TO
INCREASE TEMPERATURES THIS AFTERNOON. MAY SEE SOME LOCATIONS INTO
THE MID 50S AT THE BASE OF THE FOOTHILLS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 115 AM MST TUE NOV 18 2014

...SNOW RETURNS TO THE MOUNTAINS THIS WEEKEND...

FOR WEDNESDAY AND THURSDAY...STRONG NORTHWEST FLOW DOMINATES AS AN
UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE BUILDS IN FROM THE
WEST. WINDS FROM AN UPPER LEVEL JET AND STRONG GRADIENT WILL
START TO RELAX BY WEDNESDAY AFTERNOON WITH WINDS GUSTING 30 TO 35
OVER THE HIGHER MOUNTAIN PASSES. TEMPERATURES FOR THESE DAYS WILL
BE CLOSER TO SEASONAL NORMALS THAN WE HAVE SEEN LATELY AND WILL
CONTINUE INTO THE WEEKEND. WITH THE DRIER AIRMASS IN PLACE WE WILL
BE PRECIPITATION FREE WITH PARTLY CLOUDY SKIES OVER THE PLAINS
THROUGH THURSDAY. FOR THE MOUNTAINS MOISTURE ASSOCIATED WITH A
WEAK TROUGH MOVING THROUGH THE WEST STARTING THURSDAY AFTERNOON
WILL BRING MOSTLY CLOUDY SKIES AND A SLIGHT CHANCE OF LIGHT SNOW
FOR THE HIGH COUNTRY INTO FRIDAY.

FRIDAY WILL SEE LIGHT SNOW IN THE MOUNTAINS WITH THE PLAINS
REMAINING FREE OF ANY PRECIPITATION DUE TO A LEE SURFACE TROUGH IN
PLACE AND SOUTHERLY DRAINAGE FLOW. AS THE TROUGH MOVES EAST
SURFACE HIGH PRESSURE MOVES BACK INTO THE WEST BRINGING AN
INCREASED GRADIENT AND WINDS TO THE MOUNTAINS AND HIGHER
FOOTHILLS.

FOR THE WEEKEND MOIST ZONAL FLOW ON SATURDAY WILL CHANGE TO
COOLER NORTHWEST FLOW ON SUNDAY WHICH WILL BE FAVORABLE FOR MORE
MOUNTAIN SNOW WITH DECENT OROGRAPHIC AND CAA ALOFT. AS THE LEE
TROUGH OVER THE PLAINS ON SUNDAY BREAKS DOWN BY SUNDAY EVENING
SOME SNOW COULD MAKE IT ONTO THE PLAINS OVERNIGHT INTO MONDAY.
HAVE KEPT SLIGHT CHANCE POPS FOR THE PLAINS WHILE KEEPING AREAS
NEAR THE FOOTHILLS CLEAR DUE TO STRONGER DRAINAGE IN THAT AREA.

MONDAY WILL BE COOLER WITH THE PASSAGE OF THE COLD FRONT BUT
OTHERWISE TEMPERATURES THIS WEEK WILL RETURN TO SEASONAL NORMALS
WITH HIGHS IN THE UPPER 40S AND LOWER 50S AND LOWS A TAD COOLER
IN THE TEENS.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1019 AM MST TUE NOV 18 2014

NO AVIATION IMPACTS FROM CEILINGS OR VISIBILITIES...BUT GUSTY WEST
WINDS AT TIMES MAY BE ENOUGH TO IMPACT AIRPORT OPERATIONS AT
TIMES. WITH THE LEE TROUGH IN PLACE OVER NORTHEAST COLORADO AND
INCREASING WINDS EXPECTED OVER THE MOUNTAINS THIS
AFTERNOON...EXPECT WESTERLY WINDS TO SPREAD ACROSS THE BULK OF THE
DENVER METRO AREA. TREND IN THE CURRENT TAF IS GOING TO BE
FOLLOWED WITH THE NEW ISSUANCE.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR COZ035-036.

&&

$$

UPDATE...DANKERS
SHORT TERM...ENTREKIN
LONG TERM...BOWEN
AVIATION...DANKERS



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