Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 160423
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
923 PM MST MON DEC 15 2014

.UPDATE...
ISSUED AT 922 PM MST MON DEC 15 2014

STRONG GUSTY NWLY WINDS ON THE NORTHEAST PLAINS FOR MOST OF THE
DAY HAVE WEAKENED CONSIDERABLY IN THE PAST COUPLE OF HOURS WITH
DECOUPLING OF THE BOUNDARY LAYER. HIGH COUNTRY WINDS HAVE ALSO
EASED THIS EVENING IN RESPONSE TO LIGHTER WINDS ALOFT WITH
PASSAGE OF A MID-LEVEL SHORTWAVE HIGH PRESSURE RIDGE. IN ADDITION...
SKIES THIS EVENING WERE NEARLY CLOUD-FREE ACROSS THE CWA BUT THAT
WILL SOON CHANGE WITH THE LEADING EDGE OF A HIGH CLOUD SHIELD
APPROACHING FROM THE SOUTHWEST. WITH CLEAR SKIES AND LIGHT
BREEZES...SHOULD SEE A STEADY DROP OFF IN TEMPERATURES...AT LEAST
UNTIL THE HIGH CLOUDS SPREAD OVER THE AREA. IN AREAS WITH
EXTENSIVE SNOW COVER...SUCH AS ACROSS THE NORTHEAST CORNER OF THE
STATE AND EASTERN PORTIONS OF THE PALMER DIVIDE...COULD SEE THE
MERCURY FALLING TO THE TEENS AND UPPER SINGLE DIGITS WITHIN THE
NEXT FEW HOURS. MEANWHILE TEMPERATURES ALREADY DOWN INTO THE
SINGLE DIGITS ABOVE ZERO IN THE HIGH MTN VALLEYS. AS LONG AS
SKIES REMAIN CLEAR...TEMPERATURES IN THESE SAME AREAS COULD FALL
BELOW ZERO. HOWEVER ONCE SKIES BEGIN TO FILL WITH CLOUDS AND WITH
THE ARRIVAL OF WARMER AIR ALOFT...MAY SEE READINGS IN THESE SAME
AREAS CREEPING UP. SHOULD NOT SEE ANY PRECIP FALLING FROM THE
APPROACHING CLOUDS EXCEPT PERHAPS OVER THE HIGHER PEAKS TOWARDS
MORNING WITH CLOUD BASES LOWERING TO MTN TOP LEVEL.

CHANGES TO CURRENT FORECAST PACKAGE THIS EVENING INCLUDE
ACCELERATING THE DEVELOPMENT OF DOWNSLOPE/DOWNVALLEY WINDS IN AND
ALONG THE FRONT RANGE...MINOR ADJUSTMENTS TO HOURLY AND OVERNIGHT
MINIMUM TEMPERATURES AND TO BETTER ACCOUNT FOR THE ADVANCING HIGH
CLOUD SHIELD.

&&

.SHORT TERM...(THIS AFTERNOON THROUGH TUESDAY)
ISSUED AT 1122 AM MST MON DEC 15 2014

THE SNOW OVER THE PLAINS HAS ALMOST ENDED...BUT THE STRONG NORTH-
NORTHWESTERLY LOW LEVEL WINDS ARE GUSTING UP TO 35 KNOTS. THERE IS
VERY LITTLE TO NO SNOW FALLING IN THE MOUNTAINS. MODELS SHOW AN
UPPER RIDGE TO SLIDE ACROSS THE CWA TONIGHT AND TUESDAY. THE FLOW
ALOFT IS DUE WESTERLY TONIGHT...THEN WEST-SOUTHWESTERLY BY
TUESDAY AFTERNOON. AFTER SUNSET TONIGHT...THE STRONG WINDS OVER
THE PLAINS WILL RELAX WITH TONIGHT`S WIND FIELDS ADHERING TO
DIURNAL PATTERNS. THE PLAINS LOOK TO HAVE SOUTHEASTERLIES ON
TUESDAY WITH A WEAKER PRESSURE GRADIENT OVER THE REST OF THE CWA.
FOR MOISTURE...MODELS SHOW IT TO INCREASE AFTER MIDNIGHT FROM
WEST TO EAST. SATELLITE PICTURES CONFIRM THIS. ON TUESDAY...THERE
IS FAIRLY DECENT MOISTURE WEST OF THE DIVIDE AND IN THE MOUNTAINS
...AND THERE IS QUITE A BIT IN THE MID AND UPPER LEVELS FOR THE
PLAINS. MOISTURE LOOKS DEEP ENOUGH IN THE MOUNTAINS ALONG WITH
SOME OROGRAPHICS TO WARRANT "CHANCE" POPS OF SNOW THERE. THERE IS
EVEN SOME MINOR MEASURABLE SNOWFALL AMOUNTS ON THE QPF FIELDS IN
THE MOUNTAINS ON TUESDAY. NO POPS FOR THE PLAINS TONIGHT AND
TUESDAY. NONE FOR THE MOUNTAINS TONIGHT...THEN SOME AS MENTIONED
ABOVE FOR THE MOUNTAINS ON TUESDAY. FOR TEMPERATURES...SHOULD BE
FAIRLY COLD OUT ON THE PLAINS WHERE THE SNOW FIELD IS IN PLACE
AFTER THE WINDS SUBSIDE LATER THIS EVENING. TUESDAY`S HIGHS ARE
1-3 C WARMER THAN TODAY`S HIGHS.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1122 AM MST MON DEC 15 2014

...NEAR SEASONAL TEMPERATURES WITH A FEW WEAK DISTURBANCES FOR
THE WEEK AHEAD...

THE NEXT UPPER LEVEL DISTURBANCE OVER THE WEST COAST WILL BRING
INCREASED MOISTURE AHEAD OF IT INTO COLORADO. THIS MOISTURE
COMBINED WITH DECENT OROGRAPHIC SW FLOW WILL BRING LIGHT
SNOWSHOWERS TO THE MOUNTAINS STARTING LATE TUESDAY EVENING AND
THROUGH THE DAY WEDNESDAY. MOISTURE MOVES OVER THE PLAINS
WEDNESDAY AFTERNOON AND COMBINING WITH MORE DECENT QG ASCENT COULD
BRING SOME LIGHT SNOW. HOWEVER THE BULK OF THE SYSTEM`S ENERGY
STAYS WELL TO THE SOUTH WITH SOME SURFACE RIDGING SO WILL KEEP
POPS LOW.

FOR FRIDAY AND SATURDAY STRONG NW FLOW DOMINATES WITH RIDGING
MOVING IN BY FRIDAY AFTERNOON. THIS RIDGING WILL BRING SLIGHTLY INCREASED
TEMPERATURES AND SOME MINOR CLEARING OVER THE PLAINS ON SATURDAY.
THE RIDGING IS SHORT LIVED AS THE NEXT SYSTEM DROPS OUT OF THE NW
AND MAKES IT WAY INTO CENTRAL UTAH BY SATURDAY EVENING. BY SUNDAY
MORNING THE MODELS START DIVERGING AT THIS POINT ON THE INTENSITY
AND PLACEMENT OF THE SYSTEM`S ENERGY BUT KEPT LOW POPS FOR THE
MOUNTAINS WITH NW FLOW AND COOLER TEMPERATURES OVER THE CWA ON
SUNDAY INTO MONDAY.

&&

.AVIATION...(FOR THE TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 922 PM MST MON DEC 15 2014

A LIGHT DRAINAGE WIND PATTERN HAS ESTABLISHED ITSELF ACROSS THE
GREATER DENVER METRO AREA THIS EVENING. SPEEDS WERE GENERALLY
AT OR BELOW 12 KTS. THIS WIND FIELD SHOULD REMAIN IN PLACE
OVERNIGHT AS NO WEATHER SYSTEM WILL ACT UPON IT. MEANWHILE CLEAR
SKIES WILL BEGIN TO FILL WITH HIGH CLOUDS/CIRROSTRATUS AFTER
MIDNIGHT...SLOWING DOWN THE DROP OFF IN TEMPERATURES. BY MORNING
EXPECT SKIES TO BE MOSTLY TO COMPLETELY COVERED WITH HIGH
CLOUDS.

&&

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

$$

UPDATE...BAKER
SHORT TERM...RJK
LONG TERM...BOWEN
AVIATION...BAKER


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