Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 241823
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1123 AM MST SAT JAN 24 2015

.UPDATE...
ISSUED AT 1118 AM MST SAT JAN 24 2015

MINOR UPDATE THIS MORNING FOR MORE CLOUD COVER. STRONGER WINDS
MAINLY IN AN AMPLIFIED MOUNTAIN WAVE WEST OF BOULDER AND ALONG THE
WYOMING BORDER WITH 40-60 MPH GUSTS...LESS ELSEWHERE. THE WAVE
AMPLIFICATION SHOULD DIMINISH THIS AFTERNOON. RAISED WINDS A
LITTLE EVERYWHERE ELSE AND LOWERED TEMPS A DEGREE OR TWO FOR MORE
CLOUD COVER. SLIGHT CHANCE POPS FOR AREAS NEAR THE WYOMING BORDER
ARE STILL OK...SOME DOUBT ABOUT THE MOISTURE ACTUALLY BEING ENOUGH
AT LOWER LEVELS...MODELS HAVE BEEN OVERDOING THAT IN THIS PATTERN
THE LAST COUPLE OF DAYS.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 355 AM MST SAT JAN 24 2015

A WEAK UPPER AIR SHORTWAVE ON THE NOSE OF A STRONG JET WAS
RACING SOUTHEASTWARD OVER CENTRAL WYOMING AT THIS HOUR. FRACTURED
BANDS OF MID AND HIGH-LEVEL CLOUD EVIDENT ON IR SAT IMAGERY
ACCOMPANY THIS WAVE. LEADING EDGE OF THIS BROKEN CLOUD SHIELD IS
JUST NOW REACHING THE NORTHWEST CORNER OF THE STATE. OVER THE NEXT
SEVERAL HOURS SHOULD SEE THIS CLOUD MASS SPREADING SOUTHWARD OVER
THE FORECAST AREA...WITH SOME THINNING EXPECTED OVER THE PLAINS
AND THICKENING OVER AND NEAR THE FRONT RANGE WITH THE FORMATION
AND AMPLIFICATION OF A MTN WAVE. MESOSCALE MODELS SHOW W-NWLY
WINDS ON RIDGETOP AND EAST SLOPES OF THE FRONT RANGE STEADILY
INCREASING THIS MORNING AS THE MTN WAVE DEEPENS. COULD SEE PEAK
GUSTS OVER HIGHER AREAS IN THE 30-40 MPH RANGE...WITH GUSTS
APPROACHING 30 MPH NEAR THE BASE OF THE FOOTHILLS BY MIDDAY.
DOWNWARD TRANSPORT OF MOMENTUM FROM THE PASSING 120-135KT JET WILL
ALSO RESULT IN GUSTY NWLY SFC WINDS ON THE NORTHEAST PLAINS
DURING THE LATE MORNING AND AFTERNOON HOURS. COULD SEE GUSTS
APPROACHING 35 MPH OUT ALONG THE WYOMING/NEBRASKA BORDERS AND OVER
THE HIGHER TERRAIN IN WASHINGTON COUNTY SUCH AS AROUND AKRON. IN
ADDITION...LOWERING CONDENSATION LEVELS A BI-PRODUCT OF THE LIFT
GENERATED BY THE PASSING JET COULD SUPPORT A FEW LIGHT RAIN
SHOWERS OVER NERN WELD...LOGAN...SEDGWICK...PHILLIPS AND NRN
WASHINGTON COUNTIES AFTER ABOUT 20Z TODAY. MAY ALSO SEE A FEW
SNOW FLAKES THROWN IN LATE. RAIN AMOUNTS SHOULD BE QUITE SMALL...
PROBABLY NO MORE THAN A TRACE IN MOST AREAS. TEMPERATURES TODAY
WILL CONTINUE TO WARM EVEN WITH THE PASSING CLOUD COVER. UPPER
40S AND LOWER 50S WILL BE COMMON ON THE PLAINS WITH THE EXCEPTION
OF MID 50S ALONG THE FOOTHILLS DUE TO THE WARMING EFFECTS OF
DOWNSLOPE BREEZES. MAX TEMPS IN THE HIGH COUNTRY ONLY SLIGHTLY
WARMER THAN YESTERDAY WITH 30S THE RULE.

TONIGHT...THE MTN WAVE RELAXES AS THE NOSE OF THE JET PASSES BY
RESULTING IN A GRADUAL DROP OFF IN WIND SPEEDS DURING THE EVENING.
LOOK FOR SKIES TO CLEAR OVER THE PLAINS OVERNIGHT WITH SUBSIDENCE
AND DRYING ALOFT. NOT THE CASE IN THE MTNS PARTICULARLY DURING
THE EVENING HOURS WHEN A WEAK U/A DISTURBANCE ACCOMPANIED BY A
BATCH OF LOW/MID-LEVEL MOISTURE DROPS DOWN FROM WRN WYOMING.
MODELS NOW INDICATE POCKETS OF LIGHT QPF IN THE NRN MTNS AS THEY
INDICATED A COUPLE OF DAYS AGO. YESTERDAY/S RUNS INDICATED
NOTHING. SO BACK TO THE LOW POPS UP THERE OVERNIGHT. HOWEVER ANY
SNOW AMOUNTS SHOULD BE MINIMAL AT BEST. SIMILAR TO TODAY/S HIGH TEMPS
LOWS TONIGHT WILL ALSO TREND UPWARD WITH WARMING ALOFT. LOOK FOR
MID 20S TO MID 30S AT LOWER ELEVATIONS...AND TEENS AND 20S ACROSS
THE HIGH COUNTRY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 355 AM MST SAT JAN 24 2015

HIGH PRESSURE ALOFT WILL BE OVER THE GREAT BASIN ON SUNDAY WITH A
MODERATE NORTHWEST FLOW ALOFT. THERE WILL STILL BE SOME MOISTURE
IN THE FLOW PATTERN ALONG WITH THE JET STREAK ACROSS EASTERN
COLORADO. COULD STILL BE SOME LINGERING LIGHT SNOW SHOWERS IN THE
MORNING BUT THEN DRYING IN THE AFTERNOON AS THE JET MOVES EAST OF
COLORADO.

FOR MONDAY AND TUESDAY...THE STRONG RIDGE ALOFT WILL SHIFT ACROSS
COLORADO WITH A DRY AND WARM AIRMASS IN PLACE. TEMPERATURES WILL
CLIMB WELL INTO THE 60S FOR BOTH DAYS ACROSS THE PLAINS. EXPECT
SOME INCREASE IN HIGH LEVEL MOISTURE ON TUESDAY IN ADVANCE OF THE
SOUTHERN CALIFORNIA TROF MOVING INLAND. FOR LATE TUESDAY AND
WEDNESDAY THE DESERT TROF UNDERCUTS THE RIDGE WITH SOME MOISTURE
MAKING INTO THE COLORADO NORTHERN MOUNTAINS. EXPECT SCATTERED
SHOWERS TO DEVELOP IN THE MOUNTAINS BY TUESDAY AFTERNOON AND
EVENING. A COOLING TREND WILL FOLLOW THE TROF IN THE LATER HALF
OF THE WEEK AS THE  FLOW ALOFT SHIFTS MORE WEST AND NORTHWEST.

LONG RANGE MODEL DISCREPANCIES INCREASE FOR THURSDAY AND FRIDAY
AS THE GFS SHOWS A STRONGER TROF DROPPING DOWN THROUGH THE ROCKIES
FOR LATE FRIDAY WHILE THE EUROPEAN SOLUTION IS MUCH WEAKER AND
DRIER WITH THIS FEATURE. FOR NOW A LOW POP WILL SUFFICE WHILE
TEMPERATURES RETURN TO MORE SEASONAL NORMALS.

&&

.AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON)
ISSUED AT 1118 AM MST SAT JAN 24 2015

VFR THROUGH TONIGHT. WINDS WILL TREND TOWARD THE WNW BY 20Z WITH
OCCASIONAL GUSTS TO 20 KNOTS AT KDEN/KAPA AND 30 KNOTS AT KBJC.
THE WINDS WILL GO BACK TO A LIGHTER WSW BY 03Z. THERE WILL BE SOME
LOWERING OF THE CEILING...BUT EXPECTED TO STILL BE HIGH ENOUGH FOR
VISUAL APPROACHES TO KDEN.

&&

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

$$

UPDATE...GIMMESTAD
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...GIMMESTAD


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