Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 231533
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
933 AM MDT THU JUL 23 2015

.UPDATE...
ISSUED AT 927 AM MDT THU JUL 23 2015

SATELLITE IMAGERY CONTINUES TO SHOW CLEARING OVER LINCOLN COUNTY
AS THE REGION IS UNDER A DRIER WEATHER PATTERN. WITH DECREASED
MOISTURE AND CLEARING SKIES HAVE INCREASED TEMPERATURES OVER THE
FRONT RANGE A FEW DEGREES BUT OVERALL ON TRACK TO REACH THE MID
90S TODAY. LATEST HRRR GUIDANCE SHOWING SOME DEVELOPMENT OVER THE
SOUTHERN MOST PORTIONS OF THE REGION SOUTH OF I-70 ALONG THE
FOOTHILLS AS WELL AS DOUGLAS AND LINCOLN COUNTIES LATER THIS
AFTERNOON. THIS COINCIDES WITH SOME MOISTURE THAT WILL MAKE ITS
WAY INTO THE AREA LATER THIS AFTERNOON BUT NOT VENTURE ANY
FURTHER NORTH THAN I-70. DO NOT EXPECT MUCH OUT OF THESE STORMS
BUT SOME LIGHT TO MODERATE RAIN.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 419 AM MDT THU JUL 23 2015

A LITTLE BIT OF WARMING ALOFT SHOULD LIMIT CONVECTION
TODAY...THOUGH THERE IS STILL ENOUGH MOISTURE AROUND FOR SOME
CLOUD DEVELOPMENT AND ISOLATED STORMS. MOISTURE WILL BE BETTER IN
THE SOUTHERN PART OF THE AREA. PREVIOUS FORECAST LIMITED THE
MENTION OF POPS TO THE MOUNTAINS SOUTH OF INTERSTATE 70...AND THEN
AREAS NEAR THE FOOTHILLS FROM DENVER SOUTHWARD DURING THE EVENING.
WILL STICK WITH THIS IDEA...JUST ENDING THE THREAT BY MID EVENING.
TEMPERATURES SHOULD BE A FEW DEGREES WARMER...WHICH MEANS MOSTLY
MID 90S ON THE PLAINS.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 419 AM MDT THU JUL 23 2015

AMPLIFIED WAVE PATTERN OVER THE WESTERN CONUS FIRST HALF OF THE
PERIOD WITH UPPER RIDGE OVER THE LOWER GREAT PLAINS AND TROUGH
OVER THE PACIFIC NORTHWEST FLATTENS OUT WITH FLOW ALOFT BECOME
NEARLY ZONAL LATE IN THE PERIOD. MODELS IN REASONABLY GOOD
AGREEMENT THOUGH THE GFS CONTINUES TO BE THE WETTER OF THE MEDIUM
RANGE MODELS AS IT IS RELUCTANT TO SEVER THE TIE TO THE SOUTHWEST
MONSOON. ON FRIDAY...COLORADO REMAINS SANDWICHED BETWEEN A STRONG
UPPER RIDGE AND BERMUDA SFC HIGH OVER THE SOUTHERN GREAT PLAINS
AND AN UPPER TROUGH WHICH MODELS SHOW SLIPPING SOUTH DOWN THE
PACIFIC NORTHWEST COAST. THE TWO SYSTEMS KEEP THE FORECAST AREA
UNDER SWLY FLOW ALOFT. AGAIN GFS APPEARS WETTER AS IT SHOWS A
COLUMN OF MID/HIGH LEVEL MOISTURE SPREADING OVER THE STATE DURING
THE DAY. WHEREAS THE EUROPEAN AND CANADIAN MODELS SHOW A DRIER AND
SLIGHTLY MORE WESTERLY FLOW ALOFT. AT ANY RATE...INTEGRATED
PRECIPITABLE WATER VALUES START THE DAY ON THE LOW SIDE...E.G.
AROUND A HALF INCH ALONG THE FRONT RANGE...AND THEN STEADILY RISE
THROUGH THE DAY TO AROUND AN INCH WITH THE BNDRY LAYER FLOW
TURNING E-NELY. AND YET..THE PLAINS AIRMASS APPEARS TO REMAIN
STRONGLY CAPPED WITH WARMING ALOFT. CAPE AND STEEP LAPSE RATES
REMAIN LARGELY CONFINED TO HIGHER DEWPOINT AIR ALONG THE EASTERN-
SOUTHEASTERN FRINGE OF THE FCST AREA. FOR THAT REASON WILL ASSIGN
LOW POPS IN THIS AREA...AND INCLUDE LOW POPS IN THE FOOTHILLS AND
SOUTH PARK AREAS. TEMPS ON FRIDAY REMAIN ABOVE AVERAGE WITH
LOW/MID 90S AT LOWER ELEVATIONS AND MOSTLY 70S IN THE HIGH
COUNTRY.

OVER THE WEEKEND...THE SRN PLAINS RIDGE APPEARS TO WEAKEN SLIGHTLY
AND SLIP A BIT FARTHER SOUTHEAST. THIS ALLOWS FOR MORE MONSOONAL
MOISTURE TO MAKES IT WAY UP INTO COLORADO ON SWLY FLOW. GFS
CONTINUES TO RUN WETTER THAN THE OTHER MODELS ALTHOUGH THE EUROPEAN
AND CANADIAN ALSO LOOK WETTER AT LEAST AT MID-LEVELS. PW VALUES ON
THE PLAINS START THE DAY ON A HIGH NOTE AROUND AN INCH...BUT THEN
DROP OFF DURING THE DAY WITH THE SFC-700MB FLOW BNDRY BECOMING W-
SWLY/DOWNSLOPE. HOWEVER SELY BNDRY LAYER FARTHER OUT ON THE PLAINS
KEEPS PW VALUES UP AROUND AND INCH PRODUCING 0-3KM CAPES IN THE 500-
1000 J/KG SUFFICIENT  TO KEEP A LOW CHANCE OF AFTERNOON/EVENING T-
STORMS OUT THERE AS WELL AS OVER THE SRN FOOTHILLS AND SOUTH PARK.
ELSEWHERE SHOULD REMAIN STORM FREE. TEMPS ON SATURDAY 1-3DEG F COOLER
THAN FRIDAY DUE IN PART TO GREATER CLOUD COVER. ON SUNDAY...FLOW
ALOFT TURNS MORE WESTERLY LEADING TO LOWER HUMIDITY...LESS CLOUD
COVER AND SLIGHTLY HIGHER TEMPS.

MONDAY-WEDNESDAY...THE PACIFIC NORTHWEST TROUGH IS PROGGED TO
MIGRATE EASTWARD ALONG THE U.S/CANADIAN BORDER FLATTENING OUT THE
FLOW ALOFT. HOWEVER AS THE UPPER TROUGH PASSES TO OUR NORTH ON
TUESDAY...MODELS SHOW A WEAK COLD FRONT PUSHING UP AGAINST THE FRONT
RANGE AND WITH A MOIST UP SLOPE FLOW...SHOULD SEE RAIN CHANCES CREEP
UP. TEMPS ON THE PLAINS TUESDAY AS MUCH AS 4-6 DEG F COOLER. ZONAL
FLOW ON WEDNESDAY WILL DRY THINGS OUT AND LARGELY CONFINE ANY
PRECIP/T-STORMS TO THE HIGHER TERRAIN. LOOK FOR TEMPS ON WEDNESDAY
TO BE A DEG OR TWO WARMER.


&&

.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 927 AM MDT THU JUL 23 2015

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD FOR ALL AIRPORTS.
SOME MID TO HIGH LEVEL SCATTERED DECK WILL PERSIST ON AND OFF
THROUGH THE AFTERNOON WITH LIGHT TO VARIABLE WINDS FROM THE SW.

&&

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

$$

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


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