Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 281623
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1023 AM MDT SAT MAR 28 2015

.UPDATE...
ISSUED AT 1020 AM MDT SAT MAR 28 2015

WARMUP WELL UNDERWAY THIS MORNING WITH CURRENT TEMPERATURES ON
THE PLAINS RUNNING ANYWHERE FROM 4 TO 14 DEGS F AHEAD OF THOSE 24
HOURS AGO. WARMUP NOT AS ROBUST IN THE HIGH COUNTRY ALTHOUGH
VALLEY TEMPS ARE RUNNING 4-10 DEGS WARMER THAN YESTERDAY AT THIS
TIME. NOT A CLOUD ANYWHERE...BUT PROBABLY NOT TOO MUCH LONGER
BEFORE CONVECTIVE TEMPS ARE REACHED IN THE HIGH COUNTRY RESULTING
IN A SMATTERING OF FAIR WEATHER CUMULUS. MAIN FOCUS TODAY WILL BE
ON THE CRITICAL RANGELAND FIRE CONDITIONS EXPECTED TO DEVELOP BY
AROUND MIDDAY ON THE PLAINS NEAR THE WYOMING BORDER IN LARIMER AND
WELD COUNTIES. IT NOW APPEARS BASED ON NEW DATA COMING IN THAT
AREAS ALONG THE BASE OF THE FOOTHILLS IN BOULDER AND JEFFERSON
COUNTIES ARE LIKELY ALSO TO SEE CRITICAL FIRE DANGER CONDITIONS
DEVELOP THIS AFTERNOON FOR THE SAME REASONS. THESE AREAS ARE UNDER
A RED FLAG WARNING WHICH RUNS FROM NOON TO 6 PM MDT TODAY.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 431 AM MDT SAT MAR 28 2015

DRIER AND SLIGHTLY WARMER AIR OVER OUR AREA TODAY. EXPECT SURFACE
WINDS TO STAY WESTERLY WITH MIXING OF WESTERLIES ALOFT
OVERWHELMING THE SOUTHERLY SURFACE TENDENCY AS PRESSURE FALLS
DEVELOP NORTH OF US. WITH THE DRIER AIR HUMIDITIES WILL BE LOWER
TODAY...INCREASING THE FIRE DANGER. MOST AREAS WILL NOT HAVE
ENOUGH WIND FOR A WARNING...BUT NEAR THE WYOMING BORDER IT WILL BE
WINDIER. A RED FLAG WARNING WILL BE ISSUED FOR EASTERN LARIMER AND
NORTHERN WELD COUNTIES FOR THIS AFTERNOON WHERE CONDITIONS WILL BE
WORST. THESE AREAS ALSO MISSED OUT ON THE RAIN A FEW NIGHTS AGO.
FOR THE FOOTHILLS...STRONGEST WINDS WILL ALSO BE NEAR THE WYOMING
BORDER...LESS WIND IN MOST AREAS...COOLER TEMPERATURES AND BETTER
FUEL MOISTURE SO NO WARNING THERE THOUGH THE LIVERMORE AREA WILL
HAVE SIMILAR CONDITIONS TO THE PLAINS AREAS IN THE WARNING.

SHORTWAVE MOVES ACROSS THE NORTHERN ROCKIES TONIGHT DROPPING A
COLD FRONT ACROSS COLORADO. NOT MUCH BEYOND A WIND SHIFT AND THE
COOLING...I DID HOLD ON TO VERY LOW POPS FOR THE NORTHERN
MOUNTAINS AND NORTHEAST CORNER THIS EVENING WITH THE FRONTAL
BAND...IT IS MORE LIKELY THAT THERE WILL BE NOTHING. COOLED
TONIGHTS LOWS A LITTLE AS THE MODELS ARE SHOWING ABOUT 15 DEGREES
OF COOLING WITH THE FRONT...AND TEMPS IN THE NORTHERN HIGH PLAINS
ARE IN THE 30S TO LOWER 40S.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 431 AM MDT SAT MAR 28 2015

ON SUNDAY...IT WILL BE FAIRLY QUIET WITH A WEAK WEST TO
NORTHWESTERLY FLOW ALOFT...AND LITTLE IN THE WAY OF A SURFACE
PRESSURE GRADIENT TO DRIVE THE WIND. THE MDLS DO INDICATE SOME
MINIMAL QPF IN ZONES 34 AND 37 IN THE AFTN. THE NAM12 SOUNDINGS
SHOW SOME INSTBY IN THE AFTN...MAYBE ENOUGH TO PRODUCE A SHOWER OR
TSTM SO WL GO WITH ISOLD COVERAGE THERE...OTHERWISE DRY. THE RIDGE
OF HIGH PRESSURE WILL BUILD OVER THE WESTERN U.S. ON MONDAY WITH
THE FLOW ALOFT A BIT STRONGER. IN ADDITION...A LEE SIDE TROUGH
DEVELOPS OVER EASTERN CO. BEST CHC OF ANY SHOWERS WILL BE IN THE
MOUNTAINS...WITH DOWNSLOPE NEGATING THE SHOWER POTENTIAL OVER THE
NORTHEAST PLAINS. TEMPERATURES WILL AGAIN MODERATE TO WELL ABOVE
SEASONAL NORMALS...MID 70S. THE UPPER RIDGE AXIS SHIFTS EASTWARD
OVER COLORADO BY TUESDAY. OVERALL...CONTINUED VERY WARM AND DRY
WITH JUST SOME ISOLD SHOWER POTENTIAL IN THE HIGH COUNTRY TUESDAY
AFTERNOON AND TUESDAY NIGHT. LATE TUESDAY NIGHT INTO WEDNESDAY...
A STRONGER WEST-SOUTHWESTERLY FLOW WILL BE OVER COLORADO AS A
SYSTEM BRUSHES ACROSS NORTHERN COLORADO. A DECENT SFC PRESSURE
GRADIENT AS WELL. IT WILL BE COOLER WITH THE PASSAGE OF A COLD
FRONT...BUT TEMPERATURES WILL STILL BE ABOVE NORMAL. LIMITED
MOISTURE WL REMAIN MAINLY NORTH OF THE CWA SO MAINLY DRY AND WINDY
WITH SOME HIGH BASED SHOWERS ASSOCIATED WITH THE PASSAGE OF THE
FRONT ON WEDNESDAY. A STRONG ZONAL FLOW ALOFT WILL BE OVER
COLORADO ON THURSDAY...WITH ANOTHER SYSTEM PROGGED TO DROP OUT OF
THE NORTHWEST AND INTO THE REGION THURSDAY NIGHT INTO FRIDAY
MORNING. BEST CHC OF SHOWERS WILL BE FROM THE FRONT RANGE
FOOTHILLS EASTWARD. COOLER AS WELL WITH TEMPERATURES CLOSER TO
NORMAL ON FRIDAY. BOTH THE GFS AND ECMWF SHOW A TROUGH MOVING OVER
THE AREA AT THAT TIME...WITH THE ECMWF GENERATING A LITTLE MORE
QPF OVER NORTHEAST COLORADO ON FRIDAY.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1020 AM MDT SAT MAR 28 2015

SOUTH-SOUTHWESTERLY WINDS OF 6-12KTS AT THE PRESENT TIME ARE
EXPECTED TO SHIFT TO A WESTERLY COMPONENT AT THE DENVER AREA
TERMINALS BY AROUND NOON TODAY. SPEEDS WILL THEN INCREASE...FIRST
ALONG THE FOOTHILLS AND THEN SPREAD OUT ACROSS NORTHERN AND
CENTRAL PORTIONS OF THE DENVER METRO AREA DURING THE EARLY
AFTERNOON HOURS. THE SOUTH SIDE OF THE METRO AREA SUCH AS KAPA MAY
NOT SEE THESE WEST WINDS GUST AS HIGH. KBJC AND KDEN COULD SEE
GUSTS IN THE 18-22KT RANGE BETWEEN 19Z AND 24Z TODAY. AFTER 00Z
THIS EVENING...WIND SPEEDS WILL STEADILY DIMINISH AS THEY SHIFT
TO A SOUTHWESTERLY COMPONENT. HOWEVER...A SHIFT TO GUSTY NORTH-
NORTHWESTERLY WINDS IS STILL ANTICIPATED NOT LONG AFTER MIDNIGHT
WITH THE PASSAGE OF A DRY COLD FRONT. LOW CLOUDS AND PRECIPITATION
NOT EXPECTED WITH THIS WEAK FRONTAL SYSTEM.

&&

.FIRE WEATHER...
ISSUED AT 1020 AM MDT SAT MAR 28 2015

FIREWEATHER ZONE 239 ALONG THE BASE OF THE FOOTHILLS IN BOULDER
AND JEFFERSON COUNTIES HAS BEEN ADDED TO THE RED FLAG WARNING
ALREADY IN EFFECT FOR FIREWEATHER ZONES 238 AND 242 UP ALONG THE
WYOMING BORDER. THIS WARNING RUNS FROM 1200 TO 1800 MDT TODAY.
GUSTY WEST WINDS...LOW RELATIVE HUMIDITY AND ABNORMALLY WARM
TEMPERATURES WILL COMBINE WITH INCREASINGLY DRY FUEL CONDITIONS TO
POTENTIALLY PRODUCE CRITICAL RANGELAND FIRE BEHAVIOR THIS
AFTERNOON.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ238-239-242.

&&

$$

UPDATE...BAKER
SHORT TERM...GIMMESTAD
LONG TERM...COOPER
AVIATION...BAKER
FIRE WEATHER...BAKER



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