Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 271720
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1020 AM MST TUE JAN 27 2015

.UPDATE...
ISSUED AT 1020 AM MST TUE JAN 27 2015

NO NEED TO MAKE ANY CHANGES TO THE FORECAST AT THIS POINT. THE
MORNING SOUNDING SHOWED TEMPERATURES ALOFT THAT WERE UNCHANGED
FROM YESTERDAY AFTERNOON...SO THE FORECAST OF MAX TEMPERATURES
AROUND THE 70 DEGREE MARK LOOKS GOOD. SOME MID AND HIGH LEVEL
CLOUDS WILL MOVE ACROSS NORTHERN COLORADO THROUGH THE AFTERNOON
BUT SHOULD HAVE LITTLE IMPACT ON SENSIBLE WEATHER.

IT IS HARD TO TELL HOW MUCH SNOW WILL DEVELOP IN THE MOUNTAINS
LATER TONIGHT BASED ON CURRENT SATELLITE AND RADAR INFORMATION.
BUT THE POPS IN THE FORECAST ARE FAIRLY LOW...SO WILL NOT CHANGE
THEM NOW.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 300 AM MST TUE JAN 27 2015

HIGH PRESSURE RIDGE AXIS IS ACROSS COLORADO THIS MORNING AND WILL
SHIFT INTO THE CENTRAL PLAINS TONIGHT. THIS IS IN RESPONSE TO
WEAKENING UPPER LEVEL TROF MOVING NORTHEAST OVER SOUTHERN
CALIFORNIA AND THE DESERT SOUTHWEST TODAY. INITIALLY...JUST SOME
THIN CIRRUS FOR MUCH OF THE DAY ACROSS EASTERN COLORADO AHEAD OF
THE TROF. LIKE YESTERDAY AM...FOG HAS DEVELOPED AT KREMMLING SO
WILL ADD SOME PATCHY FOG IN ZONE 32.

TEMPERATURES WILL BE VERY SIMILAR TO YESTERDAY WITH
READINGS AROUND 70 DEGREES ACROSS THE PLAINS. THE TROF WILL MOVE
OVER NORTHERN COLORADO LATER TONIGHT WITH SOME MOISTURE AND A BIT
BETTER OROGRAPHIC FLOW INTO THE MOUNTAINS. SCATTERED SNOW SHOWERS
WILL INCREASE IN THE MOUNTAINS TONIGHT BUT WITH MOISTURE RATHER
SHALLOW AND WEAK QG FORCING...EXPECT ONLY VERY LIGHT AMOUNTS.

EXPECT INCREASING DOWNSLOPE WINDS TONIGHT WITH APPROACHING TROF
WITH SPEEDS IN THE 40-60 MPH RANGE OVER HIGHER MOUNTAINS AND EAST
SLOPES.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 300 AM MST TUE JAN 27 2015

A WK UPPER LEVEL TROUGH WILL MOVE ACROSS NRN CO BY WED AFTN AND
THEN BE EAST OF THE AREA BY WED EVENING. CROSS-SECTIONS SHOW
MOISTURE WITH THIS SYSTEM RATHER LIMITED SO SNOW AMOUNTS IN THE
MTNS WILL BE LIGHT. OVER NERN CO IT WILL BE DRY WITH A RATHER STG
SFC GRADIENT IN PLACE THRU MID AFTN AS A PACIFIC TYPE FNT MOVES
ACROSS. THIS WILL ALLOW FOR GUSTY NW WINDS ACROSS THE PLAINS. IN
ADDITION WILL SEE GUSTY WINDS IN THE FOOTHILLS AS WELL HOWEVER
SPEEDS SHOULD STAY BLO HIGH WIND CRITERIA. HIGHS WILL BE COOLER
WITH READINGS IN THE 55 TO 60 DEGREE RANGE ACROSS NERN CO.

FOR WED NIGHT INTO THU A WK UPPER LEVEL RIDGE WILL BUILD ACROSS THE
AREA.  CROSS-SECTIONS SHOW SOME MINOR UPSLOPE IN AND NR THE
FOOTHILLS WITH QUITE A BIT OF LOW LVL MOISTURE BY 12Z THU.  THUS IT
WOULD NOT BE A TOTAL SURPRISE TO SEE SOME VERY LIGHT SNOW FOR A
BRIEF PERIOD OF TIME IN AND NR THE FOOTHILLS THU MORNING.  OTHERWISE
THE REST OF THE DAY LOOKS DRY EXCEPT FOR A SLIGHT CHC OF -SHSN IN
THE MTNS.  AS FOR HIGHS READINGS WILL DROP BACK TO SEASONAL LEVELS
OVER NERN CO.

ON FRI A WK UPPER LEVEL LOW WILL DVLP OVER THE SWRN US WITH SW FLOW
ALOFT.  MID LVL MOISTURE WILL INCREASE ACROSS THE AREA THRU THE DAY
WITH A CHC OF -SHSN IN THE MTNS ESPECIALLY SOUTH OF I-70.  OVER NERN
CO IT WILL BE DRY EXCEPT FOR SLIGHT CHC OF -SHRA OVER THE PALMER
DIVIDE BY LATE AFTN.  AS FOR HIGH WILL KEEP READINGS IN THE 40S OVER
THE PLAINS.

FOR SAT THRU SAT NIGHT THE GFS TAKES THE WEAK UPPER LEVEL OVER THE
SWRN US AND MOVES IT ENE ACROSS SRN CO/NRN NM WHILE TRYING TO MERGE
IT WITH ANOTHER WEAK SYSTEM TRACKING SE IN NWLY FLOW ALOFT.  AS A
RESULT IT HAS ABUNDANT MOISTURE SPREADING OVER THE AREA ALONG WITH
SOME WK MID LVL ASCENT. IN ADDITION A CDFNT IS FCST TO MOVE INTO
NERN CO WITH AN INCREASE IN UPSLOPE FLOW LATE IN THE AFTN INTO SAT
EVENING.  THIS LEADS TO A GOOD CHC OF SNOW FM SAT INTO SAT EVENING
ACROSS THE AREA.  MEANWHILE THE ECMWF KEEPS THE UPPER LEVEL TROUGH
FURTHER SOUTH AND DOES NOT MERGE IT WITH THE WEAKER SECONDARY SYSTEM
IN NWLY FLOW ALOFT.  HOWEVER DESPITE THESE DIFFERENCES EVEN THE
ECMWF SHOWS SOME WK MID LVL ASCENT OVER THE AREA ON SAT ALONG WITH
AN INCREASE IN MOISTURE.  FURTHERMORE IT ALSO HAS SURGE OF COOLER
AIR AS WELL BY AFTN INTO SAT EVENING SO EVEN THIS SCENARIO WOULD
LEAD TO A CHC OF SOME LIGHT PCPN.  THUS WILL MENTION A CHC OF SNOW
IN MOST AREAS ON SAT WITH COOLER TEMPS.

BY SUN APPEARS DRIER AIR IN NWLY FLOW ALOFT WILL MOVE INTO THE AREA
WITH ONLY A SLIGHT CHC OF SNOW IN THE MTNS.  850-700 MB TEMPS ARE A
DEGREE OR TWO COOLER THAN SAT SO WILL KEEP HIGHS IN THE 30S OVER
NERN CO.  FOR MON MAY SEE AN INCREASE IN MOISTURE IN THE MTNS WITH A
CHC OF SNOW.  OVER NERN CO A SFC LEE TROUGH IS FCST TO DVLP WHICH
WOULD LEAD TO DRY CONDITIONS AND WARMER TEMPS.

&&

.AVIATION...(FOR THE TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1020 AM MST TUE JAN 27 2015

NO AVIATION IMPACTS EXPECTED THROUGH THE NEXT 24 HOURS. WINDS ARE
SOUTHWESTERLY THIS MORNING...AND EXPECTED TO SWITCH TO NORTH OR
NORTHWEST DURING THE AFTERNOON. DRAINAGE SOUTHERLIES WILL RE-
DEVELOP AFTER SUNSET.

&&

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

$$

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


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