Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 271629
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1029 AM MDT WED APR 27 2016

.UPDATE...
ISSUED AT 1025 AM MDT WED APR 27 2016

DRIER LOW TO MID-LEVEL AIR ROUNDING THE BACKSIDE OF THE EXITING
UPPER LOW NOW SPINNING OVER ERN NEBRASKA HAS GENERATED A LONG
SWATH OF CLEAR/MOSTLY CLEAR SKIES ACRS NENR COLORADO THIS MORNING.
IN ADDITION...STRONG NWLY FLOW AROUND THE UPPER LOW CONTINUES TO
PRODUCE GUSTY N-NWLY WINDS ON THE PLAINS GENERALLY EAST OF THE
CHEYENNE-GREELEY-LIMON LINE. PEAK GUSTS HAVE BEEN IN THE 30-35KT
RANGE PAST COUPLE OF HRS. CLOSER INTO THE FRONT RANGE...LIGHT WINDS
WERE TURNING INTO THE TERRAIN WHICH HAS PROVIDED SUFFICIENT
OROGRAPHIC LIFT WITH SOLAR HEATING TO GENERATE THE BATCH OF LOW TO
MID-LEVEL CLOUDS OVER AND ALONG THE FRONT RANGE. NOT SEEING ANY
PRECIP FALLING FROM THEM ON RADAR...AT LEAST NOT YET WITH A STG
STABLE LAYER NEAR MTN TOP LEVEL. MEANWHILE...MOISTURE WRAPPING
INTO THE HIGH COUNTRY WITH THE SAME NWLY FLOW MENTIONED ABOVE
HAS KEPT A NEARLY SOLID BLANKET OF LOW TO MID-LEVEL CLOUD OVER
AREA ROUGHLY ALONG AND WEST OF THE CONT DIVIDE. HOWEVER WITH THE
RIDGE TOP SUBSIDENCE WITH THE PASSING MID-LEVEL SHORTWAVE RIDGE
ANY PRECIP...IE SNOWFALL SHOULD BE CONFINED TO THE HIGHER WEST-
NORTHWEST FACING SLOPES REST OF THE DAY WITH PERHAPS NO MORE THAN
AN INCH OR SO OF NEW ACCUMULATION. ON THE PLAINS...ISOLATED SHOWERS
TRACKING SEWRD OFF THE FRONT RANGE THIS AFTERNOON ARE NOT EXPECTED
TO PRODUCE MORE THAN A COUPLE HUNDREDTHS OF AN INCH OF RAIN...AND
MAINLY WEST OF I-25 AND OVER THE PALMER DIVIDE. OTHERWISE TODAY`S
FORECAST IS PRETTY MUCH UNCHANGED WITH NO BIG CHANGES TO WIND AND
TEMPERATURE GRIDS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM MDT WED APR 27 2016

AREAS OF LIGHT SNOW WILL CONTINUE TO DISSIPATE THROUGH 5 AM WITH
LINGERING CLOUDS OVER THE FRONT RANGE. LITTLE OR NO ADDITIONAL
SNOWFALL ACCUMULATION IS EXPECTED. THE MAIN UPPER LOW CONTINUES
TO SPIN OVER WESTERN KANSAS AND WILL GRADUALLY LIFT INTO NEBRASKA
BY THIS EVENING. THIS WILL RESULT IN CONTINUED WRAP AROUND CLOUDS
AND STILL SOME SHOWERS OVER FAR NORTHEAST COLORADO THROUGH THIS
EVENING. THERE WILL BE SOME WEAK INSTABILITY OVER MOUNTAINS AND
ADJACENT PLAINS THIS AFTERNOON RESULTING IN ISOLATED LIGHT SHOWERS
THIS AFTERNOON/EARLY EVENING. TEMPERATURES WILL BE A BIT WARMER
TODAY WITH READINGS IN THE LOWER TO MID 50S OVER THE PLAINS.

WEAK AND TEMPORARY RIDGING ALOFT FOR THIS EVENING BEFORE AN
INCREASE IN MOISTURE AGAIN FROM THE WEST WITH THE NEXT STORM
SYSTEM. SOME WEAK QG ASCENT MOVES IN LATER TONIGHT INTO THE
MOUNTAINS FOR AN INCREASING THREAT FOR SNOW SHOWERS. ANY
SIGNIFICANT SNOWFALL WILL HOLD OFF UNTIL LATER THURSDAY.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 218 AM MDT WED APR 27 2016

THU AND THU NIGHT...THE NEXT SYSTEM OVER SOUTHERN NEVADA AT 12Z
THU IS PROGGED TO MOVE INTO NORTH CENTRAL AZ BY 00Z FRI AND INTO
THE FOUR CORNERS REGION BY 12Z FRI. WEAK QG ASCENT WILL DEVELOP
FROM THE SOUTHWEST ON THU...WITH A DIFFLUENT SOUTHWESTERLY FLOW
ALOFT OVER THE REGION THU. THE AIRMASS WILL CONTINUE TO MOISTEN UP
THROUGH THE DAY...WITH A LOW LEVEL E/SELY UPSLOPE FLOW IN THE
AFTN. IN THE MOUNTAINS...THE SNOW LEVEL WILL BE FAIRLY HIGH
INITIALLY...9500-10000 FT...SO SNOW OR A MIX OF RAIN/SNOW IN THE
AFTN WILL LIMIT ACCUMULATING SNOWFALL. THURSDAY NIGHT INTO
FRIDAY...COOLER TEMPERATURES WITH A DEEPER SELY FLOW DEVELOPING
TO AROUND 600 MB. MORE SIGNIFICANT ACCUMULATIONS WILL BE
POSSIBLE...ESPECIALLY IN ZONES 34 AND THE NORTH PART OF ZONE 37
THURSDAY NIGHT. BY LATE THURSDAY NIGHT...COULD SEE SNOW INCREASING
IN COVERAGE AND INTENSITY IN THE FOOTHILLS. ON FRIDAY...MDT QG
ASCENT PROGGED FOR THE CWA...AS THE TROUGH LIFT NORTHEAST INTO
CNTRL CO BY 00Z SAT. BEST PERIOD OF UPSLOPE/QG ASCENT WILL BE
LATE THU NIGHT AND FRI. CANNOT RULE OUT TSTMS ESPECIALLY IN THE
AFTN/EVNG PERIOD BUT OVERALL COVERAGE SHOULD BE ISOLATED. THE
UPSLOPE BREAKS DOWN FRI NIGHT AS THE TROUGH SHIFTS INTO SWRN
NB/NWRN KS BY 12Z SAT. THE MDLS ARE PRETTY CONSISTENT WITH ONE
ANOTHER REGARDING THE TIMING/TRACK OF THIS SYSTEM THROUGH 00Z
SAT...WITH SOME DISCREPANCIES CROPPING UP FRI NIGHT. THE NAM12 MDL
GENERATES UP TO 20 INCHES IN THE MOUNTAINS BY 12Z SATURDAY. PREFER
THE SNOWFALL/RAINFALL AMOUNTS GENERATED BY THE NAM/ECMWF AT THIS
TIME...AS THE GFS APPEARS WAY OVERDONE WITH UP TO 30 INCHES IN
COMPARISON. ACROSS THE NORTHEAST PLAINS...PRIMARILY RAIN SHOWERS
EXPECTED THROUGH FRIDAY EVENING...THEN A RAIN/SNOW MIX OVERNIGHT.
THE MDLS DO GENERATE SIGNIFICANT ACCUMULATIONS OUT ON THE PLAINS
AS WELL...6-12 INCHES FM THE NAM12 AND WITH ANYWHERE FM 2-40
INCHES FM THE GFS. HARD TO BUY THESE AMOUNTS SO LATE IN THE
MONTH...SO FOR NOW HAVE DISCOUNTED THE GFS SOLUTION ALTOGETHER AT
THIS TIME. THE NAM12 SOLUTION MORE REASONABLE BUT STILL LOOKS TOO
HIGH. MAIN CONCERN WILL BE THE PALMER DIVIDE WHICH SHOULD KICK
OVER TO SNOW THURSDAY NIGHT. WILL LIKELY NEED TO HOIST A WINTER
STORM WATCH FOR THE FRONT RANGE MOUNTAINS/FOOTHILLS AT SOME
POINT...BUT THIS IS STILL PRIMARILY THE FOURTH/FIFTH PERIODS AT
THIS POINT. THE PALMER DIVIDE SOUTH OF DENVER...MAY ALSO NEED SOME
SORT OF HIGHLIGHT AT SOME POINT AS WELL. FRIDAY NIGHT INTO
SATURDAY...THE FOCUS FOR PCPN WILL BE ALONG THE PALMER DIVIDE AS
THE LOW LEVEL WINDS BECOME NORTH/NORTHWESTERLY. SAT AFTN/SAT
NIGHT...SHOWERS SHOULD DECREASE WITH ONE SYSTEM EXITING TO THE
EAST WHILE ANOTHER STARTS TO DROP INTO SRN NV. SOUTHWESTERLY FLOW
OVER CO ON SUN...WITH A CLOSED LOW OVER NWRN AZ...THIS SYSTEM
LIFTS NORTH INTO UT BY 12Z MONDAY. NOT REALLY SURE WHERE THIS WILL
END UP AT THIS POINT...SO BASICALLY CHC POPS IN THE GRIDS SUN
NIGHT AND MONDAY. AS THE LOW LIFTS A BIT FURTHER NORTH ON
TUE...LESS PCPN COVERAGE BUT STILL UNSETTLED WITH AFTN/EVNG
SHOWERS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1025 AM MDT WED APR 27 2016

SCATTERED LOW CLOUDS THIS MORNING AT DENVER AREA AIRPORTS WITH
BASES IN THE 2000-3000 FT AGL LEVELS DUE TO A LIGHT NORTHEASTERLY
UPSLOPE FLOW. THIS LOW CLOUD COVER IS EXPECTED TO THIN OUT AND
EVEN DISSIPATE AROUND MIDDAY WITH A SHIFT TO A DRIER NORTHERLY
WINDS WHICH COULD GUST 20-30KT IN AREAS EAST OF THE I-25 FOR THE
1ST PART OF THE AFTERNOON. THEN LOOK FOR WINDS TO RETURN TO A
EAST-NORTHEAST UPSLOPE COMPONENT LATE THIS AFTERNOON WHICH WILL
ENHANCE CLOUD DEVELOPMENT OVER THE METRO AREA AND POSSIBLY RESULT
IN A FEW LIGHT RAIN SHOWERS. MOST OF THIS SHOWER ACTIVITY IS
EXPECTED TO END DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME
HEATING.


&&

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

$$

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



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