Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 261119
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
419 AM MST THU FEB 26 2015

.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 419 AM MST THU FEB 26 2015

LIGHT SNOW CONTINUED IN THE FOOTHILLS AND ACROSS MOST OF THE
PLAINS OVERNIGHT AS THE ARCTIC AIRMASS MOVED INTO THE FORECAST
AREA. ADDTIONAL ACCUMULATIONS AFTER PASSAGE OF THE MAIN FRONT HAVE
BEEN AROUND AN INCH ALONG THE FOOTHILLS. MOST OF THE SNOW
ACCUMULATION WAS DURING THE EVENING HOURS IN THE UNSTABLE AIRMASS
AHEAD OF THE ARCTIC FRONT. FOR THE REMAINDER OF THIS
MORNING...LIGHT SNOW FLURRIES ARE EXPECTED TO EVENTUALLY COME TO
AN END. WITH TEMPERATURES IN THE UPPER SINGLE DIGITS AND LOW
TEENS...IT DOES NOT TAKE MUCH TO PRODUCE LIGHT FLURRY ACTIVITY.
SATELLITE IMAGERY IN SHOWING DECREASING DEEP MOISTURE ACROSS THE
STATE...SO NO ADDITIONAL SNOW ACCULATIONS ARE EXPECTED THROUGH
ABOUT MIDDAY. ALL HIGHLIGHTS WILL BE CANCELLED WITH ISSUANCE OF
THE MORNING FORECAST PACKAGE.

LATER TODAY...A WEAK DISTURBANCE CURRENTLY MOVING OUT OF IDAHO AND
INTO NORTHERN UTAH WILL BE MOVING OVER NORTHERN COLORADO. THIS
WILL PRODUCE ANOTHER ROUND OF LIGHT SNOW OVER THE MOUNTAINS AND
ADJACENT PLAINS THIS AFTERNOON AND EVENING. EXPECTED SNOWFALL
AMOUNTS SHOULD BE LIGHT...MAINLY BECAUSE THE ARCTIC AIRMASS WILL
LIMIT THE AMOUNT OF AVAILABLE MOISTURE. EACH OF THE MESOSCALE
AND SYNOPTIC MODELS INDICATE LIGHT PRECIPITATION OVER THE FORECAST
AREA THIS AFTERNOON AND EVENING. SOME MOUNTAIN AREAS COULD PICK UP
3 TO 6 INCHES OF SNOW...BUT ON THE PLAINS AMOUNTS SHOULD BE LESS
THAN 3 INCHES. TIMING OF THE AFTERNOON SNOWFALL MAY PRODUCE
ANOTHER TROUBLESOME EVENING COMMUTE ALONG THE FRONT RANGE
CORRIDOR. VERY COLD TEMPERATURES ARE EXPECTED OVERNIGHT AS WEAK
EASTERLY FLOW HOLDS THE ARCTIC AIRMASS IN PLACE.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 419 AM MST THU FEB 26 2015

THE FLOW ALOFT WILL BECOME MORE WLY ON FRIDAY WITH NOT AS MUCH
MOISTURE.  WEAK WLY FLOW AT 700 MB WILL COMBINE WITH LINGERING
MOISTURE IN THE MTNS TO PRODUCE AREAS OF LIGHT SNOW THRU THE DAY.
OVER NERN CO THE LOW LVL FLOW WILL BECOME MORE SLY AS COLD SFC HIGH
PRES IS OVER THE CNTRL US.  THERE MAY BE SOME LIGHT SNOW OVER THE
FAR ERN PLAINS FRI MORNING AS SOME MID LVL ASCENT OCCURS BEFORE
EXITING THE AREA BY MIDDAY.  AS FOR AS HIGHS 850-700 MB TEMPS DO NOT
CHANGE MUCH ON FRI SO HIGHS WILL STAY MOSTLY IN THE 20-25 DEGREE
RANGE OVER THE PLAINS.

FOR SAT THRU SAT NIGHT AN UPPER LEVEL TROUGH WILL DVLP OVER NEVADA
AND CALIFORNIA WITH THE FLOW ALOFT GRADUALLY BECOMING SWLY.  OVERALL
WITH SWLY FLOW AT 700 MB THIS WOULD FAVOR ZN 31 AND PORTIONS OF ZN
33 FOR OROGRAPHIC SNOW.  OVER NERN CO A CDFNT WILL MOVE ACROSS THE
PLAINS BY AFTN WITH SOME INCREASE IN UPSLOPE COMPONENT.  QG FIELDS
SHOW SOME MINOR MID LVL ASCENT BY AFTN INTO SAT EVENING SO WILL SEE
A GOOD CHC OF LIGHT SNOW.  MEANWHILE A STRONGER CORE OF UPPER LEVEL
WINDS WILL MOVE ACROSS SRN CO LATE LATE IN THE AFTN INTO SAT EVENING
WHICH MAY PUT NERN CO IN FAVORED LEFT FNT QUAD WHICH COULD
POTENTIALLY ENHANCE SNOWFALL IN SOME AREAS.  AS FOR HIGHS ON SAT
ONCE AGAIN WILL KEEP HIGHS IN THE 20 TO 25 RANGE AS 850-700 MB TEMPS
CHANGE LITTLE.

BY SUN SWLY FLOW ALOFT WILL REMAIN OVER THE AREA AS THE UPPER LEVEL
TROUGH CONTINUES OVER NEVADA AND CALIFORNIA.  CURRENT CROSS-SECTIONS
SHOW SOME DRIER AIR SPREADING ACROSS IN THE MID LVLS THRU THE AFTN
SO SNOW CHANCES MAY DECREASE IN THE MTNS.  OVER NERN CO WEAK UPSLOPE
IS SHOWN SUN MORNING WITH WINDS BECOMING MORE SELY BY AFTN.  OVERALL
THERE IS STILL SOME MID LVL ASCENT OVER THE AREA ON SUN SO WILL KEEP
IN A CHC OF LIGHT SNOW IN AND NR THE FOOTHILLS AND ACROSS THE PALMER
DIVIDE.  OF SOME CONCERN IS PLACEMENT OF UPPER LEVEL JET WHICH IS
FCST TO BE OVER THE AREA THRU SUN AFTN WHICH COULD LEAD TO BANDED
PCPN.  AS FOR HIGHS WILL KEEP READINGS IN THE 20S OVER NERN CO.

FOR MON INTO MON NIGHT THE UPPER LEVEL TROUGH WILL EJECT ENE ACROSS
COLORADO WITH INCREASING MOISTURE IN THE MID LVLS.  THE FLOW ALOFT
IN THE MTNS WILL BE SWLY THRU THE MON AFTN AND THEN TURN MORE WLY BY
MON NIGHT.  OVERALL THERE WILL BE DECENT LAPSE RATES SO SHOULD SEE A
BETTER CHC OF SNOW IN THE MTNS.  OVER NERN CO SFC LOW PRES WILL
INTENSIFY OVER THE PLAINS WITH SSW LOW LVL FLOW.  DESPITE
UNFAVORABLE LOW LVL FLOW DECENT LAPSE RATES COMBINED WITH SOME MID
LVL ASCENT COULD LEAD TO A CHC OF SNOW SHOWERS BY AFTN ESPECIALLY
OVER THE PLAINS.  AS FOR HIGHS READINGS OVER NERN CO MAY RISE BACK
INTO THE LOWER TO MID 30S.

BY TUE AN UPPER LEVEL TROUGH WILL DIG INTO THE GREAT BASIN AND THEN
WILL MOVE ACROSS THE AREA ON WED.  SFC LOW PRES WILL DEVELOP OVER
SWRN CO AS ANOTHER CDFNT MOVES INTO NERN CO WHICH INCREASES UPSLOPE
FLOW TUE AFTN INTO WED.  IF THIS PTRN ENDS UP VERIFYING THEN WOULD
HAVE ANOTHER GOOD CHC OF SNOW TUE AFTN INTO WED.  HIGHS BOTH DAYS
WOULD BE WELL BLO NORMAL.

&&

.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 419 AM MST THU FEB 26 2015

WILL STICK WITH A RATHER PESSIMISTIC TAF PRODUCT THAT ADVERTISES
MOSTLY MVFR CEILINGS...SINCE CROSS SECTIONS AND MODEL SOUNDINGS
SHOW THE AIRMASS REMAINING NEAR SATURATION THROUGH THE DAY. ANY
SURFACE WARMING COULD BE ENOUGH TO GENERATE WEAK SHOWER ACTIVITY
WHICH WILL REDUCE CEILINGS AND VISIBILITIES. LATER THIS
AFTERNOON...AN UPPER DISTURBANCE MOVING OUT OF THE MOUNTAINS WILL
GENERATE MORE WIDESPREAD SNOWFALL THAT SHOULD EXTEND OUT TO KDEN.
SNOW ACCUMULATIONS DURING THE LATE AFTERNOON AND EARLY EVENING
COULD ADD UP TO 1 OR 2 INCHES.   WINDS SHOULD REMAIN EASTERLY
THROUGH MUCH OF THE DAY AND THEN TRANSITION TO A LITTLE MORE
SOUTHERLY LATER THIS EVENING.

&&

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

&&

$$

SHORT TERM...DANKERS
LONG TERM...RPK
AVIATION...DANKERS


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