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000
FXUS65 KBOU 081117
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
417 AM MST SUN DEC 8 2013

.SHORT TERM...SHORT WAVE OVER WESTERN COLORADO WILL MOVE EAST
ACROSS THE FORECAST AREA THIS MORNING. AHEAD OF IT...LIGHT SNOW
HAD OVERSPREAD THE MOUNTAINS WHILE A FEW FLURRIES WERE OCCURRING
ON THE PLAINS. THERE IS MODERATE Q-G LIFT...ALTHOUGH A BIT WEAKER
THAN ADVERTISED YESTERDAY...ASSOCIATED WITH THIS WAVE. MID LEVEL
CLOUD DECK WAS FINALLY SPREADING OVER THE PLAINS. SEE LITTLE
REASON TO CHANGE THE EXISTING FORECAST WITH THE CHANCE OF LIGHT
SNOW/FLURRIES ON THE PLAINS AND OCCASIONAL SNOW IN THE HIGH
COUNTRY THIS MORNING GIVEN THE CURRENT OBSERVATIONS AND SATELLITE
TRENDS. BY AFTERNOON...LARGE SCALE SUBSIDENCE KICKS IN WHICH WILL
BRING DRIER MID LEVEL AIR ACROSS THE PLAINS. IN THE MOUNTAINS...
STILL ENOUGH OROGRAPHICS AS WELL AS SHALLOW MOISTURE AND
INSTABILITY TO KEEP SNOW SHOWERS GOING THERE. ADDITIONAL SNOWFALL
IN THE MOUNTAINS EXPECTED TO BE IN THE 1-4 INCH RANGE TODAY.  ON
THE PLAINS...HAVE DECREASED THE AFTERNOON POPS AS SUBSIDENCE MOVES
IN ALTHOUGH CANT RULE OUT A FEW FLURRIES IN SHALLOW BOUNDARY
LAYER MOISTURE. TOUGH CALL WHETHER WE CLEAR OUT OR STAY SOCKED IN
WITH THE LOW CLOUDS THIS AFTERNOON...ALWAYS DIFFICULT WHEN THESE
ARCTIC AIRMASSES ARE IN PLACE AS EVIDENCED OVER THE LAST FEW DAYS.

WITH REGARD TO TEMPERATURES...THERE HAS BEEN SOME WARMING NOTED ON
THE HOURLY OBSERVATIONS SPREADING DOWN THE FRONT RANGE FOOTHILLS.
THERE ARE SIGNS THAT WE COULD SCOUR THE ARCTIC AIRMASS OUT OF THE
FOOTHILLS TODAY AS SHORT WAVE PASSES BY...BUT COLD ADVECTION WILL
KEEP A LID ON TEMPS ANYWAY. THE IMPROVED MIXING COULD LEAD TO SOME
WARMING ON THE NEARBY ADJACENT PLAINS AND I-25 CORRIDOR AS WELL.
AT THIS TIME...WILL CONTINUE THE COMPROMISE IN THE HIGH
TEMPERATURE FORECAST BETWEEN THE BETTER MIXING WITH PASSING
SHORTWAVE AND ARCTIC AIR REMAINING FULLY ENTRENCHED...LEANING
TOWARD THE LATTER. WHILE MOST LOCATIONS SHOULD BE ABLE TO REACH
DOUBLE DIGITS FOR A CHANGE...THERE IS STILL POTENTIAL FOR SINGLE
DIGIT HIGHS ESPECIALLY ON THE EASTERN PLAINS WHERE THE ARCTIC
AIRMASS WILL LIKELY REMAIN IN FULL FORCE.

FOR TONIGHT...ENOUGH CLEARING IS EXPECTED TO ALLOW TEMPERATURES TO
DROP LIKE A ROCK. THEREFORE LOWERED MIN TEMPS A FEW MORE DEGREES.

.LONG TERM...WINTER WILL SLOWLY EASE ITS GRASP ON COLORADO THROUGH
THE WEEK...BUT THE WARMING MAY TAKE A COUPLE MORE DAYS THAN SOME
PEOPLE WANT. IN THE WAKE OF THIS AFTERNOONS PASSING UPPER
TROUGH...THE UPPER LEVEL FLOW PATTERN WILL BE TRANSITIONING TO A
NORTHWESTERLY DIRECTION. HOWEVER...OBSERVATIONS OVER OREGON THIS
MORNING SHOW STATIONS ACROSS THE STATE SETTING NEW RECORD LOWS...
BY SEVERAL DEGREES AT MOST LOCATIONS. HENCE...THE AIR THAT IS
COMING OUR WAY WILL NOT BE THAT WARM. AFTER A COLD START MONDAY
MORNING...THE 700 MB TEMPERATURE FIELDS FROM THE VARIOUS MODELS
SHOW THE CORE OF THE LAST ARCTIC SURGE MOVING OVER COLORADO
THROUGH THE AFTERNOON. THAT MEANS ONE MORE CHILLY DAY WITH HIGHS
FAILING TO REACH THE 20 DEGREE MARK. MONDAY NIGHT...MODELS BEGIN
SHOWING SOME CHINOOK WARMING AS NORTHWEST FLOW STRENGTHENS AND THE
CORE OF THE ARCTIC AIR BEGINS MOVING ONTO THE NORTHERN PLAINS.
STILL...OVERNIGHT LOWS WILL BE DROPPING TO THE LOWER AND MID
SINGLE DIGITS. NORMALLY COLDER LOCATIONS LIKE GREELEY AND LIMON
MAY SEE ANOTHER NIGHT BELOW ZERO. TUESDAY WILL SEE ADDITIONAL
WARMING AS CHINOOK FLOW SETS UP IN EARNEST. HIGH TEMPERATURES
AROUND THE FREEZING MARK WILL BE QUITE POSSIBLE.

ANOTHER WEAK FRONTAL SURGE IS EXPECTED TUESDAY NIGHT WHICH MAY
HOLD WEDNESDAYS HIGHS SIMILAR TO TUESDAY...IN SPITE OF CONTINUING
NORTHWEST FLOW. THE LATTER HALF OF THE WEEK WILL BE WHEN THE THAW
FINALLY ARRIVES...WITH TEMPERATURES AROUND NORMAL...IN THE LOWER
AND MID 40S.

VERY LITTLE SNOW IS EXPECTED THROUGH THE WEEK. THE PLAINS WILL BE
DRY...BUT THE MOUNTAINS MAY SEE SCATTERED SHOWERS MONDAY AS SOME
MOISTURE IS LEFT BEHIND FROM TODAYS WEATHER SYSTEM. SOME MORE
MOUNTAIN SNOW WILL BE POSSIBLE ON WEDNESDAY...ASSOCIATED WITH THE
WEAK COLD FRONT THAT MOVES IN TUESDAY NIGHT.

&&

.AVIATION...STRATUS DECK AROUND 1000 FT AGL HAS BECOME MORE
WIDESPREAD BUT STILL SOME BREAKS AROUND THE FRONT RANGE AIRPORTS
TO CONTEND WITH. AS WEAK NORTHERLY FLOW IS EXPECTED TO DEVELOP
THIS MORNING...THE MAIN AREA OF STRATUS WILL LIKELY BE THE
PREVAILING SKY CONDITION ALONG WITH A FEW FLURRIES AND SLIGHT
VISIBILITY RESTRICTION TO AROUND 3-5SM. CONDITIONS ARE EXPECTED TO
IMPROVE THIS AFTERNOON OR EARLY EVENING...BUT CONSIDERABLE
UNCERTAINTY WITH REGARD TO STRATUS BREAKUP EXISTS CONSIDERING
ARCTIC AIRMASS AND SHALLOW UPSLOPE COMPONENT. MAINLY VFR
CONDITIONS SHOULD PREVAIL BY 23Z-03Z AS WEAK DRAINAGE FLOW
DEVELOPS.

&&

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

$$

SHORT TERM...BARJENBRUCH
LONG TERM....DANKERS
AVIATION...BARJENBRUCH