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000
FXUS65 KBOU 080721
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1221 AM MST SAT MAR 8 2014

.UPDATE...WITH CLEARING FROM THE NORTH PUSHING THE SNOW
SOUTH...HAVE ENDED THE ADVISORIES OVER ZONE 39 AND CANCELLED THE
WARNING FOR THE NORTHERN MOUNTAIN ZONE 33. HAVE ADDED FOG INTO THE
PLAINS FORECAST TONIGHT AS OBSERVATIONS ARE BEGINNING TO SHOW THIS
DEVELOP AS SKIES CLEAR. MAY EXPERIENCE SOME AREAS OF LOCALLY DENSE
FOG TOWARDS MORNING....WILL KEEP MONITORING.

&&

.AVIATION...LOW CIGS/VSBYS STILL POSSIBLE THROUGH THE NIGHT. MOST
OF THE SNOW HAS MOVED SOUTH OF THE AREA AIRPORTS. CLEARING SKIES
LATE COULD LEAD TO POTENTIAL DENSE FOG ISSUES THROUGH 15Z...WHICH
IS ALREADY ADDRESSED IN THE CURRENT TAF. CEILINGS TO THEN INCREASE
THROUGH THE REST OF THE MORNING...BECOMING UNLIMITED BY 17Z. MVFR
CONDITIONS TO PERSIST. LIGHT SOUTHERLY WINDS TO PREVAIL THROUGH
THE DAY.

&&

.PREV DISCUSSION... /ISSUED 927 PM MST FRI MAR 7 2014/

UPDATE...HAVE DROPPED THE WINTER STORM WARNING FOR ZONE 35 AND
THE WINTER WEATHER ADVISORIES FOR ZONES 31..40 AND 45. ALTHOUGH
DRY AIR HAD INTRUDED FM THE NORTH THERE HAS BEEN SOME
REDEVELOPMENT OF LIGHT SNOW OVER THE METRO AREA.  WL HANG ONTO
THE HIGHLIGHTS FOR ZONES 33..34..36..39 AND 41. SOME LIGHT
ACCUMULATIONS IN DENVER (AN INCH OR LESS) BUT EXPECT THE SNOW TO
DIE OFF AFTER MIDNIGHT.

AVIATION...LOW CIGS/VSBYS WL LIKELY LINGER THROUGH 06Z AS LIGHT
SNOW HAS REDEVELOPED OVER DENVER BUT STILL EXPECT CONDITIONS TO
IMPROVE AFTER MIDNIGHT (07Z). CLEARING SKIES LATE COULD LEAD TO
POTENTIAL FOG ISSUES WHICH IS ALREADY ADDRESSED IN THE CURRENT
TAF. DO NOT PLAN ON MAKING ANY CHANGES TO THAT TEMPO GROUP IN THE
UPCOMING TAFS.

PREV DISCUSSION... /ISSUED 350 PM MST FRI MAR 7 2014/

SHORT TERM...PRECIPITATION CONTINUING ACROSS MUCH OF THE PLAINS.
SURFACE OBS INDICATING THE PRECIPITATION IS IN THE FORM OF
SNOW...WITH SOME RAIN MIXED IN OVER THE FAR NORTHEAST CORNER.
RADAR INDICATING A GRADUAL DECREASE IN INTENSITY WITH THE AREA OF
HEAVIER SNOW MOVING ACROSS THE PALMER DIVIDE. SNOW CONTINUING
ACROSS THE MOUNTAINS AND ALONG THE FOOTHILLS AND HAS BEEN HEAVY AT
TIMES EAST OF THE CONTINENTAL DIVIDE. SOME LOCATIONS GETTING CLOSE
TO A FOOT OF SNOW. LATEST RAP AND HRRR CONTINUE TO SHOW A
DECREASING TREND IN THE PRECIPITATION THIS EVENING AS THE MAIN
BAND OF SNOW SHIFTS SOUTHWARD. BUT UPPER TROUGH AXIS STILL
EXPECTED TO SHIFT ACROSS THE AREA DURING THE EVENING WITH
CONTINUED ASCENT ALTHOUGH THE MAIN ASCENT TO REMAIN ACROSS
SOUTHERN COLORADO. THIS SHOULD KEEP SNOW ONGOING ACROSS MUCH OF
THE MOUNTAINS AND ALONG THE FOOTHILLS THROUGH TONIGHT. FOOTHILL
AREAS TO BE HELPED BY UPSLOPE. SOME DRYING AND SUBSIDENCE TO
SPREAD INTO THE AREA AFTER MIDNIGHT...BUT FLOW ALOFT BECOMES
NORTHWEST WHICH IMPROVES MOUNTAIN OROGRAPHICS. WILL MAINTAIN
CURRENT WARNINGS AND ADVISORIES FOR THE MOUNTAINS...FOOTHILLS AND
SOUTH PARK GOING FOR TONIGHT. ACROSS PLAINS...EXPECT SNOW TO
CONTINUE THROUGH THE EVENING...GRADUALLY DECREASING FROM NORTH TO
SOUTH. ADVISORY FOR ZONES 39..40 AND 41 STILL SEEMS ON TRACK FOR
TONIGHT. SO FAR...SNOW HAS NOT AFFECTED TRAVEL OUTSIDE OF PERHAPS
LOWER VISIBILITY. BUT AS TEMPERATURES THIS EVENING...SHOULD SEE
SNOW STICK TO THE ROADWAYS WHICH WOULD CREATE A SLOW COMMUTE. SNOW
AMOUNTS MAY END UP LESS THAN ADVISORY CRITERIA. SNOW TO DECREASE
OVERNIGHT AS TROUGH MOVES EAST OF THE AREA. ON SATURDAY...
NORTHWEST FLOW WILL BE OVER THE AREA AS RIDGE BUILDS ACROSS THE
GREAT BASIN. SOME LIGHT SNOW MAY LINGER OVER THE SOUTHERN
MOUNTAINS...FOOTHILLS AND SOUTH PARK DURING THE MORNING. OTHERWISE
DRY CONDITIONS TO PREVAIL. WARM AIR ADVECTION DURING THE
AFTERNOON...BUT EXISTING SNOW COVER WILL LIMIT WARMUP.

LONG TERM...MODELS HAVE NORTHWESTERLY JET LEVEL FLOW OVER THE CWA
SATURDAY NIGHT INTO SUNDAY AFTERNOON. THE FLOW ALOFT BECOMES
NORTHWESTERLY SUNDAY NIGHT...THEN ZONAL ON MONDAY. BY MONDAY
NIGHT...A WEST-SOUTHWESTERLY JET MAXIMUM IS PROGGED OVER COLORADO.
AN UPPER RIDGE AXIS PUSHES SOUTH SETTLING ON COLORADO SATURDAY
NIGHT INTO SUNDAY EVENING. THE QG VERTICAL VELOCITY FIELDS HAVE
DOWNWARD MOTION OVER THE FORECAST AREA SATURDAY NIGHT INTO SUNDAY
EVENING...THEN NEUTRAL FORCING IS PROGGED WELL INTO MONDAY. BY
MONDAY NIGHT...UPWARD ENERGY MOVES IN AHEAD OF THE NEXT TROUGH.
THE BOUNDARY LAYER FLOW LOOKS TO BE DOMINATED BY SOUTHWESTERLY
DOWNSLOPING SATURDAY NIGHT THROUGH SUNDAY NIGHT. NORMAL DIURNAL
PATTERNS LOOK GOOD FOR MONDAY...THEN SOME OF THE MODELS BRING IN
UPSLOPE WITH THE NEXT TROUGH MONDAY NIGHT. SOME SHOW THE FRONT IN
HERE ON TUESDAY. FOR MOISTURE...IT IS PRETTY SPARSE SATURDAY NIGHT
THROUGH SUNDAY. SUNDAY NIGHT AND MONDAY...MODELS HAVE INCREASING
UPPER LEVEL MOISTURE. ON MONDAY NIGHT...MOISTURE INCREASES AND
DEEPENS OVER THE MOUNTAINS. THE QPF FIELDS SHOW NO MEASURABLE
PRECIPITATION FOR THE CWA SATURDAY NIGHT THROUGH MONDAY. THERE IS
A TAD OF MEASURABLE SNOWFALL OVER THE MOUNTAINS MONDAY NIGHT. WILL
KEEP POPS OUT THROUGH MONDAY...THEN BRING SOME IN MONDAY NIGHT
OVER THE MOUNTAINS. FOR TEMPERATURES...SUNDAY`S HIGHS ARE 7-13 C
WARMER THAN SATURDAY`S. MONDAY`S HIGHS ARE 2-3 C WARMER THAN
SUNDAY`S. FOR THE LATER DAYS...TUESDAY THROUGH FRIDAY...MODELS
HAVE AN UPPER TROUGH TO MOVE ACROSS COLORADO TUESDAY INTO TUESDAY
NIGHT ON THE ECMWF...THE GFS IS SLOWER AND KEEPS IT AROUND WELL
INTO WEDNESDAY. THE REST OF WEDNESDAY AND THURSDAY LOOK TO BE
DOMINATED BY UPPER RIDGING. MORE UPPER TROUGHING IS POSSIBLE FOR
FRIDAY BUT MODEL AGREEMENT IS NOT GOOD.

AVIATION...LIGHT SNOW CONTINUING ACROSS AREA WITH IFR CONDITIONS
PREVAILING ALONG WITH OCCASIONAL LIFR CONDITIONS. THE LIGHT SNOW
WITH MVFR CONDITIONS WILL CONTINUE THROUGH THE EVENING. NORTHEAST
WINDS TO GRADUALLY DECREASE DURING THE EVENING...BECOMING
SOUTHEAST BY 06Z. THE SNOW IS THEN EXPECTED TO DECREASE AFTER 06Z
AND COME TO AND END AROUND 09Z AS DRIER AIR MOVES IN FROM THE
NORTH. CONDITIONS TO SLOWLY IMPROVE AFTER 06Z WITH VFR CONDITIONS
EXPECTED BY 10Z ALTHOUGH THERE MAY BE CEILINGS AROUND 5000 FEET
AGL FOR A SHORT TIME. CEILINGS TO THEN INCREASE THROUGH THE REST
OF THE MORNING...BECOMING UNLIMITED BY 17Z. MFR CONDITIONS TO
PERSIST. LIGHT SOUTHERLY WINDS TO PREVAIL THROUGH THE DAY.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR
COZ041.

WINTER STORM WARNING UNTIL 2 AM MST EARLY THIS MORNING FOR
COZ036.

WINTER STORM WARNING UNTIL 5 AM MST EARLY THIS MORNING FOR
COZ034.

&&

$$

SHORT TERM...D-L
LONG TERM....RJK
UPDATE/AVIATION...KRIEDERMAN