FXUS65 KPUB 051102
AFDPUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
402 AM MST SAT DEC 5 2009
.SHORT TERM...
(TODAY AND TONIGHT)
CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING
MODERATE TO STRONG WESTERLY FLOW ALOFT ACROSS THE STATE AS AN UPPER
TROUGH CONTINUES TO DIG INTO THE NORTHERN GREAT BASIN WITH ITS
ASSOCIATED JET CORE TRANSLATING ACROSS THE NORTHERN ROCKIES ATTM.
WATER VAPOR IMAGERY ALSO INDICATING MORE CANADIAN ENERGY DIVING DOWN
THE BACKSIDE OF TROUGH INTO THE PAC NW ATTM. AT THE SFC...WEAK LEE
TROUGHING ALONG THE I-25 CORRIDOR KEEPING BREEZY WESTERLY WINDS AT
TIMES ACROSS THE LOWER EASTERN SLOPES WITH TEMPS IN THE 20S TO LOWER
30S FOR THE HIGHER TERRAIN WEST OF I-25...WITH TEENS TO SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE REST OF THE AREA ATTM.
TODAY AND TONIGHT...MODELS REMAIN IN DECENT AGREEMENT WITH NORTHERN
ROCKIES JET CORE CONTINUING TO TRANSLATE ACROSS THE NORTHERN HIGH
PLAINS THROUGH THE LATE MORNING WITH UPPER TROUGH ELONGATING ACROSS
GREAT BASIN AS CANADIAN ENERGY CONTINUES TO DIG ACROSS THE PAC NW.
PASSING NORTHERN ROCKIES JET CORE ALLOWS FOR A WEAK BACKDOOR FRONT
TO SLIDE ACROSS THE EASTERN PLAINS WITH EAST TO NORTHEAST LOW LEVEL
FLOW DEVELOPING THROUGH LATE MORNING AND AFTERNOON. HAVE AGAIN
STAYED ON THE COOL SIDE OF GUIDANCE FOR HIGHS WITH WARMEST READINGS
ACROSS THE SOUTHEAST MTS AND RATON MESA AREA. SHOULD CONTINUE TO
SEE INCREASING HIGH CLOUDS ACROSS THE AREA THROUGH THE AFTERNOON AND
HAVE CUT POPS ACROSS THE CENTRAL MTS FOR THE AFTERNOON AS MOISTURE
REMAINS WELL ABOVE MT TOPS. WILL SEE INCREASING AVAILABLE MOISTURE
ACROSS THE AREA THROUGH THE EVENING WITH GREAT BASIN TROUGH FINALLY
LIFTING OUT ACROSS THE NORTHERN ROCKIES AS SECONDARY CANADIAN JET
CORE ROUNDS THE BASE OF THE SYSTEM ACROSS THE SOUTHERN GREAT BASIN.
WITH INCREASING MOISTURE...UVV AND OROGRAPHICS FLOW...SHOULD SEE
LIGHT SNOW DEVELOPING ACROSS THE SW AND CENTRAL MTS THROUGH THE LATE
EVENING AND HAVE INCREASED POPS TO MATCH. HAVE GONE WITH 1 TO 3
INCHES FOR THE TONIGHT PERIOD AND LATER SHIFTS MAY NEED TO HOIST AN
ADVISORY FOR THE CENTRAL MTS AS SNOW SHOULD CONTINUE THROUGH THE DAY
ON SUNDAY. ACROSS THE PLAINS...SECONDARY SURGE OF COLD AIR FILTERS
DOWN AND SATURATES THE LOW LEVELS WITH STRATUS FILLING IN ACROSS
THE PLAINS THOUGH THE EVENING. H7 FLOW BECOMES SOUTH TO
SOUTHEASTERLY ACROSS THE EASTERN MTS THROUGH THE LATE EVENING AHEAD
OF PASSING TROUGH AND SHOULD SEE LIGHT SNOW DEVELOPING WITH MOISTURE
OVERRUNNING THE COLD DOME AT THE SFC. BEST OVERRUNNING LOOKS TO BE
OVER THE MID ARKANSAS RIVER VALLEY THROUGH THE PIKES REGION AND
NORTHWARD...AND HAVE INCREASED POPS ACROSS THESE AREAS WITH ACCUMS
OF 1 TO 2 INCHES POSSIBLE AFTER MIDNIGHT THROUGH EARLY SUNDAY
MORNING. -MW
.LONG TERM...
(SUNDAY THROUGH FRIDAY)
ACTIVE WEATHER PATTERN IS IN STORE...WITH SIGNIFICANT SNOW LIKELY
FOR THE SOUTHWEST MOUNTAINS AND PORTIONS OF THE CENTRAL MOUNTAINS.
ON SUNDAY AN UPR TROF WL MOVE FROM OVR UT IN THE MORNING ACRS CO
DURING THE DAY. THIS SYSTEM SHOULD BRING SNOW TO THE MOUNTAINS AND
TO PORTIONS OF THE LOWER ELEVATIONS OVR NRN AREA OF THE CWA. TEMPS
SUN WL BE WELL BELOW NORMAL. STRONG WESTERLY FLOW THEN DEVELOPS OVR
THE AREA SUNDAY NIGHT AS AN UPR LOW MOVES OVR NRN CA/SERN OR AND
NRN NV. PCPN CHANCES WL DECREASE SOME FOR SUNDAY NIGHT BEING IN
BETWEEN SYSTEMS...BUT WITH A 120KT JET OVERHEAD ALONG WITH SOME
MSTR AND AREAS OF FAVORABLE UPSLOPE WINDS...WL KEEP ISOLD TO SCT
POPS IN THE FORECAST THRU THE NIGHT.
MON BEGINS A PERIOD OF SIGNIFICANT SNOW FOR THE SW MTS AND PORTIONS
OF THE CENTRAL MTS. UPR LOW WL BE SITTING ALONG THE NORTHERN
BORDER AREA OF CA AND NV...SO THE FLOW OVR OUR AREA BECOMES MORE
SOUTHWESTERLY AND REMAINS STRONG. THE UPR LOW IS EXPECTED TO
WEAKEN BY TUE MORNING AND THE UPR TROF BEGINS MOVING EASTWARD INTO
UT BY MIDDAY TUE. A GOOD FETCH OF DEEP MOISTURE ALONG WITH
FAVORABLE OROGRAPHIC FLOW INTO THE SW MTS DURING THIS PERIOD WL
LEAD TO SIGNIFICANT SNOWFALL. PORTIONS OF THE CENTRAL MOUNTAINS WL
ALSO SEE SIGNIFICANT SNOWFALL...BUT THE HIGHEST ACCUMULATIONS WL
BE IN EASTERN SAN JUAN MTS...WHERE A FEW FEET OF SNOW WL BE
LIKELY.
THE GFS IS A LITTLE QUICKER MOVING THE UPR TROF INTO CO THAN THE
NAM...AN IT HAS THE TROF INTO WRN KS BY 00Z WED. AS THE UPR TROF
WORKS ITS WAY EAST...THE MSTR AND FAVORABLE OROGRAPHICS WL
DECREASE OVR THE WRN MTS AND WL SEE THE PCPN CHANCES DECREASE. THE
GFS HAS THE SFC LOW MIDDAY TUE IN THE VCNTY OF KLHX WITH THE
BETTER PCPN CHANCES MAINLY NORTH OF THE CWA AT THIS TIME. THE
ECMWF LOOK QUITE SIMILAR. HOWEVER...THE SFC LOW IS THEN FORECAST
TO MOVES SOUTHEASTWARD...WHICH THEN LEADS TO STRONG NORTHERLY FLOW
OVR THE PALMER DVD AND PORTIONS OF THE SERN CO PLAINS...WITH SNOW
CHANCES THEN BEING QUITE GOOD IN THESE AREAS ALONG WITH BLOWING
SNOW...ALTHOUGH IT LOOKS LIKE IT WILL BE A FAIRLY QUICK SHOT. AT THIS
TIME THE GFS REALLY DOES NOT SHOW ALL THAT MUCH FOR ACCUMULATION
IN THESE AREAS...HOWEVER THERE IS PLENTY OF TIME FOR THE TRACK OF
THIS STORM TO CHANGE. THE LOW IS FORECAST TO THEN CONTINUE ITS
FAST TRACK AWAY FROM THE FORECAST AREA TUE NIGHT WITH PCPN CHANCES
DECREASING.
UNSETTLED NORTHWEST FLOW THEN WL BE FOUND OVR THE AREA WED AND WED
NIGHT WITH THE POTENTIAL FOR SOME LIGHT MT SNOWS. THEN FOR THU THE
GFS SHOWS THE FLOW TRANSITIONING TO A WESTERLY DIRECTION AND IT
LOOKS FAIRLY DRY FOR THU...BUT ON FRI A NEW SHORTWAVE TROF IS
FORECAST TO MOVE OVR THE AREA AND BRING SOME PCPN...MAINLY TO THE
SW AND CENTRAL MTS.
TEMPS WL BE QUITE COOL THROUGH WEDNESDAY AND MAY FINALLY WARM TO
AROUND NORMAL BY THU.
&&
.AVIATION...
VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE LATE AFTERNOON
WITH WEAK EAST TO NORTHEAST WINDS DEVELOPING ACROSS THE EASTERN
PLAINS THROUGH THE AFTERNOON. A SECONDARY SURGE OF COLD AIR WILL
MOVE ACROSS THE EASTERN PLAINS THIS EVENING WITH MVFR AND IFR CIGS
DEVELOPING THROUGH THE OVERNIGHT ACROSS THE PLAINS. OCCASIONAL LIGHT
SNOWFALL IS EXPECTED TO DEVELOP AFTER MIDNIGHT ACROSS THE EASTERN
MTS...THOUGH ANY ACCUMULATION IS EXPECTED TO ACROSS THE PIKES PEAK
REGION AND NORTHWARD. -MW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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