FXUS65 KPUB 090638 AAB
AFDPUB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PUEBLO CO
1138 PM MST TUE DEC 8 2009
.UPDATE...
UPDATING FORECAST TO DROP LOW TEMPERATURES SOME MORE AS MINS HAVE
ALREADY DROPPED TO NEAR 20 DEGREES BELOW ZERO ACROSS PORTIONS OF
TELLER COUNTY WITH NEGATIVE TEENS ACROSS THE PALMER DIVIDE AND WET
MOUNTAIN VALLEY. WINDS HAVE COME DOWN AT VTP SENSOR...SO THINK
BLOWING SNOW IS PROBABLY NO LONGER AN ISSUE ACROSS THE
SANGRES...WETS AND PIKES PEAK EXCEPT FOR PERHAPS THE HIGHER PEAKS.
WINDS STILL GUSTING TO 40 KTS AT LATEST MYP SENSOR...AND 33 KTS AT
CPW SO WILL KEEP WINTER WEATHER ADVISORIES GOING THOUGH THINK MAIN
ISSUE IS TRANSITIONING TO MORE OF A BLOWING SNOW THAN FALLING SNOW
EVENT. WIND CHILLS QUITE COLD ACROSS MUCH OF THE AREA...DOWN TO
-25 ACROSS PORTIONS OF THE PLAINS...AND AS LOW AS 38 BELOW AT THE
WINDIEST MYP LOCATION. THUS WIND CHILL ADVISORIES LOOK ON TRACK. -KT
&&
.PREV DISCUSSION... /ISSUED 514 PM MST TUE DEC 8 2009/
UPDATE...
QUICK LOOK AT WEB CAMS AND VIS AT WOLF CREEK SKI AREA AND MONARCH
PASS STILL LOOK PRETTY LOW. MYP REPORTING GUSTS TO 49 KTS. SEEMS
TO WARRANT KEEPING A HIGHLIGHT FOR BLOWING SNOW ACROSS THE HIGHER
PEAKS THROUGH THE OVERNIGHT HOURS. THUS HAVE LET MOST OF THE
ADVISORIES AND WARNINGS EXPIRE AT 5 PM (EXCEPT THE WIND CHILL
ADVISORY WHICH IS GOOD THROUGH WED MORNING)...AND WILL HOIST A
WINTER WEATHER ADVISORY FOR THE HIGHER PEAKS OF THE CENTRAL AND
SOUTHWEST MOUNTAINS FOR A BRIEF PERIOD OF SNOW THIS
EVENING...ALONG WITH BLOWING SNOW THROUGH THE NIGHT. EXPECT
IMPROVING CONDITIONS ALONG THE LOWER SLOPES AS WINDS CONTINUE TO
DECOUPLE OVERNIGHT.
PREV DISCUSSION... /ISSUED 346 PM MST TUE DEC 8 2009/
SHORT TERM...
.EXTREMELY COLD TEMPERATURES ACROSS COLORADO TONIGHT...
CURRENTLY...
SKIES ALONG THE I-25 CORRIDOR AND THE EASTERN PLAINS ARE CLEARING
AS THE UPPER LEVEL LOW CONTINUES TO MOVE EASTWARD. THE REMNANTS OF
THIS SYSTEM CONTINUE TO BRING INTERMITTENT SNOW TO THE HIGHER
ELEVATIONS. THE STRONG PRESSURE GRADIENT CREATED BY THIS SYSTEM
WILL CONTINUE THROUGH THE FIRST FEW HOURS OF THE EVENING ALLOWING
FOR GUSTY WINDS ALONG THE FAR EASTERN PLAINS...AND IN THE
MOUNTAINS...ESPECIALLY THE SAN JUANS AND THE SAWATCH RANGES. HAVE
KEPT THE WINTER STORM WARNINGS IN FOR THE FIRST FEW HOURS FOR THIS
REASON.
TONIGHT...PATCHY AREAS OF BLOWING SNOW WILL PERSIST UNTIL MIDNIGHT
IN THE MOUNTAINS. AFTER MIDNIGHT THE LOW WILL BE FURTHER
EAST...ALLOWING FOR THE GUSTY WINDS TO CEASE. THE CLEARING SKIES AND
THE NORTHERLY FLOW WILL CAUSE AN INFLUX OF A COLD ARCTIC AIR MASS
WHICH SHOULD ALLOW FOR TEMPERATURES TONIGHT TO BE BITTERLY COLD. WITH
NEAR STEADY WINDS...HAVE ISSUED A WIND CHILL ADVISORY THAT WILL BE
VALID THROUGH 15Z. TEMPERATURE RANGES WITH THE WIND CHILL WILL BE
-15 TO -30 DEGREES ON THE PLAINS AS -25 TO -35 DEGREES IN THE
MOUNTAINS.
TOMORROW...SKIES WILL CONTINUE TO CLEAR AS THE DAY CONTINUES.
TEMPERATURES WILL REMAIN COLD WITH MAXIMUMS ONLY IN THE LOW 20'S.
WITH GOOD UPPER LEVEL FLOW PERSISTING OVER THE AREA...THE ELEVATED
TERRAIN WILL CONTINUE TO HAVE GUSTY DAYTIME WINDS...WITH A CHANCE
FOR SNOW THROUGH TOMORROW...AND PATCHY BLOWING SNOW. JMC
LONG TERM...
(WEDNESDAY NIGHT THROUGH TUESDAY)
UPPER TROUGH ACROSS THE CENTRAL PLAINS WILL BEGIN TO SHIFT
EASTWARD WITH COLD NORTHWEST FLOW ENTRENCHED OVER THE ROCKIES. THE
LAST IN A SERIES OF SHORTWAVE TROUGHS WILL BE TRANSVERSING THE
AREA WEDNESDAY EVENING AND INTO KS BY THURSDAY MORNING. EXPECT
LIGHT SNOW TO BE ONGOING OVER THE CENTRAL MOUNTAINS WEDNESDAY
EVENING. UPSLOPE NORTHWESTERLY FLOW AND VERY COLD TEMPERATURES
WILL COMBINE TO PRODUCE AN ADDITIONAL 1 TO 2 INCHES OF SNOWFALL
THROUGH THURSDAY MORNING. BITTER COLD TEMPERATURES WILL ONCE AGAIN
SPREAD ACROSS THE PLAINS BY THURSDAY MORNING. LOWS WILL DROP TO AS
LOW AS -10F OVER THE EASTERN PLAINS WITH COLDER TEMPERATURES IN
THE HIGHER ELEVATIONS. NOT ANTICIPATING MUCH IN THE WAY OF WINDS
OVER THE PLAINS WHICH WILL LIKELY KEEP WIND CHILL VALUES ABOVE
ADVISORY THRESHOLDS. THE ONLY PLACE OF CONCERN WILL BE THE
CENTRAL MOUNTAINS CLOSER TO THE UPPER LEVEL JET WHERE WINDS COULD
PRODUCE POSSIBLE WIND CHILL VALUES BELOW ADVISORY CRITERIA.
OPERATIONAL MODELS AND ENSEMBLES ARE IN REMARKABLE AGREEMENT WITH
EACH OTHER AND THE EXPECTED GLOBAL PATTERN. UPPER TROUGH WILL
PROGRESS INTO THE EASTERN CONUS WITH SUBTROPICAL BRANCH
UNDERCUTTING THE STRONG ALASKAN HIGH. GFS/ECMWF/GEM ALL
INDICATING A BREAK ON THURSDAY AND FRIDAY BEFORE A SERIES OF
TROUGHS MOVE OUT OF THE DESERT SOUTHWEST OVER THE WEEKEND INTO
EARLY NEXT WEEK. WHILE THERE ARE TIMING DIFFERENCES AMONG THE
MODELS...THEY ARE PRETTY MUCH IN LINE FOR THIS FAR OUT.
WEAK SHORTWAVE ACTIVITY WILL MOVE ACROSS THE DESERT SOUTHWEST AND
INTO NEW MEXICO ON THURSDAY AND FRIDAY WITH ALL THE FORCING
REMAINING WELL TO THE SOUTH. TEMPERATURES WILL BE SLOW TO REBOUND
EACH AFTERNOON WITH HIGHS IN THE UPPER 20S ON THURSDAY AND MID 30S
BY FRIDAY. STRONGER SHORTWAVE TROUGH WILL BE PROGRESSING ACROSS
THE INTERMOUNTAIN WEST ON FRIDAY WITH MODELS GENERATING LIGHT
SNOW ACROSS THE CENTRAL AND WESTERN MOUNTAINS BY LATE IN THE DAY
ON FRIDAY AND SATURDAY WITH LITTLE TO NO ACCUMULATIONS EXPECTED.
TEMPERATURES WILL WARM ON SATURDAY AND SUNDAY WITH WESTERLY FLOW
MIXING DOWN. HIGHS WILL TOP OUT IN THE MID 40S OVER THE EASTERN
PLAINS.
A MUCH STRONGER TROUGH WILL DEVELOP ALONG THE WEST COAST AND DIG
INTO THE DESERT SOUTHWEST BY SUNDAY AND ACROSS THE AREA ON MONDAY.
BEGAN TRENDING POPS UPWARDS FOR BOTH DAYS WITH ANOTHER ROUND OF
ACCUMULATING SNOWS FOR THE WESTERN AND CENTRAL MOUNTAINS IS POSSIBLE.
ALSO TRENDED TEMPERATURES DOWNWARD WITH COLD FRONT DROPPING ACROSS
THE PLAINS SUNDAY BRINGING COLDER AIR INTO THE REGION. SNOW WILL
SPREAD EASTWARD LATE SUNDAY INTO THE EASTERN PLAINS BEFORE COMING
TO AN END MONDAY. WHILE MODELS ARE IN GOOD AGREEMENT...UNCERTAINTIES
EXIST AND CHANGES CAN OCCUR WITH FUTURE MODEL RUNS. HIGH PRESSURE
IS FORECAST TO BUILD OVER THE ROCKIES BY THE MIDDLE OF NEXT WEEK
WITH WARMER AND DRIER CONDITIONS. 88
AVIATION...
VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD. SNOW FOR
MOST AREAS HAS STOPPED. THERE STILL WILL BE INTERMITTENT SNOW IN THE
ELEVATED TERRAIN...AS WELL AS GUSTY WINDS WHICH WILL LEAD TO AREAS
OF PATCHY BLOWING SNOW ALONG THE FAR EASTERN PLAINS AND IN THE
MOUNTAINS. WINDS WILL BE GUSTY FOR ALL TAF SITES UNTIL AROUND 01Z.
WINDS WILL BECOME SOUTH SOUTH EASTERLY BY EARLY MORNING. JMC
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 8 AM MST WEDNESDAY FOR COZ058>089-
093>099.
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY FOR COZ058-060-
066-068.
&&
$$
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