FXUS65 KPUB 241528 AAA
AFDPUB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PUEBLO CO
828 AM MST THU DEC 24 2009
.UPDATE...
SENDING OUT A QUICK UPDATE TO REMOVE POPS ALL ZONES TODAY...AND
CUT BACK POPS OVR THE NRN MTNS THIS EVE. BASED ON SAT AND
OBS...ALONG WITH MOST RECENT MODEL DATA...DO NOT SEE ANY
APPRECIABLE CHANCE OF MEASURABLE PRECIP TODAY. MAY SEE A FEW
FLURRIES OVR THE DVD. NEXT WAVE COMES IN LATE TONIGHT...WHEN
SAWATCH AND LAKE COUNTY COULD SEE SOME LIGHT SNOW LATE. ROSE
&&
.PREV DISCUSSION... /ISSUED 430 AM MST THU DEC 24 2009/
SHORT TERM...
(TODAY AND TONIGHT)
..MAIN CONCERNS ARE BLOWING SNOW POTENTIAL FOR PORTIONS OF THE
SOUTHEAST PLAINS TODAY...AND WIND CHILLS TONIGHT ESPECIALLY ACROSS
THE HIGHER TERRAIN AND ADJACENT LOWER EASTERN SLOPES...
ONE LAST BAND OF SNOW FINALLY WANING ACROSS THE SOUTHEAST MTS/PLAINS
..A PRODUCT OF ARCTIC AIR...AND WEAK UPSLOPE FROM SYSTEM DROPPING
IN FROM THE NORTH. SOME WEAK ISENTROPIC UPGLIDE STILL ONGOING ACROSS
THE FAR EASTERN PLAINS ON VERY NORTHERN FRINGES OF UPPER LOW MOVING
THROUGH TX. ALL THE MODELS HAVE THIS AREA OF PRECIP QUICKLY
DIMINISH AFTER 15Z...SO WILL DECREASE MORNING POPS IN CURRENT GRID
SET. MAIN CONCERN STILL REVOLVES AROUND WIND AND BLOWING SNOW
ISSUES ACROSS PORTIONS OF THE SOUTHEAST PLAINS. AREAS WITH THE
GREATEST SNOW COVER...SUCH AS PORTIONS OF NORTHERN AND EASTERN EL
PASO COUNTY...AND THE SOUTHEAST PLAINS WHICH RECEIVED MORE THAN A
COUPLE INCHES...ARE LIKELY TO SEE REDUCED VISIBILITIES IN BLOWING AND
DRIFTING SNOW. GREATEST IMPACT AREA WILL BE ACROSS THE EASTERN-MOST
COUNTIES WHERE CURRENT WINTER WEATHER ADVISORY IS IN EFFECT. SO
PLAN TO KEEP THIS HEADLINE GOING THROUGH TODAY. GUSTS UP TO 40 MPH
WILL BE POSSIBLE THROUGH THE DAY ACROSS THESE COUNTIES BEFORE
DIMINISHING BY LATE AFTERNOON/EARLY EVENING. BLOWING SNOW ACROSS
HIGHWAYS ARE LIKELY TO KEEP THEM SLICK AND HAZARDOUS IN SPOTS.
ACROSS THE MOUNTAINS...ONLY GETTING VERY LIGHT SNOW REPORTS FROM
SPOTTERS AND ANY ADDITIONAL SNOWFALL WILL REMAIN LESS THAN AN
INCH...SO WILL CANCEL THESE HEADLINES WITH MORNING ISSUANCE.
WITH COLD AIR ADVECTING IN FROM THE NORTH...MAX TEMPS TODAY WILL
ONLY MAKE IT INTO THE 20S FOR HIGHS ACROSS THE PLAINS...WITH SINGLE
DIGITS FOR THE HIGHER MOUNTAIN PEAKS. THIS WILL PUT WIND CHILLS IN
THE SINGLE DIGITS AND TEENS DURING THE DAY. WINDS DIMINISH ACROSS
THE LOWER ELEVATIONS BY EARLY EVENING...AND WITH COLD AIR IN
PLACE...SHOULD SEE MIN TEMPS DROP INTO THE SINGLE DIGITS ABOVE AND
BELOW ZERO WITH NEGATIVE TEENS IN THE MOUNTAINS/TRAPPING VALLEYS.
AS UPPER LOW TO THE NORTH DROPS THROUGH THE NRN PLAINS...SHOULD
START TO SEE WINDS INCREASE ACROSS THE HIGHER PEAKS AND NRN EL PASO
COUNTY TOWARDS MORNING. THESE AREAS MAY NEED A WIND CHILL ADVISORY
FOR LATER TONIGHT. FOR NOW THINK THESE AREAS WILL BE CONFINED TO THE
HIGHER MOUNTAIN LOCATIONS...WITH WINDS MOSTLY DECOUPLED ACROSS THE
LOWER ELEVATIONS. SHOULD WINDS MIX DOWN THE LOWER EASTERN
SLOPES...TEMPS WILL WARM SOME WHICH MAY KEEP THEM JUST ABOVE THE -18
THRESHOLD FOR A WIND CHILL ADVISORY. EITHER WAY...WILL LET LATER
SHIFTS TAKE A LOOK AT THIS AND BETTER HONE DOWN AREA FOR POTENTIAL
WIND CHILL HIGHLIGHTS.
LONG TERM...
(FRIDAY THROUGH WEDNESDAY)
CHRISTMAS DAY...THE SECOND UPPER LOW DROPS DOWN ACROSS WESTERN NE
AND THE NE CORNER OF COLORADO FRIDAY MORNING...THEN ACROSS KANSAS
AND INTO MO BY THE EVENING. NAM...GFS AND ECMWF MODELS ARE NOW IN
FAIRLY GOOD AGREEMENT WITH THIS SOLUTION...KEEPING LIGHT PCPN MAINLY
ACROSS THE NORTHERN HALF OF THE STATE THRU THE DAY FRI...THEN ENDING
PCPN AS THE LOW PULLS AWAY. THE PROXIMITY OF THE MODEL QPF INFERS
THAT AT LEAST ISOLATED POPS FOR THE CENT MTS...RAMPART RANGE AND
PALMER DVD IS REASONABLE...AND ONLY ADJUSTED THE ONGOING POP GRIDS
SLIGHTLY. A TIGHT PRESSURE GRADIENT MEANS VERY GUSTY WINDS FOR THE
PLAINS ON FRI...WITH THE STRONGEST WINDS EXPECTED IN THE MORNING AND
AFTN UNTIL AROUND 00Z.
SATURDAY THROUGH MONDAY...DRY AND GRADUALLY WARMING OVER THE WEEKEND
AND INTO MON AS THE UPPER LOW SLOWLY HEADS TOWARDS THE GREAT
LAKES...AND TEMPORARY RIDGING DEVELOPS OVER THE GREAT BASIN AND 4
CORNERS REGIONS. MEANWHILE...ANOTHER UPPER LOW WAITS
OFF-SHORE...FOLLOWING SOUTHWARD ALONG THE WEST COAST TO SOUTHERN CA
THRU THE DAY MON.
TUESDAY AND WEDNESDAY...THE WEST COAST LOW MOVES ONSHORE ACROSS S CA
AND THE CA BAJA LATE MON NIGHT/EARLY TUE MORNING...THEN QUICKLY
TRACKS ACROSS AZ AND NM BEFORE OPENING UP AND MOVING INTO THE
CENTRAL US ON WED. MEANWHILE...ANOTHER DISTURBANCE MOVES ACROSS THE
N ROCKIES AS AN OPEN WAVE ON WED...BEFORE MERGING INTO THE CENTRAL
US AS WELL. GFS AND ECMWF ARE CLOSE IN THE EXTENDED SOLUTION...BUT
OBVIOUSLY THERE IS SOME UNCERTAINTY CONCERNING PCPN POTENTIAL AND
TIMING. CURRENT GRIDS PAINT ISOLATED PCPN BEGINNING ALONG THE
CONTDVD AS EARLY AS MON...THEN ISOLATED POPS SPREADING ACROSS THE
ENTIRE CWA THRU TUE NIGHT. FEEL THAT MON MAY BE A BIT EARLY FOR THE
ONSET OF PCPN...BUT SINCE THE TIMING OF THE INCOMING LOW IS
QUESTIONABLE THERE IS NO NEED TO CHANGE THIS JUST YET. EXPECT
ENHANCED CLOUD COVER AND COOLER TEMPS FOR TUE AND WED. 27
AVIATION...
VFR CIGS EXPECTED AT TAF SITES THROUGH THE MORNING WITH GUSTY
NORTH WINDS 15-30 KTS AT KCOS AND KPUB THROUGH THE MORNING/EARLY
AFTERNOON. WINDS WILL DECREASE LATER THIS AFTERNOON AND SWING
AROUND FROM THE EAST. VFR CONDITIONS EXPECTED AT ALL THREE TAF
SITES TONIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR
COZ095>099.
&&
$$
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