FXUS65 KPUB 230229
AFDPUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
729 PM MST TUE DEC 22 2009
.UPDATE...
CURRENTLY...LIGHT SNOW IS NOTED ACROSS MANY AREAS ALONG THE I-25
CORRIDOR. RADAR LAST FEW VOLUME SCANS HAS STARTED TO LIGHTEN UP
ACROSS S EL PASO...N PUEBLO...CROWLEY AND OTERO COUNTIES. THIS
APPEARS TO BE THE LOCATION OF THE 700 MB TROUGH AXIS SEPARATING SW
WINDS FROM 700 MB SE WINDS.
FOR THE NEXT 24 HOURS...BASED ON NEW NAM GUIDANCE COMING IN...DO NOT
REALLY SEE ANY SIGNIFICANT CHANGES TO CURRENT FCST AND PLAN TO
LEAVE THINGS AS IS. BEST SNOW FOR THE PUEBLO-PIKES PEAK REGION
WILL BE FROM NOW THROUGH MID MORNING...WITH ANOTHER SHOT COMING IN
WITH THE ARCTIC AIR MASS TOMORROW EVENING/NIGHT.
AS 700 MB LOW MOVES EAST OF REGION EARLY TOMORROW...SNOWS SHOULD
PICK UP ACROSS THE E FACING SLOPES OF THE S MTNS AND THEN ALONG
THE RATON MESA. STRONGER SFC WINDS SHOULD ALSO BEGIN TO PICK UP BY
LATER TOMORROW AFTERNOON AS 700 MB GRADIENT BEGINS TO TIGHTEN.
\/HODANISH
&&
.PREV DISCUSSION... /ISSUED 330 PM MST TUE DEC 22 2009/
SHORT TERM...
(TONIGHT AND WEDNESDAY)
..SNOW AND COLD FOR TOMORROW...
WINTER STORM IS ON TRACK TO DELIVER LIGHT TO MODERATE SNOWFALL TO
THE REGION...ALONG WITH A BLAST OF COLD AIR. TEMPS HAVE STRUGGLED TO
GET OUT OF THE 30S OVR THE NRN I-25 CORRIDOR TODAY...WITH LOWERING
CIGS THRU THIS MORNING AND EARLY AFTERNOON. TO THE WEST...SNOW IS
COMING DOWN MODERATE TO HEAVY OVR THE SAN JUANS PER THE WOLF CREEK
SKI CAMS...AND IS LIKELY TO CONTINUE THRU AT LEAST THIS EVE. WARNING
CRITERIA LOOKS LIKELY TO BE MET THERE. ELSEWHERE...STORM DOES NOT
LOOK COLD ENOUGH...AND MID LEVEL WINDS NOT STRONG ENOUGH...FOR MAJOR
ACCUMULATIONS. HOWEVER...STILL FORESEE HAZARDOUS TRAVEL CONDITIONS
OVR A LARGE PORTION OF THE CWA...PARTICULARLY BY WED MORN AND LATER
AS WINDS PICK UP AND BLOWING SNOW BECOMES A CONCERN. OVERALL...4 TO
8 INCHES LOOKS ON TRACK IN GENERAL...WITH LESSER AMTS OVR THE
VALLEYS AND SOME HIGHER ACCUMS OVR THE HYR ELEVS. HAVE CONVERTED
REMAINING ZONES AND PREVIOUS WINTER STORM WATCH OVR THE PLAINS TO
SNOW AND BLOWING SNOW ADVISORIES. SHOULD BE A BRIEF WINDOW OF NE
WINDS OVR THE I-25 CORRIDOR...WHICH SHOULD ALLOW SOME ACCUMULATING
SNOW FOR EVEN THE KPUB-KCOS AREA...ALTHOUGH SHIFT TO N WINDS
TOMORROW MORN WILL MEAN AN END TO GOOD SNOW POTENTIAL THERE. BEST
SHOT FOR THIS AREA WILL BE IN THE 06Z-18Z TIME FRAME TONIGHT AND WED
MORNING. TEMPS NOT LIKELY TO RISE MUCH IF ANY TOMORROW AFTERNOON
WITH SNOW COVERAGE...LOW CLOUDS...AND FALLING TEMPS ALOFT. MID TO
UPPER 20S SHOULD HOLD FOR A GOOD PORTION OF THE PLAINS...WITH SOME
TEENS IN THE MTS IN DEEPER POWDER. 44
LONG TERM...
(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
UPPER LOW EJECTS INTO THE SOUTHERN PLAINS...WITH MID LEVEL CENTER
MIGRATING FROM EASTERN COLORADO WED EVENING INTO CENTRAL KS BY
EARLY THU MORNING. BEST LIFT OVERNIGHT LOOKS TO BE ALONG AND
NORTH OF THE PALMER DIVIDE...THOUGH COMBINATION OF SATURATED AIR
MASS AND WEAK SURFACE UPSLOPE GRADIENT WILL KEEP AT LEAST SOME
LIGHT SNOW GOING MOST AREAS THROUGH THE NIGHT. ADDITIONAL
ACCUMULATIONS LOOK FAIRLY LIGHT...GENERALLY 2 INCHES OR LESS. WINDS
WILL INCREASE OVER THE EASTERN HALF OF THE AREA AFTER 06Z AS
SURFACE LOW DEEPENS...WITH INCREASING CHANCES OF BLOWING SNOW OVER
THE PLAINS BY MORNING. WITH THE WINDS...EXPECTING BELOW ZERO WIND
CHILLS OVER MOST OF THE REGION FROM LATE WED NIGHT INTO MIDDAY
THU. ON THURSDAY...FIRST PIECE OF THE UPPER SYSTEM EJECTS
EASTWARD INTO THE MISSOURI VALLEY...WHILE SECOND UPPER LOW
PINWHEELS SOUTH INTO EASTERN COLORADO. LOW AND MID LEVEL FLOW
BECOMES INCREASINGLY DOWNSLOPE OVER THE AREA DURING THE DAY...THOUGH
AIR MASS MAY BE JUST MOIST AND UNSTABLE ENOUGH TO GENERATE FAIRLY
WIDESPREAD SNOW SHOWERS THROUGH SUNSET. KEPT THE WINTER WEATHER
ADVISORY GOING UNTIL EARLY THU EVENING MAINLY DUE TO POTENTIAL FOR
BLOWING AND DRIFTING SNOW...AS NORTHERLY WINDS ON THE PLAINS COULD
GUST TO 50 MPH ALONG THE KS BORDER THROUGHOUT THE DAY.
UPPER SYSTEM PULLS SLOWLY EASTWARD THU NIGHT...THOUGH QUICK LOOK
AT 18Z GFS SUGGESTS EASTWARD PROGRESSION MAY BE EVEN SLOWER THAN
12Z MODELS INDICATED. THIS SLOWER MOVEMENT MAY ALLOW SNOW SHOWERS
AND BLOWING SNOW TO CONTINUE OVER THE FAR EASTERN PLAINS THROUGH
MUCH OF THU NIGHT...ESPECIALLY NEAR THE KANSAS BORDER. AT THIS
POINT...WILL LET HIGHLIGHTS EXPIRE THU EVENING AND WILL WAIT TO
SEE HOW MUCH SNOW FALLS ON THE PLAINS BEFORE ANY EXTENSION.
CHRISTMAS DAY LOOKS COLD AND BREEZY...WITH MASSIVE UPPER LOW
LIFTING SLOWLY NORTHEAST INTO THE MISSISSIPPI VALLEY BY EVENING.
COULD BE ENOUGH WRAP AROUND MOISTURE FOR A FEW FLURRIES THROUGH
THE DAY...THOUGH CHANCES LOOK TOO LOW TO MENTION. WILL BE A WHITE
CHRISTMAS MOST AREAS...AS ANY SNOW THAT FALLS WED/THU WON'T BE
MELTING WITH DAYTIME TEMPS ONLY IN THE 20S.
BOTH GFS AND ECMWF PUSH THE UPPER LOW FAR ENOUGH EAST TO ALLOW AN
UPPER RIDGE TO BUILD OVER THE ROCKIES...THOUGH BOTH MODELS SUGGEST
A RATHER DEEP POCKET OF RESIDUAL COLD AIR WILL LINGER OVER THE
SOUTHERN ROCKIES...KEEPING MAX TEMPS COOL BOTH SAT AND SUN. WENT
AT OR BELOW GUIDANCE BOTH DAYS...ESPECIALLY RATHER EXTENSIVE SNOW
COVER.
FOR MON/TUE...FAIR AGREEMENT AMONG THE MODELS WITH RATHER
SUBSTANTIAL ENERGY UNDERCUTTING THE RIDGE...THOUGH DETAILS BEGIN
TO DIVERGE BY TUE...AS GFS KEEPS MOST ENERGY SUPPRESSED WELL SOUTH
OVER TEXAS...WHILE ECMWF LIFTS A RATHER HEALTHY UPPER LEVEL LOW
INTO THE SOUTHERN PLAINS...SPREADING MODERATE TO HEAVY SNOW OVER
TO THE SOUTHERN HALF OF THE FORECAST AREA BY LATE TUE. LOW POPS
FROM MON NIGHT INTO TUE LOOK FINE FOR NOW...WITH TEMPERATURES
REMAINING ON THE COOLER SIDE OF GUIDANCE. --10
AVIATION...SHOULD SEE DETERIORATING CONDITIONS TONIGHT OVR ALL OF
THE AREA...WITH WORST CONDITIONS OVR THE MTS AND PORTIONS OF THE
PALMER DVD AND ERN CO PLAINS TOMORROW MORN. WORST CONDITIONS FOR
THE TAF SITES SHOULD BE IN THE 09Z-15Z TIME FRAME...WHEN KCOS AND
POSSIBLY KPUB COULD SEE LIFR CONDITIONS IN SNOW. N WINDS WILL
INCREASE THRU THE DAY ON WED OVR THE ERN COUNTIES NR THE KS
BORDER...RESULTING IN BLSN AT THE SURFACE. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM WEDNESDAY TO 5 PM MST THURSDAY
FOR COZ087>089-093-094-097>099.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THURSDAY FOR COZ058>066-
072>082-084.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 5 PM MST
THURSDAY FOR COZ083-085-086-095.
WINTER STORM WARNING FROM 11 PM THIS EVENING TO 5 PM MST
THURSDAY FOR COZ096.
WINTER STORM WARNING UNTIL 11 AM MST WEDNESDAY FOR COZ068.
WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY FOR COZ067.
&&
$$
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