FXUS65 KPUB 251117
AFDPUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
417 AM MST FRI DEC 25 2009

.SHORT TERM...
(TODAY AND TONIGHT)

WINDY CONDITIONS ARE OCCURRING OVR THE HIGHER ELEVATIONS THIS 
MORNING...WITH REPORTS AT MONARCH PASS INDICATING GUSTS TO ABOUT 50 
MPH...AND REPORTS ON PIKES PEAK INDICATING GUSTS OF 50 TO 60 MPH.  
THESE WINDS ALONG WITH THE SUB-ZERO TEMPS ARE LEADING TO VERY COLD 
WIND CHILL TEMPS.  WL LEAVE WIND CHILL ADVISORY IN PLACE FOR THE 
HIGH COUNTRY.  

THE EXISTING MSTR AND FAVORABLE NW FLOW OVR PORTIONS OF THE CENTRAL 
MTS HAS LEAD TO SOME LIGHT SNOW IN THIS AREA TONIGHT...WITH LITTLE 
CHANGE EXPECTED TODAY OR TONIGHT...SO WL HAVE SOME LIKELY POPS IN 
THE FORECAST...BUT EXPECT ONLY SOME LIGHT ACCUMULATIONS. 

A NEW UPR LOW WL CONTINUE DROPPING SOUTH...MOVING INTO KS 
TODAY...PUSHING EVEN COLDER AIR ALOFT INTO THE AREA.  HIGH TEMPS FOR 
TODAY WL BE WELL BELOW NORMAL AGAIN.   EXPECT PCPN CHANCES TO BE 
LIMITED TO THE CENTRAL MTS THIS MORNING.  WITH THE UPR DYNAMICS OVR 
THE AREA ASSOCIATED WITH THE UPR LOW THIS AFTERNOON...AND SOME 
INCREASE IN MSTR OVR NRN PORTIONS OF THE CWA...WL KEEP SOME LOW POPS 
OVR THESE AREAS IN ADDITIONS TO SOME LOW POPS OVR THE SW AND SE 
MTS.  THE MODELS KEEP THE BEST MSTR TONIGHT TO THE NORTH AND EAST OF 
THE AREA...ALONG WITH THE PCPN CHANCES...WITH THE EXCEPTION OF THE 
CENTRAL MTS.  THEY ALSO SHOW THAT SOME LIGHT PCPN WL BE POSSIBLE OVR 
PORTIONS OF THE PALMER DVD AND EASTWARD OVR KIOWA COUNTY...SO WL 
KEEP THIS IN THE FORECAST.  

.LONG TERM...
(SATURDAY THROUGH THURSDAY)

SATURDAY THROUGH TUESDAY...THE UPPER LOW IS FORECAST TO STAGNATE 
SOMEWHAT OVER ILLINOIS SATURDAY INTO SUNDAY...KEEPING A HINT OF PCPN 
OVER NORTHERN CO THRU SAT MORN. BY SAT EVE THE PRESSURE GRADIENT 
RELAXES...AND WINDS ARE EXPECTED TO DECREASE AS WELL AS ANY PCPN 
THREAT. THE UPPER FLOW THEN BECOME NONDESCRIPT AND WEAK AS THE NEXT 
UPPER LOW FINALLY MOVES ONSHORE MON...WELL SOUTH ACROSS OLD MEXICO. 
MODELS WANT TO DEVELOP A LONGWAVE TROUGH OVER THE WESTERN HALF OF 
THE COUNTRY THAT WOULD EVENTUALLY START MOVING ACROSS THE GREAT 
BASIN AND ROCKIES ON TUE...BUT AGAIN THE UPPER PATTERN REMAINS VERY 
CHAOTIC AND THE END RESULT LOOKS TO BE COOLER NW FLOW FOR THE STATE 
AS WELL AS ISOLATED PCPN POPS ONCE AGAIN FOR THE HIGHER TERRAIN. 
THEREFORE...LIGHTER WINDS WILL HAVE A HARD TIME SCOURING OUT THE 
COLD POOL...AND THE WARMING TREND FROM SAT THROUGH TUE WILL BE VERY 
SLIGHT. AFTER THE FIRST HALF OF SAT...FORECAST STAYS DRY UNTIL MON 
MORNING WHEN INCREASING MOISTURE OVER THE DESERT SW SHOULD BRING 
INCREASED CLOUDINESS AND AT LEAST AN ISOLATED THREAT OF PCPN FOR THE 
CONTDVD.

WEDNESDAY AND THURSDAY...GFS AND ECMWF MODELS CONTINUE WITH THE 
LONGWAVE TROUGH SOLUTION FOR THE EXTENDED PERIOD...WITH THE TROUGH 
AXIS FINALLY CROSSING THE STATE LATE WED. A REINFORCING SURGE OF 
COLD AIR ON THU SHOULD COMBINE WITH AVAILABLE MID AND HIGH LEVEL 
MOISTURE FOR COOLER TEMPS BY THU...AS WELL AS ISOLATED POPS FOR THE 
MTS BOTH WED AND THU. LOTS OF UNCERTAINTY WITH THIS SOLUTION AT THIS 
TIME...SO WILL NOT ADJUST OUTER PERIODS. MOORE

&&

.AVIATION...
EXPECT VFR CONDITIONS AT THE THREE TAF SITES TODAY. SNOW OVR THE
CENTRAL MTS TODAY AND TONIGHT WL OBSCURE THE MTS. LIGHT SNOW
SHOWERS WL ALSO BE POSSIBLE OVR THE SE MTS THIS AFTERNOON AND
TONIGHT...AND IF THIS OCCURS WL CAUSE SOME MOUNTAIN OBSCURATIONS.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 8 AM MST THIS MORNING FOR COZ058>061-
063-065>068-072>075-082.

&&

$$

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