FXUS65 KCYS 291222
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
522 AM MST SUN NOV 29 2009

.SHORT TERM...TODAY THROUGH MONDAY NIGHT...IR SATELLITE LOOP SHOWS
MOSTLY CLEAR SKIES OVER SOUTHEAST WYOMING THIS MORNING WITH
CURRENT OBS SHOWING SOME PATCHY FREEZING FOG WEST OF THE LARAMIE
RANGE ALONG I80. LARAMIE AIRPORT HAS REPORTED A QUARTER MILE
VISIBILITY AND FOG THROUGH MOST OF THE NIGHT DUE TO CLEAR SKIES
AND LIGHT WINDS. WITH THE EXCEPTION OF SOME PATCHY FOG...QUIET
WEATHER IS EXPECTED THROUGH MONDAY AS MODELS SHOW THE COLD
FRONT...WHICH MOVED ACROSS THE AREA YESTERDAY MORNING...PUSHING
WELL SOUTHEAST OF THE AREA AND A WEAK RIDGE OF HIGH PRESSURE
BUILDS OVER CNTRL AND NRN ROCKIES. NAM AND GFS ALSO SHOW THE UPPER
LEVEL LOW OVER SRN CALIF AND ARIZONA DRIFTING FURTHER SOUTHEAST
INTO NRN MEXICO AND WELL AWAY FROM THE FORECAST AREA INTO MONDAY
NIGHT. WITH HIGH PRESSURE ALOFT AND DRY CONDITIONS...KEPT POP
AROUND ZERO WITH CLEAR SKIES THROUGH THE PERIOD. ADDED SOME PATCHY
FREEZING FOG SUNDAY NIGHT ACROSS THE LARAMIE VALLEY WITH NAM
SOUNDINGS SHOWING A SIMILAR PROFILE TO THIS MORNING...AS A VALLEY
INVERSION DEVELOPS IN THE EVENING UNDER CLEAR SKIES AND LIGHT
WINDS. AS THE RIDGE SHIFTS EASTWARD ON MONDAY AND MODELS SHOW
WINDS BACKING MORE OUT OF THE WEST AND INCREASING...EXPECT TEMPS
TO RETURN TO THE 50S EAST OF THE LARAMIE RANGE WITH SOME LOW 60S
POSSIBLE ACROSS THE LOWER ELEVATIONS OF THE NEBRASKA PANHANDLE.
EXPECT WEST WINDS TO INCREASE TO 15 TO 30 MPH WITH GUSTS UP TO 50
ALONG AND WEST OF THE LARAMIE RANGE BY LATE MONDAY. LOW TEMPS WILL
ALSO NOT BE AS COLD WITH MINS IN THE 20S AND LOW 30S OVER MOST OF
THE AREA.

.LONG TERM...TUESDAY THROUGH SATURDAY...
NEXT CLIPPER SYSTEM WILL BE SWEEPING DOWN INTO THE NORTHERN PLAINS
ON TUESDAY. THIS WILL PUSH A COLD FRONT ACROSS THE CWA FROM THE
NORTH DURING LATE MORNING AND AFTERNOON. TEMPS WILL ONLY BE A
LITTLE COOLER THAN MONDAY DUE TO THE TIMING OF THIS FRONT. WITH
LIMITED MOISTURE ACCOMPANYING THIS SYSTEM...ONLY LOW POPS NEEDED
MAINLY OVER THE WESTERN CWA. FAIRLY STRONG NNW FLOW ALOFT WILL
PREVAIL FOR WED AND THU...WITH DRY AND COOLER CONDITIONS EXPECTED.
CHANGES WILL BE MOVING IN FOR NEXT WEEKEND AND MODELS ARE HAVING
DIFFICULTIES RESOLVING THINGS. IT DOES LOOK LIKE A NARROW UPPER 
RIDGE WILL SHIFT OVER THE CWA ON FRIDAY WITH A LEE TROUGH SETTING 
UP AT THE SURFACE. THIS WILL BRING WINDY AREAS AND SLIGHTLY WARMER
TEMPS. AFTER FRIDAY THOUGH...THERE ARE A WIDE VARIETY OF SOLUTIONS
AND HAVE LEANED TOWARD CANADIAN FOR NOW WHICH IS AT LEAST SOMEWHAT
OF A COMPROMISE. GFS LOOKS TOO FAST AND A LITTLE BULLISH WITH
UPPER LOW MOVING INTO MT/ND LATE FRIDAY AND FRIDAY NIGHT...CANADIAN
HAS THIS MORE BACK OVER NORTHERN ID. ON THE OTHER HAND...ECMWF IS
TOO SLOW BRINGING ANY UPPER ENERGY INTO THE ROCKIES INSTEAD OPTING
TO KEEP RIDGING OVER THE AREA. GOING WITH THE CANADIAN WOULD MEAN
COOLER TEMPS AND SOME LIGHT SNOW SPREADING IN LATE SAT AND SUNDAY.

&&

.AVIATION...IFR AND EVEN LIFR CEILINGS AND VSBYS IN FOG OVER
PARTS OF WESTERN CWA INCLUDING KLAR/KRWL AND KSAA UNTIL 16Z THIS
MORNING. SOME OF THIS FOG AND MOUNTAIN OBSCURATION MAY REDEVELOP
IN THE SAME AREAS SUNDAY NIGHT. OTHERWISE...VFR CONDITIONS ARE
EXPECTED THROUGH MONDAY. 

&&

.FIRE WEATHER...COOL TEMPERATURES WILL CONTINUE THROUGH THE WEEK
WITH HUMIDITIES TRENDING SLIGHTLY LOWER MONDAY AND TUESDAY...BUT
ARE EXPECTED TO REMAIN ABOVE 20 PCT. NO FIRE CONCERNS THIS WEEK
WITH MUCH COLDER AIR PUSHING ACROSS SOUTHEAST WYOMING AND THE
PANHANDLE OF NEBRASKA BY THURSDAY AND FRIDAY.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM/FIRE WEATHER...TJT 
LONG TERM/AVIATION...JLH