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NOUS75 KCYS 102053

ADMCYS



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE CHEYENNE WY

253 PM MDT MON MAR 10 2009



.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...

FIRST SHORTWAVE HAS MOVED OUT ONTO THE CENTRAL PLAINS...WITH A 

SECONDARY TRAILER SHORTWAVE MOVING THROUGH WESTERN MONTANA ATTM. 

WINDS REMAIN LIGHT EAST OF THE DIVIDE...BUT HAVE COME UP ACROSS 

ALONG THE I80 CORRIDOR...AS WELL AS ACROSS SOUTH PASS...WHERE 

VISIBILITIES HAVE DETERIORATED SIGNIFICANTLY IN BLOWING SNOW OVER 

THE PAST HOUR OR SO. THESE CONDITIONS WILL LIKELY CONTINUE THROUGH 

SUNSET...WITH THE GRADIENT RELAXING THEREAFTER. SOME AREAS OF LIGHT 

SNOW ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE WILL DEVELOP 

ACROSS THE NORTHERN THIRD OF THE CWA OVERNIGHT...THOUGH 

ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT WITH AN INCH OR TWO IN 

THE HIGHER ELEVATIONS...AND LESS THAN INCH ELSEWHERE. THE OTHER 

FORECAST PROBLEM OVERNIGHT WILL BE THE POSSIBLE DEVELOPMENT OF FOG 

FOR AREAS EAST OF THE CONTINENTAL DIVIDE TONIGHT THROUGH TOMORROW 

MORNING. FOG DEVELOPMENT WILL BE DEPENDENT UPON THE AMOUNT OF DRY 

AIR THAT WILL BE ENTRAINED INTO THE FLOW. AFTERNOON TEMPERATURES 

TODAY HAVE BEEN STRUGGLING IN AREAS EAST OF THE DIVIDE...ALLOWING 

FOR THE STEEP LOW-LEVEL INVERSION TO HOLD STRONG. THIS INVERSION CAN 

ONLY STEEPEN OVERNIGHT AS THE SURFACE COOLS ANDROUGH MIDNIGHT...WITH GRADUAL WEAKENING 

ANTICIPATING AFTERWARD. TERMINALS EAST OF THE CONTINENTAL 

DIVIDE...AS WELL AS KBPI CAN EXPECT THE DEVELOPMENT OF FOG...SOME OF 

WHICH MAY BE LOCALLY DENSE TONIGHT. VSBYS/CIGS MAY BE REDUCED TO IFR 

AT KBPI...KLND...KRIW...KWRL...KCOD...AND KCPR. CONDITIONS WILL 

IMPROVE TO VFR EVERYWHERE BY NOON WEDNESDAY.



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.CYS WATCHES/WARNINGS/ADVISORIES...

WY...NONE.

NE...NONE.



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$$