810  
FXUS65 KCYS 161717  
AFDCYS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHEYENNE WY  
1114 AM MDT TUE SEP 16 2014  
   
UPDATE
 
 
ISSUED AT 953 AM MDT TUE SEP 16 2014  
 
FORECAST ON TRACK WITH NO UPDATES NEEDED AT THIS TIME. AMPLE  
SUNSHINE WILL BE FOUND ACROSS THE AREA TODAY WITH NOT MUCH MORE THAN  
A FEW HIGH CLOUDS. CLOUDS WILL INCREASE FROM THE WEST LATE TODAY AS  
A WEAK SHORTWAVE MOVES THROUGH THE FRONT SIDE OF THE UPPER LEVEL  
RIDGE. TEMPERATURES PRETTY WELL ON TRACK FOR THIS AFTERNOON WITH  
HIGHS MAINLY IN THE 80S WITH MID TO UPPER 70S IN THE WEST.  
 

 
   
SHORT TERM
 
(TODAY THROUGH THURSDAY NIGHT)  
ISSUED AT 240 AM MDT TUE SEP 16 2014  
 
PRETTY BENIGN PATTERN THE NEXT FEW DAYS IN THE SHORT TERM.  
TEMPERATURES WILL BE THE PRIMARY FORECAST CHALLENGE.  
 
CURRENTLY...SURFACE HIGH PRESSURE REMAINS OVER WESTERN WYOMING  
THIS MORNING...WITH SOUTHWEST WINDS ACROSS AREAS WEST OF THE  
LARAMIE RANGE AND SOUTHEAST WINDS EAST. 11-3.9U SATELLITE IMAGERY  
SHOWING THE LOW CLOUDS FROM THE SOUTHEAST WINDS WELL SOUTH OF THE  
CWFA OVER EAST CENTRAL COLORADO. DOES NOT LOOK LIKE THIS STRATUS  
WILL MAKE ITS WAY UP INTO OUR AREA THIS MORNING. IN THE UPPER  
LEVELS...WATER VAPOR IMAGERY SHOWING SUBTROPICAL MOISTURE FROM  
HURRICANE ODILE MOVING NORTH INTO SOUTHERN ARIZONA AND WESTERN NEW  
MEXICO. NOTHING REAL CLOSE TO WYOMING FOR US TO WORRY ABOUT THE  
NEXT COUPLE DAYS.  
 
LOOKS MAINLY CLEAR AND DRY AT LEAST THROUGH THURSDAY AS UPPER  
LEVEL RIDGE AXIS SLOWLY MOVES EAST TOWARDS WYOMING. SOME PERIODS  
OF GUSTY WINDS AS GFS 700MB WINDS INCREASE DURING THE OVERNIGHT  
HOURS...BUT THEN EASE DURING THE AFTERNOON HOURS. SO WE SHOULD BE  
OK FOR FIRE WEATHER ISSUES EACH DAY. WINDIEST DAY MAY BE THURSDAY  
WHERE WE COULD MIX DOWN 25KT WINDS FROM ROUGHLY 550MBS.  
 
BY WEDNESDAY AFTERNOON...700MB TEMPERATURES CLOSE TO +14C OVER  
CARBON COUNTY AND +12C OVER THE PANHANDLE. WARM DAYTIME HIGHS EACH  
DAY...WITH WARMEST DAY THURSDAY. LOOKING AT LOW TO MID 90S IN THE  
PANHANDLE WITH LOW 80S WEST OF THE LARAMIE RANGE THURSDAY AFTERNOON.  
 
UPPER SHORTWAVE STILL ON TRACK TO MOVE INTO WESTERN WYOMING  
THURSDAY NIGHT INTO FRIDAY. BOTH THE GFS AND ECMWF AGREE ON  
MOVEMENT AND TIMING. SHOULD BEGIN TO SEE ISOLATED TO WIDELY  
SCATTERED SHOWERS LATE THURSDAY NIGHT MOVING INTO CARBON  
COUNTY...EVENTUALLY MOVING INTO EASTERN PORTIONS OF THE CWFA LATER  
FRIDAY.  
   
LONG TERM
 
(FRIDAY THROUGH MONDAY)  
ISSUED AT 240 AM MDT TUE SEP 16 2014  
 
MODELS CONTINUE TO SUGGEST THAT THE FRIDAY AFTERNOON AND EVENING  
TIME FRAME WILL FEATURE THE BEST CHANCE OF SHOWERS AND  
THUNDERSTORMS. MIDLVL HIGH THAT IS CENTERED OVER COLORADO ON THURS  
SHIFTS EASTWARD INTO THE CENTRAL PLAINS ON FRI IN RESPONSE TO A  
SHORTWAVE MOVING ACROSS THE NORTHERN ROCKIES. 700-500MB MOISTURE  
INCREASES ON FRI AS THE FLOW ALOFT BECOMES MORE SOUTHWESTERLY.  
DEEPER MOISTURE ASSOCIATED WITH THE REMNANTS OF ODILE WILL NOT  
IMPACT THE REGION (IT MOVES OVER NEW MEXICO). THE COMBINATION OF  
WEAK UPPER DYNAMICS AND SFC CONVERGENCE ALONG THE FRONT WILL  
PRODUCE SCATTERED SHOWERS AND TSTMS OVER THE CWA THROUGH FRI  
EVENING. LARGE SCALE SUBSIDENCE ENSUES BY LATE FRI NIGHT WITH THE  
FRONT SURGING ACROSS THE EASTERN PLAINS. TEMPS ON FRI WILL BE  
SLIGHTLY ABOVE SEASONAL NORMS AND THEN WILL COOL 10-15 DEGREES FOR  
SAT. THE WEEKEND LOOKS VERY NICE WITH WEAK WINDS AND HIGHS  
GENERALLY IN THE UPPER 60S AND 70S. THE ECMWF IS STILL FASTER AT  
INCREASING HEIGHTS OVER THE INTERMOUNTAIN WEST BY SUN INTO EARLY  
NEXT WEEK. STILL NO GOOD CHANCES OF PRECIP IN THE EXTENDED OTHER  
THAN ON FRI.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)  
ISSUED AT 1114 AM MDT TUE SEP 16 2014  
 
VFR CONDITIONS THROUGH THE TAF PERIOD UNDER WNW FLOW ALOFT.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 240 AM MDT TUE SEP 16 2014  
 
HIGH PRESSURE OVER WESTERN WYOMING WILL CREATE WARM TEMPERATURES  
AND AFTERNOON HUMIDITIES IN THE UPPER TEENS TO CREATE ELEVATED  
FIRE WEATHER CONDITIONS ACROSS SOUTHEAST WYOMING EACH AFTERNOON  
THROUGH THURSDAY. FORTUNATELY...FUELS IN MOST FIRE WEATHER ZONES  
ARE REPORTED NON-CRITICAL...SO FIRE WEATHER CONCERNS SHOULD BE  
MINIMIZED. NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS LOOKS TO BE  
FRIDAY AS A COLD FRONT MOVES INTO THE AREA FROM THE NORTHWEST.  
FRONT LOOKS TO MOVE THROUGH SOUTHEAST WYOMING FRIDAY AFTERNOON  
WITH WINDS SWITCHING NORTHEAST BEHIND THE FRONT.  
 

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

 
 

 
 
UPDATE...SML  
SHORT TERM...CLAYCOMB  
LONG TERM...FINCH  
AVIATION...RE  
FIRE WEATHER...CLAYCOMB  
 
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