052  
FXUS65 KCYS 051126  
AFDCYS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHEYENNE WY  
526 AM MDT THU MAY 5 2016  
   
SHORT TERM
 
(TODAY THROUGH SATURDAY NIGHT)  
ISSUED AT 258 AM MDT THU MAY 5 2016  
 
ANOTHER NICE DAY IN STORE WITH CONDITIONS VERY SIMILAR TO YESTERDAY.  
THE UPPER RIDGE AXIS WILL BE OVERHEAD WITH WEAK WINDS. HIGHS WILL  
BE A FEW DAYS WARMER THAN WEDNESDAY. THE GFS SHOWS LI VALUES OF 0C  
TO -2C OVER AREAS ALONG AND WEST OF THE LARAMIE RANGE...SO COULD SEE  
AN ISOLATED SHOWER/TSTM NEAR THE HIGHER TERRAIN DURING THE AFTN. THE  
PATTERN BEGINS TO CHANGE ON FRIDAY AS THE CLOSED UPPER LOW OVER THE  
SOUTHWESTERN U.S. BEGINS TO INFLUENCE OUR WEATHER. INSTABILITY IS  
BETTER ON FRIDAY AFTN/EVENING AND WITH INCREASING UPPER LEVEL  
DIFFLUENCE...WILL SEE SCATTERED CONVECTION DEVELOP OVER SOUTHEAST  
WY. THE STORMS COULD VERY WELL CONTINUE INTO THE EARLY NIGHT WITH  
LLVL MOISTURE ADVECTION AND FORCING FROM A WEAK SHORTWAVE.  
 
LLVL EASTERLY WINDS WILL OCCUR THROUGH SATURDAY WITH WIDESPREAD LOW  
CLOUDS TO THE EAST OF THE LARAMIE RANGE. THE PERSISTENT UPSLOPE AND  
CLOUDINESS WILL MEAN TEMPS WILL BE 15-20 DEGREES COOLER. THE MODELS  
CONTINUE TO SHOW A STRONG SHORTWAVE LIFTING NORTHWARD FROM COLORADO  
INTO OUR CWA BY SATURDAY EVENING. WIDESPREAD STRATIFORM RAIN WITH  
ISOLATED TSTMS WILL OCCUR ON LATE SATURDAY AFTN AND SATURDAY EVENING  
OVER THE SOUTHERN HALF OF THE CWA. RAISED POPS INTO THE 70-80  
PERCENT RANGE. THE RAIN WILL BE MODERATE TO LOCALLY HEAVY WITH GOOD  
DEEP LAYER ASCENT. WET BULB ZERO HEIGHTS DO FALL TO 8500-9000 FT BY  
06Z SUNDAY...SO WILL LIKELY SEE A CHANGEOVER TO SNOW IN THE SIERRA  
MADRE AND SNOWY RANGES. HOWEVER NOT EXPECTING SIGNIFICANT  
ACCUMULATIONS AS PRECIP WILL BE DECREASING IN INTENSITY BY LATE  
SATURDAY NIGHT.  
   
LONG TERM
 
(SUNDAY THROUGH WEDNESDAY)  
ISSUED AT 258 AM MDT THU MAY 5 2016  
 
AN UNSETTLED WEATHER PATTERN IS LIKELY TO PERSIST THROUGH THE MIDDLE  
OF NEXT WEEK WITH LARGE SCALE TROUGHING IN PLACE. WRAP-AROUND PRECIP  
CAN BE EXPECTED ACROSS MUCH OF THE CWA ON SUN WITH LOW-LEVEL UPSLOPE  
REMAINING INTACT OVER THE PLAINS AND DECENT MID-LEVEL PVA ASSOCIATED  
WITH THE UPPER LOW. THAT SYSTEM MEANDERS SLOWLY EASTWARD ON MON WITH  
ANOTHER PACIFIC SHORTWAVE QUICKLY ON ITS HEELS. THE GFS/ECMWF ARE IN  
GOOD AGREEMENT WITH THE OVERALL PATTERN...SO WE EXPECT AT LEAST ISO/  
SCT SHOWERS TO CONTINUE FOR TUE/WED. TEMPERATURES SHOULD BE SOMEWHAT  
STEADY THROUGH THE PERIOD...GENERALLY IN THE 50S AND LOW 60S OUTSIDE  
OF THE MOUNTAINS.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)  
ISSUED AT 525 AM MDT THU MAY 5 2016  
 
VFR CONDITIONS PREVAIL. SCT-TO-BKN COVERAGE OF CLOUDS ABOVE 20K FT  
AGL THROUGH THE TAF PERIOD.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 258 AM MDT THU MAY 5 2016  
 
NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. TEMPERATURES  
WILL BE ABOVE NORMAL THROUGH FRIDAY. MINIMUM HUMIDITY VALUES WILL  
DROP TO AROUND 20 PERCENT THIS AFTERNOON...HOWEVER WINDS WILL BE  
LIGHT. A GOOD CHANCE OF WIDESPREAD WETTING RAIN WILL OCCUR SATURDAY  
AFTERNOON INTO SUNDAY MORNING. TEMPERATURES WILL BE COOLER OVER THE  
WEEKEND WITH INCREASING RELATIVE HUMIDITY.  
 

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

 
 

 
 
SHORT TERM...ZF  
LONG TERM...CLH  
AVIATION...CLH  
FIRE WEATHER...ZF  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab WY Page
The Nexlab NE Page Main Text Page