607  
FXUS65 KBYZ 290255  
AFDBYZ  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BILLINGS MT  
855 PM MDT SUN MAY 28 2017  
   
UPDATE
 
 
INHERITED POP TRENDS ARE STILL INTACT FOR THE EVENING. DRIER AIR  
BEHIND BACK DOOR FRONT IS TAKING OVER AND DIMINISHING MOST OF THE  
CONVECTION OVER THE PLAINS. SCATTERED SHOWERS AND MAYBE A LONELY  
THUNDERSTORM MAY LINGER OVER THE WESTERN MOUNTAINS AND FOOTHILLS  
THROUGH THE REST OF THE EVENING. ONLY MADE A FEW TWEAKS FOR THE  
EVENING UPDATE. BT  
 

 
   
SHORT TERM...VALID FOR MON AND TUE
 
 
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THIS  
EVENING. SOME OF THESE THUNDERSTORMS COULD PRODUCE SOME GUSTY  
WINDS AS THE DEWPOINT SPREADS ARE FAIRLY LARGE. MOST OF THE  
CONVECTION SO FAR THIS AFTERNOON HAS BEEN GENERALLY SHORT LIVED  
WITHOUT MUCH STRONG DEVELOPMENT. WHILE CAPE VALUES 200 TO 500 J/KG  
WILL REMAIN OVER THE AREA INTO EARLY EVENING, SHEAR IS VERY  
BORDER LINE FOR SUPPORTING STRONGER DEVELOPMENT. WHILE SOME SMALL  
HAIL IS POSSIBLE, THE MAIN HAZARD WILL JUST THE WINDS FROM THE LOW  
LEVEL DRYNESS.  
 
THE RIDGE WILL CONTINUE TO BUILD INTO THE AREA TOMORROW, BUT THE  
AREA WILL BE ON THE EDGE OF THE RIDGE. SOME ENERGY WILL BE ABLE TO  
WORK INTO THE AREA, BUT THE RISING HEIGHTS WILL SUPPRESS  
THUNDERSTORM ACTIVITY TO MAINLY JUST THE HIGHER TERRAIN. TUESDAY WILL  
BE SIMILAR WITH EVEN MORE LIMITED CONVECTION. BY TUESDAY  
TEMPERATURES WILL BE IN THE MID TO UPPER 70S AS THE RIDGE REALLY  
BEGINS TO SETTLE INTO THE AREA. REIMER  
   
LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN
 
 
MODELS START OFF IN FAIRLY GOOD AGREEMENT IN THE LONG TERM WITH  
AN UPPER RIDGE OVER THE NORTHERN ROCKIES SHIFTING EAST ON THURSDAY  
AS AN UPPER TROUGH MOVES INTO THE PACIFIC NORTHWEST. AN  
ASSOCIATED SHORTWAVE WILL SWING THROUGH THE AREA DURING THE  
AFTERNOON ALLOWING FOR SHOWERS AND THUNDERSTORMS TO DEVELOP.  
BEYOND THURSDAY, MODELS CONTINUE TO STRUGGLE WITH DIVERGING  
SOLUTIONS. KEPT POPS MOSTLY UNCHANGED THROUGH THE LONG TERM TO  
ACCOUNT FOR THE HIGH LEVEL OF UNCERTAINTY. REGARDLESS, AFTERNOON  
SHOWERS AND THUNDERSTORMS LOOK TO BE POSSIBLE MOST DAYS, WITH THE  
BEST CHANCES OVER THE HIGHER TERRAIN.  
 
TEMPERATURES WILL WARM FROM THE 70S AND INTO THE 80S DURING THE  
SECOND HALF OF THIS WEEK AND INTO THE WEEKEND. WITH THE ABOVE  
NORMAL TEMPERATURES, AN INCREASE IN SNOWMELT IS EXPECTED, CAUSING  
FLOWS TO INCREASE ON AREA WATERWAYS BY THE END OF THE WEEK. WILL  
CONTINUE TO MONITOR THIS CLOSELY AS THE WEEK PROGRESSES. STP  
 

 
   
AVIATION
 
 
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE OVER CENTRAL AND  
WESTERN ROUTES, BUT SHOULD DIMINISH OVERNIGHT. MAIN THREATS FROM  
THE THUNDERSTORMS ARE GUSTY WINDS AND SOME SMALL HAIL. IN GENERAL,  
VFR CONDITIONS WILL PREVAIL, ALTHOUGH MVFR CONDITIONS ARE  
POSSIBLE NEAR HEAVIER SHOWERS OR THUNDERSTORMS. MOUNTAINS WILL BE  
PARTIALLY OBSCURED THROUGH THE EVENING. NORTHWEST WINDS GUSTING UP  
TO 30 KTS ACROSS EASTERN AREAS WILL DECREASE THROUGH THE EVENING.  
AAG/STP  
 

 
   
PRELIMINARY POINT TEMP/POPS
 
 
MON TUE WED THU FRI SAT SUN  
-----------------------------------------------------------  
BIL 047/073 047/077 050/084 055/084 054/080 053/081 051/079  
21/U 10/U 01/U 11/B 22/T 22/T 22/W  
LVM 040/070 040/076 044/082 047/080 046/076 044/076 042/077  
31/U 11/U 11/U 13/T 22/T 22/T 22/T  
HDN 046/072 042/077 047/085 051/086 051/081 049/082 048/079  
20/U 00/U 01/U 11/B 22/T 22/T 22/T  
MLS 044/069 042/074 047/084 055/087 056/081 052/081 051/079  
00/U 00/U 00/U 01/U 22/T 22/T 21/B  
4BQ 043/068 041/073 046/084 052/086 054/080 051/080 049/077  
10/U 00/U 00/U 01/U 22/T 22/T 21/B  
BHK 040/064 037/069 041/079 049/082 052/076 048/075 046/075  
00/U 00/U 00/U 01/U 23/T 32/T 22/T  
SHR 042/067 040/073 044/082 048/083 050/078 047/079 046/077  
21/U 11/U 11/U 11/B 22/T 22/T 22/T  
 

 
   
BYZ WATCHES/WARNINGS/ADVISORIES
 
 
MT...NONE.  
WY...NONE.  
 

 
 

 
WEATHER.GOV/BILLINGS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MT Page
The Nexlab WY Page Main Text Page