229  
FXUS65 KBYZ 241420  
AFDBYZ  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BILLINGS MT  
820 AM MDT SUN JUN 24 2018  
   
UPDATE
 
 
MADE SOME MINOR ADJUSTMENTS TO POP'S FOR THE MORNING AND AFTERNOON  
BASED ON CURRENT TRENDS AND THE LATEST HIGH-RESOLUTION MODELS.  
THIS TENDED TO RESULT IN SOMEWHAT LOWER POP'S EARLY ON FOR THE  
CENTRAL AND WESTERN ZONES. HIGH-RESOLUTION MODELS TRENDING TOWARD  
BETTER CHANCE OF CONVECTION OVER YELLOWSTONE COUNTY AND ADJACENT  
AREAS AFTER 2-3 PM. BT  
 

 
   
SHORT TERM...VALID FOR TDY AND MON
 
 
SATELLITE IMAGERY SHOWS UPPER LOW SAGGING INTO NORTHERN WY WITH  
REGION OF DIFFLUENCE LIFTING THROUGH NORTHEAST WY. SHOWERS WITH A  
FEW LIGHTNING STRIKES CONTINUE TO DEVELOP NEAR SHERIDAN AND ACROSS  
FAR SOUTHEAST MT. THERE HAVE ALSO BEEN A FEW SHOWERS IN OUR  
NORTHEAST. TO THE WEST, DRIER AIR AND DOWNSLOPING W-NW WINDS HAVE  
YIELDED A MOSTLY DRY NIGHT.  
 
MORE NON-SEVERE SHOWERS AND THUNDERSTORMS ARE IN STORE TODAY. THE  
ACTIVITY SHOULD HAVE GREATEST COVERAGE IN OUR EAST ALONG  
CONVERGENT MID LEVEL TROF, AND THIS IS WHAT THE LATEST CAMS ARE  
SUGGESTING. WE WILL SEE MAINLY DIURNAL AND MORE ISOLATED  
CONVECTION IN OUR WEST UNDERNEATH CYCLONIC FLOW ALOFT WITH WEAK  
ASCENT PROVIDED BY TROWAL AS THE UPPER LOW MOVES TO THE SOUTHEAST.  
WESTERN SHOWERS SHOULD END AROUND SUNSET, BUT EXPECT SOME  
ACTIVITY TO PERSIST OVERNIGHT IN OUR EAST WITH LINGERING ASCENT  
AND ELEVATED INSTABILITY.  
 
MONDAY WILL BE DRY/WARMER AS THE LOW FINALLY SHIFTS TO THE CENTRAL  
PLAINS AND RIDGING BUILDS FROM THE WEST. AREAS ALONG THE DAKOTAS  
BORDER WILL PROBABLY SEE A FEW WEAK SHOWERS AND PERHAPS A  
THUNDERSTORM, BUT THE INSTABILITY WILL BE COMPETING WITH A  
DEVELOPING SUBSIDENCE INVERSION AS HEIGHTS RISE, SO THERE IS SOME  
UNCERTAINTY HERE.  
 
NEXT PACIFIC TROF AND COLD FRONT PUSH THROUGH THE NORTHERN ROCKIES  
MONDAY NIGHT. GREATEST FORCING WILL EXIST ACROSS NORTHERN MONTANA,  
BUT WE SHOULD SEE A FEW SHOWERS BY LATE EVENING IN OUR NORTHWEST,  
THEN ACROSS MORE OF OUR WESTERN CWA LATE MONDAY NIGHT, PERHAPS  
REACHING BILLINGS ALONG THE COLD FRONT BEFORE SUNRISE.  
 
TEMPERATURES WILL REMAIN BELOW NORMAL WITH HIGHS MOSTLY IN THE  
70S TODAY. TEMPS WILL GET BACK TO THE 80S MONDAY.  
 
JKL  
   
LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT
 
 
LITTLE IN THE WAY OF CHANGES WITH LATEST MODEL RUNS.  
 
A WEAK COLD FRONT STILL ON TAP FOR TUESDAY. MODELS CONTINUE TO  
PRODUCE LIMITED QPF, DO SEEM TO HINT AT A LITTLE MORE EACH RUN, SO  
HAVE CONTINUED WITH SLIGHT POPS AT THIS TIME, ESPECIALLY WHEN  
CONSIDER BOUNDARY LAYER MOISTURE IN PLACE.  
 
DRY CONDITIONS WILL PREVAIL WEDNESDAY AND MUCH OF  
THURSDAY AHEAD OF THE NEXT PACIFIC TROF THAT MOVES IN LATE  
THURSDAY NIGHT/FRIDAY. MODELS CONTINUE TO SHOW ANOTHER ACTIVE  
PATTERN THROUGH THE REMAINDER OF THE PERIOD, AS A LOW DROPS DOWN  
INTO THE NORTHERN ROCKIES. MODELS DO LOOK A BIT DRIER THAN  
PREVIOUSLY ADVERTISED, BUT STILL ACTIVE. AAG  
 

 
   
AVIATION
 
 
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE ON TAP FOR  
ALL ROUTES ONCE AGAIN TODAY. LOCALIZED MVFR TO IFR CONDITIONS ARE  
POSSIBLE IN HEAVY RAINFALL. OCCASIONAL MOUNTAIN OBSCURATION CAN BE  
EXPECTED THROUGH TODAY. OTHERWISE, VFR CONDITIONS WILL PREVAIL  
TONIGHT. AAG  
 

 
   
PRELIMINARY POINT TEMP/POPS
 
 
TDY MON TUE WED THU FRI SAT  
-------------------------------------------------------  
BIL 074 055/085 060/079 055/081 058/078 054/072 053/070  
4/T 20/U 22/T 20/U 12/T 43/T 44/T  
LVM 072 048/085 054/077 047/080 050/076 049/069 047/066  
2/T 10/U 22/T 20/U 12/T 43/T 44/T  
HDN 074 053/085 057/080 054/082 057/080 053/073 052/072  
4/T 31/U 12/T 20/U 12/T 43/T 34/T  
MLS 075 058/082 061/081 056/081 059/081 057/075 056/072  
4/T 31/U 02/T 20/U 12/T 33/T 33/T  
4BQ 072 055/080 058/083 055/082 059/083 057/074 055/072  
5/T 41/B 01/U 20/U 12/T 34/T 33/T  
BHK 073 055/077 056/083 053/079 057/082 055/076 053/073  
6/T 52/T 01/U 20/U 12/T 43/T 33/T  
SHR 070 051/080 056/080 052/081 055/080 052/073 050/070  
4/T 30/U 01/U 20/U 12/T 34/T 44/T  
 

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

 
 

 
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