Area Forecast Discussion
Issued by NWS Billings, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KBYZ 011526
AFDBYZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
926 AM MDT SAT AUG 1 2015

.UPDATE...

ONLY MINOR CHANGES WERE MADE TO TODAY/S FORECAST...NAMELY TO RAISE
FORECAST HIGHS TO 100+ F FROM FORSYTH TO MILES CITY AND TO LOWER
AFTERNOON HUMIDITIES EVER-SO-SLIGHTLY TO JUST UNDER 10 PERCENT IN
SOME PLACES. BOTH MOVES WERE BASED ON EXPECTED DEEP MIXING TO NEAR
550 MB AND DOWNSLOPE WEST-NORTHWEST WINDS...WHICH WILL GUST AROUND
20 MPH THIS AFTERNOON AND EARLY EVENING...PRODUCING NEAR-CRITICAL
FIRE WEATHER CONDITIONS. WIND SPEEDS AREN/T QUITE HIGH ENOUGH FOR
US TO ISSUE A RED FLAG WARNING...AND THEY WON/T STAY ELEVATED FOR
MORE THAN A FEW HOURS...BUT THIS SITUATION IS VERY CLOSE TO NEED-
ING A RED FLAG OVER PARTS OF SOUTHEASTERN MT WHERE WINDS WILL BE
STRONGEST. SCHULTZ

&&

.SHORT TERM...VALID FOR TDY AND SUN...

THIS WILL BE A HOT AND DRY WEEKEND. DRY NORTHWEST FLOW WILL
PROVIDE ABUNDANT SUNSHINE AND ALLOW MIXING TO GENERATE HIGHS IN
THE MID TO UPPER 90S. BILLINGS WILL BE AROUND 3 DEGREES FROM
RECORD HIGHS BOTH TODAY AND SUNDAY. HUMIDITY LEVELS WILL BE VERY
DRY WITH MANY LOCATIONS FALLING TO AROUND 10 PERCENT IN THE
AFTERNOON. A WEAK SURFACE TROUGH WILL SLIDE ACROSS NORTHERN
MONTANA TODAY AND PROVIDE SOME NORTHWEST BREEZES. MONSOON MOISTURE
WILL BE SUPPRESSED TO THE SOUTH. SOME CUMULUS DEVELOPMENT WILL
OCCUR OVER THE MOUNTAINS...ESPECIALLY ON SUNDAY...AS MONSOON
MOISTURE CREEPS NORTH. THE WILL BE THE ONLY CHANCE AND LOCATION
FOR CONVECTION THIS WEEKEND. TWH

.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...

ONLY MINOR CHANGES TO THE EXTENDED PERIOD...AS MODELS REMAIN IN
GOOD AGREEMENT THROUGHOUT THE BULK OF THE PERIOD. GREAT
IMPROVEMENT IN MODEL AGREEMENT HAS BEEN MADE IN MOVEMENT OF
PACIFIC TROF ACROSS SOUTHERN CANADA THROUGH THE PERIOD.

PERSISTENT UPPER LEVEL RIDGE REMAINS IN CONTROL OVER THE REGION
FOR MUCH OF THE DAY MONDAY. A DISTURBANCE...WITH ASSOCIATED
MONSOONAL MOISTURE PUSHED INTO THE WEST MONDAY EVENING FORCING A
SLIGHT AMPLIFICATION BEFORE FLATTENING THE RIDGE. THIS IS A
SLOWER TRANSITIONS THAN PREVIOUS RUNS. THIS SHOULD LEAD TO
SLIGHTLY HIGHER TEMPERATURES FOR MONDAY...WITH GREATER IMPACTS
FROM RIDGING...POTENTIAL COMPRESSIONAL HEATING...AND LESSER CLOUD
COVER THAN PREVIOUSLY INDICATED. FROM THIS POINT ON SEVERAL
WAVES...WITH ASSOCIATED MONSOONAL MOISTURE...RADIATE OFF THE
PACIFIC LOW THAT SLOWLY PUSHES EAST...BRINGING AFTERNOON AND
EVENING SHOWER AND THUNDERSTORM POTENTIAL EACH DAY.  FROM THIS
POINT MODELS DIVERGE...MAINLY DIFFERING ON HOW QUICKLY THE RIDGE
REDEVELOPS. THE STRONGEST WAVE CROSS THING THE REGION APPEARS TO
BE WEDNESDAY EVENING INTO THURSDAY. DID RAISE POPS A BIT WITH THIS
SYSTEM...AS MODELS ARE IN SUCH GOOD AGREEMENT. THIS WAVE MARKS THE
END OF SOUTHWEST FLOW ACROSS THE REGION...INTRODUCING ZONAL FLOW
AS UPPER LOW CROSSES TO THE NORTH. ALTHOUGH ZONAL FLOW AND SOME
POTENTIAL FOR DOWNSLOPE FLOW DEVELOPS...COOL AIR INTO THE REGION
BEHIND THE TROF...SHOULD BRING COOLEST DAY OF THE PERIOD
FRIDAY...BUT STILL WITH LOW TO MID 80S. HAVE ALSO KEPT SLIGHT POPS
IN PLACE AT THIS TIME...WITH POSSIBLE INFLUENCE OF CYCLONIC FLOW
OVER THE REGION. MODELS DIVERGE A BIT AT THIS POINT...DIFFERING ON
HOW QUICKLY TO BUILD IN THE UPPER LEVEL RIDGE BEHIND THE PASSING
LOW. AAG

&&

.AVIATION...

VFR CONDITIONS WILL BE THE RULE TODAY AND TONIGHT. IT WILL BE A
BIT BREEZY THIS AFTERNOON AND EARLY EVENING WITH WEST-NORTHWEST
WINDS GUSTING TO AROUND 20 KT IN MANY PLACES. SCHULTZ

&&

.PRELIMINARY POINT TEMP/POPS...

    TDY SUN     MON     TUE     WED     THU     FRI
-------------------------------------------------------
BIL 099 061/097 062/096 064/089 061/086 060/087 059/083
    0/U 00/U    02/T    23/T    24/T    43/T    22/T
LVM 096 054/094 056/092 057/085 055/083 053/084 052/081
    0/U 00/U    02/T    33/T    24/T    43/T    22/T
HDN 100 057/100 059/099 063/091 059/088 059/088 057/085
    0/U 00/U    02/T    23/T    23/T    33/T    22/T
MLS 101 060/098 062/096 065/087 062/089 062/086 060/085
    0/G 00/U    01/U    33/T    33/T    44/T    33/T
4BQ 099 059/099 060/094 062/086 060/088 060/086 059/085
    0/U 00/U    01/B    24/T    33/T    33/T    33/T
BHK 098 057/094 058/091 060/082 058/085 058/082 058/081
    0/U 00/U    01/U    34/T    33/T    44/T    33/T
SHR 098 055/097 057/094 058/088 056/086 055/085 054/084
    0/U 00/U    02/T    33/T    33/T    33/T    22/T

&&

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

&&

$$
WEATHER.GOV/BILLINGS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.