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
FXUS65 KBYZ 192329

Area Forecast Discussion
National Weather Service Billings MT
529 PM MDT Sat May 19 2018

.SHORT TERM...valid for Sun and Mon...

A weak short wave trough was tracking south to north across our
western zones this morning resulting in some scattered/numerous
showers. In the meantime, many areas also saw fog and drizzle
during the morning. Models indicate some building of 500 mb
heights tonight into Sunday behind the short wave with decreasing
mid level moisture. So, aside from some lingering showers this
evening and some scattered late day mountain showers tomorrow, the
rest of the weekend looks relatively dry. Temps should be warming
back up nicely for Sunday as well with highs in the 60s to lower

Flow will continue to be out of the SW in the mid to upper levels
Monday as an upper low drops into the Great Basin. This may push
some moisture into our western mountains and nearby areas of the
western CWA. However, flow is weak and models do not hint at any
notable energy tracking this way, so we do not anticipate any
severe thunderstorms Monday/Monday evening. BT

.LONG TERM...valid for Tue...Wed...Thu...Fri...Sat...

Weak upper trof along the Pacific coast is still progged to lift
slowly through the Great Basin and into our region Tuesday and
Wednesday. Convection will become more widespread across our CWA
Tuesday and Wednesday per the weak synoptic scale ascent and
anomalously high precipitable waters (0.75-1.00 inches). So
relatively high PoP`s still look good. Wind shear should remain
low (25 kts or less) so we do not see a significant threat of
severe weather at this time, but definitely could see pockets of
heavy rain.

Trof will lift to our north Thursday, but weak shortwaves will
keep the potential for some diurnal showers/thunderstorms through
Friday. These should also generally be non-severe storms.

Despite the trof passage, the overall air mass will see little
temp change, so highs will remain above normal in the lower 70s
to lower 80s, then a bit warmer by the end of next week. BT



There will be a few showers from KBIL to KSHR W through this
evening, then it will be dry into Sunday morning. MVFR to IFR
conditions are expected from KBIL W to KLVM through this evening,
then conditions should improve to VFR. Cannot rule out some
localized patchy dense fog between KBIL and KLVM overnight. Areas
of mountain obscuration will decrease through Sun. morning. Arthur


    Sun     Mon     Tue     Wed     Thu     Fri     Sat
BIL 043/072 050/079 053/076 055/071 054/077 055/079 055/080
    20/U    12/T    23/T    56/T    44/T    33/T    22/W
LVM 040/069 045/074 048/070 048/067 048/073 049/075 048/075
    23/T    24/T    46/T    66/T    45/T    44/T    32/W
HDN 043/074 047/081 052/079 055/073 054/078 054/080 053/081
    20/U    02/T    22/T    45/T    44/T    33/T    22/W
MLS 044/072 049/080 056/079 057/075 056/076 056/079 055/080
    00/U    00/U    22/T    25/T    43/T    22/T    21/U
4BQ 041/070 046/080 053/080 055/077 056/076 055/077 054/078
    00/U    01/U    22/T    34/T    44/T    22/T    22/W
BHK 038/067 044/075 052/078 054/076 054/074 054/078 053/077
    00/N    00/U    12/T    24/T    33/T    22/T    21/U
SHR 039/069 044/076 049/075 052/072 051/075 050/075 050/078
    10/U    12/T    23/T    66/T    44/T    33/T    23/W




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