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 261609

Area Forecast Discussion...Updated
National Weather Service Billings MT
1009 AM MDT Fri Apr 26 2019


Minor update to adjust forecast to latest observations and model
guidance. Rain showers (and mountain rain/snow showers) have
developed west of Billings this morning. Expect showers to expand
eastward across southern MT and northern WY this afternoon as an
upper-level shortwave trough and associated surface trough move
eastward. Heaviest rainfall looks to fall south of Billings based
on progged band of 700 mb frontogenesis. Isolated thunderstorms
are possible as cooler air moves in aloft and destabilizes the
atmosphere this afternoon and evening. Update sent. RMS


.SHORT TERM...valid for Tdy and Sat...

An active weather pattern ahead for today through the weekend.
The weather will remain quite active into next week as well
(please look at the long term discussion). Heights will
dramatically lower through Sunday. This will allow for a good
chance of showers, along with temperatures turning much cooler
late in the weekend into next week.

A strong shortwave will rush through the area this afternoon and
tonight. This wave will pull up some unstable air up from the
south for an increasing chance of showers and thunderstorms. Some
thundestorms have already developed overnight in central Idaho,
which given the time of year, is pretty remarkable. GFS was very
aggressive with QPF totals, while the EC was a bit more subdued,
went with ensemble solution for QPF solution, which puts totals
this afternoon and tonight in the .25 to .50 range for many
locations of south central Montana. So difficult to pin point
exact amounts given the nature of convection. At any rate, kept
high PoPs in for south central Montana. Snow levels fall to around
8 thousand feet this afternoon, then to around 6 thousand feet
tonight. Snow will likely be heavy at times over the high country,
with 4 to 8 inches expected, mainly above 8 thousand feet today
and tonight.

Precipitation tapers off tonight and early Saturday, before the
next wave moves in for Saturday afternoon and night. This system
will cause the surface pressure gradient to increase quite a bit
over southeast Montana, with southeast gusts to 50 mph possible at
Baker Saturday night ahead of a strong cold front. The cold front
will race in Saturday night and this will contain 850mb air
temperatures below zero, so some of the rain showers Saturday
afternoon could change to, or mix with, wet snow late Saturday
night into Sunday morning. Highs today and Saturday will be
seasonal, with maxes around 60 degrees. Much colder temperatures
expected for Sunday into next week. TWH

.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...

Models are coming into better agreement of a pattern change next
week with a cooler and wetter weather.

A low will drop down from the northwest late Saturday night bringing
stronger winds, cooler temperatures, and precip to much of the
area. A tightened surface pressure gradient will increase wind
speeds across the CWA to 35 to 50 mph from the northwest for a
period of time. There is uncertainty on the location of heaviest
precip at this time since the location is dependent of where the
low sets up. Temperatures will drop below freezing Sunday night
allowing any rain to switch over to snow. Accumulations appear to
be light at this time if at all.

The low moves to the east on Monday allowing for a drier day with
few lingering showers. Temperatures are going to stay much below
normal for this time of year. The next low drops down from the
northwest on Tuesday morning.

There is still uncertainty with the specifics of this system from
Tuesday through Wednesday as the type of precip depends on the
high temperatures. This system has a potential to bring heavy wet
snow or at least a mix of rain and snow to portions of the CWA but
specific locations are unknown at this time.

High temperatures on Sunday will remain in the 40s before dropping
into the high 30s and low 40s Monday through Wednesday. A warm up
is expected late next week with highs in the mid 50s and
potentially into the 60s by Friday in southeast Montana. Low
temperatures should remain consistent with mid 20s to mid 30s
across the CWA. Carrothers


A Pacific cold front will bring showers and isolated thunderstorms
this afternoon and evening. Temporary MVFR and erratic wind gusts
of 20-30 kts can be expected in these showers, especially south
of KBIL, and including KSHR. Mountains will become obscured in
rain/snow. Reduced visibility in wet snow is possible at KBHK and
K97M after midnight, but locations to the west should see VFR late
tonight behind the front. JKL



    Tdy Sat     Sun     Mon     Tue     Wed     Thu
BIL 059 039/062 038/048 028/040 031/041 033/045 031/054
    9/T 83/T    64/W    23/W    55/W    54/W    21/B
LVM 057 036/059 031/042 022/038 027/039 027/046 030/053
    9/T 42/T    73/W    23/W    55/W    54/W    21/B
HDN 062 037/062 037/048 029/042 031/045 033/044 030/056
    9/T 82/T    65/W    43/W    45/W    66/W    21/U
MLS 060 036/057 038/048 031/042 032/044 034/043 033/055
    6/T 82/T    75/W    51/E    44/W    55/W    21/B
4BQ 064 037/058 038/050 030/042 031/046 034/044 032/056
    6/T 92/W    54/W    41/E    34/W    55/W    31/B
BHK 055 033/050 036/047 029/040 029/043 033/042 030/052
    4/W 94/W    65/W    42/J    24/W    56/W    31/B
SHR 064 036/062 035/048 026/040 030/048 031/044 029/055
    8/T 81/B    45/W    43/W    44/W    65/W    21/U




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