Laurel, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

664
FXUS65 KBYZ 180950
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
250 AM MST Sat Jan 18 2025

.KEY MESSAGES...

- Occasional light snow with areas of blowing snow continue today
  into Sunday; greatest amounts along north aspects of the
  Beartooth, Pryor & Bighorn Mountains (2-5").

- Very cold temperatures today through Monday. Highs will range
  from single digits below to teens above zero (coldest east).
  Monday morning wind chills could reach -20 to -40 degrees.

- Windy in the foothills late Monday night through Tuesday. Much
  warmer temperatures on Tuesday.

&&

.DISCUSSION...

Through Sunday night...

Cyclonic flow over the area and weak embedded waves were producing
areas of light snow overnight. Expect periods of light snow to
continue over the area today as additional energy drops in, with
greatest amounts down along the southern mountains and foothills
(up to a few inches). For the lower elevations, most areas could
see an inch or less of snow accumulation today with locally a
couple inches. Snow decreases into the evening as surface high
pressure settles over the area bringing drier conditions. Winds
will be gusty at times over the area today as well with the
pressure rises and additional cold air advection moving south.
Patchy to areas of blowing snow are possible over portions of the
area today, especially near Judith Gap. Have gone ahead and
extended the Winter Weather Advisory for the Judith Gap area to
account for this. High temperatures today will reach the single
digits to teens, coldest over the east.

Lows will fall well below zero across most of the region tonight,
with light winds and an anticipated period of clearing skies.
Look for lows to drop to 5 below to 15 below zero most places,
and around 20 below zero in the far east. Wind chill values of
25 to 35 below zero are forecast tonight over the east. Have gone
ahead and issued a Cold Weather Advisory, in effect from this
afternoon through Tuesday morning for these locations. Additional
cold weather highlights will likely be needed for other areas over
the coming days with wind chill values lower than 25 below zero.

Heading into Sunday, cold temperatures continue, with another
shortwave dropping through the region bringing a period of snow to
the upslope areas of the southern mountains and foothills late
Sunday afternoon and evening. At this time it looks like 1 to 3
inches of snowfall are possible, with the probability of 2 or more
inches of snowfall currently around 30 percent for the Red Lodge
area. Highs on Sunday are forecast to range from the single digits
below zero over the east, to the teens over the west. Low
temperatures Sunday night look to range from the teens below zero
for many locations to around 20 below zero over the east. STP

Monday through Saturday...

Active weather week in store with periods of snow and windy
conditions. A wave exits to the S of the forecast area on Monday
and N flow overtakes the region. 850 mb mean temps from the
Clusters ranged from -12 degs C W to -22 degs C E. GFS and ECMWF
were different in their depictions of this airmass. Extreme
Forecast Index (EFI), showed .7-.95 (highest values E) for the max
temps, indicating an unusually cold airmass compared to model
climatology. The above supports the high temps of -6 E to 15 degs
W. KBIL is forecast to be around -12. EFI showed Mon. night lows
in the SE at .7-.8, still indicating unusual cold. Low temps will
be around 10 degs in the W to around -16 in the far E. Heights
build in from the W Mon. night with N flow still over the area.
Brief anticyclonic flow moves over the area on Tue. before a
shortwave trough moves in from the NW Tue. afternoon. 700 mb winds
will be NW at 40-50 kt Mon. night into Tuesday. The surface
pressure gradient from IDA-LWT strengthens to 18 mb on the GFS by
03Z Tue., then exceeds 20 mb on Tuesday. Gradient orientation is
favorable for strong winds at KLVM/Nye, K6S0 and K3HT. Thus, have
increased speeds and gusts from 03Z Tue. to 00Z Wednesday in these
areas. Wind highlights are likely.

The shortwave and lingering energy behind it, will move through
the area through Wednesday, bringing a 20-30% chance of snow to
areas E and S of KBIL. It will be breezy across much of the area,
especially in the far E. Will need to watch for blowing snow
potential. Tuesday and Wed. will be much warmer with highs in the
20s and 30s. Highs in the 20s and 30s continue through Friday
with highs in the 20s expected Saturday. Forecast area will be on
the E side of an upper ridge on Thursday, but Clusters differed in
their depictions of the flow over the area. Pattern differences
continued on Friday and all the Clusters showed some kind of
trough affecting the area on Saturday. Thursday was forecast to be
dry at this time, and then the NBM had low to moderate chances
for snow through Saturday. Arthur

&&

.AVIATION...

Expect MVFR/IFR conditions due to low CIGS/VIS in light snow
today. There will also be areas of mountain obscuration. Surface
winds will be gusty beginning late this morning from the N and NW
with gusts of 20 to 30 kt. Chances for snow will linger over the
Beartooths/foothills and over and near the NE Bighorns this
evening. Conditions will gradually become VFR across the area
tonight. Arthur

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sun     Mon     Tue     Wed     Thu     Fri
-------------------------------------------------------
BIL 014 908/011 910/012 003/030 019/032 017/035 023/036
    5/S 02/S    20/U    00/Q    11/B    11/B    23/S
LVM 013 905/015 909/015 009/032 014/030 014/035 023/036
    2/S 02/S    20/U    00/N    11/B    11/N    24/S
HDN 015 911/009 915/009 907/031 017/032 014/035 018/036
    7/S 01/B    20/U    01/E    22/S    11/B    24/S
MLS 008 916/000 915/901 912/028 019/027 013/030 015/031
    3/S 00/U    00/I    01/E    22/S    11/B    22/S
4BQ 011 916/004 913/001 911/029 019/027 015/031 016/033
    5/S 10/U    00/U    00/B    23/S    11/B    12/S
BHK 004 922/902 921/906 916/025 015/025 009/025 011/029
    3/S 00/I    00/I    00/N    22/S    11/B    12/S
SHR 013 914/010 915/007 909/035 014/029 012/035 014/037
    5/S 32/S    30/U    00/B    22/S    11/B    13/S

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 5 PM MST this
      afternoon FOR ZONE 63.
WY...None.

&&

$$
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