Winter Storm Warning 6, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
251 AM MDT Fri Mar 31 2023

.DISCUSSION...Showers will continue to cause brief visibility
reductions and light snow accumulations this morning, but are
expected to have a decreasing trend today.

Moisture quickly returns this evening with a trough moving into
the Pacific Northwest. Model guidance continues to highlight heavy
snow in the mountains of northwest Montana, along the ID/MT
border, and the Clearwater Mountains tonight through Saturday. The
combination of 1 inch per hour snow rates and gusty winds will
create poor backcountry conditions. Travel conditions over Lookout
and Marias passes look to be poor on Saturday and a winter storm
watch remains in effect.

Gusty winds are expected throughout the region with the passage
of the cold front on Saturday. Wind gusts of over 40 mph still
have a 70-90 percent probability of occurrence. 50 mph winds
cannot be ruled out in the Mission Valley and southern Flathead
Lake with the NBM showing a 70 percent probability of these
stronger winds. Most of the high resolution models show the cold
front passing during the afternoon but a few do show an earlier
frontal passage. These models also show the Butte/Blackfoot region
being impacted by a burst of moderate to heavy snow and gusty
winds with the frontal passage, so travel conditions are likely to
be poor for a period of time at some point between early Saturday
afternoon and early evening.

Winds are forecast to become westerly throughout the vertical
profile behind the cold front, that along with sufficient moisture
is a good setup for banded snow showers. Most valley locations
have around an 80 percent probability of measurable snow from
Saturday evening through Sunday morning. A cool, showery, and
breezy day is expected on Sunday.

Forecast model ensembles continue to show another cold low
pressure system early next week that could lead to impactful snow,
primarily south of the Interstate 90 corridor. Below normal and
wet conditions look to continue through mid next week.

&&

.AVIATION...
Showers continue to pass through the region this morning, which
have been causing periods of lowered visibility and low ceilings,
especially from KMSO to KBTM. High resolution models show showers
decreasing in coverage throughout the morning. Obscured terrain is
forecast to remain for most of the day, and afternoon winds gusts
between 20-25 knots are expected. The next weather system will
begin to spread mountain snow into north-central Idaho and western
Montana during this evening. Gusty winds are expected in the high
terrain during Saturday, and valleys will have gusty winds with
and behind a cold front passage, especially Saturday afternoon.
There is around a 70 percent probability for widespread wind gusts
greater than 34 knots by Saturday evening.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Watch from late tonight through Saturday evening
     ABOVE 4000 FEET for the West Glacier Region.

     Winter Storm Watch from late tonight through Saturday evening
     ABOVE 4000 FEET for the Lower Clark Fork Region.

ID...None.
&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
1025 AM MDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 AM     SNOW             4 WNW WEST VALLEY       46.17N 113.10W
03/31/2023  M5.2 INCH        DEER LODGE         MT   TRAINED SPOTTER

            24 HR TOTAL, SWE OF 0.28 INCHES.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
1205 PM MDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 AM     SNOW             1 E SEELEY LAKE         47.18N 113.46W
03/31/2023  M2.0 INCH        MISSOULA           MT   COCORAHS

            COCORAHS STATION MT-MS-26 1 E SEELEY LAKE.

0830 AM     SNOW             10 SSE OROGRANDE        45.57N 115.45W
03/31/2023  M1.9 INCH        IDAHO              ID   CO-OP OBSERVER

            CO-OP OBSERVER STATION DXEI1 DIXIE 1 N.

0700 AM     SNOW             TURAH                   46.84N 113.83W
03/31/2023  M1.5 INCH        MISSOULA           MT   COCORAHS

            COCORAHS STATION MT-MS-23 TURAH.

0700 AM     SNOW             2 W CHARLOS HEIGHTS     46.13N 114.22W
03/31/2023  M1.0 INCH        RAVALLI            MT   COCORAHS

            COCORAHS STATION MT-RV-18 2 W CHARLOS
            HEIGHTS.

&&