Marine Weather and Tide Forecast for Big Sky, MT

DISCUSSION
/Issued 250 PM MDT Sat Mar 14 2026/

- Meteorological Overview:

This afternoon snow will continue across North-central, Central, and Southwestern Montana. Along the Rocky Mountain Front through the I- 15 Corridor there will be blizzard conditions for the next several hours. This afternoon snow showers will affect Southwestern Montana as a cold front moves southward. These snow showers will primarily affect the I-90 corridor between Three Forks and Bozeman. These snow showers will end by around 6 PM. Some of these snow showers will be heavy. Most of the snow in North-central Montana will end by around 6PM. Across the Montana Highway 200/US Highway 87 Corridor and the Little Belts snow will linger into early Sunday morning with most of the heavy snow ending by around 6 PM. Due to the cold front combined with skies beginning to clear by tomorrow morning it will be cold across North-central, Central, and Southwestern Montana tomorrow. On Sunday an upper-level ridge begins to move over North-central, Central, and Southwestern Montana. This will bring dry weather and allow temperatures to warm up some across the area. Sunday night into Monday the pressure gradient will increase. This combined with the strengthening low-level and mid-level winds will bring windy conditions to the Rocky Mountain Front and plains west of I-15.

On Monday the upper-level ridge remains over North-central, Central, and Southwestern Montana. This will allow temperatures to warm up some more with breezy conditions. An upper-level shortwave will move through the upper-level flow and bring light precipitation to some of the mountains across North-central, Central, and Southwestern Montana. Due to the increasing winds Monday morning there is the potential for blowing snow along the Rocky Mountain Front and Highway 200/US Highway 87 Corridor. On Tuesday the upper-level ridge remains over North-central, Central, and Southwestern Montana. This will allow temperatures to warm up some more. On Tuesday the pressure gradient increases and there will be strong low-level and mid-level winds. As a result on Tuesday it will be windy across North-central Montana with the strongest winds along the Rocky Mountain Front. Wednesday through Friday the upper-level ridge remains over North-central, Central, and Southwestern Montana this will allow temperatures to continue to warm up with mostly dry weather. On Wednesday and Thursday the pressure gradient and upper-level winds remain strong over North-central Montana. As a result on Wednesday and Thursday it will be windy across North-central Montana. -IG

- Forecast Confidence & Scenarios:

Sunday morning there is a 40 - 80% chance for low temperatures of zero degrees or colder across most of North-central Montana. On Monday there is greater than a 90% chance for wind gusts of 55 mph or greater along the Rocky Mountain Front and plains west of I-15.
Across portions of the lower-elevations of Cascade County and Judith Basin County there is a 30 - 60% chance for wind gusts of 55 mph or greater. On Monday there is greater than an 80% chance for wind gusts of 75 mph or greater along the Rocky Mountain Front. Tuesday and Wednesday along the Rocky Mountain Front there is greater than a 60% chance for wind gusts of 75 mph or greater. On Tuesday across much of the rest of North-central Montana there is a 40 - 80% for wind gusts of 55 mph or greater. On Wednesday there is greater than a 50% chance for high temperatures of 70 degrees or greater across the lower-elevations of North-central, Central, and Southwestern Montana. -IG

AVIATION
15/00Z TAF Period

At the KEKS and KBZN terminals light snow will occur for the first few hours of this TAF Period and then VFR conditions will prevail.
At the KHLN and KGTF terminal IFR to LIFR conditons due to snow will prevail for the first two hours of this TAF Period before gradually improving to VFR conditions by 15/06Z. At the KCTB terminal there will be a couple hours of blowing snow which will reduce visibility to IFR conditions but then as the winds begin to decrease after 15/02Z the threat for blowing snow to be lofted enough to reduce visibility diminishes. At the KHVR terminal light snow and blowing snow will reduce visibility to IFR conditions for the first couple hours of this TAF Period with an improvement to VFR conditions expected by 15/04Z. At the KLWT terminal it will snow through at least the first half of this TAF Period. The heaviest snow will occur during the first 4 hours of this TAF Period with LIFR conditions expected. By 15/08Z conditions will gradually improve to MVFR-levels. -IG

PRELIMINARY POINT TEMPS/POPS
GTF 0 27 15 47 / 70 0 20 30 CTB -4 25 13 45 / 20 0 10 10 HLN 6 34 23 50 / 80 0 40 60 BZN 11 34 21 53 / 60 10 40 60 WYS 0 28 16 41 / 50 10 50 70 DLN 14 36 27 55 / 40 0 20 20 HVR 1 26 10 45 / 70 0 0 10 LWT 2 24 10 46 / 80 10 10 30

TFX WATCHES/WARNINGS/ADVISORIES
Winter Weather Advisory until 6 PM MDT this evening for Bears Paw Mountains and Southern Blaine-Eastern Toole and Liberty-Hill County-Northern Blaine County-Western and Central Chouteau County.

Blizzard Warning until 9 PM MDT this evening for Cascade County below 5000ft-Eastern Pondera and Eastern Teton.

Winter Storm Warning until 6 PM MDT this evening for Big Belt, Bridger and Castle Mountains-Elkhorn and Boulder Mountains-Gates of the Mountains-Helena Valley-Little Belt and Highwood Mountains-Meagher County Valleys-Northwest Beaverhead County- Upper Blackfoot and MacDonald Pass.

Blizzard Warning until midnight MDT tonight for Fergus County below 4500ft-Judith Basin County and Judith Gap-Snowy and Judith Mountains.

Blizzard Warning until 6 PM MDT this evening for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera- Northern High Plains-Southern High Plains-Southern Rocky Mountain Front.

High Wind Warning until 9 PM MDT this evening for Beaverhead and Western Madison below 6000ft-Gallatin and Madison County Mountains and Centennial Mountains-Madison River Valley- Northwest Beaverhead County-Ruby Mountains and Southern Beaverhead Mountains.