textproduct: Great Falls

KEY MESSAGES

- It will remain dry through the day today.

- Periods of mostly light mountain rain/snow expected this week.

- There will be periods of strong winds Monday-Friday along the Rocky Mountain Front and North-Central MT plains.

- There will be warmup in temperatures starting Monday, reaching well above normal towards the end of the week.

DISCUSSION

/Issued 222 PM MDT Sun Mar 15 2026/

- Meteorological Overview:

High pressure over the region today will keep dry weather through the rest of the day. Warm air advection with a small increase in moisture moves in overnight Monday morning. This will develop light snow for mainly the mountains. A warm front lifting to the east will bring slight chances for light rain/snow to lower elevations throughout the day Monday. The upper-level ridge flattening out through the week will result in westerly flow aloft bringing light, orographic rain/snow over the Continental Divide. Temperatures are expected to warm up throughout the week, with temperatures reaching the 60s-70s across lower elevation towards the end of the week. Some melting of the recent snowpack is expected with the warmer temperatures. However, overnight lows in the mountain peaks look to stay in the 30s, which will help the moderate melting overall. Also, any rain in the mountains if any will be light, and doesn't look to have an impact for enhanced snow pack melting. Increased stream/river flows are expected, but overall flooding risk is low at the moment.

Increasing westerly flow aloft will bring in a persistent mid level jet through the week. These stronger winds mixing down to the surface will bring periods of strong winds to the Rocky Mountain Front and the North-Central MT plains throughout the week.

- Forecast Confidence & Scenarios:

There is a little uncertainty in how soon the strong winds begin to mix down to the surface Monday. Some models begin having stronger 700mb winds in the morning, while some push it back more towards the afternoon to evening. There seems to be better agreement that the winds peak Tuesday morning with the better jet. There is good enough confidence for these winds to mix down to the surface at times to upgrade to a High Wind Warning. With the uncertainty in how quickly the strong winds come in, and using the latest HREF ensembles runs, I decided to bump up the start time for the warning to earlier in the day Monday. This also will decide how impactful blowing snow will be before temperatures warm up Monday. Since guidance did hint at winds picking up sooner Monday morning before the snow pack settles in the afternoon along the Rocky Mountain Front, I decided to issue Winter Weather Advisories to account to that. Farther east across the North- Central MT plains, blowing snow will be more patchy/isolated so they were left out of the Advisory for now.

Synoptics also support Wednesday being another windy day for the Rocky Mountain Front. Another 700mb jet of 60-85kt winds and a pressure gradient tightening brings the concern for another round of strong winds. There is a 50-70% chance for 75 mph wind gusts along the Rocky Mountain Front foothills and a 70% chance for 58 mph wind gusts farther east towards Cut Bank. -Wilson

AVIATION

16/00Z TAF Period

Clouds will increase from SW to NE heading into the overnight hours with increasing chances for precipitation across Southwest Montana. At KBZN, KEKS, and KHLN, precipitation will start off as snow and transition to a rain/snow mix by the mid-morning before becoming all rain by the late morning/early afternoon. Periods of MVFR/IFR conditions are possible after 16/06Z both as a result of low ceilings and reduced visibility around heavier showers. Mountain obscuration will remain a concern over the next 24-30 hours.

Surface winds along the Rocky Mountain Front will start to increase after 16/12Z with high winds expected by the afternoon. Gusty winds will spread out along the Hi-Line and portions of Central Montana by the late afternoon/early evening with the potential for high winds lasting through Tuesday afternoon. With the initial increase in winds, there is a concern for BLSN at KCTB and KGTF which may reduce visibility at times. In general, the main threat for BLSN is expected to subside by 16/18Z but depending on if the stronger winds take longer to reach KGTF, there is a potential some BLSN may last into the mid-afternoon. -thor

PRELIMINARY POINT TEMPS/POPS

GTF 17 48 42 57 / 20 20 30 10 CTB 15 47 39 56 / 10 10 10 10 HLN 22 50 39 61 / 40 50 30 10 BZN 20 53 38 64 / 40 40 50 10 WYS 16 42 28 53 / 40 60 50 0 DLN 27 55 38 64 / 20 20 10 0 HVR 11 46 35 62 / 0 10 10 0 LWT 10 46 38 56 / 10 20 20 10

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from 3 AM to noon MDT Monday 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 from 9 AM Monday to 6 PM MDT Tuesday 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 from 3 PM Monday to 6 PM MDT Tuesday for Bears Paw Mountains and Southern Blaine-Eastern Toole and Liberty- Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Northern Blaine County-Snowy and Judith Mountains- Western and Central Chouteau County.