textproduct: Great Falls

KEY MESSAGES

- Lingering snow this morning, mainly over the plains.

- Cooler temperatures linger for a few days, with opportunities for morning fog.

- After today the region looks dry through the weekend, with daytime highs reaching back above average by the weekend.

DISCUSSION

/Issued 236 AM MDT Mon Oct 12 2026/

- Meteorological Overview:

An upper level low centered over eastern OR will continue to sag southward this morning. Lingering mid and upper level support for snow will continue to wane as this occurs. Most lingering light snow diminishes through the morning, with some light precipitation over SW MT south of I-90 this afternoon as a weak embedded upper disturbance pivots in on the northeastern side of the upper low.

Subtle ridging begins to move in late tonight, which will help clear skies a bit. Given recent precipitation the concern will be for both cold overnight lows as well as for fog by Tuesday morning in many areas. This concern more or less exists Wednesday morning as well, though there will be uncertainty with how much snow pack remains by then.

After upper troughing moves across AB/SK Wednesday night into Thursday an upper level ridge begins to move in. Dry conditions remain in place, with highs trending back above average by the weekend. -AM

- Forecast Confidence & Scenarios:

Lingering snow this morning:

As of issuance of this discussion, impactful snow has come to an end across SW MT. Improvements spread further north and northeast through the remainder of the morning, with areas near Havre being the last to see the improvements. While snow is coming to an end, impacts from the snow that has fallen will not immediately follow. Continue to plan for additional time to get to your destination today.

Fog concerns the next few mornings:

Forecast soundings suggest there will be a few mornings of fog across the region early this week. While confidence in dense fog at this time horizon is lower for any specific area, those with travel plans the next few mornings should be aware of this potential.

A few soundings feature rather deep saturated layer near the surface. While a drizzle or freezing drizzle is not presently forecast (Fog is favored), it will bear monitoring, especially in areas where surface temperatures fall below freezing each morning. -AM

AVIATION

12/12Z TAF Period

The initial and primary concern this TAF period will be for persistent low clouds in many areas. Patchy fog or drizzle/freezing drizzle will also be around this morning and again late tonight as skies at least partially clear. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 35 20 42 23 / 40 0 0 0 CTB 34 18 44 22 / 30 0 0 0 HLN 37 20 43 22 / 20 0 0 0 BZN 35 19 40 18 / 20 10 0 0 WYS 45 19 46 15 / 50 20 10 10 DLN 36 21 42 19 / 40 10 0 0 HVR 39 17 45 20 / 40 0 0 0 LWT 35 19 42 22 / 40 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.