textproduct: Great Falls

KEY MESSAGES

- Cooler temperatures and gusty west to northwest winds today.

- Light rain or wet snow showers today with a period of steadier wet snow possible this evening in northern Gallatin and Madison counties.

- Confidence is increasing in a spring storm system to affect the area Thursday and Friday with widespread precipitation and impactful winter weather. |

DISCUSSION

/Issued 516 AM MDT Mon Mar 30 2026/

A shortwave disturbance, currently moving through southern BC tracks east along the US/Canadian border today, allowing a broad W-E baroclinic/frontal zone producing mainly light precipitation across portions of N-central MT early this morning to sag south through central and southwest MT by this afternoon. Steadier snow affecting Marias pass and areas near the continental divide south to MacDonald Pass early this morning will taper to snow showers by mid-morning. Further south and east, areas of light precipitation/showers will sag south with the frontal zone, which may stall for a period late this afternoon or early this evening along/south of the I-90 corridor before continuing on the the ID/WY border overnight.

While precipitation impacts today will be minimal for most areas, cooling aloft will support lowering snow levels and a period of steadier wet snow is possible in the Gallatin/Madison county vicinity as the front stalls briefly there early this evening. Temperatures will be marginal for snow accumulation in the Gallatin valley, but areas from Gallatin Gateway to Big Sky and perhaps also Bozeman Pass could see a window of snow accumulation on road surfaces this evening before precipitation shifts south.

The passing shortwave and increased westerly flow will lead to gusty west winds across much of the area by late this morning. A secondary frontal boundary moving south out of Alberta will shift winds to the NW/N across north-central MT by this afternoon with winds shifting the north this evening across southwest MT .

Mainly dry but cool conditions follow for central/North-central MT Monday night through Tuesday with some warming on Wednesday as flow aloft turns southwesterly ahead of an incoming upper level trough from the Pacific. Moisture and mainly weak upper level disturbances continue to stream across southwest MT through at least Tuesday as the baroclinic/frontal zone remains in place and gradually lifts north, maintaining some chances for precipitation there with snow levels rising back to 6000 ft or higher by Tuesday afternoon.

Confidence is increasing with a potential spring storm system to affect the area later this week with models/ensembles converging on a closed mid level circulation within the larger scale trough to track from ID Thursday across northern WY or SE MT Friday. This is a favorable track for widespread precipitation, particularly across central and southwest MT. Reasonable agreement also exists for enough cooling aloft to lower snow levels to most of the valleys/plains Thursday night. More specific track, timing and location details will evolve with the forecast over the next few days but expect some winter weather impacts across the area late this week with cold/wet/raw conditions also being impactful to newborn livestock. Hoenisch

AVIATION

30/18Z TAF Period

The cold front will continue to progress its way south to Southwest MT throughout the afternoon and evening. This will continue to produce mountain snow and lower elevation rain, transitioning to snow late in the evening. This front will also bring MVFR ceilings with MVFR to IFR vis. Across KLWT and the Hi- line, precipitation will continue to bring MVFR clouds and down to IFR visibility through the early afternoon. Overcast to broken low to mid level clouds will clear out in the evening. Cloud obscuration will persist at times due to precipitation. -Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 46 18 49 27 / 30 10 10 0 CTB 36 13 42 20 / 20 0 0 0 HLN 50 21 49 29 / 50 10 20 20 BZN 58 21 47 27 / 70 70 50 60 WYS 55 26 46 31 / 50 70 80 90 DLN 59 24 53 32 / 30 40 60 40 HVR 44 16 44 23 / 20 0 0 0 LWT 45 17 41 23 / 80 20 20 20

TFX WATCHES/WARNINGS/ADVISORIES

None.