textproduct: Great Falls

KEY MESSAGES

- Light snow will develop along the Idaho and Montana border this evening and persist through Monday afternoon.

- Temperatures moderate further through the first half of the work week before cooling slightly on Wednesday and Thursday as a fast moving disturbance moves over the Northern Rockies.

- The potential exists for another strong wind event from the end of the work week into the first half of the upcoming weekend.

DISCUSSION

/Issued 1247 PM MST Sun Mar 1 2026/

- Meteorological Overview:

An upper trough undercutting the broad ridging over the Pacific shifts toward northern CA later today, moving onshore and eventually over NV late tonight into Monday. Areas along the Idaho border in Southwest Montana look to be on the northern periphery of this system, which will result in some light precipitation at times tonight into Monday. The system overall isn't particularly cold, but will be cool enough to result in snow as the primary precipitation type in the mountains, with a mix of rain and snow at times at lower elevations.

Elsewhere across the region mild and dry conditions continue into at least Tuesday night. There continues to be some timing discrepancies between guidance for the next round of troughing moving onshore from the Pacific Wednesday into Thursday. The slower solution would keep the region dry through the day Wednesday, while the faster brings precipitation across the Continental Divide by the afternoon Wednesday. Additional discussion on this uncertainty will be in the confidence and scenarios section. The main takeaway at this point will be for slightly cooler temperatures by Thursday, with the best opportunity for precipitation across terrain of Southwest Montana and vicinity. - AM

Quasi-zonal flow looks to develop by Friday and persist into the weekend in wake of the mid-work week shortwave. This pattern would support daily chances for mountain precipitation, especially along the Continental Divide, along with moderating temperatures and the potential for strong to very strong winds over portions of the Central and North Central Montana plains. - Moldan

- Forecast Confidence & Scenarios:

Wednesday into Thursday:

There still remains a nearly 50/50 split between ensemble members that keep the troughing consolidated over this timeframe vs members that result in some magnitude of splitting. Solutions that maintain the troughing (Would favor the higher end of the envelope for precipitation for most areas) progress the system through faster, while the scenarios that split the troughing (Would favor the drier end of the envelope) are slower to arrive. At this point areas along the Continental Divide and the mountains of Central and Southwest Montana are the only areas with a greater than 50% probability to see 0.25" worth of liquid from this system. - AM

Strong Winds from Friday night through next Sunday morning...

Climate anomaly indicators such as the NAEFS and ECMWF EFIs both indicate an extended period of anomalous to unusual winds throughout period, with even the possibility very unusual to extreme winds occurring along the Rocky Mountain Front and portions of the MT Hwy 200/US Hwy 87 corridor in Central Montana. Deterministic guidance by the evening hours on Friday supports a rapidly intensifying surface pressure gradient across the aforementioned areas of Central and North Central Montana, with values peaking and then persisting through much of the day on Saturday at between 0.15 to 0.25 mb/km. H700 winds per NAEFS analysis over this timeframe are prog'd to range from between 40-50kts, which is generally 1.5 to 2 standard deviations above normal for early March. The wind speeds combined with favorable thermal profiles within BUFKIT soundings supports enhanced wind speeds/gusts due to mountain wave activity.

Current NBM25Pct guidance supports wind gusts from Friday night through Saturday night of between 50-70kts for areas west of a Cut Bank to Choteau line, with values along the Montana Hwy 200/US Hwy 87 corridor ranging from between 40-50kts. These values support a reasonably "best case", or low end, scenario; with a 75% chance that winds will be higher than what has been listed.

On the other hand the latest NBM75Pct guidance supports wind gusts from Friday night through Saturday night of between 70-90kts for areas west of a Cut Bank to Choteau line, with values along the Montana Hwy 200/US Hwy 87 corridor ranging from between 50-70kts. These values support a reasonably "worst case", or high end, scenario; with a 75% chance that winds will be lower than what has been listed.

Given that most plains locations will remain relatively dry leading up to this potential wind event, and with grasses being dormant, fire weather concerns will be at least elevated. - Moldan

AVIATION

02/00Z TAF Period

The only concern this TAF period will be for intermittent precipitation and low clouds near the ID border. VFR conditions prevail otherwise with generally light surface winds through the TAF period. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 26 56 30 63 / 0 0 0 0 CTB 23 57 31 55 / 0 0 0 0 HLN 30 54 29 57 / 0 0 0 0 BZN 31 54 27 58 / 10 20 0 0 WYS 27 41 16 45 / 60 60 30 0 DLN 33 51 26 57 / 20 30 20 0 HVR 20 52 26 58 / 0 0 0 0 LWT 29 52 29 58 / 0 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.