textproduct: Great Falls

KEY MESSAGES

- Scattered showers and thunderstorms across the region this afternoon with isolated severe wind gusts possible.

- Breezy winds and warm temperatures will lead to elevated fire weather conditions through Friday.

- Cooler temperatures, gusty winds, and precipitation continue this weekend into the beginning of next week.

DISCUSSION

/Issued 1158 PM MDT Wed Aug 26 2026/

- Meteorological Overview:

Strong southwesterly flow ahead of an approaching upper-level trough will bring ample moisture and forcing into the region allowing for scattered to widespread afternoon showers and thunderstorms on Thursday and Friday. A few may become severe with the main concern being strong wind gusts. Additionally, lightning will be a concern as these thunderstorms are expected to be a mix of wet and dry with the dry thunderstorms posing the highest risk for new fire starts.

Towards the weekend the trough starts to move eastward and turns into a cutoff low which will bring cooler temperatures and a chance for widespread precipitation to the region through Sunday. By the beginning of next week some weak transient ridging tries to build over the intermountain west but it does not last long as another Pacific trough starts to make its way towards Montana by the middle of next week bringing yet another chance for more unsettled weather. -thor

AVIATION

27/12Z TAF Period

Southwesterly flow becomes more established over the Northern Rockies on today and brings increased southerly breezes and multiple waves of scattered showers and thunderstorms through southwest and north- central MT. The most impactful convective activity will be between 27/20 and 28/04Z. These storms will be capable of localized strong wind gusts, brief heavy downpours, and cloud to ground lightning. Primarily VFR conditions will prevail, except for the brief MVFR/IFR beneath the stronger convective cores.

For KGTF : Primary concern will be scattered showers and thunderstorms again today, mostly between 27/22 and 28/03Z. Localized strong, erratic wind gusts, brief heavy downpours, and cloud to ground lightning will be the primary hazards. Even without a direct terminal impact, nearby thunderstorms could produce outflow boundaries that result in crosswinds exceeding 15 kts. Away from thunderstorms, winds become southerly and will gust to around 20 kts at times. There is around a 50% chance of crosswinds over 15 kts. - RCG

FIRE WEATHER

Very warm, dry, and breezy conditions will combine with thunderstorm activity for elevated fire weather conditions for the next couple of days, especially for southwest and portions of central Montana. The primary concern will be passing waves of showers and thunderstorms, some with little rainfall and cloud to ground lightning. The strongest storms may produce erratic gusty winds over 50 mph,which may help spread new fires. Today and Friday look to be the breeziest and driest days for central and southwestern locations north of I90, with up to a 20% chance for the Hot Dry Windy Index to exceed the 90th percentile. Fire weather products are not planned to be sent out at this time given the marginal conditions, but the situation will continue to be monitored. A Pacific trough brings additional showers and thunderstorms and periods of gusty winds this weekend; however, cooler temperatures and more productive storms looks to reduce the fire risk. - RCG

PRELIMINARY POINT TEMPS/POPS

GTF 93 57 87 57 / 30 30 10 10 CTB 86 55 80 50 / 20 10 0 0 HLN 89 54 83 56 / 40 30 10 20 BZN 89 52 81 51 / 30 30 30 60 WYS 82 43 71 40 / 20 40 70 80 DLN 86 51 79 49 / 40 20 20 50 HVR 97 59 90 56 / 10 30 10 20 LWT 93 57 84 55 / 30 30 20 20

TFX WATCHES/WARNINGS/ADVISORIES

None.