textproduct: Great Falls

KEY MESSAGES

- Additional rounds of showers and thunderstorms through Wednesday.

- Trending warmer and drier toward the end of the week and weekend.

DISCUSSION

/Issued 147 AM MDT Mon Jul 6 2026/

Meteorological Overview:

A wave progressing through a southwesterly flow aloft will promote another day of showers and thunderstorms that initiate across Southwest Montana and move northeastward through the afternoon and evening. The main threat still looks to be gusty winds and large hail from stronger thunderstorms. Briefly heavy rainfall may also accompany the strongest thunderstorms give PWATs approaching or exceeding an inch. The aforementioned wave takes its time moving across the region tonight, which will allow for nocturnal showers and thunderstorms across the plains.

Although shortwave ridging will be in its initial stages of building in Tuesday afternoon, there looks to be enough support for another round of showers and thunderstorms. Eastern areas will have the best opportunity for this activity given the most favorable forcing will briefly linger there Tuesday afternoon.

Another wave moves across the region Wednesday, though the best forcing looks to remain further north in Canada. Additional showers and thunderstorms will develop as this moves through, though there is not a lot of confidence as to how widespread they will be.

Thereafter upper level riding looks to build in across the central US and interior west. This will result in temperatures trending warmer through the remainder of the week. Though the ridging will be in place, a southwesterly flow aloft across the Northern Rockies will keep precipitation probabilities non-zero into the weekend. Areas near terrain would be most favored for a rogue shower or thunderstorm over this timeframe. -AM

Uncertainty:

Today and tonight:

A low probability but potentially higher impact scenario today involves multiple rounds of showers or thunderstorms over any given area. Given PWATs near or in excess of an inch, repeated thunderstorms over any area could lead to excessive rainfall capable of producing flash flooding. This threat looks to persist into the overnight tonight given favorable forcing lingering on the plains.

Wednesday:

As of now the best forcing looks to remain further north in Canada. Should this trend much further south it would result in an environment favorable for at least a few organized strong to severe thunderstorms. Without the stronger forcing the overall threat for a strong to severe thunderstorm looks to be more isolated. -AM

AVIATION

06/12Z TAF Period

While VFR conditions are expected to prevail through the morning and early afternoon, showers and thunderstorms moving northeastward from Central Idaho will bring some turbulence, gusty winds, small hail, and localized heavy rainfall. SHRA and TSRA will move onto the plains after 3z, where they will linger through the remainder of the TAF period. Ludwig

PRELIMINARY POINT TEMPS/POPS

GTF 76 56 81 55 / 10 60 30 0 CTB 73 54 80 54 / 0 40 30 10 HLN 78 57 84 56 / 20 50 20 0 BZN 80 52 82 53 / 20 50 20 10 WYS 81 48 79 46 / 20 40 20 10 DLN 78 50 81 52 / 40 60 10 10 HVR 80 57 77 53 / 0 60 60 10 LWT 75 51 76 51 / 10 70 70 10

TFX WATCHES/WARNINGS/ADVISORIES

None.