textproduct: Great Falls

KEY MESSAGES

- Scattered showers and thunderstorms this afternoon and evening.

- Additional showers and perhaps a few thunderstorms develop late tomorrow and persist into Saturday morning, mainly across North-central Montana.

- Mainly warm and dry Sunday into most of next week.

UPDATE

Afternoon radar and satellite imagery shows ample cumulus development and showers across nearly all of North-central and Central Montana. PoPs were increased to ensure at least a slight chance mention for showers and thunderstorms across the aforementioned areas through the remainder of the afternoon. -AM

DISCUSSION

/Issued 1244 PM MDT Thu May 7 2026/

An embedded wave diving southeastward within a building ridge along the west coast of the CONUS is resulting in showers and a few thunderstorms this afternoon. This activity wanes this evening and tonight as the wave shifts southeast of the region. Although ridging is technically building in toward tomorrow morning, flow aloft doesnt really trend anti-cyclonic, which will keep some mid and high level cloud cover around. The reason this is mentioned is that these clouds will largely limit the spatial extent of any fog that develops tonight where measurable precipitation falls through the remainder of the day today.

As quickly as the ridging shifts east toward the Northern Rockies late tonight, it is broken down almost as quickly during the afternoon Friday. An upper level wave moves east from WA during the day tomorrow, eventually diving southeastward as it moves overhead. Areas north and east of a Cut Bank to Great Falls to Lewistown line will be most favored for a mix of showers and stratiform rain with this system Friday evening into Saturday.

Thereafter from Sunday into most of next week the weather looks to be characterized by lower amplitude upper level ridging with at least one attempt at a ridge breakdown. The result is for a stretch of above average temperatures, with opportunities for a few showers or thunderstorms when any brief ridge breakdown occurs. Any ridge breakdown would also feature at least brief increases to winds, though not anywhere near High Wind criteria. -AM

AVIATION

07/18Z TAF Period

Showers, scattered to numerous in coverage, will continue to through 03-06z Friday across portions of North Central through Southwest Montana. Coverage of these showers will be greatest northeast of a KHLN to KBZN line and southwest of a KCTB, to KGTF, to KLWT line, especially between 07/20z and 08/02z. While an isolated thunderstorm can't be ruled out this afternoon and evening the probability of lightning occurring near any given terminal was too low to mention. Main impact from showers will be gusty and erratic winds up to 30kts, along with reduced CIGS to low-VFR. Otherwise periods of mountain obscuration are likely through 06z Friday near shower activity. Areas that see rainfall this afternoon and evening followed by clearing skies overnight could see patchy fog development. - Moldan

PRELIMINARY POINT TEMPS/POPS

GTF 43 75 50 67 / 20 10 20 20 CTB 40 73 46 66 / 30 10 50 30 HLN 41 75 47 71 / 40 0 0 0 BZN 37 72 41 68 / 30 0 0 0 WYS 31 68 35 64 / 10 0 10 0 DLN 38 72 40 70 / 10 0 0 0 HVR 39 78 46 68 / 10 10 40 40 LWT 39 71 44 60 / 20 10 50 60

TFX WATCHES/WARNINGS/ADVISORIES

None.