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

/Issued 506 PM MDT Thu May 7 2026/ 5 PM Update...Scattered showers/thunderstorms continue over Central and North Central MT. Thus pops increased through at least 9 PM this evening. Otherwise, the rest of the forecast is on track. Brusda

2 PM 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 506 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

08/00Z TAF Period

Scattered showers and isolated thunderstorms continue into the evening hours, with precipitation winding down between 08/02z to 08/06z. Chances for lightning at a given terminal is low and isolated, resulting in it not being in the TAF. The only exception is KCTB, where lightning has been more numerous this evening. Calm winds are expected overnight with mid to high level clouds. We will have to monitor the isolated chance for fog development Friday morning if TAF sites get decent moisture from showers. Breezy west to northwest winds pick up Friday afternoon. -Wilson

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 / 20 10 40 40 LWT 39 71 44 60 / 20 10 50 60

TFX WATCHES/WARNINGS/ADVISORIES

None.