textproduct: Great Falls

KEY MESSAGES

- A few showers and isolated thunderstorms today.

- Seasonable temperatures expected for the first half of the work week.

- A spring storm expected to arrive late on Wed, with rain changing to snow at all elevations by Thursday, along with much cooler temperatures.

- Turning drier and mild over the weekend.

DISCUSSION

/Issued 529 AM MDT Mon Apr 13 2026/

- Meteorological Overview: An upper level disturbance continues to move northward through the CWA this morning. Rain showers are diminishing, with some patchy clearing taking place. This could result in some fog developing over Central and North Central MT through the morning hours today. For this afternoon, the airmass becomes slightly unstable with the cold air aloft. This will result in some scattered afternoon showers or an isolated thunderstorm.

For tonight through Tuesday, overall expect a drying trend, with showers decreasing, along with seasonable temperatures for Tuesday. Winds will be on the increase along the Rocky Mountain Front and in the Cut Bank area though. Even though it will be windy these areas, wind speeds are expected to remain below warning criteria.

For Wednesday into Friday, the next upper level trof starts to approach the CWA by late Wednesday into Wednesday night, with colder air arriving by Thursday morning. Expect rain showers to change to snow at all elevations by Thursday. Snow accumulations look light at lower elevations, with heavier snowfall amounts in the mountains. Afternoon temperatures on Thursday will be about 15 to 20 degrees below normal. The precipitation continues into Friday, but overall, much of the precipitation will end by Friday afternoon.

Saturday and Sunday...other than a few mountain showers, generally dry conditions are expected. Additionally, we will have a nice warming trend towards above normal temperatures by Sunday afternoon.

Next Monday...mild temperatures continue, but the next upper level disturbance will approach the CWA by Monday afternoon. Expect a return of scattered showers across the CWA by Monday evening.

- Forecast Confidence & Scenarios:

There is less than a 40 percent chance for strong winds Tuesday and Wednesday along the Rocky Mountain Front and in the Cut Bank area. Thus no high wind statements are expected at this time.

Overall, right now, the spring storm for Wed night through Friday will be a normal April spring storm in terms of impacts. Overall liquid precipitation will range from a quarter to a half inch over the north...to about 1/2 inch to an inch over the Southwest. The rain will change to snow at all elevations by Thursday, and we will have much below normal temperatures on Thursday. There will be the potential for some heavy snow in the mountains of Southwest MT, especially around Pony, Big Sky and West Yellowstone. Winter statements will likely be needed for this event. Brusda

AVIATION

13/18Z TAF Period

Initial concern this TAF period will be for patchy lingering low clouds or fog. Concern quickly transitions to showers and a few isolated thunderstorms through early evening. Heading into Tuesday morning, a few instances of fog cannot be ruled out in wind protected areas, otherwise breezy west to southwest winds develop late morning or early afternoon. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 58 38 58 42 / 50 30 0 0 CTB 58 36 54 34 / 40 20 0 0 HLN 57 35 60 37 / 50 20 0 10 BZN 57 31 60 36 / 50 30 0 0 WYS 44 25 47 28 / 70 50 20 10 DLN 53 29 57 35 / 50 20 0 0 HVR 57 37 63 38 / 60 30 0 0 LWT 57 34 60 36 / 40 30 0 0

TFX WATCHES/WARNINGS/ADVISORIES

None.