textproduct: Great Falls

KEY MESSAGES

- This afternoon through Tuesday there will be cooler temperatures with isolated rain/snow showers.

- Wednesday through Friday it will warm back up.

- Thursday through Saturday there will be isolated showers and thunderstorms across North-central, Central, and Southwestern Montana.

DISCUSSION

/Issued 157 PM MDT Mon May 4 2026/

- Meteorological Overview:

This afternoon there is northwest flow aloft over North-central, Central, and Southwestern Montana. This combined with a cold front that moved through last night/early this morning will bring well- below seasonal average temperatures to the area. This afternoon due to the northwest flow aloft there will be isolated showers over North-central, Central, and Southwestern Montana. This afternoon due to a strengthening pressure gradient it will be windy. On Tuesday an upper-level ridge begins to approach Montana and this will bring northerly flow aloft to North-central, Central, and Southwestern Montana. Tuesday afternoon there will be isolated rain/snow showers across the area. Due to northerly flow aloft on Tuesday it will be cold across North-central, Central, and Southwestern Montana. Tuesday afternoon due to an increasing pressure gradient it will be windy across North-central, Central, and Southwestern Montana with the strongest winds in north-south orientated valleys of Southwestern Montana.

On Wednesday an upper-level ridge builds in over North-central, Central, and Southwestern Montana. This will allow temperatures to warm up with mostly dry weather. Wednesday morning due to clear skies and the cold temperatures on Tuesday it will be chilly with wind chills in the 10s to 20s across North-central, Central, and Southwestern Montana. On Thursday there will be northwest flow aloft over North-central, Central, and Southwestern Montana. This will bring isolated showers and thunderstorms to North-central, Central, and Southwestern Montana. On Friday an upper-level ridge briefly builds in over North-central, Central, and Southwestern Montana. This will bring warm and mostly dry weather to the area on Friday. On Saturday and Sunday northwest flow aloft returns to North- central, Central, and Southwestern Montana. This will bring isolated showers and thunderstorms with cooler temperatures to the area on Saturday. On Sunday it will be warmer and mostly dry. -IG

- Forecast Confidence & Scenarios:

On Tuesday across north-south oriented valleys of Southwestern Montana and the Judith Gap area there is greater than a 50% chance for wind gusts of 40 mph or greater. Wednesday morning along the Hi-Line and across the lower-elevations of Fergus and Judith Basin Counties there is greater than a 50% chance for low temperatures of 25 degrees or colder. Wednesday morning there is a 50% chance for wind chills to be 20 degrees or colder along the Hi-Line. On Thursday there is a 15 - 30% chance for thunder across the majority of North-central, Central, and Southwestern Montana. On Friday there is a 15 - 25% chance for thunder in Hill, Blaine, and Fergus Counties. On Saturday there is a 15 - 25% chance for thunder across the majority of North-central, Central, and Southwestern Montana. -IG

AVIATION

05/00Z TAF Period

A secondary trough moves southward tonight into Tuesday and brings additional widely scattered rain/snow showers, low VFR/MVFR clouds, and northerly breezes. Areas over and near higher terrain will see the most numerous shower activity and generally lowest and most persistent cigs. Mountain obscuration will be present for much of the TAF period. - RCG

PRELIMINARY POINT TEMPS/POPS

GTF 34 51 28 69 / 20 40 0 0 CTB 30 50 26 69 / 10 30 0 0 HLN 35 52 30 67 / 10 30 0 0 BZN 30 51 24 63 / 40 30 10 0 WYS 28 46 19 55 / 20 30 10 0 DLN 33 52 24 65 / 20 10 0 0 HVR 27 52 24 65 / 10 10 0 0 LWT 28 46 24 59 / 20 40 10 0

TFX WATCHES/WARNINGS/ADVISORIES

None.