336 FXUS65 KBYZ 051938 AFDBYZArea Forecast Discussion National Weather Service Billings MT 138 PM MDT Fri Sep 5 2025
.KEY MESSAGES...
- Seasonably cool again tonight to Saturday; frost possible in eastern sheltered valleys tonight into Saturday morning.
- Warming trend through the weekend leading to above average temperatures to start the work week.
- Chance for precipitation in south-central Montana Sunday afternoon and evening.
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.DISCUSSION... Through Sunday Night...
Another cold night is in store for much of the region as a large high pressure continues to dominate central North America. Locations in far Eastern Montana and lower lying areas/valleys may see their first frost or freeze overnight tonight. Be sure to cover any sensitive vegitation. Some patchy fog may develop in some of the low lying areas as well but confidence remains low on this as the dew points may be just a couple degrees too low. The city of Billings is not forecast to drop below 40F.
A shortwave will move out of the PNW into our area during the day Sunday. This will briefly put the SW portion of the CWA under a southwesterly flow regime which will advect in Pacific moisture. The mountains in south central Montana seem to be the only location where there is a moderate to high chance (50-70%) of precipitation occurring Sunday afternoon and evening. Locations in the foothills have roughly a 30% chance of seeing a shower while places near Billings have a very low chance (10%) as the precipitation will likely have great difficulty becoming detached from the terrain and moving downstream into the lee side flow. Accumulations are expected to remain under 0.25". WMR
Monday through Friday...
The first half of the work week looks to be fairly benign as ridging builds back into the intermountain west after the previously mentioned shortwave zips out of the area Monday morning. Highs Monday through Wednesday will be anywhere between 5-15F above average. It would not be surprising to even see a localized 90F high on Tuesday. As this heat will be driven by the ridging, the good news is that winds will remain light which, in combination with wetter than average fuels, should keep fire weather conditions relatively low.
Mid-week this ridge is forecast to break down as a deep trough is progged to move ashore off the Pacific. There is surprisingly good agreement amongst all of the models and cluster members in this occurring. Being that this event is still nearly a week out though, there are still some minor discrepancies in strength and orientation. Regardless, this will likely return the CWA to a southwesterly flow regime with Pacific and monsoonal moisture being advected in aloft resulting in chances for showers and storms.
There is a signal that we could see some late season strong thunderstorms Wednesday and Thursday. The experimental NSSL Severe Probability model does already show a 5-15% severe probability for the eastern half of the CWA. This signal is also evident when looking at the CSU severe prob model as well. Of course it is far too early to talk specifics, however, these two days are something to watch as we move into next week. WMR &&
.AVIATION...
VFR conditions expected through Saturday. Northwest winds could gust to 20 mph along the eastern state line this afternoon, otherwise generally light winds expected through Saturday. Chambers &&
.PRELIMINARY POINT TEMP/POPS...
Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 044/078 048/087 059/087 056/084 056/083 057/080 055/074 00/U 01/B 11/B 01/B 22/W 33/W 35/W LVM 040/082 047/084 049/083 049/079 048/077 047/075 046/069 00/U 02/T 21/B 13/T 34/T 44/T 45/W HDN 038/079 043/087 054/087 052/085 055/085 053/081 053/076 00/U 00/B 10/B 01/B 22/W 32/W 44/W MLS 039/073 044/085 054/087 054/084 058/082 059/082 058/077 00/U 00/B 00/B 00/U 22/W 32/W 44/W 4BQ 039/071 044/082 055/084 054/082 057/081 059/082 057/075 00/U 00/U 00/B 00/U 21/B 22/W 33/W BHK 034/070 039/080 050/084 049/081 051/078 053/080 053/077 00/U 00/U 00/B 00/U 22/W 32/W 33/W SHR 036/076 043/084 052/084 050/082 052/084 051/082 050/074 00/U 00/B 11/B 02/T 22/W 32/W 35/W
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.BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None.
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$$ weather.gov/billings
NWS BYZ Office Area Forecast Discussion