Area Forecast Discussion

KEY MESSAGES

- Fog is possible again tonight into Saturday morning across much of the region.

- The chance of precipitation has increased on Saturday ahead of the late weekend weather system, although precip amounts remain light.

- A weather system brings widespread precipitation (70-90% chance) and breezy conditions (20-40 mph) Sunday into Monday, as well as slightly cooler temps to portions of the region.

- Southeast Montana into north central and northeast Wyoming are most favored for precipitation Sunday into Monday, with a 50-70% chance for more than 0.50".

- Stronger winds are possible over the Bighorn foothills and along the Dakota border Monday. There is a 60% chance for gusts greater than 50 mph.

DISCUSSION

The rest of today through Thursday...

Fog will impact portions of the region again tonight into Saturday morning. The highest chance (60-80%) will be in low-lying areas, especially along river channels. Fog could become locally dense, significantly reducing visibility in spots.

By this evening, isolated to scattered (20-50% chance) showers will develop over the Absaroka/Beartooth mountains as weak shortwaves enter the region. Then, these showers will spread into the plains Saturday morning into afternoon as a slightly stronger shortwave moves through the region. Overall, precipitation totals will remain light with this system, with only a 10-30% chance of more than 0.10" outside of the mountains. The mountains may see an inch of snow (50% chance) above 8,500 ft, with locally higher amounts over the highest south facing slopes.

Sunday into Monday, a stronger weather system arrives, bringing a better chance (70-90%) for widespread precipitation. Precip begins over the Absaroka/Beartooth mountains Sunday morning, spreading east through the afternoon and evening, and exiting Monday afternoon into evening. Models continue to trend toward favoring southeast Montana and north central and northeast Wyoming for precip, with a 50-70% chance of more than 0.50" of rain and a 20-40% chance for more than 1". Snow remains mostly limited to the mountains as snow levels will begin above 9,000 ft Sunday afternoon, falling to around 6,500 ft by Monday afternoon (when the system begins to exit the region). As a result, precip may begin as rain or a rain/snow mix over the mountains before transitioning to snow. Currently, there is a 45% chance for more than 6 inches of snow over the northern Bighorns and a 40% chance of the same over the Absaroka/Beartooth mountains. As the system exits Monday evening, there is a low chance (<20%) for a few snowflakes over the higher hills.

Late Sunday into early Monday, a cold front moves through the region. The primary impact will be widespread breezy winds Monday of 20 to 40 mph. Far southeast Montana along the Dakota border and the Bighorn foothills are expected to see the strongest winds, with a 60% chance of gusts stronger than 50 mph and a 20% chance of gusts stronger than 60 mph. Winds are expected to peak during the day Monday before coming to an end Monday night.

Tuesday into Thursday look to be mostly warm and dry under upper level ridging. The current track of a trough moving through south of the region will help to keep temperatures near seasonable (low 50s) and may allow an occasional isolated shower (<20% chance), mainly over the mountains.

Highs Saturday and Sunday will be a little warmer than today, generally in the 50s to low 60s. Behind the cold front Monday, highs will fall back into the 40s and 50s. Then, as ridging builds in, highs will return to the 50s to low 60s for Tuesday, before potentially trending towards 50s for midweek. Archer

.AVIATION...

Fog and low stratus are expected to develop after sunset tonight becoming widespread after 06Z Saturday. IFR and LIFR conditions will be common. Conditions should begin to improve during the late morning hours with fog ending in the early afternoon. Torgerson

PRELIMINARY POINT TEMP/POPS

Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 034/052 037/053 042/054 034/058 036/055 034/055 035/058 14/W 02/W 96/W 00/U 00/B 00/B 01/B LVM 031/055 034/050 031/047 024/054 028/053 027/054 028/054 23/W 14/W +4/W 00/B 00/B 01/B 11/B HDN 030/051 032/057 038/054 029/060 031/057 029/057 030/059 14/W 00/E 98/W 10/U 00/B 00/B 00/B MLS 036/053 037/058 043/052 032/055 034/054 032/055 033/056 02/W 11/E 88/W 21/U 00/B 00/B 00/B 4BQ 039/059 037/063 043/048 034/055 034/054 033/055 035/057 00/E 01/E 79/W 31/U 00/U 00/B 10/B BHK 038/061 037/061 040/052 029/053 030/053 027/052 029/054 11/E 20/E 99/W 51/U 00/B 00/B 10/B SHR 032/056 031/058 033/046 027/059 030/056 028/056 030/058 01/E 01/E 99/W 10/U 00/B 01/B 11/B

BYZ WATCHES / WARNINGS / ADVISORIES

MT...None. WY...None.