Area Forecast Discussion

KEY MESSAGES

- Breezy west to northwest winds with gusts of 20-45 mph today. Highest gusts in the foothills west of Billings and along the Dakotas Border.

- Cooler and potentially wetter with a cold front, Friday night into Saturday.

UPDATE

Trowal continues to produce widespread showers over the east half of our cwa, while drier downslope west winds have overcome showers to the west. The rain at Billings is coming to an end. Precip further east will diminish from west to east thru the morning. Mesonet stations have shown 0.10-0.25" of rain over the east in the past 6hrs. High elevation web cameras show accumulating snow in the Bighorns (especially at Granite Pass but even a dusting at Burgess Jct at ~7700'). Upslope snow showers have ended over the Beartooth-Absarokas and have cancelled the Winter Weather Advisory for the Beartooth Highway, where 1-2" likely fell during the night. Have adjusted pops/wx per current trends, and have expanded isolated pops in the afternoon over our far east as high res models show some weak diurnal development, which seems reasonable as the area will still be under the PV axis. Regarding wind, gusts are mainly in the 20s and 30s, and generally breezy conditions will persist through the afternoon. Expect gusts in the 30-40 mph range until mid afternoon. Winds will diminish this evening. JKL

DISCUSSION

Today through Wednesday...

Breezy winds continue across the region into this afternoon, as an upper low continues it's slow eastward progression over southern Canada. Look for the strongest gusts through the early morning hours, in the 20s to 40 mph. Locally greater gusts are possible for the foothills west of Billings, approaching 50 mph. Winds will diminish from west to east through the afternoon.

Lingering showers and a weak thunderstorm or two remain possible into the early afternoon, mainly over southeastern Montana and northern Wyoming. Northwest flow looks to take over into the weekend, bringing slightly cooler than normal temperatures in the upper 60s to low 70s and mostly dry conditions through Friday afternoon. An upper shortwave is shown dropping through the region along with a surface cold front. These features look to bring an increased chance of precipitation, especially over the mountains of southern Montana. Cooler 850-700mb temperatures look to accompany the wave, with 850mb temps between 5-10C. Meanwhile 700mb temps look to be around to below 0C, bringing a low probability for light snow over the highest elevations of the Absaroka/Beartooth and Bighorn Mountains, impacts to recreation and travel through the mountains is low at this time.

The aforementioned upper low over southern Canada looks to get stuck over Ontario into next week, keeping much of the region in a northwesterly flow pattern with the chance for isolated to scattered showers and thunderstorms most afternoons/evenings. The threat of strong to severe storms remains very low through the forecast period at this time.

Temperatures are currently forecast to be in the upper 60s to mid 70sF each day, potentially back into the 80s by Tuesday and Wednesday. Overnight lows are forecast to be in the 40s and 50sF each night.

Matos

AVIATION

Issued 12Z. Showers continue from KBIL eastward, while drier downslope winds have overcome showers to the west. Expect areas of MVFR east of KBIL this morning, while mountains are obscured in light rain and snow showers (snow level near 7000ft). Precip will taper off west to east thru the mid and late morning, although isolated showers may redevelop in the east near KMLS-KBHK-K97M this afternoon. VFR will prevail this afternoon through tonight. Gusty W-NW winds will continue through the day with widespread gusts of 25-40kts (highest in the east after noon). Winds will diminish this evening. JKL

PRELIMINARY POINT TEMP/POPS

Tdy Fri Sat Sun Mon Tue Wed ------------------------------------------------------- BIL 074 049/078 051/066 045/071 047/077 052/087 059/088 3/W 00/B 75/W 01/U 01/B 00/B 11/U LVM 070 041/076 043/062 038/068 039/074 044/084 050/087 1/N 00/U 66/W 11/U 01/U 00/N 01/N HDN 073 045/077 048/066 042/071 044/075 048/085 055/087 6/W 00/B 74/W 01/U 01/B 00/B 12/T MLS 070 047/075 049/066 045/071 047/073 049/081 055/084 +/W 00/U 31/B 00/U 11/B 00/B 12/W 4BQ 068 046/076 049/064 043/068 045/071 048/080 055/084 9/W 00/B 65/W 00/U 02/W 00/B 11/U BHK 068 044/073 044/064 040/069 044/069 045/076 051/080 +/T 20/B 11/N 00/B 02/T 00/B 22/W SHR 070 041/076 044/060 037/065 039/071 043/081 051/085 9/W 00/U 69/W 33/T 11/B 00/B 11/N

BYZ WATCHES / WARNINGS / ADVISORIES

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