textproduct: Billings

KEY MESSAGES

- Mountain wave activity could bring strong, erratic, and potentially damaging wind gusts to the mountains and foothills this evening into Friday.

- Strong gap winds are expected over the western foothills this evening into Friday.

- Small chance of light freezing rain in far eastern Montana early Friday morning (15 percent chance or less).

- Cold front Friday afternoon and evening ends strong wind threat and brings a band of precipitation (rain transitioning to snow) through the area. Impacts to Friday evening commute possible.

- Periods of moderate to heavy snowfall over the Absaroka- Beartooth Mountains today into Saturday. Generally 1 to 2 feet of snow forecast, greatest on south and west aspects.

AVIATION

06z Discussion...

A mountain wave setup is looking more likely overnight tonight. KSHR/KRED should expect erratic and potentially strong winds through at least 16z this morning. Winds may vary by over 40kts over extremely short distances and altitude. In addition to the mountain wave activity, LLWS should be expected at all sites overnight; including KBIL through 16z. If a particularly strong mountain wave takes place overnight, erratic winds may reach KBIL (30% chance). In addition to the LLWS this would result in erratic wind speeds and direction.

The other main hazard this morning is there is a slight chance (30%) that KMLS/KBHK may see some isolated -FZRA between 08-15z. CIGs are forecast to lower to MVFR towards the end of the period with an area of snow in the foothills. There exists a slight chance (30%) that SHRASN may occur at KBIL between 20-01z, but the greater chances are expected adjacent to the mountains at KSHR/KLVM where IFR VIS may prevail after 00z at KSHR.

Mountain will be obscured through the period. AMD NOT SKED at KLVM due to an ASOS power outage. WMR

PRELIMINARY POINT TEMP/POPS

Fri Sat Sun Mon Tue Wed Thu ----------------------------------------------------------- BIL 034/057 026/042 026/043 033/053 030/049 030/052 028/044 16/W 50/U 01/E 13/W 21/B 11/B 21/B LVM 038/051 021/037 021/044 036/050 032/050 036/052 031/047 39/W 50/N 02/W 45/W 32/W 23/W 32/W HDN 031/057 022/042 020/043 029/051 027/047 027/051 024/042 16/W 70/U 00/B 12/W 10/B 01/B 21/B MLS 024/048 017/034 018/039 028/046 026/043 026/043 023/039 23/W 20/U 00/B 01/E 10/E 00/B 21/B 4BQ 028/055 023/038 021/042 031/053 029/047 030/053 028/045 14/W 60/U 00/B 01/B 10/B 00/B 11/B BHK 016/048 013/031 015/041 025/047 024/041 023/045 021/040 22/W 20/U 00/U 00/E 10/B 00/B 11/B SHR 028/057 017/037 016/043 028/053 026/051 029/054 026/045 17/W 91/U 00/B 01/B 00/B 00/B 11/B

BYZ WATCHES/WARNINGS/ADVISORIES

MT...High Wind Warning in effect until 2 PM MST Friday FOR ZONES 56-65-66-138-141-169-171-172. High Wind Warning in effect until 5 PM MST Friday FOR ZONES 63-228. Winter Storm Warning in effect until 5 AM MST Saturday FOR ZONE 67. WY...High Wind Warning in effect until 2 PM MST Friday FOR ZONES 198-199.