Marine Weather and Tide Forecast for Gardiner, MT

DISCUSSION

Today through next Monday...

Satellite imagery shows NW flow over the region and a distinct shortwave upstream over central BC/AB. Surface analysis indicates pressure falls continuing in central MT and the latest IDA-LWT gradient is 15mb at 08z. Mid level flow has backed to the WNW with 700mb winds ~40 knots and warm advection increasing the stability. Surface winds have responded recently with gusts ~50 mph at Livingston and near Nye. Cold advection/pressure rises arrive between 12-15z so the potential for 50+ mph gusts at the gap locations is short-lived early today. Probability of reaching 60 mph is 30%.

Frontal winds will turn NW and gusty across the plains this morning, after sunrise, and widespread 30-45 mph gusts are anticipated. In addition to the wind, the aforementioned wave will bring a period of snow showers, mainly to our east and southern upslope areas and especially between 12-21z (when forcing will be strongest), though areas of light snow/flurries should linger over our east into the evening w/ shallow instability. Favored areas are looking at snow accums of 0.5-2.0", greatest over the hills.
Chances of exceeding 2" is 10-20". With consideration to the wind and snow, along with near or slightly below freezing temps, have issued a Winter Weather Advisory for snow and blowing snow today in Custer, Fallon, Carter, Powder River, Southern Rosebud, Southern Big Horn and the Sheridan Foothills. Main concern is travel over places like Lame Deer and Home Creek Divides (US-212), and I-90 through Aberdeen Hill and Sheridan.

Billings has not yet seen a measurable snow in January, actually not since Dec 12th, and that probably won't happen today per the downsloping NW winds. But cannot completely rule it out.

Winds die down this evening but another wave from the north will bring another period of pre- and post-frontal winds late tonight and Wednesday. This wave looks drier but has greater wind potential, especially over the east. Models show >50kts at 850mb with cold advection yielding steep low level lapse rates starting 09-12z. Ensembles continue to show good confidence (>60% chance)
of 50+ mph gusts, and gusts to 60 mph are possible (30-40% chance in Fallon/Carter and along the east side of thew Bighorns). If there is existing snow cover after today's light snow, this could produce a near-surface inversion and reduce the wind potential a bit. This is something to monitor. Have raised forecast wind gusts to show gusts near 50 mph. There could also be some light snow in our far east tomorrow but any accumulation would be minimal. We finally get out of the train of windy clipper systems Wednesday night as the gradient reverses itself in response to colder Canadian high pressure sagging into the region...though that in itself will keep NW winds somewhat breezy over our east into Thursday (i.e. falling temps & wind chills).

Couple of colder days coming Thursday and Friday as a near 1050mb high drops into the Dakotas. This is supported by confluent/ cyclonic NW flow as a piece of the Hudson Bay low pushes as far west as southern Manitoba. Moisture is largely lacking and thus this looks like a mostly dry period, but would be surprised if there weren't some periods of light snow or flurries as the cold air mass settled in, with upslope surface winds. Model soundings also show some mid level instability on top of the cold air, so this is something to watch. In any event, look for highs in the single digits east to teens/20s west on Thursday and Friday, with nighttime lows below zero east and single digits west. Baker has a 40% chance of reaching -20F Friday morning.

Indications are for rising heights and a warming trend this weekend. For this there is confidence, but models are starting to show some wrinkles. There is a chance we could see another Canadian shortwave and some magnitude of cold advection next weekend, holding off the onset of Pacific flow. Ensembles show high spread but lean on the warmer downsloping scenario.
Yesterday's cluster analyses also favor the warmer solutions, with a lee side trof or weaker high pressures. Saturday looks like a transition day. Look for temps to warm into the 30s and 40s by early next week. This would be accompanied by gusty foothills winds too, of course.

JKL

AVIATION

Strong winds are expected across the region today with wind gusts in the 30-40 kt range. Strong winds will be over the western foothills initially this morning before spreading over the lower elevations in the late morning and early afternoon. Winds decrease overnight while remaining breezy in the 20-30 kt range for the western foothills and near the Dakotas border. A cold front today will bring snow chances (50-80%) to locations east of Billings from 12-21Z. Snow combined with strong winds will lead to blowing snow concerns and a 40-60% chance for IFR conditions at KBHK, KMLS, and KSHR. Snow will likely create mountain obscurations.
Torgerson

PRELIMINARY POINT TEMP/POPS

Tdy Wed Thu Fri Sat Sun Mon ------------------------------------------------------- BIL 039 025/035 015/026 003/017 004/034 017/039 025/046 3/J 00/N 01/B 22/S 11/B 11/B 11/E LVM 035 022/034 017/029 005/024 005/036 020/041 026/045 2/J 00/B 01/B 11/B 11/U 11/B 11/B HDN 038 020/035 011/023 002/016 001/032 011/037 019/046 7/J 01/N 01/B 22/S 11/B 11/B 11/B MLS 030 018/029 007/013 908/006 906/021 004/027 014/039 7/J 21/N 01/E 11/B 11/B 11/B 11/B 4BQ 033 020/032 010/018 901/011 901/025 007/031 016/043 7/J 21/N 01/B 12/S 11/B 10/B 11/B BHK 027 012/023 000/008 918/000 914/017 000/024 009/034 8/J 22/J 01/E 11/B 11/B 11/B 11/B SHR 037 021/034 009/022 002/017 901/031 010/037 016/047 7/J 01/N 01/B 22/S 11/U 11/B 11/B

BYZ WATCHES/WARNINGS/ADVISORIES
MT...Winter Weather Advisory in effect from 5 AM early this morning to 8 PM MST this evening FOR ZONES 32-33-36-37.
Winter Weather Advisory in effect from 8 AM this morning to 5 PM MST this afternoon FOR ZONES 58-138.
WY...Winter Weather Advisory in effect from 8 AM this morning to 5 PM MST this afternoon FOR ZONE 199.