textproduct: Glasgow

KEY MESSAGES

- The now-exiting cold front toward the SE will become a stationary front across southern Montana

- Expect a hard freeze most nights, with wind chills near 0 degrees through this morning.

- Another organized snow storm is possible between Thursday and Saturday.

DISCUSSION

WEATHER PATTERN OVERVIEW:

The advancing cold front through our region from north to south will clear any remaining snow flurries out of northeast Montana, but will stall as a stationary front across southern Montana through the middle of this week. Occasional temporary disturbances within this stationary front may allow for a few flurries or light snow showers to sneak up as far north as MT-Highway 200 from time to time. The coldest period of the forecast is now, through this morning with a hard freeze into the teens above zero. Some wind chill values could easily approach zero degrees, especially near the Canadian border.

Temperatures may moderate a bit through the week, but not by much, as overall, northeast Montana will remain on the cooler side of any air mass movements.

East winds tonight, Wednesday, and Thursday will be strong enough at times that a Lake Wind Advisory may be needed for Fort Peck Lake.

Our attention is turning more toward a better organized storm system moving into our region later this week between Thursday and Saturday. 500 mb model data indicates the possibility of a closed low pressure system moving through Idaho, then Wyoming, then turning north into the Dakotas. Historically, this storm track has been known to favor northeast Montana with accumulating snow. Given the time of year, near the changing of the seasons, uncertainty in the details of this storm is still high. A small change in the storm track and/or a slight change in the expected temperatures could mean the difference between rain or snow. All said, there exists some potential for accumulating snow through many eastern Montana locations. Details, of course, will begin to iron themselves out over the next few days. Stay tuned for the latest forecast information and this is a very dynamic storm system.

FORECAST CONFIDENCE & DEVIATIONS: Main deviations are winds and PoPs. Used a mix of NBM, NBM 90, and other hi-res model data best consensus. Left everything as NBM for Day 3 onward.

Confidence is average to better than average for temperatures.

There is average confidence in rain and snow occurring from Thursday into Friday evening for the entire area, with low confidence on snowfall and precipitation amounts. There is moderate to high confidence on the precipitation being wind driven, which has potential to reduce visibility in this period.

AVIATION

LAST UPDATE: 0800Z

FLIGHT CATEGORY: VFR - MVFR

DISCUSSION: Lingering MVFR level low clouds will clear early this morning with mostly clear skies expected by 13z. Mid and high clouds will move in from the south this afternoon. Mid level clouds are expected this evening and low clouds will move in late tonight with chances for light snow and MVFR ceilings mainly at KGDV and KSDY.

WIND: Northwest at 10 to 20 knots early with winds diminishing and becoming light and variable by 12z. Winds will become east to southeast 6 to 15 knots after 18Z and increase to 10 to 20 knots after 00z.

GGW WATCHES/WARNINGS/ADVISORIES

None.