textproduct: Great Falls

KEY MESSAGES

- Snow dwindles through the morning and early afternoon.

- Warmer and drier conditions this weekend into early next week.

- Tuesday is trending to be a windier day ahead of unsettled weather toward the latter half of the week.

DISCUSSION

- Meteorological Overview:

The core of the upper level low responsible for winter weather across the region is exiting eastward, presently across Wyoming. Snow lingers through the morning and early afternoon, particularly in northerly/northwesterly upslope favored areas. If traveling this morning, be prepared for winter driving conditions. A few isolated showers look to develop this afternoon, but appear to be short lived.

Thereafter upper level ridging slowly builds in for late Friday into the weekend, bringing dry and warmer conditions to the region through early next week. An upper level system then looks to break down the ridge on Tuesday, initially bringing gusty westerly winds to the plains ahead of a cold front.

Upper level troughing hangs around in some capacity from the middle to late portion of next week, which will at the very least cool temperatures across the region. Uncertainty builds with respect to how much precipitation results from this stretch of troughing. -AM

- Forecast Confidence & Scenarios:

Lingering Snow This Morning:

Lingering snow within a northwesterly regime will impact several areas at lower elevations through the morning, particularly the Bozeman area, Lewistown, and the area between Belt and Geyser. The heavy, wet nature of the snow will pose impacts to infrastructure, including potential for a few power outages before snow dwindles late this morning or early afternoon. Those traveling in these areas, or over most passes today should be prepared for winter driving conditions.

Winds on Tuesday:

The European Extreme Forecast Index continues to highlight Tuesday as a day for gusty winds, mostly across the plains and adjacent areas. Forecast soundings over this timeframe do not show much ridgetop stability, which will make this a pressure gradient and diurnally driven mixing type of event. There is quite a bit of uncertainty associated with it however, as cooler air sinking southward from Canada late Tuesday afternoon or Tuesday evening would shut down the winds rather quickly. Should this front arrive a bit quicker the threat for stronger winds Tuesday would be shorter in duration and more localized.

Unsettled Wednesday through Friday:

Cluster guidance favors troughing across the region over this timeframe, but struggles mightily with respect to timing and strength of the troughing. This results in a lower confidence from a precipitation perspective. Confidence is higher with respect to cooling temperatures however. The main takeaway over this timeframe will be for overall cooler and unsettled conditions at times. -AM

AVIATION

03/06Z TAF Period

Areas of snow, patchy fog, and IFR/LIFR stratus will slowly improve from west to east through 03/15Z. While most locations will trend towards VFR conditions after 15Z, KHVR and KLWT will continue to observe MVFR/IFR conditions heading into the afternoon hours. Expect mountain obscuration to persist through 04/00Z, particularly for central/north-central locations east of I15. - RCG

PRELIMINARY POINT TEMPS/POPS

GTF 30 50 28 58 / 100 20 0 0 CTB 23 49 27 55 / 60 0 0 0 HLN 30 50 26 59 / 70 20 0 0 BZN 27 48 21 57 / 80 60 0 0 WYS 20 42 14 49 / 90 50 0 0 DLN 28 49 23 58 / 70 10 0 0 HVR 29 44 25 56 / 90 30 0 0 LWT 27 41 23 52 / 80 70 10 0

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 6 AM MDT Friday for East Glacier Park Region-Elkhorn and Boulder Mountains-Northwest Beaverhead County-Ruby Mountains and Southern Beaverhead Mountains-Southern Rocky Mountain Front-Upper Blackfoot and MacDonald Pass.

Winter Storm Warning until noon MDT Friday for Big Belt, Bridger and Castle Mountains-Gallatin and Madison County Mountains and Centennial Mountains-Little Belt and Highwood Mountains.

Winter Weather Advisory until noon MDT Friday for Cascade County below 5000ft-Fergus County below 4500ft-Gallatin Valley-Judith Basin County and Judith Gap-Snowy and Judith Mountains.