textproduct: Great Falls

KEY MESSAGES

- Mild this afternoon, along with windy conditions along the Rocky Mountain Front.

- Sunday will be the last mild day for a while, as cooler temperatures return on Monday.

- Rain and snow develop along the Rocky Mountain Front tonight and then spread out over the Plains by Sunday night.

DISCUSSION

- Meteorological Overview: An upper level ridge is currently over MT this morning, however, it is also quickly breaking down, as an upper level trof/Pacific cold front approach from the west. It will be mild today, but not quite as mild as previous days. A record high is possible at a few locations. Overall, cloud cover will limit afternoon warming a bit today.

Strong winds are expected to develop by late afternoon along the Rocky Mountain Front and in the Cut Bank area. Thus the high wind watch was changed to a high wind warning. The warning was extended a few hours into Sunday morning, as the GFS model as a period of stronger winds continuing from 5 AM to 9 AM on Sun morning.

For tonight, expect rain/snow to develop along the divide. The freezing level is currently over 10,000 feet this morning, so rain is likely at first, with snow levels gradually lowering overnight. No winter weather advisory will be issued at this time for tonight, as snow levels are expected to remain fairly high.

During the day on Sunday, expect snow levels to continue to lower over the mountains, with some impacts developing over Marias Pass. Sunday night into Monday looks to be the highest impact period, as the Pacific cold front moves from west to east across the CWA. Widespread precipitation will accompany the cold front. The main concern with the cold front will be how fast does the cold air move in Sunday night, changing the rain to snow at lower elevations. The change over time will have significant impacts on how much snow falls at lower elevations on Monday morning.

For Tue through Fri of next week, expect more seasonable February temperatures across the CWA, but overall precipitation chances will be quite low by later next week. Isolated mountain shower can't be ruled out, but the probability is low.

The next chance for a bit more widespread precipitation returns by Saturday over the western portions of the CWA.

- Forecast Confidence & Scenarios: There is up to an 80 percent chance of wind speeds reaching warning criteria along the Rocky Mountain Front and in the Cut Bank area this evening through Sunday morning.

In terms of snowfall, the time the rain changes to snow will have significant impacts on the total snowfall over the Plains of North Central MT. An earlier switch to snow could increase snow amounts by 1 to 2 inches over the Plains of North Central MT. In the mountains of the Rocky Mountain Front, Little Belts, along with areas around Big Sky/West Yellowstone could see 4 to 8 inches of snowfall. Thus winter statements are likely to be issued for this event later today or tonight. Brusda

AVIATION

07/12Z TAF Period

VFR conditions will prevail over Southwest MT and the northern Plains through the period. However, do expect passing mid/high level clouds through the period. Along the Rocky Mountain Front, rain/snow will develop along the divide after Midnight, with gusty winds developing along the east slopes and adjacent Plains this evening. Expect mountains/passes over the northern Rockies to become obscured starting this evening. Brusda

FIRE WEATHER

The main concern from today through Sunday will be the gusty winds and low afternoon humidity over North Central MT. The lowest humidity will occur today, with humidity in the teens along the I-15 corridor from Great Falls to Cut Bank. Also, winds will increase this afternoon, with strong winds in the Cut Bank area by this evening. This could result in difficult conditions to contain any new fire starts. Humidity should increase on Sunday, reducing the impact a bit. Brusda

PRELIMINARY POINT TEMPS/POPS

GTF 61 44 58 31 / 0 0 10 60 CTB 57 39 52 30 / 0 0 10 50 HLN 58 36 56 32 / 0 0 20 80 BZN 58 33 56 33 / 0 0 10 70 WYS 42 21 41 27 / 10 0 10 70 DLN 56 33 54 32 / 0 0 0 60 HVR 60 38 57 31 / 0 0 10 50 LWT 60 39 57 30 / 0 0 10 60

TFX WATCHES/WARNINGS/ADVISORIES

High Wind Warning from 3 PM this afternoon to 10 AM MST Sunday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front.