textproduct: Great Falls

KEY MESSAGES

- Critical fire weather conditions continue through the rest of the day due to warm, windy, and dry conditions.

- A mostly dry cold frontal passage will bring well below normal temperatures for Monday.

- Drier conditions through the week with a gradual warm-up in temperatures through Friday after Monday.

DISCUSSION

- Meteorological Overview:

With the upper-level troughing still passing through the area, windy conditions still persist through the rest of the day as decent 700mb winds aloft linger. A secondary wave moving through the area overnight into Tuesday will push a boundary south across North- Central MT. This brings along another wave of windy conditions with winds of 30-45 mph and very light precipitation. This boundary will also help usher in cooler temperatures for Monday. Monday's temperatures are expected to be well below normal across the region, with lower elevation highs only reaching mid 60s to lower 70s. Higher mountain peaks are forecasted to drop into the 30s Monday morning. Therefore, they could see light flurries if they receive any appreciable precipitation.

Northwest flow aloft settles in through mid week as another upper- level ridge builds in across the Western U.S. This ridge will slowly move to the east and into the area through the week. As a result, temperatures gradually warm to back above normal during the second half of the week. There is not much moisture associated with the ridge, so precipitation chances remain low through the week and any amounts will be little if an area receives rain. Wildfire smoke will continue to affect the region this week. North winds help push out a good chunk of smoke across North-Central MT Monday and Tuesday into Southwest MT. -Wilson

AVIATION

02/18Z TAF Period

VFR to MVFR conditions are expected to be the norm across North Central and Southwestern Montana today as areas of smoke continue to move through the area. The thickest smoke is likely to remain along the US-2 Corridor through this evening as smoke from the Little Giant Fire in Washington continues to blow through the area. A cold front coming in from the north overnight tonight will bring about a sharp wind shift to the north, along with some near MVFR clouds and a brief reduction in visibility as the front picks up the surface smoke across Northern MT and Southern Alberta. Monday will see conditions improve as clearer air moves in from the north.

For KGTF: Winds will continue to increase this afternoon ahead of a cold front that will push through the area this evening. Crosswinds have already begun to push 15kts as of noon/18z during wind gusts, and are likely to increase further as winds shift further to the west and eventually northwest. The aforementioned cold front moving southward over the plains late this evening will result in a push of gusty northerly winds arriving some time between 06Z and 07Z and persisting into the early morning. Increased humidity in the 0C to-10C layer will result in at least brief/minor icing concerns by early Monday morning. -AM/Ludwig

FIRE WEATHER

Critical fire weather conditions are expected through the rest of the day across all fire weather districts. Although cooler temperatures are forecast today, very low relative humidity will persist. This combined with gusty winds will lead to critical fire weather conditions. A cold front will move through the area this evening into early Monday morning and bring a sharp wind shift from westerly to more northerly. Winds will increase to 30 to 45 mph during this wind shift. To account for the wind shift and increase in winds behind the boundary, the Red Flag Warning was extended through 3am Monday.-IG/Wilson

PRELIMINARY POINT TEMPS/POPS

GTF 49 71 45 78 / 10 10 0 0 CTB 44 66 41 74 / 10 20 0 0 HLN 50 73 47 79 / 10 10 0 0 BZN 49 73 42 79 / 10 0 0 0 WYS 39 72 34 76 / 0 0 0 0 DLN 46 73 42 77 / 0 0 0 0 HVR 48 71 42 79 / 10 10 0 0 LWT 46 65 41 73 / 20 20 0 0

TFX WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 3 AM MDT Monday for Central and Eastern Lewis and Clark National Forest Areas-Chouteau and Fergus Counties-Eastern Glacier/Toole/Central/Eastern Pondera/Liberty- Helena and Townsend Ranger Districts of the Helena National Forest-Hill and Blaine Counties-Lewis and Clark National Forest Rocky Mountain District-Rocky Mountain Front-Lincoln Ranger District of the Helena National Forest.