textproduct: Great Falls

KEY MESSAGES

- Unseasonably mild temperatures and periods of windy conditions continue through Saturday.

- A Pacific trough and cold front brings cooler temperatures and a brief period of showery conditions this weekend.

- Temperatures briefly warm again early next week before another Pacific cold front brings more scattered showers, windy conditions, and cooler temperatures around the middle of next week.

DISCUSSION

/Issued 103 AM MDT Thu Mar 19 2026/

- Meteorological Overview:

An anomalously strong ridge of high pressure will remain entrenched over the Great Basin and southwestern CONUS through the first half of the weekend. The Northern Rockies will be situated on the northern periphery of this feature, which will continue to bring dry and unseasonably warm conditions while strong westerly flow aloft maintains periods of windy conditions, scattered to broken mid- and higher level cloudiness, and even a few isolated showers. The combination of H700 flow between 60 and 70 kts, mountain wave activity, and diurnal mixing will produce the strongest winds along the Rocky Mountain Front and the plains west of I15 for today.

A stronger 60 to 80 kt H700 jet still looks to cross the Northern Rockies Friday through early Saturday in advance of an approaching Pacific trough/cold front and bring an opportunity for more widespread stronger winds. The focus will initially be along the Rocky Mountain Front/adjoining plains and over and near the central MT island ranges. By Saturday portions of southwest Montana will begin to see stronger winds with 50 kt H700 flow coming in from the southwest in addition to scattered shower activity helping transfer some of these stronger winds to the surface. Winds decrease in a northwest to southeast fashion by Saturday evening.

Ridging aloft looks to build in briefly early next week before another Pacific trough and cold front moves through Wednesday into Thursday. It's kind of early to start interrogating some of specifics with this system, but the ensembles are hinting at stronger end H700/H500 flow on the order of 70 to 100 kts. Should this occur, then we may be looking at another higher end wind event depending on diurnal timing and other factors. - RCG

- Forecast Confidence & Scenarios:

Windy conditions continue through Saturday...

Stronger winds along the Rocky Mountain Front and the plains west of I15 will be powered by a 60 to 70 kt H700 jet, mountain wave activity, and diurnal mixing. This will result in winds being a little stronger than the previous couple of days. It won't be out of the question for wind gusts to exceed 90 mph (40 to 60% chance) for Rocky Mountain Front locations along and west of the highway 89 corridor. Other high plains locations west of I15 will see gusts up to 75 mph. Other plains locations will generally see winds gusting in the 35 to 55 mph range. The Geyser area in Judith Basin County was given consideration to add to the warning, but held off for now due to the short duration and localized area of the higher winds. Impacts look to be greatest for those operating high profile and or light weight vehicles.

Friday through Saturday, stronger winds aloft associated with the Pacific trough and cold front look to sweep through the Northern Rockies. The uncertainty that impacts the magnitude of winds for northern areas will be how fast a Canadian front moves south and undercuts the elevated winds aloft. The GFS suite typically handles these scenarios a little better than other ensembles and times the front to move southward into the plains sometime Saturday morning or early afternoon. This suggests the opportunity for stronger winds along the Rocky Mountain Front and the plains will roughly run from Friday morning through early Saturday before shifting the focus southward into southwest MT. NBM probabilities for 60 mph wind gusts on Friday and Saturday continue to be less than ideal for high wind products, but it still shapes the normal problem areas with a rough 30 to 60% chance, including the Rocky Mountain Front, plains west of of I15, central MT 87/200 corridor, and the narrow south to north oriented valleys of southwest MT. Given the meteorological set up, I went ahead and put a watch out for the higher confidence locations with anticipation of better model agreement prior to upgrading to warnings. - RCG

AVIATION

19/12Z TAF Period

VFR conditions will prevail throughout the duration of the 1912/2012 TAF period beneath scattered to broken upper level cloudiness. Biggest concern over the next 24 hours will be continued strong and gusty southwest to west surface winds, particularly along and west of the I-15 corridor across Central and North Central Montana. Extensive mountain wave activity will continue through 20/06Z over these areas, with instances of low level wind shear across portions of Central and North Central Montana. - Moldan

FIRE WEATHER

Warm, breezy, and dry conditions are expected through the end of the work week as we remain under the northern edge of an upper level ridge. While this will result in elevated fire weather conditions, RH values outside of the southwest MT valleys should mostly remain above 20%, and recent snowfall and snowmelt should keep fine fuels and soils moist enough to prevent conditions from becoming critical. The southwestern valleys, however, will be much drier and will continue to be monitored for elevated to critical fire weather conditions. - RCG/Ludwig

PRELIMINARY POINT TEMPS/POPS

GTF 68 51 72 51 / 0 0 0 10 CTB 63 45 65 43 / 10 10 10 20 HLN 69 43 74 45 / 0 0 0 0 BZN 74 42 77 45 / 0 0 0 0 WYS 62 27 64 30 / 0 0 0 0 DLN 72 42 74 44 / 0 0 0 0 HVR 71 44 73 45 / 10 0 10 0 LWT 67 46 71 45 / 0 0 0 0

TFX WATCHES/WARNINGS/ADVISORIES

High Wind Warning until midnight MDT tonight for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera- Northern High Plains-Southern High Plains.

High Wind Watch from Friday morning through Saturday morning for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front-Upper Blackfoot and MacDonald Pass.

High Wind Watch from Friday morning through Saturday morning for Big Belt, Bridger and Castle Mountains-Cascade County below 5000ft-Fergus County below 4500ft-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains-Western and Central Chouteau County.