FXUS65 KTFX 080740 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1240 AM MST Sun Mar 8 2026 .KEY MESSAGES... - Strong to very strong winds are expected today, with the strongest winds primarily along the Rocky Mountain Front out to the I-15 corridor. - Numerous rounds of precipitation are likely through the week, especially across the mountains - Yet another round of widespread strong winds looks likely on Thursday. && .DISCUSSION... - Meteorological Overview: An active week is expected across the Northern Rockies as moist and fast quasi-zonal flow remains in place, with numerous rounds of precipitation, seesawing temperatures, and potentially several additional high wind events (i.e. Wednesday thru Saturday); however, given the impactful weather within the first 24-36 hours of the forecast period we will devote the rest of this section to discussing this period in more detail. Forecast period (i.e Sunday morning through Monday) begins with a potent H500 jet max (in excess of 100kts) nosing south and east from the Gulf of Alaska towards the western seaboard of the Pacific Northwest and Canada. H500 heights will continue to fall across all the Pacific Northwest, Northern Rockies, and Southwest Canada as this longwave trough rapidly digs to the southeast, with height falls of ~60 to 120 meters overspreading much of North Central thru Southwest Montana from 12z Sunday through 18z Monday. Increasing cross barrier flow will not only help to advect an abundance of Pacific moisture eastward and over the Northern Rockies through this period, but will also bring a prolonged period of strong and gusty surface winds to areas north of the I-90 corridor. Precipitation will initially be confined to the Continental Divide north of the US Hwy 12 corridor through the early morning hours due to strong downsloping in lee of the Divide; however, a cold front diving south from Alberta and Saskatchewan during the mid- to late afternoon hours combined with Pacific moisture overrunning the aforementioned front will help to support a southward advancing band of moderate, to at times heavy, rain/snow over the adjacent plains. This cold front will also help to end the strong to very strong westerly winds over the plains of Central and North Central Montana; however, prior to its arrival a long duration of high sustained and/or gusts will impact most communities. Strong, potentially high, winds look to return to portions of Central Montana from the late morning through afternoon hours on Monday as surface winds veer back to the southwest and become unidirectional with the mid-level flow. - Moldan - Forecast Confidence & Scenarios: High Winds through this afternoon/evening... Confidence remains high that an impactful and damaging wind event will occur along and north of the I-90 corridor through today. H700 winds per NAEFS analysis continue to run 3 to nearly 4 standard deviations above normal at around 50-80kts north of the aforementioned line, with the strongest core of winds being orientated along and west of the I-15 corridor north of Cascade. While strong winds typically occur from the late fall through spring across these areas the overall magnitude of the winds with this particular event are only observed every 5-10 years. NBM probabilities with respect to wind gusts exceeding 60 mph are in excess of a 60% chance north of the I-90 for most locations, with the probability for exceeding 80 mph ranging between a 60-90% chance along the Rocky Mountain Front. Even more impressive there is a 10-30% chance that winds exceed 100 mph along the immediate eastern slopes from Gibson Reservoir to the Hudson Bay Divide. While confidence remains high that strong winds will occur during the day today there remains some uncertainty with the overall duration of the winds for areas east of Shelby and north of the US Hwy 2 corridor where the cold front will advance through first. Here latest guidance supports a shorter, 3-6 hour window for high winds as compared to areas south and west that will see high winds for some 6-18 hours. This shorter window for high winds will likely require the current High Wind Warnings to be cancelled sooner than the current midnight expiration. Accumulating Snow from this evening through Monday morning... Confidence is increasing that a band of moderate to heavy snow will advance south from the late afternoon/early evening hours through Monday morning over the plains of Central and North Central Montana, with the highest snowfall amounts of 1-4" occurring along the US Hwy 2 corridor from Marias Pass through Fort Belknap. Given warm antecedent conditions the current thought is that this accumulating snow can be addressed with a Special Weather Statement since warm ground temperatures will lead to mainly slushy accumulations on roadways. High Winds on Monday... Lingering strong, zonal flow combined with diurnal mixing may help to support another rounds of strong winds along the Rocky Mountain Front and across the US Hwy 200/US Hwy 87 corridor from the late morning through afternoon hours. NBM probabilities for wind gusts exceeding 60 mph across these areas range from a 45-90% chance. - Moldan Thursday winds... Models are in unusually good agreement that yet another (and possibly stronger) upper level jet streak affecting the area on Thursday. While I hesitate to start “sounding the alarm” on an event before a separate event has even started, I will note that current model guidance for the Thursday event is concerning for a few reasons. First is that models are quite consistent in their handling of this event, though I will admit that this may be limiting my view of the possibilities of how this event will unfold. However, the solutions that are presented both show 700 mb winds of 60-90kts (70-100 mph), and 500 mb winds in the 90-110kt range (100- 130 mph), which would make this event stronger than the one tomorrow, with the core of these winds primed to affect mainly Central and Southwestern Montana. At this point, it is a bit difficult to say just how efficiently these winds would mix to the surface. I will, however, note that some indices are eerily reminiscent of what we were seeing at similar lead times to a very impactful event earlier this season. While the wind event tomorrow will remain our focus for the next 24 to 36 hours, we will be keeping a very watchful eye on the forecast for Thursday as well. Ludwig && .AVIATION... 08/06Z TAF Period VFR conditions will prevail during this TAF Period at all terminals. At all terminals during much of this TAF Period it will be windy. At the KGTF and KCTB terminals it will be very windy after 08/12Z through approximately 08/23Z for the KCTB terminal and 09/01Z for the KGTF terminal with several hours of winds gusting in excess of 60 kts at the KGTF terminal and several hours of winds gusting in excess of 65 kts at the KCTB terminal. Across North-central Montana between 08/12Z and 08/24Z there will be instances of blowing dust across North-central Montana. At this time, dust is not expected to reduce visibility at any terminals. During the duration of this TAF Period across North-central, Central, and Southwestern Montana there will be instances of low-level wind shear and mountain wave turbulence across North-central and Central Montana. At the end of this TAF Period a cold front from Canada will sag south and bring a northerly wind shift to the KCTB, KHVR, KGTF, and KLWT terminals. At the KHVR and KCTB terminals between 08/21Z and 08/23Z there is a 15 - 40% chance for rain and/or a rain/snow mix. At the KCTB and KHVR terminals between 09/00Z and the end of the TAF Period a heavy snow band will move through and reduce visibility to 3 miles or less with greater than a 30% chance to reduce visibility to 1 mile or less. At the KGTF and KLWT terminals between 09/00Z and the end of the TAF Period there is a 30 - 50% chance for rain and/or a rain/snow mix. At the end of this TAF Period across North-central Montana there will be mountain obscuration. -IG && .FIRE WEATHER... Strong winds today will result in increased fire danger across the plains of North Central Montana, even with RH values in the 20-30 percent range. Winds are expected to continue to be gusty through the early afternoon, but a cold front coming in from the north will bring both a wind shift to the north and a rapid decrease in wind speeds. Ludwig && .PRELIMINARY POINT TEMPS/POPS... GTF 62 29 45 22 / 10 80 20 0 CTB 53 17 37 13 / 60 90 20 10 HLN 61 33 45 21 / 10 60 50 10 BZN 62 33 47 19 / 10 20 50 40 WYS 43 30 45 16 / 20 20 40 40 DLN 60 38 54 21 / 0 10 10 10 HVR 59 20 42 16 / 60 80 30 10 LWT 60 27 40 19 / 10 70 80 20 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning until midnight MST tonight for Cascade County below 5000ft-East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Judith Basin County and Judith Gap- Northern High Plains-Southern High Plains-Southern Rocky Mountain Front. High Wind Warning until midnight MST tonight for Bears Paw Mountains and Southern Blaine-Big Belt, Bridger and Castle Mountains-Canyon Ferry Area-Eastern Pondera and Eastern Teton- Eastern Toole and Liberty-Elkhorn and Boulder Mountains-Fergus County below 4500ft-Gates of the Mountains-Helena Valley-Hill County-Little Belt and Highwood Mountains-Meagher County Valleys- Missouri Headwaters-Northern Blaine County-Snowy and Judith Mountains-Upper Blackfoot and MacDonald Pass-Western and Central Chouteau County. && $$ http://www.weather.gov/greatfalls