Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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378 FXUS65 KTFX 011029 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 429 AM MDT Sat Jun 1 2024 .SYNOPSIS... Expect warmer temperatures starting this afternoon and lasting through the rest of the weekend into early next week. A weak disturbance will bring the chance for showers and isolated thunderstorms today and tomorrow to some areas. Starting Monday, a stronger weather system will move through the area bringing more widespread rain and gusty winds to the region. By Thursday, this system is expected to move out, allowing for warmer and drier conditions to settle by later in the week. && .DISCUSSION... Saturday and Sunday... Generally quiet conditions will persist through the weekend with some isolated showers and thunderstorms possible Saturday afternoon through Sunday evening as a couple weak shortwaves move across the region. Minimal accumulations are expected except in isolated stronger showers. Highs this afternoon will be around 10 degrees warmer than yesterday and put temperatures slightly above normal for this time of the year. This will kick off a trend of above normal temperatures that is expected to last through all of next week. Monday through Wednesday... The next impactful system will start Monday afternoon as a surface low develops over southern Alberta and a mid-level trough starts to dig in east of the Rocky Mountains. Showers and thunderstorms will be possible Monday for most locations along the Rocky Mountain front, central, and southwestern Montana. During this time, winds will start picking up, first along the Rocky Mountain front and then spreading across north-central Montana overnight Monday into Tuesday morning. The strongest wind gusts are currently expected early Tuesday morning through Tuesday afternoon. Ensemble guidance maintains widespread probabilities of at least 60% for wind gusts over 58 mph for regions currently outlined in the high wind watch. Outside the watch area, widespread gusts over 40 mph will be possible for much of north-central and central Montana through Tuesday evening. The main change with this forecast was winds did increase along the Bears Paw Mountains and the hi-line east of Havre. However, gusts are still well below criteria at this point in time. When looking at updated probabilities for gusts over 58 mph, there is a trend over the last couple runs of the NBM that suggest some of the higher wind gusts may last a little into early Wednesday morning, mainly at higher elevations of the Rocky Mountains. For now, given that this signal has only shown up in the most recent model runs and with probabilities remaining under 50%, there is not enough confidence to extend or modify the timing of the high wind watch. However, this will be something to observe with future updates. Thursday through Next Weekend... As the trough departs to the east, an upper level ridge will build over the western CONUS bringing above normal temperatures and drier conditions. For Thursday through Saturday there is at least a 60% chance or greater of hitting 80 degrees or higher across the lower elevations of north-central, central, and southwestern Montana. By Sunday the latest ensembles start to have some disagreement on the placement of the ridge. However, the chances for above normal temperatures are expected to continue into the following week with CPC placing most of Montana in a slight (20%) risk of excessive week through the second week of June. -thor && .AVIATION... 01/06Z TAF Period VFR conditions prevail through the TAF period. A westerly flow aloft persists with mid-high level clouds gradually increasing through the day on Saturday ahead of weak weather disturbance. Expect a period of broken mid level clouds at most TAF sites Saturday evening with scattered showers and an isolated thunderstorm or two possible across central and southwest MT. Generally light surface winds prevail through Saturday afternoon with west to northwest winds increasing some Saturday evening. Hoenisch Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 75 48 72 54 / 10 20 0 20 CTB 70 44 68 50 / 10 10 0 20 HLN 77 50 74 55 / 10 30 10 10 BZN 75 46 72 51 / 10 30 30 10 WYS 67 41 64 44 / 0 30 30 10 DLN 74 44 71 52 / 10 20 10 10 HVR 75 50 75 53 / 0 20 0 10 LWT 72 45 69 50 / 10 40 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Monday evening through Tuesday evening for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls