textproduct: Great Falls

KEY MESSAGES

- Breezy today and tonight across the plains, then winds subside. - Cooler through the end of the work week, then warming again up early next week. - Generally dry through the next week with only low chances for light precipitation.

DISCUSSION

- Meteorological Overview:

Upper level zonal (westerly) flow will be fairly persistent over the coming week, keeping temperatures close to average through the remainder of the week. While this upper level flow will be on the stronger side today and tonight, winds aloft and at the surface will weaken tomorrow as our upper level flow weakens and high pressure builds in over the plains. Although the zonal flow will keep a steady supply of clouds streaming overhead, any precipitation will be light and largely confined to the immediate Continental Divide, save for a low chance of some light rain east of a Great Falls to Havre line on Thursday.

Upper level ridging will briefly build in over the area for early next week, but this ridge may quickly give way to an upper level trough that would bring another cooldown early next week.

- Forecast Confidence & Scenarios:

Wind tonight: Winds will remain elevated through the overnight hours tonight, particularly along the Rocky Mountain Front where some gusts in excess of 60 mph will be possible along the immediate Rocky Mountain Front. There is a low risk (~10-20 percent) of these waves attempting to propagate a bit onto the plains, but the overall profile of the atmosphere is generally not supportive for these to cause impacts further out on the plains. As such, I have opted against a High Wind Warning for the overnight hours tonight. Ludwig

AVIATION

29/18Z TAF Period

VFR conditions will prevail across all terminals during this TAF Period except for at the KWYS terminal. At the KWYS terminal there will be a period of intermittent low ceilings for the first few hours of this TAF Period. At the KWYS terminal between 30/06Z and 30/14Z there is a low chance for fog. At the KGTF, KCTB, and KHVR terminals during the first 6 hours of this TAF Period there will be gusty winds. During the duration of this TAF Period there will be isolated instances of low-level wind shear across North-central Montana. -IG

PRELIMINARY POINT TEMPS/POPS

GTF 54 66 41 63 / 0 10 0 10 CTB 47 56 35 58 / 0 10 0 0 HLN 48 69 39 67 / 0 0 0 0 BZN 45 70 38 67 / 0 0 0 0 WYS 34 67 29 64 / 0 0 0 0 DLN 44 71 38 70 / 0 0 0 0 HVR 52 64 38 62 / 0 10 0 20 LWT 50 65 39 62 / 0 10 0 20

TFX WATCHES/WARNINGS/ADVISORIES

None.