textproduct: Great Falls

KEY MESSAGES

- Hot through the entire week, hottest Friday into Saturday.

- Widely scattered showers and thunderstorms each afternoon this week, focused mostly near terrain.

DISCUSSION

- Meteorological Overview:

Persistent upper level ridging, with axis off to the east, will keep a southwesterly flow aloft in place across the Northern Rockies through this week. Hot daytime temperatures will continue this week, peaking late week and Saturday. A few weaker shortwaves progressing through the southwesterly flow aloft will foster some afternoon and evening showers and thunderstorms at times through the week. That said, this activity looks to be rather isolated most days. Gusty winds would be the primary concern from a stronger thunderstorm that develops.

Confidence is increasing in a ridge breakdown this weekend, which would result in a breezy stretch over the plains and adjacent areas. Although some troughing looks to move through over this timeframe, confidence in any precipitation remains low. -AM

- Forecast Confidence & Scenarios:

Forecast high temperatures this week:

Wildfire smoke will look to put a damper on forecast high temperatures at times this week. Where confidence was high in ample smoke, either aloft or at the surface, temperatures for Monday were adjusted cooler. Trends will continue to be monitored for additional adjustments to forecast high temperatures. -AM

AVIATION

26/18Z TAF Period

Initial concern across the region will be for wildfire smoke impacting visibility, both surface and slant-range, through the entire TAF period. Widely scattered showers and thunderstorms develop this afternoon and early evening across portions of Southwest Montana, bringing the risk for gusty and erratic winds. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 61 93 59 96 / 0 0 0 0 CTB 54 88 54 91 / 0 0 0 0 HLN 63 94 60 94 / 0 0 10 0 BZN 60 94 57 95 / 20 20 20 0 WYS 56 85 49 87 / 20 20 20 0 DLN 57 92 54 91 / 20 0 0 0 HVR 59 95 59 99 / 0 0 0 10 LWT 59 91 57 93 / 20 0 10 10

TFX WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 9 PM MDT this evening for Beaverhead and Western Madison below 6000ft-Canyon Ferry Area-Cascade County below 5000ft-Eastern Glacier, Western Toole, and Central Pondera- Eastern Pondera and Eastern Teton-Eastern Toole and Liberty- Gallatin Valley-Gates of the Mountains-Helena Valley-Hill County- Judith Basin County and Judith Gap-Madison River Valley-Meagher County Valleys-Missouri Headwaters-Northern Blaine County- Western and Central Chouteau County.

Extreme Heat Warning until 9 PM MDT this evening for Bears Paw Mountains and Southern Blaine-Fergus County below 4500ft.