textproduct: Great Falls

KEY MESSAGES

- Impactful heat through the weekend, with little overnight relief in some areas.

- Widely scattered showers and thunderstorms most days through the weekend, mostly in Southwest and Central MT.

- Increased fire weather concerns Friday and Saturday as hot temperatures combine with low relative humidity and breezy winds.

DISCUSSION

A building upper level ridge with axis across the central CONUS will largely remain in place over the upcoming week, resulting in an extended stretch of hot temperatures. Flow aloft initially will be more zonal before transitioning more southwesterly as the ridge nudges back westward ever so slightly toward the weekend. Monsoonal moisture is decreasing, but remains across the region today, highest across Southwest Montana. Although upper level support isn't particularly great, widely scattered showers and thunderstorms look to develop through the afternoon and evening, with a few persisting into the overnight.

Monsoonal moisture decreases further Friday as a drier zonal flow aloft remains for another day. That said, lingering moisture still looks to result in isolated showers and thunderstorms, mostly across Southwest Montana. Breezy west winds and hot temperatures will result in increased fire weather concerns over the plains Friday, particularly near the Canadian border where precipitation recently has been minimal.

The southwesterly flow aloft works back in this weekend as temperatures peak across most areas. Additional round of primarily afternoon and evening widely scattered showers and thunderstorms will be around, mostly across Southwest MT and vicinity.

That story more or less persists into next week. Hot temperatures remain with opportunities for widely scattered showers and thunderstorms most afternoons, primarily across Southwest MT and vicinity. Areas further north on the plains look to remain hot and dry over this timeframe. Anyone that has to be outside for any extended stretch over the upcoming week should prepare for plenty of hydration breaks in the shade. -AM

AVIATION

23/18Z TAF Period

Main concern this TAF period will be for primarily afternoon and evening showers and thunderstorms, mostly across SW MT and vicinity near terrain. Briefly gusty winds, small hail, lightning, and briefly heavy rain will be the concern with the most robust thunderstorms today. A few showers or thunderstorms look to linger into the overnight, though this coverage looks isolated at best. Breezy westerly winds return to the plains late tomorrow morning. Wildfire smoke will be around through the TAF period, though confidence in any sub-VFR visibility was too low to warrant mention at this time. Slant-range visibility issues look to remain through the entirety of the TAF period. -AM

FIRE WEATHER

Intensifying heat, critically low minimum humidity, and westerly winds routinely gusting in the 20 to 30 mph range will raise daily elevated to critical fire weather concerns this weekend into next week. In the near term, the worst fire weather conditions will be over the north-central plains Friday and Saturday. Additionally, isolated to widely scattered showers and thunderstorms may produce localized strong wind gusts and cloud to ground lightning, mostly for central and southwest Montana Saturday afternoon and evening. A fire weather watch has been issued for zones 112, 113, 114, 115, and 117 for Friday and Saturday to address the elevated to critical fire weather conditions that may develop in this setup. - RCG

PRELIMINARY POINT TEMPS/POPS

GTF 64 98 63 102 / 20 0 0 10 CTB 61 91 58 97 / 20 0 0 0 HLN 63 97 63 99 / 20 20 0 20 BZN 60 97 60 97 / 20 20 20 30 WYS 50 87 51 87 / 30 20 20 40 DLN 57 93 57 92 / 20 20 20 20 HVR 64 101 62 107 / 20 0 0 0 LWT 61 94 61 100 / 20 0 20 30

TFX WATCHES/WARNINGS/ADVISORIES

Fire Weather Watch from Friday morning through Saturday evening for Central and Eastern Lewis and Clark National Forest Areas- Chouteau and Fergus Counties-Eastern Glacier/Toole/Central/Eastern Pondera/Liberty-Hill and Blaine Counties-Lewis and Clark National Forest Rocky Mountain District- Rocky Mountain Front.

Heat Advisory from noon Friday to 9 PM MDT Sunday for Beaverhead and Western Madison below 6000ft-Canyon Ferry Area-Eastern Glacier, Western Toole, and Central Pondera-Eastern Pondera and Eastern Teton-Eastern Toole and Liberty-Gallatin Valley-Gates of the Mountains-Helena Valley-Madison River Valley-Meagher County Valleys-Missouri Headwaters.

Heat Advisory from noon Friday to noon MDT Saturday for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft- Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Northern Blaine County-Western and Central Chouteau County.

Heat Advisory from 9 PM Saturday to 9 PM MDT Sunday for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft- Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Northern Blaine County-Western and Central Chouteau County.

Extreme Heat Warning from noon to 9 PM MDT Saturday for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft- Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Northern Blaine County-Western and Central Chouteau County.