textproduct: Great Falls

KEY MESSAGES

- Breezy through the remainder of the day and early evening.

- Some high elevation snow this evening and tonight.

- Intermittent unsettled weather through the weekend.

- Ridging looks to build in by early next week, promoting a warmer and drier stretch.

DISCUSSION

- Meteorological Overview:

Broad upper level troughing with a few embedded shortwaves is progressing across the region this afternoon, and will continue into early Thursday. A mix of stratiform and showery precipitation will continue, with areas south of US-12 having greatest probability for a thunderstorm the remainder of the afternoon and evening. Snow levels will begin to rise this evening, but will remain low enough to support some high mountain snow as the stratiform precipitation progresses southward tonight. Gusty winds continue across the region through the evening, slowly diminishing in most areas near or after sunset.

Lingering northwesterly flow aloft behind the departing trough will combine with daytime heating to support showers and a few thunderstorms tomorrow afternoon east of a Cut Bank to Great Falls line over the plains.

East to west oriented troughing in BC/SK Friday will slowly sag southward in the afternoon and evening, allowing for a cold front to drop south across the region into Friday night. A stretch of rain and high elevation snow looks to develop as a result along and behind the front, perhaps lasting into Saturday.

By Sunday high amplitude upper level ridging begins to develop across the eastern Pacific Ocean, slowly nudging east into early next week. How quickly this occurs will play a large role in how quickly the region trends warmer and drier late this weekend into early next week. -AM

- Forecast Confidence & Scenarios:

Winds through tonight:

Stronger northwesterly flow aloft will progress across the region tonight. Areas southeast of terrain from the Little Belts eastward will see gusty winds persist into the night. The overall risk for 50+kt gusts in these areas is too low to warrant a High Wind Warning, however.

Crisp overnight lows this weekend:

Temperatures cool across the region Friday into Saturday behind a cold front. Overnight lows Saturday night into Sunday look to drop into the 30s in many areas. While temperatures less than 32 F are low probability at most lower elevation locations, these temperatures are still worth a mention given we are approaching mid- June. -AM

AVIATION

10/18Z TAF Period

Initial concerns this TAF period will be for an area of rain moving south over the plains, with areas of showers and a few thunderstorms across Central and Southwest Montana this afternoon and evening. Additionally, breezy winds will continue across the region through the evening, slowly subsiding from west to east tonight.

Mountain obscuration will increase from north to south through the afternoon and into tonight as the area of rain progresses through the region. Lingering low clouds slowly erode tomorrow morning. -AM

PRELIMINARY POINT TEMPS/POPS

GTF 46 72 44 72 / 50 10 0 10 CTB 42 67 42 64 / 40 20 0 70 HLN 44 72 44 75 / 20 10 0 0 BZN 38 70 39 75 / 30 10 0 0 WYS 24 62 29 70 / 10 10 0 0 DLN 33 70 38 79 / 10 0 0 0 HVR 43 70 43 69 / 80 30 20 60 LWT 39 66 40 68 / 90 20 10 10

TFX WATCHES/WARNINGS/ADVISORIES

None.