I know summer just began but the first cool down of the new season is coming. After a warm and sunny Wednesday that felt like a real summer's day, a new storm system will bring in Canadian air for the end of the week and first weekend of summer. Temperatures will not be cold but there will be a crispness to the air from Friday into Sunday. Overnight lows in some areas may drop down close to frost territory which is something some of you will need to watch. Thursday will turn partly cloudy with a few isolated thunderstorms over central and eastern Montana. Highs will be in the 60s and 70s in western Montana, and 80s to around 90 for central and eastern areas. The wind will be stronger with some gusts over the plains up to 50mph. A sharp cold front will move through Thursday with the cooler airmass arriving for Friday. Highs will generally be in the 50s and 60s on Friday. There will be a few showers moving through Montana in the afternoon. This Canadian airmass will bring in the threat for a frost and/or freeze for some areas Friday night into Saturday morning. Some areas including the Helena Valley and Great Falls could drop into the low to mid 30s by early Saturday morning. Some of the normally colder spots like the Little Belt Mountains could have a hard freeze. While the overnight lows will be chilly, overall the first weekend of summer will be gorgeous with abundant sunshineand comfortable temperatures. Saturday will have crisp highs in the 60s, but Sunday will warm into the 70s for most of the state. Temperatures will continue to warm early next week and some areas will be up around 90 by Tuesday. Along with the heat comes the chances of thunderstorms on Tuesday and Wednesday.
Curtis Grevenitz
Chief Meteorologist