Issued Sunday July 6, 2025 7:55 P.M. MDT
Tonight…Fair skies. Lows in the lower 40s to lower 50s except near 60 in thermal belts on slopes and hillsides with mid 50s around 5000 feet. Light wind.
Monday…Mostly sunny and warmer. Highs in the lower 80s to lower 90s with lower 70s around 5000 feet. Afternoon west to southwest wind 5 to 15 mph.
Monday night…Fair skies. Lows in the mid 40s to mid 50s except upper 60s in thermal belts on slopes and hillsides with near 60 around 5000 feet. Light wind.
Tuesday…Mostly sunny and hot. Highs in the upper 80s to upper 90s with upper 70s around 5000 feet. Afternoon southwest winds 10 to 20 mph with gusts to 30 mph along portions of Lake Koocanusa, through favored canyons and across ridge tops.
EXTENDED OUTLOOK (WEDNESDAY THROUGH SUNDAY):
Wednesday…Dry, locally breezy to windy and a little cooler. Lows in the 50s to near 60 with near 60 around 5000 feet. Highs in the mid 80s to lower 90s with lower 70s around 5000 feet.
Thursday…Cooler with a chance of showers and thunderstorms along the Canadian border with a slight chance of showers and thunderstorms elsewhere. Lows in the upper 40s to mid 50s with lower 50s around 5000 feet. Highs in the lower 70s to lower 80s with lower 60s around 5000 feet.
Friday through Sunday…No precipitation. Lows in the 40s Friday warming to the mid 40s to mid 50s Saturday and Sunday except lower 60s in thermal belts on slopes and hillsides. Highs in the upper 70s to upper 80s Friday warming to the mid 80s to lower 90s Saturday and Sunday. Around 5000 feet lows in the lower 50s Friday warming to near 60 Saturday and Sunday. Highs near 70 Friday warming to the lower to mid 70s Saturday and Sunday.
In-Depth Weather Discussion for Northwest Montana/North Idaho/Northern Rockies
ISSUED 07/06/2025 8:45 P.M. MDT/7:45 P.M. PDT
SHORT TERM (SUNDAY NIGHT THROUGH TUESDAY):
Fairly pleasant weekend across the region with temperatures running a few degrees above seasonal averages for early July, a nice break from the hot and dry conditions we have had for much of the Spring and Summer season thus far and also rather unusual but certainly not unheard of. Upper level ridging will amplify across the region ahead of a Gulf of Alaska trough that will be brushing by the region later in the day on Wednesday bringing mainly fire weather concerns but also some precipitation chances as well. Before then our atmosphere will continue to dry and warm with a stable airmass remaining in place. By Tuesday which will likely be the hottest day this week, high temperatures will be running a solid 10 to 15 degrees above seasonal averages once again but no records are likely at this time. The thermal trough will be right overhead to start the day on Tuesday which will help temperatures rise rapidly before the thermal trough axis shifts east and south which will allow for west to southwest breezes to pick up and increase fire danger.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY):
As the Gulf of Alaska upper level trough begins to swing inland it will result in rapidly falling atmospheric height and thickness falls as this will be a rather strong and cool trough by July standards pushing into the region. With the rather robust thermal gradient between in the incoming airmass and the retreating hot airmass surface pressure falls on the lee side of the Continental Divide along with rapidly rising surface pressures along the coast will create a tight surface pressure gradient across our region. Anticipate a very breezy to windy day on Wednesday across the region and although temperatures will likely drop about 10 degrees from Tuesday’s hot readings they will still be above average and conditions will be rather dry thus increasing the fire danger. Fortunately the rains that fell late last week will help mitigate the danger slightly. By late in the day a vort max associated with the cool upper level low will move along the International border and will trigger isolated to scattered showers and thunderstorms. The main question as of now is how far south will the vort max travel. For now thinking that the precipitation threat will mainly be along and within 30 miles or so of the Canadian border but if this feature looks to track further south chances will need to be expanded as well. Thursday will see temperatures near or perhaps even a couple of degrees below mid July seasonal averages and looks to overall be a very pleasant day. By Friday the next transient upper level ridge will push through the region bringing another warm up with temperatures rising to 6-10 degrees above average once again with yet another upper level trough likely to follow up by the following Monday but that is beyond this forecast cycle. Stay tuned!