Issued Tuesday July 1, 2025 8:20 P.M. PDT

* POTENTIAL FOR DRY LIGHTNING STRIKES OUTSIDE OF THUNDERSTORM RAIN CORES WEDNESDAY *

Tonight…Fair skies this evening then increasing clouds and warmer. Lows in the 50s to near 60 except upper 60s to lower 70s in thermal belts on slopes and hillsides with near 60 around 6000 feet. Light wind.

Wednesday…Variable cloudiness with isolated to scattered showers and thunderstorms developing. Hot with highs in the upper 80s to lower 90s except locally near 80 along the immediate shorelines of Pend Oreille and Priest Lakes with mid 70s around 6000 feet. Afternoon west to southwest winds 10 to 20 mph. Gusty winds possible near thunderstorms.

Wednesday night…Partly cloudy in the evening with isolated showers and thunderstorms then clearing overnight. Lows in the upper 40s to upper 50s with lower 50s around 6000 feet. Evening west to southwest winds 10 to 20 mph becoming light. Ridge top winds west 15 to 25 mph.

Thursday…Mostly sunny, locally breezy and cooler. Highs in the upper 70s to mid 80s with mid 60s around 6000 feet. West to southwest winds 15 to 25 mph with gusts to 30 mph across ridge tops.

EXTENDED OUTLOOK (FRIDAY THROUGH TUESDAY):

Independence Day and Saturday…Mainly dry and warm except for a slight chance of mountain thunderstorms. Lows in the mid 40s to mid 50s with upper 40s around 6000 feet. Highs in the mid 70s to mid 80s with lower 60s around 6000 feet.

Sunday through Tuesday…Dry with a warming trend. Lows in the mid 40s to mid 50s Sunday warming to the upper 40s to upper 50s by Tuesday except upper 60s in thermal belts on slopes and hillsides by Tuesday. Highs in the mid 70s to mid 80s Sunday warming to the upper 80s to mid 90s by Tuesday except locally near 80 along the immediate shorelines of Pend Oreille and Priest Lakes. Around 6000 feet lows near 50 Sunday warming to near 60 by Tuesday. Highs in the mid 60s Sunday warming to the mid 70s by Tuesday.

In-Depth Weather Discussion for Northwest Montana/North Idaho/Northern Rockies

ISSUED 07/01/2025 9:00 P.M. MDT/8:00 P.M. PDT

SHORT TERM (TUESDAY NIGHT THROUGH THURSDAY):

Another hot and dry day unfortunately across the region on Tuesday with just about all valley locations away from the larger lakes rising up into the 90s. A fairly dynamic upper level low continues to spin off the California coastline as of this writing as was evidenced by a lot of lightning over the ocean during the day on Monday with the vort max associated with that lightning rotating back northward Tuesday evening as of this writing and creating an impressive MCC(Mesoscale Convective Complex) across southern Oregon and Northern California. Thunderstorms have also developed across much of Central Oregon and up the spine of the Cascades as far north as Mount Adams. High resolution models are not handling this convection very well and are showing much less activity than what is actually occurring. This is a bit concerning for our region as the upper level low is forecasted to slowly begin to move northeast towards our region with the vort max triggering the convection Tuesday night also forecasted to move over our region during the mid to late morning hours on Wednesday yet HI-RES models are not showing much in the way of convection associated with it. The HI-RES WRF is picking up on a convergence zone of convection developing in the late afternoon hours on Wednesday but is the only model showing this. Have seen our region get surprised many times in the past by these types of patterns as models really struggle with elevated convection across our region at times. It appears that the approaching cool upper level trough off the British Columbia coastline will slowly move down the coast to near the northern tip of Vancouver Island with the left front quadrant of the jet becoming aligned over our region. If this lines up with the incoming vort max then convection could be rather widespread at some point during the day on Wednesday. The main concern with this set up is that the convection is highly unlikely to be surface based and will be of the elevated, dynamically forced convection which tends to move quickly causing little beneficial rains but the potential for a lot of lightning strikes outside of the rain cores. If a convergence zone does develop on Wednesday afternoon then this convection is likely to be surface based and slower moving which would increase the chances of beneficial rains but over a small area. Have gone ahead and increased the chances of convection across the region for Wednesday as given how dry it is and the potential for lightning strikes wanted to give a heads up to the public and our wild land firefighters. A cool front will move through the region Wednesday night which will keep winds elevated across higher elevations and cause winds to pick up region wide on Thursday. Temperatures will also drop between 8-12 degrees on Thursday from Wednesday’s highs but will still be around 5 or so degrees above early July seasonal averages. Another shortwave will begin to approach the region on Thursday night and this will need to be watched as models continue to waffle with the placement of this feature which could have significant impacts on the Independence Day holiday. Read below for more details.

LONG TERM (THURSDAY NIGHT THROUGH TUESDAY):

Models continue to struggle with where another shortwave and upper level feature will track later Thursday night into the Independence Day holiday. As of this writing the track takes this feature further south across West Central Montana which is far enough north and portions of Northwest Montana mainly east of a line from Noxon to Lake Koocanusa could see a fair amount of shower and thunderstorm activity. While this rain would be very welcome and much needed it could affect celebration activities outside. A few models track this feature further north and west which would include the entire region for a chance of showers and thunderstorms and still others track it further south and east which would keep our region dry and possibly a little cooler with a greater influence from the upper level low moving into British Columbia. Hopefully models will come to a consensus soon. Beyond Saturday all models are in good agreement on the continental ridge rebuilding once again across the Intermountain West and bringing another increase in temperatures along with dry and stable conditions unfortunately. By next Tuesday there is a good chance that temperatures will once again be just as hot as they were across the region today. Not what our region needs given how dry we are. Stay tuned.