ISSUED 06/01/2025 7:45 P.M. MDT/6:45 P.M. PDT
SHORT TERM (SUNDAY NIGHT THROUGH TUESDAY):
A dry and stable upper level trough that moved over the region on Sunday finally brought daytime temperatures back down close to seasonal averages although still a couple of degrees warmer than typical for the first day of June. If you were up earlier on Sunday then you may have noticed an all too familiar sky for our summer months with an orange glow to it, wildfire smoke that was transported into our region from large wildfires burning in Manitoba and Saskatchewan. The surface low that helped to bring our gusty winds on Saturday lifted northeast into these Canadian provinces overnight with our region on the backside of the low and flow coming down from the north helped to move some of that smoke into our region. It has since cleared out. Another weak shortwave will drop down in northwest flow late tonight into Monday morning. Most of the lift and dynamics will remain over and east of the Continental Divide unfortunately so not much in the way of rainfall for our region with the exception perhaps of far northeast Lincoln County up around Rexford, Eureka and Trego as these areas will be closest to the shortwaves passage. Elsewhere just some passing cloud cover. Temperatures for the next two nights and mornings will be chilly, cold enough for frost and even freezing conditions in our typically colder valleys especially in Northwest Montana such as Yaak, Happys Inn and McGinnis Meadows. These colder valleys may dip into the upper 20s however having said that the average last frost date for these colder valleys is typically not until the second week of June. Elsewhere with the threat of frost away from the shorelines of larger lakes such as Thompson, Pend Oreille, Priest, Cocolalla to name a few, is there so gardeners may want to take precautions to protect sensitive plants. Once the Monday shortwave passes through the region by afternoon upper level ridging will build to our west and bring northwest flow aloft into the region with slowly warming temperatures, dry conditions and a stable environment, not really what our region needs right now.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY):
Dry and stable conditions will continue across the region throughout much of the upcoming week with little to no sign of any shortwave passages, instability and therefore precipitation. Ridging looks to remain somewhat flat which will allow for breezy conditions with passing shortwaves just north of the Canadian border but yet strong enough to also prevent the lift and instability associated with these features to also be kept further north. The result is an extremely dry and somewhat warm start to what is historically one of the wettest months of the year for our region, and, in the case of parts of Northwest Montana the wettest month of the year. If we look out into fantasy land there are not really any clear signals of a pattern change showing up at this time. That being said, we did have a cooler and somewhat unsettled pattern for about 2-3 weeks in May that unfortunately did not bring much widespread rainfall but still at least brought some rainfall. We have just closed out the first week of this dry stretch and so if pattern recognition holds and then we can expect about another 2 weeks of warm and dry conditions before potentially seeing the pattern flip back to a wetter and cooler one. Time will tell. Unfortunately fire danger will continue to increase and finer fuels are already beginning to cure and dry out, almost 6 weeks earlier than typical. For all of the newer arrivals to the region, despite all of the rain than fell this past winter, that rain fell on frozen ground which did not soak into the soils and therefore simply ran off into the lakes and rivers which did not do any benefit as our lakes and rivers are kept at lower levels during the winter and spring months before being raised to summer levels. Another reason why our region benefits from snowfall during the winter months and not rain.
ISSUED 05/25/2025 9:20 P.M. MDT/8:20 P.M. PDT
SHORT TERM (SUNDAY NIGHT THROUGH TUESDAY):
Warmest day of the year across the entire Northern Rockies on Sunday with all valley locations rising into the 80s with some of our typical hot spots hitting 90 for the first time this season around Plains and Hot Springs. These temperatures are some 10 to 20 degrees above late May seasonal averages but short of records which are rather high at this time of year. Some cumulus fields developed with daytime heating Sunday afternoon and are indicative of some minor mid level instability. An approaching shortwave will bring increasing chances of showers and thunderstorms overnight mainly across Washington as that is where the best mid level instability and lift will reside. As this feature presses eastward into North Idaho towards dawn on Monday the instability will be weakening rather rapidly along with the mid level forcing driving the convection so only some scattered showers with a rumble or two of thunder will be possible. Further east across Northwest Montana little to no activity is anticipated to make it this far east as the shortwave will be all but gone by this time as it runs into the mean upper level ridge. By Monday afternoon some surface based instability will allow for some isolated showers and thunderstorms to develop across North Idaho mainly across Boundary County and along the Canadian border in Northwest Montana. The rest of the region will see temperatures drop 10 to 15 degrees along with an increase in southwest winds as surface pressures fall across southern British Columbia and Alberta. By Tuesday ridging will be amplifying across the region once again for another dry and warming trend.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY):
Overall not much excitement in the extended forecast period and as of this writing unfortunately no signs of any widespread beneficial rains across the region either. Two shortwaves will pass through which may trigger some shower and thunderstorm activity with the first one arriving late Thursday afternoon and overnight with the second one and potentially stronger one arriving sometime on Sunday. Our fine fuels are slowly beginning to dry out especially across Northwest Montana where the past 2 weeks did not deliver as much rain as North Idaho received so it is time to start preparing for fire season. Hopefully June will turn wetter and cooler and there are some weak signals that this may occur but so far nothing definite. Temperatures will remain well above seasonal averages through the extended forecast period and without much rainfall in the forecast the pine pollen will definitely be making a strong showing this year!
ISSUED 05/11/2025 8:20 P.M. MDT/7:20 P.M. PDT
SHORT TERM (SUNDAY NIGHT THROUGH TUESDAY):
After a good rainfall in the morning across North Idaho another shortwave is rotating into the region as of this writing on Sunday evening. This feature is associated with some good upper level jet dynamics as well as a good convergence/divergence couplet located across Northwest Montana. As of 8:00 pm.m MDT/7:00 p.m. PDT there was a radar indicated severe thunderstorm that moved across northwest Sanders County with reflectivity showing ping pong ball sized hail and 60 mph wind gusts. Have not heard of any reports of damage but the most intense part of this storm appeared to located over very rural parts of Sanders County west of Noxon and south of Heron along the Idaho line and up in the Coeur d’ Alene Mountains. Instability will remain present throughout the evening hours as the incoming shortwave helps to provide the needed lift or vertical motion through the atmosphere to generate precipitation, some of which will be locally intense. Largely this will be beneficial rainfall and even some high elevation snowfall as well with our region coming off a largely dry April. The shortwave will lift north into southern Canada with a trowal feature developing around the system which looks to provide another round of beneficial rains and high elevation snowfall into Tuesday for at least parts of the region although the exact location continues to change with each model run. Outside of this feature will be a smattering of showers and thunderstorms but thunderstorms will not be strong to severe outside of Sunday evenings potential. Instability will be present and any passing shortwave within the flow will help provide additional support to generate convection. Temperatures will actually remain below average for a few days and potentially the entire week as a progressive and fairly flat flow remains in place across our region with cooler atmospheric height and thickness values remaining in place. With the upcoming weekend featuring several notable events weather will be playing a large role. Read below for more details.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY):
Lingering instability and another passing shortwave disturbance on Wednesday will provide for additional sunshine and scattered heavy, possibly thundery downpours. There is decent confidence that a transitory shortwave upper level ridge will pass overhead sometime late Wednesday night into late Thursday afternoon offering up a stable airmass with more sunshine but an active North Pacific jet stream associated with a negative height anomaly in the Gulf of Alaska will be directing yet another strong shortwave passage into the region on Friday and lasting through the weekend. This feature will also have some decent jet support for this time of year so it looks like at least periodic rounds of rain and high elevation snowfall from Friday and lasting through the weekend. The Lost in the 50s event in Sandpoint is next weekend and it looks wet for that event as well as cool. In addition there is the annual Eagle Valley Auction over by the Libby airport which also looks a bit damp and cool. Finally and not to be missed is the “Fishmas” opener in Northwest Montana as the stream fishing opener takes place. If planning on casting a line in the water for this take the jacket and rain coat as it will likely be very cool and damp especially Saturday morning. The overall trend is for the active North Pacific jet to remain focused across our region bringing typical May weather to the Northern Rockies with periodic rounds of valley rain showers and higher elevation snow showers. After the dry April the precipitation will definitely be welcome to gardeners and farmers alike although the timing may not be the best.