The wind is very strong out there this afternoon and relative humidities are dropping by the hour. The wind at the surface is generally blowing from the west, and in some places, the northwest. Red Flag Warnings are in effect through tonight for most of the state for the dangerous fire conditions stated above; namely, low humidity and strong winds. The strong winds have caused enough good dispersion to almost completely clear northwestern Montana of smoke. Libby, the Flathead Valley, Missoula, and the Swan Valley are seeing GOOD air quality this afternoon with much improved visibility. Air quality is also still GOOD in the West Yellowstone area, Billings, and most of far eastern and southeastern Montana in general. Despite the fact that surface winds are blowing mostly from the west, winds high in the atmosphere are still blowing from the southwest. The heaviest smoke in the atmosphere is contained in a sort of “cone,” with a west boundary from the Bitterroot Valley to Cut Bank, and an east boundary from Ennis to Bozeman to Fort Peck Lake. The smoke is taking this general southwest-to-northeast path across the state, and all areas under this “cone” are seeing poor air quality. In some places, air quality has gotten worse, and the change was sudden, like in Helena and Great Falls, who are now both UNHEALTHY FOR SENSITIVE GROUPS. These two locations are also affected by increasing fire activity from Montana fires to their west and southwest. Hamilton is still UNHEALTHY, although the last couple of hours have trended downward to cleaner air. In the past hour Butte has also jumped to UNHEALTHY.
Because the winds are so strong, and fire behavior and smoke production have been somewhat erratic and unpredictable today, it is best to use the Visibility Guidelines. It has been shown today that air quality has changed much quicker than the air monitors have been able to capture and report out.
For the rest of today, look for fires in Idaho to produce heavy smoke again late this evening. Atmospheric winds will likely push that smoke into Montana again, affecting communities in that “cone” described above. For the western half of the state, winds will start to die back down around 8:00 tonight, or after sunset. For eastern Montana, strong winds will persist into the night, but should be calm by morning. Winds will be much calmer tomorrow state-wide, with some usual afternoon gusts. Fire weather will not be quite as dangerous tomorrow, although it will continue to be hot and dry. Smoke will still be around parts of western Montana tomorrow morning, and late tomorrow afternoon, we may see another round of smoke from Idaho. Atmospheric winds will still push smoke from the southwest to the northeast, so northwestern Montana should stay in the clear for most of the day. By late tomorrow afternoon and through the night, those winds will start to shift, and will come more from the south rather than just the southwest. Like we saw in the last couple of days, this should push more smoke back into northwestern Montana. Friday will be very hot and dry again, as a warm front lifts over the state. The hot and dry conditions will once again bring some fire concern. Friday night and into Saturday, another cold front will pass across the state. Winds will pick up in the evening ahead of this cold front, and then winds will be strong again along the cold front. Behind the front, winds at the surface will come from the west and northwest. This will be another chance to help clear smoke out of the area. By Saturday, atmospheric winds will blow from the southwest again, so any smoke that is produced in Idaho (and even here) will blow from southwestern Montana, across the middle, and towards the hi-line. By Sunday, the winds shift again, and stay consistent for the first part of the week. Winds will come from the west, so the northern part of Montana should stay clear of smoke for the holiday weekend. Central, southern, and especially far western Montana will take the brunt of any smoke that is produced. Another cold front mid-week should help to clear smoke out once again. Unfortunately, the one thing that is severely missed in this forecast is rain! Without some sort of moisture in the forecast, conditions are not likely to improve any time soon. |
Libby, the Flathead Valley, Missoula, and the Swan Valley are seeing GOOD air quality this afternoon with much improved visibility. Air quality is also still GOOD in the West Yellowstone area, Billings, and most of far eastern and southeastern Montana in general. Smoke is taking a general southwest-to-northeast path across the state, and all areas under this “cone” are seeing poor air quality. In some places, air quality has gotten worse, and the change was sudden, like in Helena and Great Falls, who are now both UNHEALTHY FOR SENSITIVE GROUPS. These two locations are also affected by increasing fire activity from Montana fires to their west and southwest. Hamilton is still UNHEALTHY, although the last couple of hours have trended downward to cleaner air. In the past hour Butte has also jumped to UNHEALTHY. |