FXUS65 KMSO 191836 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1236 PM MDT Fri Jul 19 2024 ...Excessive Heat to Continue through the Middle of Next Week... .DISCUSSION...Hot temperatures rising into the 100 to 115 degree range are still on track to begin this weekend. One update to the hot forecast is that it now looks like the hottest temperatures could occur Sunday through Tuesday, with overall hot and dry conditions persisting through Wednesday. The ridge of high pressure just does not want to budge, which will allow for additional days of persistent heat and little in the way of overnight relief. In fact, low temperatures in central Idaho may not even drop below 70 degrees, while most of western Montana valleys should remain in the 60s each night through Tuesday. Record temperatures will certainly be in jeopardy for many locations. As the ridge shifts to the east by Tuesday and locations along the Continental Divide start to climb into the upper 90s, such as Butte, Anaconda, Seeley Lake, etc, records could be tied or broken in these locations as well. As such, additional Heat Warning and/or Advisories may be issued or expanded in the coming days. Heat safety for both humans and animals will be crucial during this time and should not be taken lightly. The presence of smoke in the air will degrade air quality, adding to the stress on the body. Those sensitive to both heat and poor air quality should take special care to ensure their well-being. Relief is expected as the high-pressure ridge is replaced by a low- pressure center moving inland from the Washington coast by Friday. Temperatures will start to cool a few degrees each day beginning as early as Wednesday (July 24), but any major improvement will depend on the timing and track of the low- pressure system. && .AVIATION... Hot and dry conditions will persist into the weekend, with light winds except for typical afternoon gusts of 10-20 knots. High- density altitude will remain a concern due to the abnormally hot temperatures. Smoke from regional and local wildfires will create hazy skies and localized visibility reductions. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Excessive Heat Warning until midnight MDT Tuesday night for Kootenai/Cabinet Region...Lower Clark Fork Region. Heat Advisory until midnight MDT Tuesday night for Flathead/Mission Valleys...Missoula/Bitterroot Valleys... Potomac/Seeley Lake Region...West Glacier Region. ID...Excessive Heat Warning until 11 PM PDT Tuesday for Lower Hells Canyon/Salmon River Region...Northern Clearwater Mountains...Orofino/Grangeville Region...Southern Clearwater Mountains. && $$