Even though the system that brought us rain on Saturday helped to remove the inversion we had in place, dense fog developed across the region Sunday night and Monday morning. Our weather pattern stabilized briefly, but another shot at rain showers returns Tuesday as the first of a couple cold fronts reaches the coast.
Unlike the low-pressure systems that made landfall in Oregon and California that have been the recent source of our precipitation, the chance of rain this week is the result of cold fronts that are being dragged by low-pressure systems. The centers of these lows will be well to our north, with landfalls occurring in Alaska and northern British Columbia.
Since these lows will be to our north, we will not be in the coldest part of the system. Temperatures will drop behind the cold fronts, but I don’t expect it will be cold enough for snow in the Tri-Cities. Snow levels may reach low enough for snow on Rattlesnake Mountain or Manastash Ridge, but even though these peaks are above pass level, snow levels should be higher over the Cascades and Blue Mountains. The snow that does fall at pass level should be limited to the coldest hours in the morning.
The best chance of rain for us here in the Columbia Basin will be from Wednesday evening to midday Thursday (a 50% chance), with a lower shot at rain showers overnight Tuesday (a 40% chance). Even with these frontal systems, fog and low clouds should persist through this time period in the basin and adjacent valleys.
Breezy conditions may develop Thursday and linger into Friday. Gusts may reach to around 40 mph, but I’ll have updated information on Tri-Cities Weather as we get closer to that event.
Looking beyond Thursday, there is a chance of another light rainmaker on Saturday, but current indications are that this will be confined to around the Bend-area. After that, it looks like a return to a ridge of high pressure. If this verifies, it will bring us back to dry conditions and a shot at another period of inversion.
