Afternoon highs in the Tri-Cities have been running above average for the last several days in the Columbia Basin with some places even approaching 70° late last week. These mild conditions are likely to come to an end with a strong upper level trough diving south out of Canada and into the Pacific Northwest. While highs should remain in the 50s to end the week, by next Tuesday lowland areas will struggle to get above freezing despite sunny skies during the afternoon hours with lows reaching into the teens.
The National Weather Service forecast, included above, brings highs down into the low 30s. While this is much colder than what has been seen the last week and a half, this will be a far cry from breaking records. The average high for this time of year in the Tri-Cities is about 50°, the average low is in the upper 20s, and records are well below that.
Unfortunately, with this trough traversing Alaska, Yukon, and British Columbia before reaching Washington (instead of coming in from off the Pacific), there won’t be much moisture to tap. The best chance of precipitation, keeping in mind that this is a low chance, is Sunday when the initial blast comes through.
Much colder temperatures aloft are expected to allow for some convective activity Monday and Tuesday. Most of this will be confined to the mountains and areas west of the Cascades, but I wouldn’t be surprised to see isolated brief rain, snow, and/or graupel in the Columbia Basin. Not everyone will see precipitation, and those that do won’t have a drought busting deluge.
A generally active and cold pattern continues Wednesday and beyond, though moisture content in the atmosphere remains low. There is a chance of a system bringing in some precipitation the weekend of the 26th but generally speaking the setup looks cold and dry for the remainder of February. Extreme drought (D3/4) conditions are currently being observed in the Lower Yakima Valley, Horse Heaven Hills, and Columbia Basin west of Hermiston with severe drought (D2/4) elsewhere in the area.
Other reporting on this cool down from voices across the Northwest:
Portland: A very dry February, plus a cold spell early next week (Mark Nelsen)
Seattle: Powerful trough incoming, models agree! (Michael Snyder)
Spokane: Colder weather is coming: Here’s why (Matt Gray)
The featured image is ECMWF modeled temperatures at 700 hPa on Monday, showing the cold air coming into the Pacific Northwest via windy.com.
