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IDZ001>004-026-027-WAZ031>038-041-043-044-047>049-230837-

Public Information Statement
National Weather Service Spokane WA
137 PM PDT Mon Apr 22 2024

Monday night and Tuesday: Currently, the Inland Northwest remains in a broad northwest flow aloft as a shortwave passes through far southeast British Columbia and a subtle ridge moves in from the west. Current radar imagery shows weak showers developing across the high terrain of northeast Washington and north Idaho, but I would not expect these to produce much precipitation. Ridging will shift over the Inland Northwest tonight as a closed upper level low moves onshore northern British Columbia. Under this ridge, temperatures on Tuesday will warm about 5 to 10 degrees compared to Monday with highs in the mid 60s to low 70s.

Wednesday: A cold front associated with the low in British Columbia will push across the Pacific Northwest on Wednesday. Zonal flow aloft will keep precipitation in the Cascades. Models have trended warmer for Wednesday as moisture increases from the southwest with a second day with highs in the mid 60s to low 70s. Winds will be breezy with the front with a minor concern for blowing dust and grass fires in the upper Columbia Basin where there is a 50-60% chance of wind gusts greater than 35 mph. 

Thursday through Monday: Models continue to show a period of active weather through the weekend with multiple systems passing through the northwestern US. Thursday afternoon, models are in good agreement with a surface low approaching the Washington coast and an upper level trough digging along the western US. Models are in general agreement for the potential of widespread precipitation across the Inland Northwest, but there still remains differences on the timing and strength resulting in uncertainty in the onset and overall precipitation amounts. Subsequent shortwaves will continue to bring additional rounds of precipitation Friday and Saturday. Models are coming into better agreement that unsettled weather will continue into the beginning of next week as large, occluded low approaches the northwest. /vmt