Increasing northerly flow reinforced by a cold arctic airmass behind a shortwave trough passage starting October 26th lead to temperatures region-wide dropping well below normal. Overnight temperatures across the lower elevations in the intermountain Pacific Northwest were able to cool well below freezing across the region for much of the overnight period. This lead to all lower elevation zones experiencing their end of season freeze by the morning of October 28th.

Frost/Freeze in EASTERN COLUMBIA RIVER GORGE, WASHINGTON
From 27-OCT-23 20:39:00 to 28-OCT-23 08:45:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS KDLS recorded temperatures at or below 32 degrees for approximately 9 hours ending at 0945 PDT. The Mesonet station FW7259 recorded temperatures at or below 32 degrees for approximately 12 hours ending at 0941 PDT. The WA Department of Transportation station TMARY recorded temperatures at or below 32 degrees for approximately 5 hours ending at 0823 PDT.

Frost/Freeze in KITTITAS VALLEY, WASHINGTON
From 27-OCT-23 18:31:00 to 28-OCT-23 09:45:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS KELN recorded temperatures at or below 32 degrees for approximately 14 hours ending at 1050 PDT. The mesonet station EW4750 recorded temperatures at or below 32 degrees for approximately 15 hours ending at 1045 PDT. The WA Department of Transportation station TRYEG recorded temperatures at or below 32 degrees for approximately 12 hours ending at 1023 PDT.

Frost/Freeze in YAKIMA VALLEY, WASHINGTON
From 25-OCT-23 23:20:00 to 26-OCT-23 07:07:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS KYKM recorded temperatures at or below 32 degrees for approximately 4 hours ending at 0655 PDT. The AWOS K1S5 recorded temperatures at or below 32 degrees for approximately 3 hours ending at 0415 PDT. The mesonet station W7YKM-3 Tieton recorded temperatures at or below 32 degrees for approximately 2 hours ending at 0220 PDT. The RAWS station YTCW1 recorded temperatures at or below 32 degrees for approximately 8 hours ending at 0807 PDT.

Frost/Freeze in LOWER COLUMBIA BASIN, WASHINGTON
From 27-OCT-23 19:30:00 to 28-OCT-23 08:35:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS KPSC recorded temperatures at or below 32 degrees for approximately 11 hours ending at 0935 PDT. The Mesonet station KF7FMI-13 Prosser recorded temperatures at or below 32 degrees for approximately 12 hours ending at 0840 PDT. The AWOS KRLD recorded temperatures at or below 32 degrees for approximately 12 hours ending at 0915 PDT. The Hanford meteorological station HHMS recorded temperatures at or below 32 degrees for approximately 9 hours ending at 0900 PDT.

Frost/Freeze in BLUE MOUNTAIN FOOTHILLS, WASHINGTON
From 27-OCT-23 20:28:00 to 28-OCT-23 08:57:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS KALW recorded temperatures at or below 32 degrees for approximately 11 hours ending at 0953 PDT. The mesonet station DW4698 recorded temperatures at or below 32 degrees for approximately 12 hours ending at 0925 PDT.  The mesonet station EW4185 recorded temperatures at or below 32 degrees for approximately 12 hours ending at 0957 PDT.

Frost/Freeze in SIMCOE HIGHLANDS, WASHINGTON
From 27-OCT-23 18:09:00 to 28-OCT-23 09:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The mesonet station EW0859 Centerville recorded temperatures at or below 32 degrees for approximately 14 hours ending at 1000 PDT. The mesonet station EW1633 Lyle recorded temperatures at or below 32 degrees for approximately 14 hours ending at 0930 PDT. The RAWS site HIBW1 recorded temperatures at or below 32 degrees for approximately 11 hours ending at 0856 PDT. The RAWS site GNLW1 recorded temperatures at or below 32 degrees for approximately 13 hours ending at 0809 PDT.