Pacific Northwest mean temperatures departed +0.7 degrees from the 1961-1990 normals (31 stations). Mean temperature departures ranged from -3.5 to 18.5 degrees.
In general, below normal precipitation and above normal temperatures for the southern half of the basin, near normal precipitation and below normal temperatures for the north.
A ridge of high pressure dominated the basin early in the month with minor disturbances progressing north into Canada. This pattern produced light precipitation and cold air in Canada, Idaho and Montana. A period of short lived southwesterly flow followed, bringing moderate rain to western Washington and light precipitation into northern Idaho and northwestern Montana. The mid and latter portions of the month were dominated by a ridge building into the south with minor disturbances brushing northwest Washington and Canada.
No daily precipitation or maximum temperature records were broken in the month of October.
A cold front moved through western Montana on October 2nd and 3rd resulting in the following daily minimum temperature records. Daily record minimum temperatures were broken at Kalispell (21 deg on the 2nd, 15 deg on the 16th), Great Falls (17 deg on the 3rd). Daily record minimum temperatures were tied at Missoula (23 deg on the 3rd).
For October, precipitation was 129 percent of normal (1961-1990) at Columbia above Coulee; 62 percent of normal at the Snake River above Ice Harbor; and 100 percent at Columbia above The Dalles.
This product will only be available on the NWRFC web page beginning June 1999.
Please direct any questions to the NWRFC at 503-326-7401.
