PACIFIC NORTHWEST WAS COOLER AND WETTER THAN NORMAL IN OCTOBER
A dry weather pattern generally held across the region early in the month. During the middle and latter part of October, the jetstream sagged south of the U.S.- Canadian border. This allowed a series of storm systems to impact the region, and pushed precipitation to above normal levels across much of the region.
The 31 station temperature index for the Pacific Northwest departed -0.4 degrees from normal relative to the 1971-2000 normals. Mean temperature departures ranged from -3.1 to 2.0 degrees.
High temperature records established in October included: 87 (tie) at Helena on the 1st, 76 at Helena on the 27th, and 76 (tie) at Havre on 27th. New low temperature records for October were all recorded on the 5th. They included: 12 at Butte, 17 at Kalispell, 19 at Pocatello, 23 at Helena, and 32 at Pendleton.
Daily precipitation records established in October included: 0.41 inches at Missoula on the 14th, 0.21 inches at Butte on the 23rd, and 0.19 inches at Havre on the 24th.
For OCTOBER, PRECIPITATION was:
128 percent of normal (1971-2000) at COLUMBIA ABOVE COULEE,
132 percent of normal at THE SNAKE RIVER ABOVE ICE HARBOR,
and 145 percent at COLUMBIA ABOVE THE DALLES.
For the 2000-2001 WATER SUPPLY SEASON, PRECIPITATION was:
51 percent of normal (1961-1990) at COLUMBIA ABOVE COULEE,
59 percent of normal at THE SNAKE RIVER ABOVE ICE HARBOR,
