GENERAL OUTLOOK

September 1, 2000

Precipitation and Temperature Summary

The Pacific Northwest experienced drier than normal weather in August. Temperatures were above normal across Idaho and western Montana. Temperatures were below normal across northwest basins and near normal elsewhere.

Early in the month, high pressure over the central United States brought monsoonal moisture northward. East of the Cascades, thunderstorms with little rain and frequent lightning sparked wild

Fires. Temperatures were generally above normal. West of the Cascades, dry weather and near normal temperatures were the rule. Late in the month, a weak trough of low pressure formed off the

West Coast, allowing a dry, zonal flow to dominate across all but far northern tier basins. Temperatures cooled to near or slightly below normal west of the Cascades and to near normal across eastside basins.

Pacific northwest mean temperatures departed +0.2 degrees from normal relative to 1961-1990 normals (31 stations). Mean temperature departures ranged from -2.5 to 3.7 degrees.

Record high temperatures reported during the month of August: 99 at Helena on the 1st, 96 at Butte on the 9th, 98 at Kalispell on the 9th, 93 at Butte on the 15th (tie).

Record low temperatures reported during the month of August: 52 at Wenatchee on the 12th, 42 at Eugene on the 12th, 39 at Eugene on the 15th, 38 at Quillayute on the 16th, 40 at Olympia on the

17th (tie), 41 at Eugene on the 20th, 32 at Kalispell on the 20th, 33 at Kalispell on the 21st (tie), 33 at Kalispell on the 22nd, and 30 at Kalispell on the 28th.

No daily precipitation records were tied or broken during the month of August.

For August, precipitation is:

36 percent of normal (1961-1990) at Columbia above Coulee,

38 percent of normal at the snake river above ice harbor,

and 35 percent at Columbia above The Dalles.

For the water supply season, precipitation is:

98 percent of normal (1961-1990) at Columbia above Coulee,

83 percent of normal at the Snake river above Ice Harbor,

and 94 percent at Columbia above The Dalles.