GENERAL OUTLOOK

September 1, 1999

Precipitation Summary

Pacific northwest mean temperatures departed +0.6 degrees from normal relative to 1961-1990 normals (31 stations). Mean temperature departures ranged from -7.8 to 3.8 degrees.

In early August, a trough of low pressure off the California coast produced a moist southwest flow at mid levels of the atmosphere. Within this flow were weather disturbances which tracked northeast and helped to initiate scattered showers and thunderstorms, which were primarily focused across the higher terrain.

In the middle of August, the jet stream lifted to the north in response to a building area of high pressure across the region. Intervals of light precipitation were reported across southern

British Columbia. Dry and warmer weather prevailed elsewhere across the Pacific Northwest.

A trough of low pressure brought unseasonably cool temperatures and unsettled conditions in late August.

Daily precipitation records were broken at Eugene (.14 in on the 6^th) and Missoula (.44 in on

the 7th).

Daily record minimum temperatures were broken at Great Falls (38 deg on the 1^st) and Kalispell

(65 deg on the 6th and 31 deg on the 31st).

Daily record maximum temperature was tied at Great Falls (97 deg on the 30th).

For August, precipitation was 131 percent of normal (1961-1990) at Columbia above Coulee; 101 percent of normal at the Snake River above Ice Harbor; and 122 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.