2008 » July » 8

Hey Ya’ll….pretty slow time (unless you are LipRipper…and sorry NO, I cannot tell you where, who with or how many-trust me I’d like to…) on the fishing front…..so I thought I’d dig up and post some historical data on our Oregon weather. Pretty interesting. Enjoy. And Dusty….if you could go ahead and bring me some Salmon into work…that’d be great…mmmmmm K?


hellcat

excerpt below from….. The Oregon Weather Book A State of Extremes
George H. Taylor & Raymond R. Hatton


Despite Oregon’s reputation as a mild, wet state, hot weather is common during long summer days. This is especially true in eastern and southern Oregon, whose valleys are sheltered from the moderating effects of the Pacific Ocean. Much of eastern Oregon lies at high elevations, tempering daytime highs. For every thousand feet of elevation gain, temperatures decrease by 3-5 degrees F. Thus, locations such as Bend, at about 4,000 feet, are 12-20 degrees cooler than they would be if the city were at sea level.

Nonetheless, there are low elevation sites in eastern and southern Oregon, and they can get very hot indeed. Even higher locations can get very hot on occasion. Oregon’s hottest weather occurs when strong high pressure over Oregon brings descending, warming air and clear skies. Winds from the east or south are customary during such periods. Sometimes heat waves in Oregon are very shortlived; in other cases, hot weather can persist for many days.

In the following sections, Oregon’s hottest days and longest heat waves are described. Record Heat The hottest days in the last 100 years in Oregon occurred in 1898. In late July, temperatures began to build slowly, then quickly, and on the 29th Prineville topped out at 119°, an alltime record for Oregon. However, the record was to be short-lived.

Following a slight moderation in temperatures (Prineville was down to 101° by August 3rd), things heated up again. Prineville reached 111° on August 7th, but this time it was Pendleton which was hottest, tying the new record of 119° on August 10th. Within a week temperatures were back into the 80’s throughout eastern Oregon, and they have never again matched the temperatures recorded on those days.

There have, however, been some near-record days. Many of the highest single-day values were recorded at Umatilla, on the Columbia River, not far from Pendleton. Before the Umatilla closed in 1965 it had reported temperatures of 117°, 115° (three times), and 114° (four times). West of the Cascades, the highest temperature recorded was 115° in Medford on July 20, 1946; Medford reached 114° in 1941.

Although the Oregon coast is associated with generally mild weather, some extreme high temperatures have been reported. Although along the immediate coastline temperatures seldom reach 90°, a short distance inland much
readings can occur. Illahe is in Curry County about 25 miles from the coast. Temperatures there have reached 110° on some occasions, and have been as high as 107° as late as September and 98° in October.

Brookings, which is on the extreme southern Oregon coast, is notorious for unusually high temperatures, even during winter. Brookings’ temperatures have been the subject of several technical reports discussing “the Brookings effect.”
Oregon High Temperature records by Month Runs of Consecutive Extreme Days During most summers, Oregon does
not experience lengthy periods of extreme high temperatures.

Marine air intrusions, although much milder and less frequent than in the cool season, move onshore often enough
to prevent heat waves from lasting more than a few days in most cases. This is especially true west of the
Cascades, where only coastal mountains separate inland areas from the cool Pacific. However, the Cascades serve
as a major climatic barrier between coastal areas and the eastern two-thirds of the state. Much of the marine air is blocked by the Cascades and prevented from reaching the eastside, and any air which does cross the Cascades is
greatly modified, becoming warmer and drier. As a result, eastern Oregon experiences much greater temperature variations than does western Oregon, and its heat waves are likely to last longer and be more intense than those west of the Cascades. Since air temperatures typically decrease with increasing elevation, highest air temperatures
generally occur at low elevations.

Most of eastern Oregon is above 4,000 feet, so high temperatures are considerably lower than in the low elevation deserts of the southwestern U.S. (such as the infamous Death Valley which is actually below sea level). In some
places, however, deep river valleys in eastern Oregon have much lower elevations, producing Oregon’s hottest summer temperatures. Pendleton, Ontario and Hermiston are examples of places which frequently experience hot
temperatures in summer.

The title “Oregon’s Heat Wave Capital” should probably be reserved for Ontario. Ontario is in the Snake River valley at an elevation of about 2,200 feet. There are several NOAA weather sites in the Ontario area; radio station KSRV
is usually the warmest. During clear summer periods, temperatures often exceed 90° and remain that way day
after day. In 1967, KSRV’s maximum temperature was 90° or more on 74 consecutive days (June 28 through
September 10). An even more significant heat wave occurred in 1971, a warm summer throughout Oregon. On July 20, the high temperature reached 102°, and not until August 21 did the high drop below 100° again.

That string of 32 Month Temp. (°F) Station Year Jan. 82° Fremont 1934 Feb. 85° Coquille 1992 Mar. 99° Merlin 1900 Apr. 102° Marble Creek 1906 May 108° Blitzen Pelton Dam 1924 1986 June 113° Blitzen 1932 July 117° Umatilla 1939
Aug. 119° Pendleton 1898 Sept. 111° Illahe 1955 Oct. 104° Dora 1980 Nov. 89° Mitchell 1936 Dec. 81° Dayville 1897
consecutive days is believed to be the longest ever recorded in Oregon. Spray, in the John Day River valley at about 1,800 feet in elevation, has also experienced a number of remarkable heat waves.

During that same hot period in 1971, Spray had 26 consecutive days (July 20 through August 15) with temperatures of 100° or more, and in 1961 there were 48 days in a row of 90° or more. The Spray station is no longer in operation, but during the 1937-1978 period when it collected weather data it was frequently the hot spot in Oregon. Its all-time
record high (116° on August 4, 1961) was the fourth highest ever recorded in Oregon.

Although most of western Oregon experiences relatively mild summer temperatures, a few inland valley locations can get quite warm. Medford and Grants Pass in the Rogue valley of southwestern Oregon are generally the warmest
west side locations. Medford has had as many as 34 consecutive days of 90° or more (July and August, 1961), and Grants Pass as many as 32 (July and August, 1971). Medford has had 10 consecutive days of 100° or more on several occasions, the most recent in 1967.