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forecast it to remain the same until 1400. Thereafter, clouds at about 9,000 to 10,000 feet would appear, increase and slowly lower during the remainder of the afternoon. East of the Cascade Mountains to Pendleton, Oregon there would be cirrus clouds only with bases at 25,000 feet. The Boise, Idaho area would be clear. To the southeast of Boise the current condition was 3,000 feet scattered, 6,000 to 7,000 feet broken to overcast, increasing to 3,000 feet broken, 6,000 feet overcast in the Malad City, Idaho area, with rain showers and a few thunderstorms over the mountains. Between 1600 and 1800 that area was forecast to become 6,000 feet scattered to broken, tops to 12,000 feet.
The briefer stated that the pilot then advised that in consideration of the foregoing, he would file a VFR flight plan and if necessary would refile enroute if southeastern Idaho and Utah did not improve as expected.
THe winds aloft forecast was given as McChord AFB to Boeing Field 3,000 feet 200 degrees at 10 knots; Boeing Field to Pendleton 10,000 feet 240 degrees 5 to 10 knots, 15,000 feet, 320 degrees 15 knots; Pendleton to Hill AFB 15,000 feet, 320 degrees 20 knots.
At the time of the briefing the pilot was provided with the then current weather conditions at certain terminals. That information was in part, as follows:
Seattle-Tacoma International Airport.--High thin overcast, visibility 15 miles, temperature 58 degrees, dewpoint 43.
Boeing Field.-- High thin overcast, visibility 15 miles, temperature 61 degrees, dewpoint 42.
Pendleton, Oregon.--High thin overcast, visibility 20 miles, temperature 61 degrees, dewpoint 40.
Boise, Idaho.--High overcast, visibility 30 miles, temperature 56 degrees, dewpoint 41.
Burley, Idaho.--Three thousand scattered, estimated 7,000 broken, visibility 30 miles, temperature 53 degrees, dewpoint 43.
Ogden, Utah.--Seven hundrer scattered, estimated 1,500 broken, 4,000 overcast, visibility more than 15 miles in light rain.
Aviation weather forecasts for Washington and Oregon are prepared by the U. S. Weather Bureau, Seattle, Washington. The forecast issued at 1045, valid for a 12-hour period beginning at 1100 was in part as follows:
High pressure over Washington and Oregon. Pacific system moving into northern British Columbia coast will cause increasing cloudiness west Washington, northwest Oregon late today. West Washington, west Oregon Mean Sea Level (m.s.l.) 3,500 scattered, 10,000 scattered to broken, top 12,000, 25,000 thin broken. Washington, north Oregon coast occasionally ceiling 3,500 broken.
