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Oregon Tornadoes: More Fact Than Fiction

Oregon Tornadoes: More Fact Than Fiction. or, from January/February 2011 Weatherwise : Oregon’s Twisted History by George R. Miller Meteorologist, NWS, Retired. Presentation: Describes some historic tornado and severe weather events in Oregon.

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Oregon Tornadoes: More Fact Than Fiction

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  1. Oregon Tornadoes:More Fact Than Fiction or, from January/February 2011 Weatherwise: Oregon’s Twisted History by George R. Miller Meteorologist, NWS, Retired

  2. Presentation: • Describes some historic tornado and severe weather events in Oregon. • Categorizes severity using F-scale, NWS documentation, and author’s estimation. • Data accumulated from newspapers, county historical documents, NWS (Weather Bureau) publications, personal interviews.

  3. “Well developed tornadoes are unknown.” Annual Meteorological Summary with comparative data 1944 “Tornadoes are unknown.”Annual Meteorological Summary with comparative data, Portland, Oregon 1922

  4. Why so few tornadoes prior to 1950? 1. Ban on using the word tornado in forecasts late 1800s to late 1930s. 2. From 1897 to 1916 official tornado documentation ceased entirely; only most obvious and damaging thereafter for a period of time. 3. General reluctance to call the event a tornado. 4. Used terms such as: Freak wind, tornado-like wind, cyclonic-like wind, freak blow, freak twister, weather freak, freak storm and the classic… 5. “The funnel did not touch the ground!” 6. Even today: “There was no hook echo on the radar.”

  5. Lexington, Oregon, June 14, 1888 F1 (estimated) Path length 15 miles Path width 2-4 miles (estimated) Damage $5000 (estimated) Several injured; 1-6 killed Lexington

  6. Long Creek, OregonJune 3, 1894 F2 (estimated) Path length 10 miles (estimated) Path width ½ mile Damage $10,000 (estimated) Six injured, 3 killed Hail reported 7 ½” circumference Large destruction of timber Long Creek

  7. Mapleton, Oregon, June 6, 1948 Hailstones as large as hen’s eggs. Some probably baseball size Chickens killed Car roofs dented Hailstones caused water to splash up 3-4’ high Siletz river Area reported numerous thunderstorms Mapleton

  8. Near Aurora, north of SalemMarch 22, 1967 F0 (estimated) Path length 2.5 miles Path width 20 yards (both estimated) Damage $2000 to nursery Injuries none Deaths 1 (author’s assessment) Not included in any WB (NWS ) documents Portland Willamette River Nursery Aurora I-5

  9. Wallowa County, north of Enterprise, Oregon, June 11, 1968 F2 Path length 8-10 miles Path width ½ to 2 miles Damage estimated $5 to $50 million in downed timber 1800 acres of prime timber destroyed Enterprise

  10. Vicinity Newberg, Oregon, December 8, 1993 Path width 300+ ft Damage $600,000 F2 Path length 6 miles (estimated) Possible microburst to start No injuries, no deaths, but six veal calves killed Marion, Yamhill and Washington Newberg

  11. AumsvilleDecember 14, 2010 EF2 Length 5 miles Width 150 yards No injuries No deaths Winds 110-120 Fifty structures damaged Two semi-trailers overturned Aumsville

  12. Does Oregon Have Its Own “Tornado Alley?” After passage of cold upper level trough, Surface winds often still southerly while, 850mb and above, winds have shifted to west to southwesterly. Enough wind shear?

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