An intense rain storm caused by a flow of warm, moist air from
the southwest, struck Oregon on Wednesday and Thursday, November
24-25. This marked the first truly intense winter storm of the
season, following a relatively dry and mild fall in most of Oregon.
Rainfall totals were very high. Tillamook recorded 3.98 inches in 24 hours (and now has over 24 inches for the month), Newport had 3.07 inches, and Florence received 3.63 inches. Willamette Valley totals included over 4 inches in 2 days at Corvallis, 2.4 inches in two days in Salem, and 3 inches in 3 days in Eugene.
Clay Creech of the Hatfield Marine Science Center in Newport sent a chart showing hourly precipitation (and cumulative 2-day total) for Nov. 24-25 at the Center, from the National Weather Service gage located there. Note how the highest rainfall intensities occurred Thursday evening (during supper?). Note also the 2-day total -- more than 10 inches!
In the Coast Range, rainfall was even heavier. John Kwait of
Siuslaw National Forest (USFS) sent data from several Remote Automated
Weather Stations (RAWS) stations: Cedar (southern Tillamook County),
Cannibal Mountain (northwest Lane County) and Dunes (along the
coast just south of Florence). Considering that Oregon's all-time
one-day record is 11.65 inches, Cedar's total on November 25th
is rather significant! Here are the daily totals for the 25th
and 26th:
| Station |
11/25 |
11/26 |
| Cedar |
11.00 |
5.54 |
| Cannibal |
3.92 |
4.33 |
| Dunes |
1.68 |
1.83 |
Rains were of sufficient duration and intensity to produce local flooding in many parts of Oregon and Washington. The daily river gage plots for the Siletz River on the central coast and the Trask River on the north coast show how quickly and how high the river levels rose.
River levels fell in a few days in most places, but remained somewhat high.
