The Olympic Blowdown of January 29, 1921

compiled by

Wolf Read

The powerful windstorm of January 29, 1921 was a major event, especially for the Washington coast and in the Olympic Mountains. This storm was big enough that its memory has survived in some circles up to the present. For example, based on my experience with the Washington Department of Natural Resources, many of the forest blowdown regions from the 1921 gale have been mapped out and turn up as discrete units in forest planning up to the present day. Winds of hurricane force were estimated to have raked the Pacific Northwest shores from Central Oregon to the Strait of Juan de Fuca [1]. The Forest Service indicated that total loss of standing timber was the greatest on record for the country at that time, with several billion board feet blown down. A Weather Bureau observer for the North Head station wrote an official report on the storm, and reflected upon the drama [2]:

"At 8 a. m. on January 29, 1921, small craft warnings were displayed as ordered by the district forecaster. At 11:40 a. m., local time, a special observation was taken and sent to the district forecaster. At this observation the sea-level pressure was 29.43 inches. The two-hour pressure change was -0.16 inch. Wind east 24 miles per hour. The barometer continued to fall rapidly until about 2 p. m. when it seemed that the center of the low had been reached, and fell very slowly. Near 2:30 p. m., as no orders had been received to change the warnings and the barometer had almost stopped falling, I concluded that the storm was similar to the one of January 16 and 17. We were in need of some supplies and the mail from Ilwaco. By using the car it required about one hour to make the trip to the post office and return. At 2:40 p. m., Mrs. Hill and I left the office. After getting the mail from the post office and a few articles from the stores in Ilwaco we started for home, but the extreme low air pressure probably affected the motor of the machine and a short delay from this cause probably saved our lives.

"The road from Ilwaco to North Head is through a heavy forest of spruce and hemlock timber for some distance. On the return trip shortly before reaching the heavy timber, the wind came with quite a heavy gust. We saw the top of a rotted tree break off and fall out of sight in the brush. About this time (near 3:20 p. m.) we were overtaken by a young man from the naval radio station at North Head who was driving a car. It is dangerous driving over this road under favorable conditions. We proceeded very slowly and with great care, passing over some large limbs that had fallen and through showers of spruce and hemlock twigs and small limbs blown from the trees. We soon came to a telephone pole across the roadway and brought our car to a stop, for a short distance beyond the pole an immense spruce tree lay across the road. We left the machines and started to run down the road toward a space in the forest where the timber was lighter. Just after leaving the car, I chance to look up and saw a limb sailing through the air toward us; I caught Mrs. Hill by the hand and we ran; and instant later the limb, which was about 12 inches in diameter, crashed where had stood. In three or four minutes we had climbed over two immense tree trunks and reached the place in which I thought was our only chance to escape serious injury or possibly death. The southeast wind roared through the forest, the falling trees crashed to the ground in every direction from where we stood. Many were broken off where their diameter was as much as 4 feet. A giant spruce fell across the roadway burying itself through the planks within 10 feet of where we stood. Three tops broke off and sailed through the air, some of the trees fell with a crash, others toppled over slowly as their roots were torn from the earth. In a few minute there were but two trees left standing that were dangerous to us and we watched every movement of their large trunks and comparatively small tops.

"Between 3:45 p. m. and 3:50 p. m. the wind shifted to the south and the velocity decreased to probably 100 miles or it may have been as low as 90 miles per hour. Shortly after 3:50 p. m. we started toward North Head. We climbed over some of the fallen trunks, crawled under others, and pushed our way through tangled masses of tops that lined the roadway. We supposed that all the houses at North Head had been leveled and the wireless station demolished for we knew that the storm was the most severe that had occurred in the vicinity of the mouth of the Columbia within the last 200 years. Mr. Seui, the young man from the radio station who was with us, hastened through the obstructions, and Mrs. Hill and I proceeded more slowly. About one-fourth of a mile from the station we were met by one of the men from the radio station, who had come to assist us had it been necessary. At 4:40 p. m. we arrived at the assistant lightkeepr's home where all the families of the Head had gathered for safety."

An Associated Press article that appeared in many papers on the day following the January 29, 1921 windstorm reported on a tragedy that occurred in Aberdeen, WA:

"A. Brown, engineer, was instantly killed and Jesse McMann, his assistant, was badly injured late yesterday when a sudden gale blew found smokestacks from their stays at the plant of the Anderson-Middleton Lumber company, plunging then through the engine room roof and filling the place with scalding steam.

"Telephone and telegraph wires out of here were all prostrated by the gale, one of the most violent in years. Communication with the outside world was not restored until today."

On January 31, 1921, the International News Services reported from Aberdeen, WA:

"Word is anxiously awaited from the North Head Naval radio station regarding the effects of the most violent gale in the history of the North Pacific. The Naval radio station at North head was put out of commission by the windstorm but was restored to operation today.

"The terrific windstorm which assumed the proportions of a cyclone swept along the Washington coast, leaving death and ruin in its wake. One man was killed and four seriously injured in this city. Buildings were wrecked, lumber was thrown many yards from piles. Railroad track were torn loose and all telegraph and telephone communications cut off. The steamer Hartwood is reported to have narrowly escaped wreck off Grays Harbor.

"Aberdeen Has Big Loss.

"It is reported that thousands of dollars in damage was done to buildings and storms in Aberdeen and Hoquiam.

"The wind velocity was estimated at from 125 to 150 miles an hour. Four steel smokestack reaching almost 200 feet into the air were the first to collapse before the terrific onslaught of the gale. The giant chimneys crashed down on dwellings crushing them like houses of cardboard.

"Alfred A. Anderson, chief engineer of the Anderson and Middleton mill was scalded to death by escaping steam, having been thrown against a broken steam pip by the collapse of the smokestacks."

Storm Data

Figure 1, above, is a rough approximation of the January 29, 1921 cyclone's track, based on available information from the January 1921 Monthly Weather Review (MWR). The storm's impact in Oregon was limited, whereas Washington's coastline received one of the strongest gales of the 20th century. Tatoosh Island's maximum winds were out of the SW, informing that the low tracked north of this station. This evidence, among other details, supports a northeast track into southern Vancouver Island, which places this storm among Class 5 events.

Hard numbers are difficult to obtain from this time period. Notes from the Severe Storms and other sections of the January 1921 MWR reveal some of the details about this devastating event. The data suggest a storm path similar to other big sou'westers, with an average speed of about 50 mph according to the MWR. Data from other sources will be added as they are located.

Note on wind readings from the pre-1928 time period: Four-cup anemometers made out of brass and weighing 550 grams, with cups four inches in diameter, were employed by the Weather Bureau pre-1928. Due to the unique inertial response of the anemometers, readings from a 4-cup system tended to be high when compared to the actual wind velocity. This physical reality was carefully studied in the late 19th century with the results reported in the MWR. What this means is that the 4-cup readings, as reported in the MWR and other sources, need to be adjusted downwards to be comparable to the 3-cup anemometers that were employed from 1928 to approximately 2006 (from about 2003 to 2007, many official cup anemometers were replaced with sonic anemometers). In general, a 4-cup system reads about 9.0% high when indicating 25 mph, 22.5% high when indicating 50 mph, 27.7% high when reading 75 mph and 30% high when reading 90 mph [3]. Original 4-cup figures are shown in the data below, with corrected readings in parenthesis. Correction factors are based on a table provided in early issues of the MWR, and the table accessed appeared in January 1894, Vol. XXII, No. 1, pp 28-29. The table only covers measured 4-cup speeds of 5 to 90 mph. A 2nd-order polynomial was fit to the available data to extrapolate the correction factor for measurments above 90 mph.

Coastal Conditions, South to North

Point Reyes Light, CA: Maximum 5-minute winds of S 86 (66) mph occurred in the early afternoon. Using a gust factor of 1.3 for a 66 mph wind, the peak instant (1-sec) gust at the lighthouse probably landed in the vicinity of 85 mph.

Eureka, CA: Maximum wind velocity indicated for the month of January 1921 was 43 (36) mph out of the N on the 9th, which puts an upper constraint on the peak velocity during the storm of the 29th. The peak gust at Eureka during the storm on the 29th probably didn't exceed 45 mph.

M. S. Sierra, Bellingham for Callao, off the Central Oregon Coast: Barometric readings in Table 1, below:

Pressure readings, M. S. Sierra, off Central OR

Time, PST

Reading, inches

09:00, 29th

29.52

10:20

29.45

12:55

29.22

15:00

29.50

20:00

29.70

00:00, 30th

29.75

The ship's observer provided further information in this brief report:

"At 9 a. m. on the 29th the wind, which previously had died down to force 3, increased to force 5, SSE.; by noon it had increased to force 12 and changed to S. and a little later to WSW., when it started to lose its force. A high and choppy sea was running and the vessel was rolling, pitching, and shipping heavy seas. For a while it seemed that we would lose our deck load of lumber and this would have happened had the wind not moderated when it did. When the wind was at its highest force, between 11 a. m. and 12 noon, the water of the sea was driven in the air in sheets just like heavy rain driven by a strong wind. It was not raining at the time althought it was cloudy."

North Head, WA: The lowest pressure of 28.90" was reached at 15:30 PST, about 2.5 hours later than the Sierra. Before 15:20, the highest wind velocity was 40 (33) mph, and it only took twelve minutes more for the wind to elevate to a 5-minute velocity of SE 126 (92) mph, with an extreme 1-minute average at 150 (106) mph. The anemometer was destroyed by a falling wireless tower before maximum winds had been attained by the storm. Applying a 1.3 gust factor to the 92 mph 5-minute average wind suggests that peak instant velocities approached 120 mph--and may have been higher (the 1.3 gust factor was developed using 1-minute average speeds; I'm being conservative here, mainly due to uncertainties in the 4-cup to 3-cup adjustment at such high wind speeds).

Tatoosh Island, WA: Minimum pressure 28.78" at 19:00 PST, and maximum 5-minute winds of SW 110 (83) mph at the same time, with possible instant gusts around 108 mph.

Interior Conditions, South to North

Portland, OR: Peak 5-minute winds SW 29 (25) mph. Extreme velocity (1-min) 32 (27) mph [4]. Estimated peak instant gust based on 1-min velocity, using a 1.3 gust factor, 42 (35) mph [5]. These wind values are comparible to the S 28 (24) mph with extreme 31 (27) mph observed on January 4, 1921 during a storm that produced Portland's lowest pressure for the month, 29.32". Available barometric readings at Portland in Table 2, below:

Pressure readings, Portland, OR

Time, PST

Reading, inches

04:49, 28th

30.04

16:49, 28th

29.88

04:49, 29th

29.87

12:00, 29th

29.56

16:49, 29th

29.61

04:49, 30th

29.78

The relatively high barometric pressure readings for Portland (the minimum for the storm was above 29.32"), when considered against the low of 28.90" at North Head and 28.78" at Tatoosh suggest that this storm passed fairly far off the Oregon coast, probably with a strong NE track as it moved into Southern Vancouver Island, which is somewhat of a different interpretation than shown in the storm track map above. This suggests that this storm should probably be included in Class 5 events, storms that make landfall in or north of Washington, instead of Class 6 the northward-trending sou'westers. Note that at North Head, the barometer read 29.43" at 11:40 with a rate-of-fall of 0.08"/hr for the last two hours, so that by 12:00, the barometer was probably at 29.40", making for a -0.16" difference (-5.4 mb) between North Head and Portland. Apparently this got more extreme as the low neared, as the 15:30 minimum of 28.90" minus the lowest possible pressure for Portland, 29.33", yields a whopping -0.43" (-14.5 mb) difference! For comparison, the max gradient for the same measure was -0.27" (-9.3 mb) at 13:00 during the October 27, 1950 windstorm, and just -0.16" (-5.4 mb) at 10:00 during the December 4, 1951 windstorm [6]. And for the similar AST-PDX measure, a peak gradient of 0.37" (-12.4 mb) was established at 19:00 for the Columbus Day Storm of 1962 (the closest match for the 1921 storm), -0.29" (-9.9 mb) at 06:00 during the November 14, 1981 winstorm, and -0.28" (-9.6) mb at 16:00 during the December 12, 1995 windstorm. It appears from the extreme easterly gradient indicated for the January 29, 1921 windstorm that the cyclone was among the most intense in history.

Tacoma, WA: Peak 5-minute wind SW 38 (32) mph. Estimated peak gust 49 (40) mph using the standard 1.3 gust factor.

Seattle, WA: Peak 5-minute wind S 59 (47) mph. Estimated peak gust 76 (59) mph.

Port Angeles, WA: Peak 5-minute wind SE 38 (32) mph. Estimated peak gust 49 (40) mph.

Walla Walla, WA: Peak 5-minute wind SE 37 (31) mph. Estimated peak gust 48 (39) mph.

References

[1] Information for this and the following statement were reported in the Monthly Weather Review, January 1921, in the Severe Storms section, page 37.

[2] This part of the Weather Bureau report was published in the Monthly Weather Review, January 1921, Severe Storms section, page 37.

[3] Ludlum, David M. "The American Weather Book." Houghton Mifflin Company. 1982. See bottom of page 59. And Monthly Weather Review, January 1894, Vol. XXII, No. 1, pp 28-29.

[4] The data for Portland are from the National Climatic Data Center, Original Monthly Record of Observations forms, U.S. Department of Agriculture, Weather Bureau, for January 1921.

[5] This gust factor is the standard for midlatitude cyclones, as described in Simpson, R. H., Riehl, H., The Hurricane and its Impact, p. 204-212.

[6] These measures, and those in the following sentence are derived from hourly observations obtained from the National Climatic Data Center, Unedited Surface Observation Forms for Astoria, North Head and Portland, and Local Climatological Data, Portland, for October 1950 and December 1951.

Last Modified: December 30, 2007
Page Created: December 11, 2002

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