The Major Windstorm of October 21, 1934

by

Wolf Read

The great storm of October 21, 1934 had devastating impact on the Pacific Northwest, especially in Western Washington, and a little less so in Northwest Oregon. From the limited hard data available, this cyclone appears to have tracked across lower Vancouver Island in a manner similar to the February 13, 1979 storm, though probably a bit further to the south. The 1934 event appears to have produced much stronger winds than the 1979 blast--in fact, 1934 may be the most extreme example of a low following this particular path. The gale of '34 appears to have been the biggest, most devastating storm to strike the Pacific Northwest in the time period delineated by the January 29, 1921 and Columbus Day 1962 windstorms. For some Puget Sound locations, such as Seattle, this was possibly the strongest storm on record. In a manner similar to a hurricane, the combination of low pressure, strong winds and high tide produced a storm surge on the Pacific Coast that flooded many neighborhoods and towns. In some cases people were trapped by the rising water and had to be rescued during the storm. The gale was also deadly, taking a human toll that is second only to the Columbus Day Storm of 1962. At least 18 people were killed in this event, many from collapsing structures and sunken vessels.

Storm Data

For some places, especially the Oregon and Washington coast, the windstorm of October 21, 1934 might have produced wind velocities that approached those of the Columbus Day Storm 28 years in the future. Seattle, clearly, had a much stronger blow than in 1962. The problem is that there were few stations in the Pacific Northwest that were noting peak gust records at the time of the 1934 blowdown, making specific comparisons of wind speed difficult.

According to the U.S. Department of Agriculture, Weather Bureau, Climatological Data for October 1934, Oregon Section, Portland had a seemingly gentle peak wind speed of 24 mph on the 21st, but it was the highest wind for the month. For comparison, the highest wind value listed for the 1880 Storm King in the extremes section of the publication was 43 mph. It would have been nice for the WB to note what the actual wind measure was in the publication--1-min, 2-min, 5-min? The low readings suggest longer time periods than 1-min, perhaps even 10 or 15 minutes. The airways record forms for Portland, obtained from the NCDC, reveal a more dramatic story, one that fits the record of damage reported in the newspapers. The location of the station in 1934 was at the Swan Island Airport administration building, along the shores of the Willamette River [1].

Figure 1, below, is the meteogram for Portland on October 21, 1934. The graph shows some notable features. The barometric trace shows a broad sweep, with fall rates reaching 0.08" an hour, and a peak rise of 0.07". Though fairly fast, these changes are short of many strong windstorms in history. Indeed, the low of 29.42" isn't that unusual for the storm season. This more relaxed barometer is the signature of a cyclone that was fairly distant when it made landfall. A more important feature of the barometric minimum is that it occurred with the arrival of a front, clearly indicated by a sudden shift in wind direction out of the southwest. According to the records, moderate rain fell during the passage of this front. Winds, which had been averaging 10-15 mph out of the east and southeast before the front, decreased markedly. Temperatures hardly changed, hovering around 51° to 52° F. The barometer started a slow rise after the front, and winds remained light for about an hour, with a gradual shift back to the east. Then, in a 30 minute period, there was a sudden jump in wind speed to 20 mph with a shift to more southerly direction. From that point, the wind slowly climbed to a screaming average speed of 47 mph, the temperature lifted to 55° F, and the barometer remained relatively flat, with a couple of minor dips. A gust of 60 mph was noted at 10:30--such notations are rare from this era, and it's pure luck that it was done during this windstorm. At the time of peak winds, the observers at the station noted "SQALY", or squally, conditions, with the onset of moderate to heavy rains in the hour after the peak. Also after the maximum winds, the barometer rose more briskly, and the gale decreased, with a tendency toward a more southwesterly direction. The temperature briefly fell to 48° F at 11:42 before climbing back to 55° by 14:42.

The significance of these features becomes more apparent when the meteogram for the Seattle Airport, Figure 2 below, is considered. There are some striking differences between the records at Seattle and Portland. The sudden onset of winds is the most eye-catching, but the behavior of the barometer is important, too. There's an initial minimum of 29.36" at 06:42. After that point, winds shifted from roughly east-southeast (when they weren't calm) to southwest, though they remained light. The records show light rain fell from 03:30 to 06:00. This initial barometric minimum is akin to Portland's at 03:42--the front arrived at Seattle three hours after it had passed through the Rose City. After the front moved through Seattle, the barometer bumped up to 29.38" for about an hour before plunging a full 0.10" by 09:42. This is the beginning of a more extreme dip that would reach 29.21" by 11:42--and is one of the rare instances when the classic "double-dip" pattern showed clearly in the Seattle area during a major windstorm. More typically, the double-dip appears in places further south, like the Willamette Valley, and is due to a cyclone's front running ahead of the parent low, which can cause a brief dip in the barometric curve ahead of the main drop produced by the closest passage of the low. A classic example of the double dip showed up in the October 2, 1967 windstorm. Using meteograms from the 1967 storm as a model, Portland and Salem in 1967 seem like a decent match for Seattle in 1934 in terms of a double-dip pressure curve and sudden wind attack. Seattle's barometer in 1934 didn't show the extreme pressure changes experienced in the Willamette Valley in 1967. This suggests that the 1934 low tracked further from Seattle than the 1967 storm did Salem, so 50-miles-plus north of Seattle, most likely significantly more--conitions at Bellingham suggest that the low tracked just to the north of that city, which places the low center around 80 to 100 miles from Seattle at its closest. Aside from the pressure bump and a shift in wind direction, this double-dipping front did little else. Little rain. Lots of clouds. The Olympic Mountain rain shadow appears to have been in full effect that day.

Figure 3, below, a pressure spectrum showing readings from Medford to Bellingham in 1934, shows the double dip occurring with vigor down south. Medford had a stunning 0.12" pressure rise in the hour from 03:42 to 04:42--the mark of a fairly strong front. Medford's minimum occurred one hour after Portland's.

Medford's strong dip can be explained by a trailing front racing southeastward from the northeastward-moving low center, as shown in the storm track map Figure 4, below. Interpretation of pressure events along the west coast reveals a hypothetical story about a low bombing rapidly far off the Southwest Oregon shores, then moving northeast towards Washington [Footnote 1]. The storm reached peak intensity long before nearing land, and the frontal system raced far ahead of the aging cyclone's center. In Oregon, barometric minimums were achieved along the front, as the low center stayed relatively far from these locations compared to stations in Washington. Portland probably would have had a stronger secondary dip in pressure if the low hadn't started weakening after 04:00. As it was, the slow degradation of the cyclone as it moved toward its closest point to Portland held pressures fairly flat, if a little unsteady, at the Rose City. The Position of the low suggests that a strong southwest jet stream probably raced over Oregon, which resulted in the heavy rainfall experienced during the storm. For Seattle, the stretching front wasn't as strong, and it was fairly dry. But the low would approach much closer to this northern city than it would Portland, and Seattle pressures show a marked drop post-front as the low neared--the classic double dip.

The cyclone's center almost passed right over Tatoosh Island, as evidenced by the meteogram in Figure 5 (still on the to-do list!). Compared to places south, peak wind speeds at Tatoosh weren't very impressive--one sign of a low passing to the south of the station. More importantly is the sudden shift of wind direction from east to northeast then northwest around the time of barometric minimum, the clear signature of a track somewhat south. The close association of minimum pressure, wind shift to the northwest and the secondary peak in wind speeds suggests that the low center tracked very close to the island. Incidentally, like with the peak gust at Portland, the fact that the barometric minimum for the day was even noted was a bit of luck in the record. It probably helped that, at 28.85", it was the lowest declension of barometer for the month. Without this one data point, the pressure trace would have been almost useless for the kind of interpretation done here, as such data at Tatoosh was only recorded at 12-hour intervals in the 1934 timeframe. The low reading and close proximity of the low suggested the 975 mb central pressure, and places the low at the northwest tip of Washington around 13:00. This is one hour after Seattle's minimum pressure, and suggests a continued weakening of the storm as it moved inland and slightly closer to the city by the sound.

Records at Bellingham are spotty. They generally were only taken at two time periods each day: 09:15 and 14:30. On October 21st, the weather observer took some initiative during a time of extreme conditions and noted readings at 10:30 and 13:00. At 13:00, sustained winds out of the south-southeast had reached 60 mph, and "Squalls to 70" were noted. The pressure was a low 29.04", which is somewhat low compared to Seattle's reading of 29.22" at 12:42, if the low center is assumed to be just east of Tatoosh Island within this timeframe (the 28.85" low was at 12:45). Tatoosh is 131 straight-line miles from Seattle, and 107 from Bellingham, so pressures would be expected to be lower at Bellingham with a low near Tatoosh, but assuming perfectly circular isobars, it suggests an unusually strong gradient of 6 mb between the (roughly) 105 and 130 mile points from the low center. This could be the mark of the hypothesized lee-low, which may have been contributing to some of the pressure declension at Bellingham and rendering the circular isobar model moot. It could also be the mark the higher pressure racing northward in the strong south winds ahead of the storm, which would also destroy the more-or-less circular perfection that may have existed when the storm was over the ocean. This relative pressure disparity between Bellingham and Seattle has turned up in other storms that have landed near Tatoosh, including the Columbus Day Storm.

The 14:30 reading at Bellingham noted a barometer at 29.00" at a time when Seattle pressures were clearly on the climb with a reading of 29.35". This resulted in the major gradient of 11.5 mb between the two locations. It is assumed, based on the low barometric reading and the slight change of pressure between 13:00 and 14:30, that the low reached its closest point to Bellingham within the hour 14:00 to 15:00. Within this timeframe, winds at Bellingham were a steady 75 mph out of the south-southeast, with squalls to 80, some of the highest readings ever recorded in the region. The onset of high winds was fairly dramatic. Between the 09:15 and 10:30 readings, the winds elevated from south-southwest 3 mph to a steady south-southeast 20. In the next 90 minutes, winds climbed to the steady 60 mph noted earlier.

At the time the barometer started its second, dramatic plunge at the Seattle Airport in 1934, the wind velocity jumped with nearly equal drama as it did in Bellingham. Between 08:30 and 09:42, the average winds climbed from a mere 3 mph to 20, and from 09:42 to 10:10-just 28 minutes!-the wind escalated to a hammering 50 mph. When compared to places south, like Portland, the onset of the gale at Seattle appears almost instantaneous! The duration of powerful winds at Seattle is also striking-winds averaged 45 to 58 mph for 6.5 hours, an incredibly long time for these high sustained rates. No peak gust was indicated in the records, but using the 1.3 gust factor for midlatitude storms, a value of 75 mph can be estimated from the maximum average wind of 58. Newspapers reported a value of 70 mph [2]. This places the 1934 windstorm among the top most powerful on record for the Seattle area, with gusts exceeding the maximum values witnessed during the Big Three sou'westers.

Figures 6 and 7, below, plot the barometric pressures for Portland and Seattle against the PDX-SEA gradient and average winds at Seattle for the October 21, 1934 and February 13, 1979 windstorms respectively. Despite the different-looking gradient curves, there's a lot of similarity between these two graphs, especially when the weaker nature of the 1979 storm is taken into account. During the 1979 event, there's the already noted kink between 23:00 and 01:00 for Sea-Tac, a small dip of the barometer from 29.31" to 29.28". Within this timeframe, a dramatic jump in the PDX-SEA gradient happens as the pressure at Portland continues to rise, and there is a corresponding sudden escalation in winds. Conditions at the Seattle Airport in 1934 were quite similar. There's a sudden escalation in gradient and wind with a marked dip in the barometer at Seattle. Only the magnitude of events is much greater. Considering the less extreme conditions during the 1979 storm--such as higher overall pressures and lower gradients--it seems a reasonable conclusion that the small dip in 1979 is an analog of the major dip in 1934. However, light rain, and a brief wind shift from east-southeast to south-southwest in the time period of the flat pressures at Sea-Tac suggest that the primary controller of the minimum pressure during the 1979 storm was a frontal system arriving at approximately the same time as the closest passage of the low's center.

At the Seattle Airport in 1934, temperatures jumped from 49° F at 08:30 to 62° F at 10:42, with most of the climb happening during the onset of gale winds out of the south and south-southwest. The sudden warmth marks a fairly hefty warm air advection field in the southwest quadrant of the low, one that didn't hit Portland as strongly. Lower temperatures appears to have been the result of Portland's rain throughout the morning and afternoon, whereas Seattle generally escaped precipitation. Seattle seemed determined to support the dry windstorm mythos in 1934, and continued the rainless trend throughout the period of strong winds, which contrasts sharply against the squally, heavy-rain conditions seen at Portland. At the most, sprinkles fell on the Seattle area from a heavy overcast between 12:42 and 15:30 while the winds raged. The high temperature of 62° F happened during a period of broken clouds at 2,000 feet with eight-tenths cover.

The peak PDX-SEA pressure gradient, 12.9 mb, though not the strongest, puts this storm in the number two spot. Only the November 3, 1958 windstorm produced a higher slope--13.6 mb--and this system had the advantage, as it nearly went right over the Seattle-Tacoma Airport, which put the area of steepest gradient near the low's center right in line with the PDX-SEA measure. This happened again on December 15, 1977, when a storm produced a 12.3 mb gradient between Portland and Seattle, which is also among the steepest on record. It should be kept in mind that the station locations in 1934 were different from those in 1958 and 1977, though the minor change in overall distance would only result in slight modifications in the gradient measure.

That the 1934 low dove into Southwest British Columbia and produced a PDX-SEA gradient that is equivalent to storms that have tracked over the Puget Sound marks the 1934 event as nothing less than phenomenal. Not even the February 13, 1979 storm, on its similar path, produced such a steep gradient-it could only manage 7.9 mb, which is below many of the windstorms on record, but fits with a low tracking fairly far north of Seattle. Figure 8, below, plots the 1979 storm pressures for the same stations depicted in Figure 3, so that the two storms can be compared (Still on the to do list!). The broader, gentler Washington curves during the 1979 event show nicely in the comparison. The strong frontal system in Oregon for the 1934 cyclone also jumps out. The magnitude of difference between the storms becomes very clear when the period of maximum relative pressure differentials are compared: values approached a broad 0.90" between Medford and Bellingham in 1934, compared to a strong 0.60" in 1979. The lower gradients in 1979 appear to be, in part, the result of a cyclone that tracked further north than its much earlier predecessor.

The powerful gradient of 1934 probably answers the apparent disparity of pressure readings between Seattle and Bellingham. This low, despite slowly weakening over time, maintained an incredibly steep pressure differential across the state of Washington and into Oregon. At approximately 13:00, with the storm center near Tatoosh Island, the gradient was 18.6 mb between Portland and Bellingham. When the center of the Columbus Day Storm sat in a similar position at 22:00 on October 12, 1962, the gradient was 14.3 mb between the two stations. Peak PDX-BLI gradients were 22.7 in 1934 and 17.7 in 1962. Clearly, the 1934 storm ranks with the strongest in recorded history.

Records for Salem and Eugene were obtained, but surface observations for other locations such as Olympia and Astoria are not available. And there was no pressure data taken for Salem and Eugene in 1934. The available information shows that peak wind velocity decreased markedly southward in the Willamette Valley. Figure 9, below, plots a "wind spectrum" for the three stations Seattle, Portland and Eugene, showing the trend toward weaker winds southward. At Salem wind velocities were estimated from 08:42 to 11:42, possibly due to a power outage that shut down the anemometer. Of course, this was the time period of peak winds. Top velocities were estimated at 35 mph for Salem, which suggests gusts into mid 40s, maybe reaching 50. Periods of moderate rain moved through the capital during the gale. Eugene had a fairly tranquil day, with the highest sustained winds at 18 mph, though moderate to heavy rain struck both in the early morning and late night, with a generally cloudy day between.

Lower peak winds southward nicely supports the idea that the 1934 low had a strong easterly component to its track. If it were a northward-trending system, then maximum winds would have been more uniform north to south. The February 13, 1979 storm produced similar results, though peak gusts tended to be fairly uniform from about Olympia south to Eugene, where gusts reached 40-44 mph at many interior reporting stations, which is a reminder that all these storms are unique, even when they appear to have followed similar paths.

Highest winds appear to have struck Oregon stations one to a few hours sooner than Seattle, suggesting that there was, as noted above, some northward motion involved with the depression. The path was probably east-northeast. The strongest winds at Seaside were between 07:00 and 10:00, as reported in the Oregonian [3]. This is about an hour ahead of the timing of strong winds at Portland, and nearly three hours ahead of Seattle. Portland's peak wind of 47 mph happened about one hour ahead of Seattle's 58. This was during the period of rapid pressure fall witnessed at Seattle. The onset of winds in a narrow range of time is another mark of a cyclone travelling more east than north.

As noted, the storm was generous with rainfall in Oregon, dropping 0.93" on Portland in 24-hours on October 21st, 1.40" on Salem, and 1.39" on Eugene. The week of the 19th to 25th was rainy in general, and offered up totals of 4.26" at Portland, 3.35" at Salem, and 3.44" at Eugene, readings close to monthly normals.

Footnotes

1. For a low tracking northward, stations north of the low center would experience pressure drops while those south simultaneously showed rises. Eastward trending lows making landfall tend to push the barometers lower at nearly equal times among stations along a north-south axis, with lower pressures occurring ever further northward up to the low's centerline.

References

[1] Unless stated otherwise, information reported in the Storm Data section is from the unedited "Airways Weather Report" forms (akin to the Unedited Surface Observation Forms of later years), acquired from the National Climatic Data Center, for Seattle, Portland, Salem and Eugene, October 21, 1934.

[2] Seattle's peak gust was reported in the Morning Oregonian, October 22, 1934, Article???

[3] Timing for the main winds at Seaside was reported in the Oregonian, October 22, 1934, in "Homes At beach Wrecked," page 12.

Last Modified: February 24, 2003
Page Created: November 27, 2002

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