New Research on the Brookings Effect greatly broadens it scope and raises new issues: We will take a look at six exceptional heat events in six widely-separated years. Do you want to correspond about this research? See e-mailer at bottom of this page.

First, an orientation to the geography of the South Coastal area of Oregon:

It's a larger area than one would first think. A basic orientation begins with noting that Brookings to Port Orford is 50 air miles, and Brookings to North Bend is 90 miles.
Brookings to Gold Beach is 25 miles.
illahe is 24 air miles inland from Gold Beach (but 33 river miles from the Pacific).
Powers is 23 air miles ENE (inland) from Port Orford.
Powers is 18 miles due north from illahe (and across a rugged mountain pass).
Brookings to Medford is 75 air miles.
Topograhically, this area is one of the most rugged, convoluted regions in Oregon, with steep, heavily wooded mountains creating an extremely complex topography which culminates just 27 miles inland at 5,316 ft. tall Brandy Peak, which stands an even 5,000 ft. above illahe just 9 miles distant! No other area of the Oregon Coast has such an extreme topography at its disposal in creating unusual weather effects.

1. September, 1955 Heat Event

Summary--- the intense Heat misses Brookings, Gold Beach and Port Orford, and centers on locations northward along the Coast, and inland. Questions: What short-circuited the Brookings Effect? Or, what different mechanism produces temperatures in the 90s at coast towns like North Bend and Newport? (I've never seen any reports of a "Newport Effect" or a "North Bend Effect").

The Data (high temps on September 3, 1955
A. The so-called Broookings Effect zone--- Brookings 69, Gold Beach 73 and Port Orford 76.
B. Northward, along the Coast--- North Bend a sizzling 91, and Newport 90. Wow.
C. Slightly inland--- illahe 96 and Powers 94.
D. Inland in Willamette Valley--- Salem 92.
E. Inland to the due east of Brookings--- Medford 96.


2. September, 1963 Heat Events

A. the entire State records record-breaking heat during September; one of the very hottest Septembers ever recorded for the State.
B. Spray, in North Central Oregon, records an unbelievable sequence of 100 degree weather right up until the final days of the month.
C. The Brookings Effect apparently misses Brookings despite the Statewide heat.

The Data---
South Coast--- Brookings' high temp for the month is only 86 , on the 18th. North Bend's high for the month is even lower, only 77, on the 3rd. And even more interestingly, late in the month, when the rest of the State is toasting, Brookings is downright chilly; here's the data:
September 27th--- Brookings high 63. Powers 93. North Bend 67. Salem 87.
Medford 102 (104 on the 26th). Spray 100 (100 also on the 26th, 28th and 29th!)
illahe's high for the month is 100, cf. that to Brooking's high of only 86.

Spray, one of Oregon's little-known hot spots: the month began with a heat wave in Spray that began on Sept. 3 with a high of 95, then got hotter-- 102, 100, 100,
96, 101 on the 8th, cooling to 99, 90, 94, and a chilly 89 on the 12th. Then a second heat wave hit late in the month--- September 25th at 98, 26th at 100, 27th at 100, 28th at 100, 29th at 100, and the final day of September finally cooling to "only" 86. Such late September heat would make Death Valley proud!

3. December, 1980 Heat Event

Summary--- the 80 degree heat that struck the South Coast on December 15th is a prime example of the Brookings Effect. It especially shows how the Effect at times stays strictly on the coastline, and doesn't move inland even a few miles to such usual hot spots as Powers and illahe.
But there is an important anomaly to explain, which is why Port Orford was actually warmer than Brookings when it is posited by Jack Capell and others that the mountain range, Chetco River drainage, and southward-facing shores at Brookings are the prime causative factors in producing the heat--- BUT Port Orford is 50 air miles north and it's unexplained how it, too, can produce such heat.
We also notice a phenomenon that may be linked to such winter heat waves on the South Coast--- Seneca, Oregon's perennial cold spot, was having a minor cold wave during the week preceding the heat wave on the South Coast. Question/Theory--- Does high pressure cold air east of the Cascades somehow actuate the Brookings Effect?

The Data---
December 15th, 1980--- Port Orford 80. Brookings 79. Gold Beach 72. North Bend 70.
Powers only 60. illahe only 55. Salem 54. Medford 48.
Other pertinent data---
Seneca's low temps: December 7 at -8. Dec. 8 at -10. Dec. 9 at -9, Dec. 10 at 2 above. Dec. 11 at -2, Dec. 12 at -9. Dec. 13th at -8. Dec. 14th at 8 above.
And on Dec. 15th, the day of the Brookings Effect, Seneca warmer, but still cold with a low of 12 above.

Powers high temp for the month is 71, occurring right after Christmas on December 27th-- it's a figure which easily exceeds both Medford's high for the month of 62, or Salem's of 66.... In the historical records, Powers is often noted during the winter months as having Oregon's warmest daily maximum for the month. What explains this? Is it related to the Brookings Effect, or not?


4. Early February, 1984 Events

The Brookings Effect can strike like a Kamakazi, in and out in a single day! And during this event, the effect restricted itself almost entirely to the coastline area and did not seep inland to any significant extent.
It is an unanswered question how and why Powers can often capture State highs in mid-winter on days when the Brookings Effect doesn't appear to be operating (or at least seems to be missing Brookings!).
The "Seneca Effect" may have again been in action (see 1980 Summary).

The Data---
South Coast: Brookings 80, Feb. 2nd. But only a single day event! Feb. 1 was only 66, Feb. 3rd had a high of only 60. The heat extended only a bit up the coast--- Gold Beach 75. Port Orford 70. But North Bend a chilling 58.
Nearby, Powers and illahe were not much-affected by the warmth--- Powers only 56 on the same day as Brookings' 80, and illahe only 65. . Inland in the Rogue Valley, Medford was entirely unaffected with only 51. Salem had 50.

Other Data---
Powers showed its mid-winter heat abilities just a few days later with a balmy 69 degrees on Feb. 5th, while Brookings had a chilly 59. Was there a Brookings Effect involved that missed Brookings? How could this be?
Medford was 58 on the 5th, but was a very warm 74 on the 4th. So was it an inland kind of heat, perhaps unrelated to the Brookings Effect, and localized only to inland Southern Oregon? The Willamette Valley was unaffected, with Salem's high on the 5th only 58.
Or maybe the Brookings Effect's warm air simply migrated eastward after the 2nd, to toast Powers and Medford, but leaving Brookings chilly?

"Seneca Effect." Cold high pressure air is entrenched at Seneca preceding and during the Brookings Effect, eg. Brookings 80 on Feb. 2nd, and Medford's 74 degree heat on the 4th.
Seneca low temps--- Feb. 1st at -8. Feb. 2nd at -9. Feb. 3rd at -4. Feb. 4th at -2. Feb. 5th at -5. And Feb. 6th at 1 above.

5. October 1991 Heat Events

Summary--- it's about the tiny town of Powers---well into October, with a seven day long heat wave that tops at a sizzling 103, Powers flaunts its ability to be the State's hottest late-season place.
This heat wave centering on Powers raises additional interesting questions about how the Brookings Effect operates (see data below), eg. in this event the Effect seems to bore in on an inland area well to the north of Brookings (Powers, North Bend, Port Orford) producing only a modest one-day long effect in the Brookings area.
It's almost like Powers becomes a hot-air generating dynamo, stagnating hot air in its little enclosed valley on the Coquille River. Hot air stagnation? Introduce California thermal air into its valley, and then it stagnates, becoming hotter each day for awhile until scoured out, whilst all around other places cool back down once the immediate influence of the thermal air moves away.

The Data---1991
October 11th. Powers 103
. Port Orford 87. Gold Beach 89. Brookings 75. illahe at 93. North Bend 71.
Medford 92. Salem 86.
The day before--- October 10th. Powers 91. Brookings 87. Gold Beach 85. North Bend 95. illahe 94. Note: on the 9th, Port Orford had heat at 88 degrees.
The day after--- October 12th. Brookings only 58 for a high! North Bend 65. But Powers is at 90. illahe is at a warm but unremarkable 77. Powers' heat wave will continue for four more days, whereas all the other coastal stations have cooled back to seasonable normals.

Here's Powers record-breaking late-season heat wave of 1991 (seven days long)--
Oct. 10th at 91.
Oct. 11th at 103. Oct. 12th at 90. Oct 13th at 80. Oct. 14th at 87. Oct. 15th at 94. Oct. 16th sizzling at 96, and Oct. 17th it eases with a high of 72......October 11 comparison values: Powers was 103 degrees; Medford's all-time record high for the date of October 11 is 92 (also set in 1991's heat wave); further north, Portland's all-time record for October 11 is only 85 (also in 1991). So, as we see, Power's 103 is really exceptional.
One also notes that the 1991 heat wave in inland areas seems quite variable, with some hot areas quite out of phase with one another, eg. Powers 94 on the 15th, and Medford a comparable 89 degrees, while on the 16th Powers is up to 96 and Medford nearly 30 degrees cooler at only 67 (Note: Powers to Medford is only 70 air miles). And most remarkable of all on the 16th, illahe, just 17 miles distant, rises to only 65 degrees, a full 31 degrees cooler than Powers! North Bend, Port Orford and Brookings both had highs this day of only 64 degrees.
Question--- What the heck happened in Powers that day with its heat lingering so remarkably while all around it things had cooled off 20-30 degrees? Is this a case for what I will dub "Hot air Stagnation?"

1991 Factoid--- On the morning of October 11th in Eastern Oregon, Seneca' low is a very frosty 18 degrees, while in Southwestern Oregon, Powers' high the very same day is a blistering 103 degrees.... That's another good example of just how extreme Oregon's climate can be!


6. August 2002 Heat Events

Summary--- It has been stated that the Brookings Effect occurs 12 months of the year, and August 2002 provides an example of it hitting Brookings twice in one summer month.

It is also a question whether or not the Brookings Effect heat wave that hit Brookings on August 10th had anything to do with the extreme heat that hit the Willamette Valley a few days later on the 13th.

The Data---

First Brookings Effect of the month was on August 10th, when Brookings burned up at 97 degrees-- but apparently it was an example of a one-day long Brookings Effect. (need to double-check what happened on the 8th and 9th).....
.... Just a few miles inland at illahe, it is hot all month, and on the 9th illahe has 98, with 100 on the 10th. And illahe's heat continued unabated--- Brookings' big cool-down did not affect it at all, eg. illahe was 102 on the 11th when Brookings reached only 74, and 107 on the 12th when Brookings reached only 69 degrees (nearly 40 degrees cooler!). And on the 14th, illahe scorched at 106, while just twenty-some miles away Brookings froze at 56 degrees! (a full 50 degrees cooler!). Is this some kind of record?? In any case, such extremes within a few miles truly re-emphasizes that Oregon is truly "A State of Extremes." (George Taylor, State Climatologist's phrase). (See this link to Seneca, Oregon's Arctic King, for another version of Oregon's extremes).
Gold Beach. 79 degrees on both the 9th and 10th.
North Bend. 73 on the 9th and only 66 on the 10th.

August 13th (opening of Clackamas Cty Fair near Oregon City)--- a burning hot 104 degrees at the Fair! Meanwhile, Brookings has slumped to a cool high of only 68.
August 14th, The Fair sees 96 degrees, but then it cools rapidly over the next few days, down to well below seasonal normals.
illahe very hot again at the end of the month, with 99 on August 28th.

The second Brookings Effect of the month--- began on August 27th, and lasted longer at Brookings, but came on very abruptly and left very shockingly fast, see data below---
Aug 24, high 55 illahe still hot with normal summer heat at 89
Aug 25, high 57 illahe at 87
Aug 26, high 65 illahe at 89
Aug 27, high 81 illahe at 96
Aug 28, high 96 illahe at 99
Aug 29, high 97 illahe cools lower than the Coast, only at 87
Aug 30, high 57, suddenly 40 degrees colder than the day before! illahe doesn't cool, is still at 87.

Powers: no report all month, which is an unfortunate data lack.


The End.
Feb. 6, 2003, updated Oct. 10, 2013

Bruce B. Johnson

E-mailer: click for a direct link



Your source for inspiring outdoor photography!

Back to Oregon Climate Main Page

Back to OregonPhotos Main page



Page last revised 10-10-2011