July 18, 1987 Summer Cold Snap Oregon/California

[Omegaraptor]

Just today I was looking into information for record cold summer days in the PNW. I had never known about the July 18, 1987 event, but records indicate that it was a pretty extreme anomaly. The largest cold anomalies hit the area just east of the Cascades between Madras and Susanville from the looks of it. Here are some daily high temps and anomalies:

 

Portland - 69ºF (-12ºF - certainly cool for summer, but not the most extreme the area has seen for sure. The cold snap did not hit NW Oregon nearly as hard, from the looks of it)

 

Madras - 55ºF (-32ºF)

Redmond - 55ºF (-32ºF)

Bend - 47ºF (-36ºF)

Wickiup Dam Station - 46ºF (-37ºF)

Chemult - 47ºF (-37ºF)

Crater Lake NP - 36ºF (-34ºF)

Klamath Falls - 53ºF (-32ºF)

Lava Beds National Monument - 45ºF (-41ºF)

Cedarville - 54ºF (-35ºF) recorded on 7/19 (no data exists for 7/18, but it likely would have been even colder)

 

Several places west of the Cascades were hit hard as well:

Sexton Summit - 45ºF (-31ºF)

Medford - 61ºF (-34ºF)

Ashland - 55ºF (-34ºF)

Yreka - 56ºF (-37ºF)

 

Does anyone have more information on this massive cold snap? Regional anomaly maps, anything? At most if not all of these stations, it is far lower than most of the other daily cold records for that month. Very interesting event.

[SilverFallsAndrew]

Just today I was looking into information for record cold summer days in the PNW. I had never known about the July 18, 1987 event, but records indicate that it was a pretty extreme anomaly. The largest cold anomalies hit the area just east of the Cascades between Madras and Susanville from the looks of it. Here are some daily high temps and anomalies:

 

Portland - 69ºF (-12ºF - certainly cool for summer, but not the most extreme the area has seen for sure. The cold snap did not hit NW Oregon nearly as hard, from the looks of it)

 

Madras - 55ºF (-32ºF)

Redmond - 55ºF (-32ºF)

Bend - 47ºF (-36ºF)

Wickiup Dam Station - 46ºF (-37ºF)

Chemult - 47ºF (-37ºF)

Crater Lake NP - 36ºF (-34ºF)

Klamath Falls - 53ºF (-32ºF)

Lava Beds National Monument - 45ºF (-41ºF)

Cedarville - 54ºF (-35ºF) recorded on 7/19 (no data exists for 7/18, but it likely would have been even colder)

 

Several places west of the Cascades were hit hard as well:

Sexton Summit - 45ºF (-31ºF)

Medford - 61ºF (-34ºF)

Ashland - 55ºF (-34ºF)

Yreka - 56ºF (-37ºF)

 

Does anyone have more information on this massive cold snap? Regional anomaly maps, anything? At most if not all of these stations, it is far lower than most of the other daily cold records for that month. Very interesting event.

 

The 47 at Bend and 61 at Medford really stand out. Had to have been pretty good precip with that event I am guessing. 

[Omegaraptor]

The 47 at Bend and 61 at Medford really stand out. Had to have been pretty good precip with that event I am guessing.

 

There was. Bend got nearly an inch that day if I’m not mistaken.

[Jesse]

Looks fun. Would be nice if we were capable of weather patterns like that in the midsummer anymore.

[Anti Marine Layer]

Looks fun. Would be nice if we were capable of weather patterns like that in the midsummer anymore.

 

69 should be pleasantly cool for someone who prefers cool weather over hot. 55 for a high would be unacceptable for the middle of summer (unless you lived in Utqiagvik, Alaska).

[Jesse]

69 should be pleasantly cool for someone who prefers cool weather over hot. 55 for a high would be unacceptable for the middle of summer (unless you lived in Utqiagvik, Alaska).

Haha, preferences.

[BLI snowman]

There was a massive deformation zone that  sprung up that day. Eugene had 2.41" of rain on the 18th, which obviously kept the temps in check. It rotated in from the south and the air stayed warm and dry to the north. Seattle hit 80 on the 18th.

[ShawniganLake]

There was a massive deformation zone that sprung up that day. Eugene had 2.41" of rain on the 18th, which obviously kept the temps in check. It rotated in from the south and the air stayed warm and dry to the north. Seattle hit 80 on the 18th.

Just out of curiosity I looked at the records for southern BC in July ‘87. The 17-18th was the warmest 2 day stretch in what was a seasonally coolish month.

[SilverFallsAndrew]

There was a massive deformation zone that  sprung up that day. Eugene had 2.41" of rain on the 18th, which obviously kept the temps in check. It rotated in from the south and the air stayed warm and dry to the north. Seattle hit 80 on the 18th.

 

Good lord. Looks like Silver Falls got about an inch.