Cooler Temps & More Gray Ahead

I just now noticed our Fox12 7 Day forecast is significantly cooler than other forecasts for Friday and beyond.  So what’s going on?

Nature’s air conditioner is beginning to kick in.   The endless days of sunshine (that I’ve really enjoyed) are about to come to an end.

First, this evening we’ve seen quite a push of cool ocean air move inland.  It’s already cloudy at Longview/Kelso and it’s down into the 50s at Eugene and Corvallis.  You can see the low clouds and fog on NOAA’s 9pm fog image:

This is a good indication that the marine air is a bit deeper than 24 hours ago.   It’s at least 2000′ deep over and west of the Coast Range.  Rye Mountain at 2,000′ west of McMinnville is 49.  Last night it was 67 at the same time!  Tidewater RAWS at 2,000′ southeast of Astoria is 50 compared to 72 last night!  These are impressive temperature drops.  Combine that with the early cloud arrival at Longview this evening and I’m worried many of us westside may wake up to at least some low cloud cover.  The extremely dry soil might help a little; at least we shouldn’t get surface-based fog.

Beyond tomorrow, the marine layer continues to deepen through Friday as an upper-level low offshore gradually moves closer.  Mesoscale models (both the WRF-GFS and our RPM) show a major push Thursday night and Friday morning.  Here is the Friday morning WRF-GFS depiction of low cloud cover:

Here’s the lower resolution (12km) RPM for Friday morning…same thing:

Looks pretty clear-cut to me.  Low clouds packed at least up to 3,000′ west of the Cascades in late September?  I don’t think they are going anywhere very quick with the weak “Equinox Sun”.  So that’s why I lowered the high temp forecast close to 70 degrees.  Heck, the average high falls from 76 today to 73 next Monday; we are entering the period in Fall where average high temperatures drop quickly.  That’s partly due to scenarios like this.  Also of course due to more rainy weather systems that (normally) show up.

So we are just about done with the unusually warm weather, we’ve got more typical late September weather on the way.  That’s minus the rain though.  Unless we get some sort of low cloud drizzle or sprinkles this weekend, the next chance for measurable rain still appears to be at least 8-10 days away.

Speaking of long-term, there have been hints the past few days of wetter westerly Pacific flow breaking through right at the end of the month, maybe somewhere between the 28th and 30th.  The 12z GFS said the upper-level ridging was still going to be the main story into early October.  00z and other runs/models show off/on westerly flow for more typical weather.  We’ll see. 

Chief Meteorologist Mark Nelsen

38 Responses to Cooler Temps & More Gray Ahead

  1. W7ENK says:

    Drizzle. 😦

  2. bgb41 says:

    9/19/2012 Oregon (All) Temperature Summary

    High:96 at DW5789 Eagle Poi(1463 ft) & EVANS CREEK(3200 ft) & MERLIN SEED ORCH(1064 ft)
    Low: 67 at CW5615 Heppner(2041 ft)

    High:53 at MEARES Cape Mear(1421 ft)
    Low: 30 at Sand Creek (US 9 (4525 ft )

    Largest Diurnal Change: 57 degrees
    DW9630 La Pine (88/31 ) (4256 ft )

    Heaviest Rainfall:
    0.01″ at Astoria Regional(10ft)

  3. Tyler Mode in Battle Ground says:

    73 here today. The marine clouds were really making a rush in here on the last visible shots last night.

    They are doing the same today. I’m guessing tomorrow will be another cloudy majority of the day. It didn’t break out here until 2 PM.

    Also on the visible, I noticed the smoke in the upper levels up in Washington is now moving back west…

  4. josh says:

    another marine push coming in i wonder if fog will last longer tomorrow

  5. Chris s says:

    Anybody know why the meteostar website is not updated the gfs runs ?

  6. Hal in Aims says:

    55 and still very foggy…….

  7. Tyler Mode in Battle Ground says:

    Probably the last additions to the summer 2012 gallery.

    The smoke from the fires have made for some great sunrises and sunsets, along with the cool mornings and ground fog.

    The newest 10 or so pictures are first in the gallery.

  8. Mr Data says:

    I’ve never understood what *Split Flow* pattern means weather wise.

    I know it has to do with two jet streams splitting apart with Oregon in the middle but does that usually mean clear skies in the winter time or lots of fog?

    • W7ENK says:

      It usually means mild and dry, very little rain in the Western valleys of the PNW, very little snow in the mountains, but not overly sunny, just a lot of random cloudiness that produces very little moisture. You’re correct in that the Jet Stream splits around us, more specifically the Pacific (subtropical) Jet strengthens, and enhances zonal flow into California, carrying all the moisture to our south. The Polar Jet weakens considerably, leaving us in a sort of weatherless wasteland of terribly dry boredom.

      I don’t think we’re going to have to worry about split flow this winter though, El Niño can’t seem to get his act together.

    • I hope you’re right Erik.

  9. Punxsutawney (aka HIOPHIL) at work by Sunset High elev ~280 says:

    12z GFS says we go straight to winter around the 28th of this month. If not winter, then solidly fall. Quite wet and highs in the mid to low 50’s.

    • Hope it pans out, it’s time for a deluge. Can’t even see the mountains through the smoke here in the west Salem hills–air quality has to be in the gutter in this area. I’m an asthmatic and allergy sufferer and have been struggling lately. Too bad the sunny weather had to be accompanied by forest fires. Good riddance to this weather I am ready for some fresh air and precip.

  10. Tyler Mode in Battle Ground says:

    Something tells me we won’t make 80 today…

  11. Steve Pierce says:


    Oregon Chapter of the American Meteorological Society (AMS) and OMSI to host the Pacific Northwest’s premier regional commemoration of the 50th anniversary of the Columbus Day Storm. Public invited to take a step back in time and “relive the storm” on Saturday, October 13th. Media strongly encouraged to advance this event!

    Portland, Oregon (Wednesday, September 19th 2012) – “The Oregon Chapter of the American Meteorological Society (AMS) is proud to announce the Pacific Northwest’s premier public commemoration of the 50th anniversary of the Columbus Day Storm. Held at the Oregon Museum of Science and Industry (OMSI), the commemoration will feature presentations, videos, television broadcasts, audio recordings, historical photographs and memorabilia. Attendees can also enter to win a $300 Davis home weather station raffle. The free event is open to all ages of the general public and will take place in OMSI’s main auditorium beginning at 10 AM on Saturday, October 13th. OMSI is located at: 1945 S.E. Water Avenue in Portland.”

    “The Columbus Day Storm is the benchmark storm for which all other storms are compared to across the Pacific Northwest. The violent and deadly storm struck on October 12th 1962 with winds gusting as high as 130 MPH in the Willamette Valley and 170 MPH along the Oregon coast. Nearly 50 people perished in the storm.” Chapter President Steve Pierce says, “we have gathered together leading experts from across the Pacific Northwest to offer the public an event that will be remembered for years to come. We will take a look deep inside the storm, as seen through the eyes of the public and the Meteorologists who tracked it. We will present rare audio and video recordings from the night of the storm featuring late KGW Meteorologist Jack Capell and those who were present when the 600ft tall KGW transmitter tower fell to the ground. We will also feature several survivor stories and plenty of photographs, some of which have rarely been seen publicly. Finally, we will take a look at the chances of seeing a similar storm in the future. The public is encouraged to attend this event and bring along anyone who may have a harrowing personal story to share or memorabilia item to display. The demographic of folks who are old enough to remember this tragic storm is shrinking with time and it would be great if these folks would attend this event and share a memory with younger generations.”

    Formal Commemoration Ceremony Lineup

    Welcome & Opening Remarks
    Steve Pierce, Oregon AMS President

    Headline Technical Presentation
    National Weather Service, Portland
    “How the storm formed and where it tracked”

    Supporting Presentations
    Jim Little, Meteorologist – Oregon Department Forestry
    “Broadcast media coverage of the storm”

    George Miller, Meteorologist Retired – National Weather Service
    “Photographic retrospective of storm damage”

    Brian MacMillan, Meteorologist / Reporter – KPTV Ch. 12 Portland
    “The damage, the survivor stories (video)”

    Wolf Read, Windstorm Expert / PhD Candidate (University of British Columbia)
    “A climatological perspective – return cycles of powerful storms to strike the Pacific NW.”

    Audience Question/Answer Session with Presenters

    Raffle – Davis Weather Station & More

    Please note — OMSI’s main auditorium will hold approximately 300 guests. Please arrive early in order to be assured a seat. Once standing room capacity has been met, the only additional viewing area will be from the hallway outside. For complete meeting details, including overnight accommodations in and around Portland, please see the Oregon AMS web site at:

    Who is the Oregon AMS? The Oregon chapter of the American Meteorological Society (AMS) was founded in 1947 and is the single largest local chapter of the American Meteorological Society (AMS) in the country, with 170 members. The national headquarters of the American Meteorological Society (AMS) has approximately 130 active local chapters across the country. The Oregon AMS chapter normally hosts eight monthly meetings from September to June that are free and open to all ages of the general public. The Oregon AMS welcomes the public to become chapter members for just $10 per year. The Oregon AMS chapter mission statement reads, “The purpose of this society shall be to advance professional ideals in the science of meteorology and to promote the development, exchange, and application of meteorological knowledge.” Our meetings are always found on our web site:


    • runrain says:

      I’ll be there, Steve. I’ll bring my copy of “West Coast Disaster”, a 180 page book devoted solely to the storm. It was published locally by Gann Publishing and has some fascinating photos as well as copies of the manual weather charts at that time. It’s falling apart and is missing its front cover but otherwise in great shape and an outstanding piece of memorabilia (along with my own recollection of the store has a seven-year-old!)

    • runrain says:

      Should read “own recollection of the storm as a seven-year-old”. I remember it quite well and give credit to the storm for generating my interest in weather. I also have a school project I did six years later on the ’68-’69 blizzard that I’ll bring.

  12. Travis says:

    I am also hoping for great weather through Halloween.

  13. W7ENK says:

    It’s so dark, and foggy. Like we went from late Summer to December in the snap of a finger… 😦

  14. Tyler Mode in Battle Ground says:

    Lots of fog up here in BG.

  15. runrain says:

    Check out this fog this a.m.!

  16. vinnybob says:

    No not cooler temps. my tomatoes aren’t done yet. Booooooooooooooooooooooooooooooo.

    • W7ENK says:

      Half mine are still green, too. I’ll give them another week or two, then I’ll pick ’em green and stick ’em in a brown paper sack with a couple apples on top of the fridge… the only way they’ll have a chance. 😦

  17. bgb41 says:

    9/18/2012 Oregon (All) Temperature Summary

    High:96 at CW3932 Central P(1290 ft) & DW5789 Eagle Poi(1463 ft)
    Low: 66 at Mount Hebo(3170 ft)

    High:54 at Clatsop Spit(30 ft) & DW4535 Cannon Be(23 ft)
    Low: 27 at CRANE PRAIRIE (5500 ft )

    Largest Diurnal Change: 58 degrees
    PRINEVILLE 4NW (94/36 ) (2840 ft )

  18. Hey I don’t know what ya’ll are talking about. I’ve been waiting for fall since winter ended. 😀 And now it is just days away!!!

    • Fred482 says:

      Me too! Lemme see if I have this ‘change of seasons’ thing down….after 32 years of VFD service.

      Chief’s vehicle prep…

      Change oil, check coolant, check chains, and after the first good rain, clean & store the fire shelter & wildland PPE in the tote bag, move the structural gear to the front seat, remove the water extinguisher, shovel & pulaski, throw in the deicer, sand, chainsaw, chaps, tools & equipment. When the roads ice up, install the mounted winter tires. Check the flares, road closure/tree down/detour sign box, insulated hi-vis coveralls, stocking cap, extra gloves, insulated box for drinking water, emergency food, etc.

      If I forgot anything, I’ll remember it after spending several icy hours, standing on a highway with a ‘stop/slow’ sign between my freezing fingers!….when is spring coming again….?

  19. *BoringOregon* says:

    Ahh no rain yet, just got all my parts for my plane. It’s going to take about a week to build oh well maybe it will hold off ?? Looks like back east in Boston got hit hard.

  20. The big story for The Dalles has been how cool the nights have been during this “very warm September.” I was expecting some lows in the upper 40s this month with the clear skies. What I was NOT expecting was to see a large number of days where it was in the low 60s just three hours after sunset and didn’t hit 70 degrees the next day until after 11am. Then it sneaks up to 90 briefly around 3-4pm before plunging again three hours later. If you take about 7-10 degrees off our temps this September, you’d have a very typical October dry spell for The Dalles.

  21. W7ENK says:

    We all knew this couldn’t last forever… 😦

    • Mark Nelsen says:

      But it’s been a great ride! If I knew every September was going to be like this I wouldn’t whine nearly as much in May and June.

    • …agreed, Mark…it’s been a magnificent run of sun…

    • W7ENK says:

      It has, but it’s still sad to see it go. Warm sunshine, that’s why many of us survive the cool, dark, damp winters here. Time to gear up for another 9-10 months of ick…

      Maybe we can actually get some real snow this winter? 3″ on the ground for 24 hours. That’s all I ask. No more of this quick inch that melts away by 6am crap!

  22. gloriousnumber1 says:

    I hope it’s not rainy the last weekend of September for a friend moving. I have enjoyed the late summer!

  23. bgb41 says:

    I want the sunshine to last till halloween Mark Nelsen 😦

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