Cooler Weather Wraps Up a Hot & Dry Summer

9pm Sunday…

Hopefully you enjoyed this last weekend of August? It was quite a bit different than the cloudy/sprinkles stuff we saw last weekend. Portland hit 87 both days

A very interesting month…blazing hot first half, then near to below normal the 2nd half

At this moment, it’s still the hottest summer (June-August) in recorded history at PDX. BUT, it’s only slightly above Summer 2015. Add in two cool days (tomorrow and Tuesday), and I have a feeling it’ll be a tie for hottest summer in Portland. Salem’s records go back into the late 1800s and it’ll definitely end up as #1 hottest there.

The drought continues of course. The six months March-August are the driest on record at PDX, totally blowing away the previous years. Hard to believe we’ve seen less than 4″ of rain since the end of February!

I did check and find that is NOT the driest six months on record at PDX. There have been just a few other years in which May-October rainfall was less than 4″ as well. But we’ve never had a spring/summer dry combo like this.


We are in a typical late summer or early fall weather pattern now. That means we don’t stay in long warm/hot periods but not much rain either. Forget the air conditioning…nights have been in the 40s/50s much of the past week and that continues. Weak ridging overhead gave us the warm weekend, now a cool trough drifts through southern B.C. the next 2-3 days. You can see the dip in the flow Tuesday up around 18,000′

That’s on top of a major marine push in progress. Already at 8:30pm much of the metro area has dropped into the upper 60s. The westerly flow is also pushing all fire smoke east; notice the plumes coming off Cascade fires this evening are all headed into the eastern half of the state. This is the most active I’ve seen those fires in quite a few days. More on fires in a minute

More onshore flow means highs only in the 70-75 degree range the next two days, but I don’t expect solid gray skies. Sun & clouds will mix.

Wednesday through Friday the trough moves east and atmosphere warms…we should be back in the 80s Thursday/Friday. It’s not a hot ridge of high pressure; no “heat dome”. Just an absence of any cool systems nearby. The Friday afternoon view


Models generally have some sort of upper-level trough swinging by around Sunday/Monday, but they are in great disagreement. Just taking a look at the ECMWF ensembles today, 21 of 51 members (a little under half) bring some real showers through Portland either Sunday or Monday. Of course that means more than half keep us dry through the holiday weekend. This chart shows each of those 51 members as one horizontal line on the upper half of the image. It’s 24 hour precipitation.

Anything with some color (not gray) means at least .10″. So details for next weekend are still to be resolved, but we know at least Saturday will be dry.


The cooldown and lack of thunderstorms the 2nd half of August has had a HUGE impact on fire weather. There has only been ONE big new fire in the state of Oregon in the past three weeks. That was the Fox Complex near Lakeview. No other new fire over 1,000 acres has ignited. Very good news. We still have 5 large fires (over 100 acres) burning in Oregon this evening, that’s down from around 10 a couple weeks ago. It’s 4 different complexes that started from lightning the first few days of August, plus the Jack Fire which began right around the 4th of July. That fire hasn’t seen much growth at all the last couple of weeks. But the other 4 keep burning steadily

The Bull Complex is an interesting one because it’s burning in a relatively small area between three of those mega-fires last September, maybe 5-8 miles north of Detroit.

That’s it for now…although I do have some “mixed emotions” news to share. Anne Campolongo has been a big part of our weather team for the past three years; the best weather team I’ve worked with. She’s one of the most professional people I know; smart meteorologist, friendly, great sense of humor, willing to learn, and really enjoys life. She came to us from Medford, just two years into a TV career after a meteorology degree. But now she moves on with 5 years experience in this business. Heading to the “big time” weather-wise! KCCI-TV in Des Moines, Iowa. That will be quite the severe-weather experience. Tornadoes, blizzards, damaging thunderstorms, etc… It’s also much closer to where she grew up in Ohio. So we’re sad she’s leaving, but happy she is headed to a good place. Goodbye Anne!

93 Responses to Cooler Weather Wraps Up a Hot & Dry Summer

  1. Ken in Wood Village says:

    If you look at the Medford radar. You can actually see the smoke from the fires on the radar. They must be very high to pick up on radar. Oh, I see the rain along the coast. I wonder how much will get into the Willamette Valley!!

    • tim says:

      The rain looks more impressive on radar then what models are showing maybe will get lucky.

      • Ken in Wood Village says:

        I was thinking the same thing. Maybe we could see a good soaking tonight!

        • Hank says:

          Not that suprized about the rain being more intense then models forecasted, im still forecasting .04 salem, .05 wilsonville .02 portland! I would like to hear other opinions on the thunderstorms

  2. tim says:

    18z gfs has a very wet storm on the 20th of course models are way over doing it like always but nice to see on the surface map.

    • Hank says:

      18z pretty similar to 00z last night. besides that, how do you think the thunderstorms will play out? Seems like they are forming right now, more than original forecasted, we’ll see.

  3. tim says:

    Looks like we could finally see some significant rains around the 20th, well see.

  4. W7ENK says:

    Looks like the thickening layer of smoke aloft is going to keep our high temperature well below 90 today.

  5. W7ENK says:

    Looking at parameters on the WRF-GFS this morning, and I see absolutely nothing indicating thunderstorms tonight or tomorrow. No CAPE overhead at any point as it all remains offshore and breaks up as it approaches, LI remains positive or at Zero (very brief patch of –1 over the N. WV, but that’s only transitory, it moves off toward the NE after one frame) and nothing showing up as far as precip goes.

    Will check the HRRR in a little bit, but I don’t expect it to show any different.

    New run just initiated. I’ll revisit the WRF in a bit, too…

  6. Hank says:

    Seems like those thunderstorms are very likely to happen Tuesday night. My forecast, .04 Salem .05 Wilsonville .02 Portland, probably not much lightning but definitely will be some, Gusts could pass 20 mph in Salem and Wilsonville but likely lighter in Portland, likely 35+ in mountain passes. the wind and lightning might be bad for the fires if its not enough precipitation. Would like other opinions


    • Anonymous says:

      GFS and Euro not showing any measurable precipitation in the valley for Tuesday- Wednesday. That 0.05 in Wilsonville seems generous.

      The GFS was looking irritatingly dry in the 18z until at least September 19th in fact.

      At least temperatures are going down to very comfortable levels after Wednesday.

      • Anonymous says:

        12z euro changed its tune, now showing more precipitation so maybe your estimates might come out ok afterall

  7. runrain says:

    Slight chance of thunderstorms Tue night. Not much of a chance but something is better than nothing. Finally.

  8. tim says:

    The cfs enso model appears to be to strong with la Nina, forecasted to be -0.5 by now and currently is -0.148 via tropical tidbits and is forecasted to be -1.2 C for 3.4 region by December I disagree, enso has been warming the past few days.

  9. Anonymous says:

    Will Tuesday be our last foray into the 90s until next spring/summer? I sure hope so.

  10. Oliver Watson says:

    It seems reasonable to assume that for the next months or years the majority of the time our weather will be on the warmer and drier side

  11. Oliver Watson says:

    It seems reasonable to assume that for the foreseeable future months mabey years our weather will be warmer and drier the majority of the time

    • Michael says:

      I think there is an 11-13 year cycle of dry to wet years. The problem this time around is this dry cycle being so extreme. Normal years many times I have not seen fall rain until the second half of September and even into the second half of October. That’s pretty normal.
      What concerns me is the weakness and lack of moisture with each passing front the last several years. One can’t help thinking something has changed in our atmosphere.

  12. Oliver Watson says:

    I think I’m just really frustrated with our new climate. The animals don’t know what to think, the computer models don’t know what the heck is going on and the scientist can’t even agree on an answer. This is a pretty big deal. I think we are all tired of smoke and fires and drought that is killing our tress and environment. I think they should just get rid of computer models forecasting weather anymore that 3 days out. It’s so damn frustrating. Except for life threatening evens like hurricanes or tornadoes or blizzards it’s stupid to try to forecast a simple rain event and not know within 3-5daya with at least 90 percent accuracy what will happen.

    • yigablademaster says:

      The problem is models have the wrong data. It’s not going to be have like 195X anymore or whatever analog they spit out. The parameters are all different now.

      • Oliver Watson says:

        Why don’t they change the parameters. If you spend all this money for fancy equipment and it’s not worth crap what good does it do.

    • Mike says:

      The models aren’t wrong; indeed, they aren’t forecasting any rain until 14 days out, and everybody knows that won’t pan out. The models did a superb job on the heat dome, and a lot of people were fooled into thinking the models were wrong. Models nail high pressure systems well. After awhile, if you have lived in droughts as long as I have (the 20 year AZ one before I moved here 7 years ago), you learn that low pressure systems weaken, entrain drier air, or go further north. That and Celexa keeps me going.

      Don’t predict rain in a drought. Eventually (I guess, I’m not so sure any more) one will be proven wrong, but few will complain.

  13. Oliver Watson says:

    Mabey I have asked this question before but does anyone understand why the models keep showing something 5-7 days out, even 3-5 days out and then it slowly fizzles out as we get within a day or two. This has been happening so much in the last two years. Supposedly they updatedthemodelsin the past year and it seems like they are worst than before. Some scientific insight would be appreciated.

    • yigablademaster says:

      They don’t account to a lot of physic changes in the earth. In short ‘It’s the sun stupid!’ Okay I’m not calling you stupid it’s just a quote.

    • yigablademaster says:

      Also in addition the parameters of gravitation have changed due to changes in the sun and global warming changes the past history they are using. You can’t use the past recent history or you will get broken results. Global warming historically lasts 200 to 400 years. It’s cycles and marks beginnings and ends of civilizations. We are likely in a long term effect. The models as long as they are outdated will keep giving us weird results.

      Also Oregon weather is dubious anyways as we sit right where things split up going north or south regardless of climate state: We just happen to be where the ocean currents split: Furthermore recent volcanos and earthquakes,(again due to the sun), has added fluctuation to the axial tilt.

      Physicists and meteorologists do not seem to communicate with each other. Physics affects meteorology.

  14. tim says:

    Thunderstorms possible Wednesday a good downpour would be nice.

  15. tim says:

    The weak front offshore is sure falling apart, be surprised if we even get a few sprinkles out of it, the 00z gfs is bone dry thru the run.

  16. tim says:

    Dew points are in the low to mid 40s which is completely unexpected considering the onshore flow and the warm blob, but I’ll take it over dew points in the 50s and 60s any day.l

  17. Anonymous says:

    I’m curious… let’s say we don’t get much precipitation until November and then we have another Spring like last year, what happens to our trees at that point? At what point would the doug firs and pines start crumbling?

    • Joshua Lake Oswego says:

      Two years ago.

    • Mountain Man says:

      Yeah I’d say they’re in pretty bad shape right now. Some will die or many more will die would be the difference.

      • Anonymous says:

        The SW side of many fir trees, crispy rust colored death. Some are even worse and some are fairing better. They lost more than they grew this year on average obviously.

        • Mountain Man says:

          In observation, even in the mountains, an exposed fir tree , hemlock, or cedar tree is pretty much scorched on the south or west side, but there’s been little change to it getting any worse. That was all the June record heat and they aren’t getting worse since then even though I thought they would get worse when I first observed in early July. It’s bad and all, but it’s not killing forests, but anywhere humans have made a clearing or road, there’s a lot of trees damaged or dying along that one side facing the afternoon sun from that 110 + degree heat. Apocalyptic from one angle and not that bad from another angle. Still bad though.

  18. Jake says:

    A few things I noticed driving from the girlfriends place:

    1) Smoke is back way up there. Very hazy forecast indeed.

    2) The sun angle has clearly moved South.

    3) And our nights can dip into the 40’s in this late Summer. Turned on the furnace last week a few times.

    I think another 90’s heatwave can sneak in before Summers end and I really hope trends move toward soaking rain in October. I’ve never felt a Summer without end till this one. When did we start hitting 80’s? I think it was April. Either way, horrible stuff.

    Frankly if next Summer is rainy and cloudy I will not complain if there’s not one day I cannot go swimming.

    Both natural and unnatural climate change factors are moving us more toward a Mediterranean weather pattern over temperate Mediterranean. That’s what I see and I don’t know what that means for our micro-climates here in the Willamette valley. It isn’t all negative news regarding climate change as Canada has slowly gotten into milder averages.

    One thing is for sure is that tropical storms or otherwise appear to benefit from the richer atmosphere.

    We’re long over due for a blizzard level storm and while statistically these atmospheric changes will shorten the window of true Winter arctic events occurring around here. When they do? Oh boy.

    I think last Winters snow and following ice storm showed this. It really tapped into the temperature difference of the Pacific vs. what backs against the Cascades from the North Pole (modified arctic air let’s be honest we never get true arctic air curtesy of the Rockies).

    I really do think with the right storm trajectories tapping into the gorge and say a La Nina’ Winter coupled with lower than average sun activity it will give windows of Winter activity probably not seen since the last mini ice age. Very curious what happens next as the earth cools from all the glaciers and polar caps melting and disrupting the ocean currents.

    I’m just throwing out what I think will happen before this season starts too. I do think we’re fast tracking ourselves toward a mini ice age which in the next 5 to 8 years will be heavily evident on the horizon. Which would be freaking awesome as I’d get to see the Columbia River frozen over just as in the black and white photos where they’d drive the Ford Model T over it. My 2 cents. Best.

    • Hank says:

      Woah, heads up somebody might get mad or offended by your comment, people get upset over weird things nowadays.
      Besides that, a mini ice age would be enjoyed, but anything more than 3 years would not be good, but skating on the Columbia would be pretty cool, crater lake would be beautiful frozen, wait now that I think about it, the Columbia better not freeze, we would likely lose power, but I guess if there was a mini ice age we could go back to nuclear power. But I don’t know how we would get a mini ice age, things like that don’t just happen randomly.


  19. Mountain Man says:

    Okay guys and gals, so here’s a little weather information to take with a few grains of salt. The enso cycle. I’m not talking about changes in climate. Just what weighs scale this way and that way. If we do infact end up in neutral territory it’s a guess with some influence from the pdo and of course the blob as with any year. Almost all enso + years are a fast wet fall and almost all enso – years are a slow dry fall. Kind of like, yes what you know about wet or dry with enso cycle, is like opposite for fall early fall on the calendar or first half of fall meteorology wise. Everything I see says, we’re likely to go into fall very slowly as far as precipitation, although an early frost would be a little more likely this year.

    • Mountain Man says:

      I also took a deep look into some trends and other influence. I’m really thinking, real fall rain doesn’t kick in until the second half of November this year, December and into January, we’ll be cool and damp. The general dry conditions will continue for several more weeks though. I did agree with… Hank? I think there will be some real winter goodies, not really a storm like last February, but several small events are more likely as we stay just slightly on the cool side of the Jetstream for several weeks. We’ll see. Not a prediction, just that the atmosphere is leaning heavy toward that kind of configuration this winter. It will be interesting to see what others predict. A few grains of salt is all it’s worth. For those who don’t know me, I do have a degree in climate science, but non practicing so I do now a few things, but otherwise it’s just a hobby to watch the weather like most of the rest of you. I’m just saying, no I’m not an expert, but I know a few things and understand a little.

      • Hank says:

        I agree with what your saying, although it’s no guarantee it is just trends and averages. Our current setup for rain is not that good for people hoping for a storm, although there is a trend we may get something in 13 days, but only take 13 days out with a grain of salt. and I totally agree with no serious repeating rain until likely mid November. but definitely above average frost, and the way the polar vortex is, snow lovers are likely to experience a good winter. It seems the high pressure in the ocean will most likely steer the low pressures that formed in the Alaska coast to North Washington/South Canada, and we will have a very dry fall in that case. But atleast there are always benefits in a dry fall.


      • tim says:

        So keep watering my lawn until mid November more or less.

  20. Weatherdan says:

    When is this years Winter Weather meeting at OMSI? Peace

  21. Paul D says:

    Go away summer!!

    • Gene says:

      Stay a little while longer, summer, but go away smoke!

      • Anonymous says:

        We need a couple of good downpours across the region to minimize these fires and kill the smoke. Then I don’t care if it’s summer weather or fall weather really, as long as we have fresh air and low fire risk!

  22. tim says:

    Every time the cpc shows cooler\wetter weather it backs off and that’s exactly what they did today, now avg temps and precip and tomorrow probably warm\dry again.

    • Anonymous says:

      It’s flip flopping like crazy. I’m sure it’ll change back to avg/cool with normal to above normal precip again. At least it’s not boring?

  23. tim says:

    The last two September’s in seattle were wetter the normal looks like that may be the case again this year if current models are right.

  24. Hank says:

    00z gfs running wet at the end, been more common in the models to show that lately. a bit selfish of me but, I would rather it be dry for another week than that, because harvesting a muddy garden isn’t necessarily a fun time, but it isn’t really that selfish of me because no matter what anyone says the weather will still end up the same way

    Also here’s a question for people, would you rather have a cool labor day, an average temperature one, a wet one, a warm one or a hot one? I personally like It hot

  25. Anonymous says:

    Dude 90s are still entirely possible into late September.

    That was said by you on August 27th in Mark’s last blog post.

    • Anonymous says:

      This was meant for Zach’s “I highly doubt that 92F verifies.” comment.

      • Zach says:

        I never said anything contradictory. I was referring to that particular day Tuesday Sept 7th. Not that it isn’t possible to hit 90s in Sept. because it happens all the time.

        Also I will say that the 12z runs today swung back in the warm direction so maybe we will get up to around 90.

        • Anonymous says:

          Lol and right as you finally open to the possibility of 90 on Tuesday, KPTV reduces their forecast to 85. Which takes us back to what I said originally about not really knowing until Saturday at best. These operational runs are all over the place and they’re taking us for a fun ride.

      • Zach says:

        Yeah, agreed there has been a lot of flip flopping. The ecmwf has been incredibly biased towards warm ridging compared to the gfs. A lot of disagreement only 7 days out.

  26. Anonymous says:

    Happy first day of meteorological fall! It certainly feels and looks like a nice early fall day.

  27. Roland Derksen says:

    Looks more like an outlook in October here, than September, starting on Saturday.

  28. tim says:

    Todays cpc is on board with the cooler/wetter pattern.

  29. tim says:

    00z gfs is wet but it appears to be an outlier, ensembles don’t support a wet period coming soon and neither does the cpc.

    • Zach says:

      The Euro made a big shift last night as well. I know better than to get my hopes up at this point, but still a good sign. The ensembles often lag behind the operational models when they pick up a new signal / pattern shift.

    • Anonymous says:

      The 00z Euro is also showing a flip from hot/dry to cold/wet now. It means squat this far out though as that high pressure off the coast will determine our fate within the 48-72 hour window before the actual event is due to arrive. As we know, that high pressure adjusting its position a notch up or down makes a huge a difference in the temps and moisture levels.

      KPTV has next Tuesday at 92 degrees on the forecast currently, but 00z says it’ll be much much cooler. We probably won’t know the actual forecast until Saturday at best.

      • Zach says:

        I highly doubt that 92F verifies.

        • W7ENK says:

          Based on what? It’s certainly not out of the question. I had a high of 87 degrees on 10/2 of last year, so 92 in the first week of September is absolutely still on the table, climatologically…

  30. tim says:

    That was for anonymous.

  31. tim says:

    12z gem has it hitting Louisiana on the 8th

  32. Weatherdan says:

    So many trees look to be dying from the drought and the heat. I hope they can last until the rainy season. Peace

  33. Anonymous says:

    GFS is showing another hurricane forming in the Gulf of Mexico mid-September… aiming for the exact spot Ida landed. Still wayyy too early of course, so hopefully it doesn’t form.

  34. tim says:

    After Sunday the flood gates open up to a long stretch of sun and warm weather.

  35. tim says:

    Since we’re having the dryest spring/summer on record why should this fall and winter be any different la Nina or not, climate change dictates that.

    • Zach says:

      Most of the climate modeling doesn’t show the PNW getting drier though. Warmer and less snowpack, but little to no change in the water year.

      • Hank says:

        Tim I’m tired of seeing people comment climate change on here, mark and cliff have already stated our winters being wetter not drier.

      • yigablademaster says:

        Models Garbage in = Garbage out. Nuff said.

        • Hank says:

          100% agreed, weather modeling and climate modeling are just wrong, especially climate modeling, 20 years ago they predicted much worse than it is, they even thought florida would be underwater now, in 1970 they thought we were heading into an ice age, I’ll never trust any forecast over 5 days away, even then they get it wrong often

      • yigablademaster says:

        That’s one of your worst mistakes to make: “Climate modeling”. About as useful as actual modeling.

  36. Weatherdan says:

    39 days at or above 90 in Salem so far this Summer. A record that will probably be broken within 3 years, Global warming is here. Peace.

  37. Anonymous says:

    That one map looks like boobies. Just sayin’.

    I will miss Ann! She was one of my fav’s …

  38. Roland Derksen says:

    looks like we’ll close out the month with a few showers here overnight/tomorrow morning. Today on this date 30 years ago (Aug.30,1991) I recorded 2.17 inches- That August was my wettest
    by far: 9.16 inches.. I doubt THAT record will ever be broken in my lifetime.

  39. tim says:

    .10 would be nice but I suspect the models are over doing it again.

  40. Brian hobson says:

    Sorry to see Ann go. When’s her last day on air?

    • Paul D says:

      It was a few days ago. She posted news of her departure after being on the air for the last time.

  41. W7ENK says:

    I can’t believe we’ve actually gone the entire Summer absent any real threat of thunderstorms in the Valley. That’s kinda incredible, actually. Incredibly boring, to be more specific.

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