Rain ahead, but October starts warm & dry

Well this is exciting…we’re going to see some widespread (light) rain for much of the region tomorrow.

It’s been very dry; in the past 3 months Portland has only picked up about 1/4″ of rain! That’s very stressful for our native vegetation, even with that huge soaking all through the spring months. And this September has been something else…warmest on record in Portland and Salem, and one of the warmest in other areas.


Right now September in Portland is running about like an average July 10-20 years ago! High 81, low 58.


So what’s ahead? Light showers both tomorrow and early Thursday, then we’re heading back to unusually warm and dry weather for the first few days of October. A weakening front is approaching the coast. Technically it’s an “occluded” front, but for TV purposes I left it as a cold front. One surge of rain arrives around sunrise, then the surface low with it’s attendant showers arrives tomorrow evening and night. There should be a brief dry period DURING THE DAYTIME tomorrow.


That surface low dies and is replaced by building high pressure late Thursday and on into the weekend. What about rain? Just perusing many different models gives somewhere between .10″ and .50″ for the metro area


Areas NOT showing color means less than .10″ rain forecast. Here’s the 18z ECMWF model’s precipitation forecast


You can see many areas east of the Cascades will just get a few showers. The Cedar Creek Fire in the central Cascades should get a soaking once again. Smoke from that fire drifted into the Willamette Valley today; I could smell it a couple of times while running errands.

We’re headed back to dry weather Friday through at least early next week, and even later NEXT week doesn’t look very wet. That’s because upper-level heights will remain higher than normal the next 8-12 days. Take a look at the 500 millibar anomaly for days 2 to 12 from the ECMWF model ensembles. Above normal heights through October’s first week (or longer).


GFS model ensembles are quite similar


Clearly the “wet season” isn’t going to arrive in the next 1-2 weeks. You can expect a very warm first weekend of October, then drier than normal through much (or all?) of that first week of the month.

Enjoy the showers, and a warm/dry weekend. I’ll be off on vacation through Sunday the 9th; hopefully we don’t get any surprises while I’m gone this time. Time for a 25th anniversary trip with my wife!

Chief Meteorologist Mark Nelsen

169 Responses to Rain ahead, but October starts warm & dry

  1. WEATHERDAN says:

    81 at 3:30 PM. What a beautiful Autumn. Peace.

  2. tim says:

    12z gfs has rain on the 18th it’s a start.

  3. tim says:

    Remember we had a very wet spring so this dry weather should be no surprise to anyone, nature does like to balance it self out it’s so obvious that’s what’s happening.

  4. Opie says:

    Although we’re going through a really dry stretch, maybe the driest mid-June to mid-October on record, there’s been even worse years overall.

    June through November at PDX
    1952: 2.68”
    1987: 2.89”

    June-September, 2022: 3.57”

    • Opie says:

      Dang, I messed up! The values for 1952 and 1987 are wrong.

      • Opie says:

        Should be….

        August – November at PDX
        1952: 2.68”
        1987: 2.89”
        June – November at PDX
        1987: 4.06”
        1952: 4.91”

    • Joshua Lake Oswego says:

      1952 was the driest 4 month period on record. That would be July – October at 1.23”. We are at .48” so far with no indication of meaningful rainfall until at least the last 1/3rd of the month.

      We haven’t had more than .16” of rain in a day since June 10th. Hence the extreme suffering of plants and trees. We have never gone this long without a soaking rain. Coupled with never-ending and record breaking warmth, it’s just too much to handle for flora.

      We are being robbed of fall this year and it’s very depressing. Instead of green grass, fall colors, snow capped peaks of volcanoes, cool days and crisp nights, we have brown grass, dust, droopy or prematurely fallen brown leaves, wilting plants, summer-like days and warm nights, and bare volcanoes.

  5. Anonymous says:

    Everything is so stagnet, it’s getting old. 83 degrees in the second week of October, pretty amazing. A LA Nina autumn should not look like this.

    • tim says:

      Technically la Nina doesn’t effect our weather until the winter months as well as El nino so this dry weather isn’t connected to enso.

  6. Roland Derksen says:

    We have an “omega block” set up over us and until that changes, the rain isn’t going to come- or at least stick around for more than a day at a time.

  7. tim says:

    We still can get a fall green up in November or December since our fall rains come with mild temps most of the time especially with a AR event.

  8. OC550 says:

    Well, here’s to hoping the ridge moves west in mid-November ushering in arctic air and lots of moisture from the Pacific. There’s always hope.

  9. Peter Christenson says:

    If, as seems likely, we get zero (or almost zero) rain through mid-Oct., it seems certain to me we will have had the driest 4-month period in Portland history. I’m too lazy to go back and look at the data, but maybe somebody out there could confirm my suspicion.

    • Joshua Lake Oswego says:

      It looks to me like our driest 4 months ever was in in 1952. We had 1.23” from July – October. 2018 was actually pretty close from May through August. 2021 might be up there too since our spring was so dry. I don’t have the stats though.

      We’re at .48” from July 1st to current. So, we need at least .75” from this point forward to avoid the driest 4 months ever.

  10. tim says:

    Good weather for fall and winter preparations at least.

  11. Roland Derksen says:

    Last year, my rain amount for September to November made up 51.9% of the year’s total. The long term mean for me is about 30% of the year. if I’m going to reach 30% for this year, I’m going to have at least 17 inches of rain from now til the end of November. Not impossible, (given last year’s November) but I ‘m increasingly doubting if we’ll even get close.

  12. tim says:

    Nws Seattle said if we don’t get any rain through mid October for Seattle I’ll be the dryest since 1987 which was a moderate El nino that fall, this year it’s a moderate La nina.

  13. Joshua Lake Oswego says:

    Tim, your trough is gone on the 00z suite.

    • tim says:

      I see that but models do bounce around from run to run the euro still has it.

      • tim says:

        I remember 91/92 and 02/03 we’re very dry seasons so I wouldn’t be surprised if this season is too we are due like it or not.

  14. tim says:

    It’s looking like a one and done event next week then back to summer for the foreseeable future.

    • Joshua Lake Oswego. says:

      I wouldn’t call what’s happening next week an event. I would call it a few days of near average temps and still drier than average as opposed to ‘’is it still July?’’.

    • Zach says:

      Outside of 10 days is mostly just nonsense from the models. Temps have actually been underperforming the past few days because of the thick fog every morning.

      • tim says:

        The cascades could get up to 2 inches of rain with the storm which will help the wildfire situation.

        • Joshua Lake Oswego says:

          Maybe one favorable spot in the WA Cascades could get 1’’ plus. The Oregon Cascades would do well to get .25’’. That could change, but for now, it looks like a complete non-event.

  15. Roland Derksen says:

    If this weather pattern persists through the middle of the month, I expect to see fog in the mornings by then. Haven’t heard much about it yet, but as nights get longer, that’s bound to happen.

  16. How about tonights GFS 00z run throwing down an inside slider within day 6-7. ECMWF 12z and many of its ensembles looks pretty similar too. Maybe something different for a change.

    • Joshua Lake Oswego says:

      Yea, the Euro was first on the call for that. Tough to get too excited about a couple of coolish days with a few light showers, but it certainly beats 80 and sunny.

      • Joshua Lake Oswego says:

        And back to a 588 dm ridge parked on top of us endlessly by early the following week. There is zero hope of a sustained pattern change or meaningful precipitation at this point.

  17. Anonymous says:

    This weather is more typical of a strong El Nino in early autumn, yet it’s a La Nina. Wonder what it would be like if it were El Nino.

    • Joshua Lake Oswego says:

      Couldn’t possibly be any less like autumn. We are rewriting the record books and what is even considered possible. As far as standard deviations from normal go, the verified and forecasted warmth in October has to rival the June, 2021 event.

      That doesn’t even consider the incredible rainfall futility, all-time hottest week in July, all-time hottest month in August, and all-time hottest September.

  18. Snomanski says:

    Well, it’s all very depressing. No rain in sight, still watering, no fall green-up this year. Not sure what the impact on mushroom season in the foothills will be, but I do know that the shrooms wait till the first big rain, and I doubt they’ll do much if the rain waits a whole lot longer. By the way, I do think the CPC 6-10 and 8-14 have some skill. I am willing to bet that the next two weeks will be warm to hot and bone dry. Alas

  19. runrain says:

    At least today FEELS like fall. 62° and cloudy Happy Valley. But back to summer in the next few days.

  20. tim says:

    Near record highs possible this weekend for both Seattle and Portland.

  21. tim says:

    Just watched Pete Parsons September update outlook and he said October will be cooler and wetter than normal and November will be warmer and dryer then normal, hmmm not sure about his October outlook, well see.

    • tim says:

      If he’s right about November I’ll bee happy about raking dry leaves,last fall was a muddy mess.

    • Joshua Lake Oswego says:

      There is zero chance October will be cooler than normal. Wetter than normal is certainly possible, but so is winning the Powerball.

      • Roland Derksen says:

        Not expecting it wetter than normal either- this October reminds me so far of October 1987, which was very dry until the final week, when we did have some rainfall, but not a whole lot. However, it’s intresting to note that this year up to now still has a higher total amount of precipitation for me than 2021. And it will still be higher up to and including the 14th. After that, i expect us to fall behind 2021 significantly.

        • tim says:

          Our last dry fall was 2013 October through December we are long over due, it will rain but I’m not expecting a above normal season.

  22. OC550 says:

    Really not liking the heat and forecast. I’m ready for real Fall. I don’t like complaining about the weather, but here I am…complaining about the weather. Seems like patterns have stuck in place for a longer time than they used to. That’s just my gut feeling. Not sure if that is actually true.

  23. X says:

    PS. I think the Stromboli volcano explosion may have added crap to the atmosphere too and we are getting delayed affects.

    I can’t remember if it was earlier this year or last year that thing went off as so much political crap happened all the weather/natural events seem to roll into one lately.

  24. X says:

    While I think Tonga may have something to do with resetting the global circulation don’t forget there were a few other smaller volcanos that went off too last year and I think this year as well.

    While there wasn’t ANY ONE volcano rumbling that was super spectacular in itself: all of them COMBINED I believe have messed up the global circulation in ways we don’t know about yet which only adds to the confusion, and we have had several glancing blows with severe solar flares lately that mostly missed us for direct hits but may have been close enough.

    The weather models both the Euro and especially the GFS relies on past historical conditions that no longer have any context in today’s climate meaning forget what happened in 1961 or 1955,etc the circulation IS NOT THERE anymore.

    It’s not going to be even close to that or whatever other years you guys can spit out.

    We are in uncharted territory here on out so hold on to your hats folks and hopefully the models get better perimeters in their next big overhauls but I highly doubt it.

    • Oliver says:

      I don’t even know why we have models that go out past 5 days. It’s such a waist of time and money especially here in the Pacific Northwest. I guess as humans we are obsessed with the future even though we and our computers stink at getting it right more than a week out

  25. Andy says:

    Nothing unusual for dry weather in the first part of October…the rains will start and probably folks will start complaining about the cold and rain later in the Fall. I wouldn’t be surprised more records are broken this Fall and Winter.

    • X says:

      Dry is not the problem Andy. There have been plenty of ‘dry’ October’s. It’s the Octune (October and June combined) that’s the freak show we are seeing. The dry Octobers in the past featured many nights in the low 40s/upper 30s with day time in the 60s to high 70s worst case scenario.

      We are not seeing any relief of temps and the latest ridge bridges look like something out of this world! It almost feels controlled somehow……never mind forget I said anything.

      The latest models have a ridge bridge all the way to Russia and it will most likely verify. I think it will bump up to 90F or higher as we get closer to the event.

    • Joshua Lake Oswego says:

      Not in and of itself, but the total precipitation since early June certainly is.

      More so, the relentless heat is unusual. In fact, it’s unprecedented. Hottest week ever in July, hottest month ever in August, hottest September ever, and hottest start to October ever with zero hope of a pattern change in the foreseeable future.

      We recently had 40 straight days above normal and we currently have 65 out of the last 70. We haven’t had a high below 70 for 105 days and we haven’t been below 50 for 133 days. Starting in 3 days, the average high is 69 and the average low is 49.

      We are obliterating many all-time heat records. I am running out of superlatives to describe how utterly ridiculous this stretch of warmth and precipitation futility is.

  26. tim says:

    It looks dry through the 20th, maybe a short storm season this year and the days will start getting longer again in January.

  27. Paul D says:

    I wonder if the grass will stop growing at all this year….

    • Joshua Lake Oswego says:

      I have thought about that too. I think this will be the first year I have ever experienced a lack of green-up in fall. Based on current model QPF output (0) the shortening days, and the quickly decreasing average temps, I think it will be too late for grass to grow whenever the heck we actually get meaningful rainfall.

      We are being robbed of arguably the most pleasant and beautiful time of year here. So sad.

      • Paul D says:

        Guess we’ll have to reseed in spring – but wait! The grass starts growing in January, so is that now spring? 🙂

    • tim says:

      2014/15 was a very warm fall and winter the only difference is it’s dryer so far this year. I do think the above normal sst in the Pacific is keeping the ridge around longer than usual.

      • tim says:

        My grass is still dead not much growing here in western Wa unless you’re watering.

      • X says:

        Oceans are major drivers of weather. Any middle school children that actively took sciences would understand the basic dynamics of ocean flow and right now it isn’t flowing.

        It’s like saying that perhaps humidity is what makes tropical jungles so humid and wet.

  28. WEATHERDAN says:

    FZ LVL at 15K this AM! 1:00PM temp is already at 81. Maybe another record warm month like the last 3. Peace.

    • X says:

      Aaaaaaaaaannnnnnnnndddddddd The Beat Goes On! Mario Party 3 Beat Goes On song:

      Duh duh duh duuuuuuuuh duuuhhhh duhhhhh dubhhhhhhhh duhhhhhhhhhhhhh or something like that.

    • X says:

      That song is how I feel about this Juntober.

  29. Oliver says:

    It would be interesting to do some research as to why it seems that ridges stick around here so much longer than troughs as of the last 10 years. This spring we couldn’t buy a ridge and yet for a lot the the time during the years recently we have ridiculously resilient ridges. What made this spring so difficult to get a ridge. What were the atmospheric conditions that contributed to that. Especially during model riding season is it important to know because it’s a complete waist of time to chase a pattern change on the models that isn’t going to happen for weeks if not longer. Model riding isn’t fun or logical anymore because the models are crap

    • X says:

      Models have been crap for a long time as they rely on pre existing perimeter’s that no longer exist for several reasons which aren’t allowed to be posted on main stream weather pages so I won’t bother here either:

      Until the scientists are allowed to speak freely without being fired for their studies we are going to have more and more broken weather models as time goes on.

      This year should’ve been a wake up call to the people in charge but they have doubled down instead.

      Science is NEVER settled it’s always being updated and needs constant tune ups and checks.

  30. tim says:

    12z gfs has a few wet systems moving through around the 11th but again models have the tendency to break down the ridge too soon,well see.

    • X says:

      As long as whatever is going on or under the oceans keeps occurring I see no reason to expect any meaningful change unless something REALLY big overrides the current scenario.

      I think what we saw last spring was that something big that temporarily displaced the ridge but the conditions causing the ridge never actually went away so right on back it comes!

  31. tim says:

    Did some research and found Seattle dryest October on record was 2006 with only 00.4 in we are long overdue so maybe this October we can beat that with climate change

  32. tim says:

    I see marks 7 day has trended warmer today with more 80’s now

  33. tim says:

    I noticed weather.com keeps pushing the 60’s and rain to the end of the forecast period, that’s been going on for weeks now and it’s still happening bottom line ignore the last few days of the 14day outlook.

  34. WEATHERDAN says:

    Sun is out and and the temperature is up to 69. Total rainfall from this system was just .12. Hardly an atmospheric river or even a creek. Now back to October Summer. Peace.

  35. lurkingsince’14 says:

    Coming down steady now in Raleigh Hills area with some big bands on radar next few hours. First time, long time! Loving this, and the fact that it goes right back to fall sunshine 😎

  36. Paul D says:

    Mark’s out of town – brace for impact!!!

    • ViRGE says:

      Right? All the interesting/extreme stuff seems to happen while Mark is not around. It’s akin to a reverse Jim Cantore effect!

  37. WEATHERDAN says:

    Yesterday Natasha Stenbock called today’s system an atmospheric river. It is not. And so far today Salem has had just .04. The skies are now mostly sunny and in the low 70,s. One more day tomorrow similar to today then a big warm up. Maybe close to 90 on Saturday. Not bad for early October. Peace.

  38. tim says:

    Got some light rain today and now we dry out for the next two weeks according to the latest models 😎.

  39. Andy says:

    Woke up to steady rain here in Albany to freshen things up…Looks like the growth of Portland over the years has really affected the low temperatures for the city. I definitely believe the microclimate affect is greater around the metro areas and is affecting the overall trend of temperatures of the past when these cities were much smaller…Part of the localized climate change affect.

    • Opie says:

      I think you’re right. I’m going to start posting temperature info for nearby locations, where there’s been less UHI changes, for comparison with PDX.

  40. tim says:

    A la Nina doesn’t guarantee a wet fall/winter I’m sure we had some really dry wet season la nina’s in the past.

  41. Roland Derksen says:

    It’s cloudy here, but no rain so far. I’m likely to end up with this September being my 3rd driest, after 1975 and 1993.

  42. OC550 says:

    Happy 25th Mark! Your quote about this September being like a typical July 10 – 20 years ago is concerning, but also not surprising in a warming climate. Wish it wasn’t so. Glad we are seeing at least a little rain before drying out again.

  43. Bethany250ft says:

    Weird that the first soaking rain of the season went to CA and the second one to NW OR rather than WA yet

    • Joshua Lake Oswego says:

      Don’t count your chickens before they hatch. No soaking rain here yet. .01’’ on the day so far.

      The potential is there for decent accumulation later this evening into early tomorrow, but it is very far from a guarantee. Even if some areas score, others will end up with very little.

      The recent CA event was much more organized and widespread. Quite an anomalously strong low. So Cal had a nice monsoonal event not too long ago as well.

  44. gravatarhojack says:

    Hey Mark. I’ve got property in central Oregon between La Pine and Klamath Falls. Can you include the whole state of Oregon on your maps. Most all the weather maps that get posted only show to about La Pine. Looking forward to some Oregon weather! Thanks

  45. JERAT416 says:

    Thanks Mark! Yeah I do remember more cooler nights in summer rather than staying over 65 or so. Let’s hope the fire activity finally drops so low its under control. Sounds like “soaking rain” within 100 miles south of us.

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