One “Bomb Cyclone” Down, One to Go!

10pm Thursday…

After a very warm day with some lower 70s in the metro area, moderate to heavy rain has arrived with a Pacific weather system. I expect steady rain for a few more hours, then the usual scattered showers behind the front the rest of tonight. Expect more showers Friday but decreasing as the day goes on.


  1. You may hear/see something about a powerful storm (or worst ever?) for the Pacific Northwest this weekend. No, there is not a mega-storm on the way for the region. THERE WILL BE A HUGE STORM OFFSHORE, but it’s far enough away that we get typical wind/rain. No big storm.
  2. Things are moving fast/furious now with a strong Pacific jet stream overhead, so weather will be changing quickly from day to day…make sure you are paying attention to forecasts.

Tonight’s front is the leftovers of a powerful “Bomb Cyclone” that moved through the northeast Pacific ocean well west of the Pacific Northwest. A bomb cyclone is simply an area of low pressure that deepens “explosively” in a short period of time. Anything over a 24 millibar drop in 24 hours is considered a “meteorological bomb cyclone”.  No, it’s not a made-up media phrase.  Meteorologists have been watching these storms develop in the north Pacific/Atlantic for decades and that’s the term we’ve always used.  Somehow national media stumbled upon the term a few winters back and decided it was appropriate for the public to hear.  Generally (for good reason) I have kept the word “bomb” out of my on-air forecasts, but apparently it’s okay now and I sure used it last night! So that first cyclone is now weakening after bottoming out at around 950 millibars well west of the 130W “danger zone”. When deep low pressure centers track through this area we watch very closely!

Our big windstorms west of the Cascades almost always occur when a low pressure center tracks within this area

Now this is amazing; we have a second (and stronger!) bomb cyclone developing Saturday night and Sunday. Yep, that’s two huge storms relatively close to the region in less than 4 days. Highly unusual.

The latest global model forecasts are in remarkable agreement this evening. All are forecasting a surface low pressure center to drop from around 993 millibars Saturday morning to 943, yes 943, millibars. You can see the track of both lows, notice this 2nd one will be a bit closer

That 943 millibar value will probably be an all-time record deep low pressure so close to the region. For comparison, the Columbus Day Storm was “only” around 960 mb, but less than 50 miles off the coastline! Tracks of the last three major regional windstorms…all well inside 130W.

Ryan Maue, a meteorologist with, checked lowest surface pressure in the 1950-2021 record. He tweeted “the minimum central pressure of 944 millibars from next storm off Pacific Northwest coast will likely be the deepest/most intense in this area of ocean at 45°N and 135°W at least since 1950” The graphic he tweeted shows that boxed area. Plus you see the lowest pressure right up against our coastline (the past 70 years) was that 960mb during the Columbus Day Storm.

This is all interesting stuff of course, but what’s the effect along the coastline and interior? A gusty east wind Sunday morning turns breezy from the south Sunday afternoon and Monday. Yet the strong wind field remains offshore through the event.

The ECMWF model shows this well, gusts over 100 mph over the open ocean, but under 70 mph along the Oregon coastline. This shows accumulated gusts (highest gust) from now through 5pm Sunday.

Most likely we’ll see gusts 55-65 mph along the beaches and 30-40 in the valleys. That’s relatively weak of course, not a windstorm, but enough to make for a windy Sunday afternoon!

That’s it for now, I’ll be off tomorrow but back at work Saturday and Sunday tracking our very wet weather pattern.

Chief Meteorologist Mark Nelsen

142 Responses to One “Bomb Cyclone” Down, One to Go!

  1. tim says:

    I think we can agree winter of 49/50 will never happen again even December 1990 is out of reach but 2013 is still possible short term.

  2. tim says:

    00z gfs and cpc is showing a break in our very active weather pattern long term, we need it let the clean up began.

    • tim says:

      We never had a active fall like this in record history this is insane all time records broken left and right can’t complain one bit.

  3. K700 says:

    Just watched Mark’s forecast on the 10 o’clock news and he said we’ve seen our peak gusts already. Wind and wind gusts will decrease through the night and into tomorrow. Sounds good to me!

  4. W7ENK says:

    “Karen” (a.k.a, I know exactly who she really is) should no longer be a problem.

    You’re welcome.

    • Ken in Wood Village says:

      Thank you 😊👏

    • Hank from Salem says:

      Thanks! Was it Kyle or someone else?

      • Matt in Keizer says:

        I’m thinking it was Ziggy—the self proclaimed Bulgarian who posted alot on this blog last year in Nov.&Dec.

      • W7ENK says:

        No, not Kyle. This person (Ziggy/Nate’s Mom/Karen/fake Kyle/fake Hank/et. al.) definitely has her own special brand of crazy though. She’s mostly a disrupter, gets her kicks through malicious trolling.

        Some things never change. I fully expect her to remap a new IP and pop back up with another alias here soon. Mark can only do so much, he’s a busy guy. I’m all for a second impartial moderator, but this blog being tied to Fox 12 makes that difficult, I’d imagine.

  5. Ken in Wood Village says:

    There are actually a lot of different marine warnings. I looked at the satellite picture, there is a line of clouds moving NE but the line is moving East. It could be an interesting night 🤔

  6. Ken in Wood Village says:

    I saw this on my radar and thought I would post it.

    Special Marine Warning
    National Weather Service Portland OR
    710 PM PDT Sun Oct 24 2021

    The National Weather Service in Portland has issued a

    Special Marine Warning for…
    Waters from Cape Shoalwater WA to Cascade Head OR from 10 to 60 nm…
    Until 745 PM PDT..
    At 709 PM PDT, a severe thunderstorm capable of producing waterspouts was located 21 nm south of Columbia River Buoy 29, moving north at 50 knots.

    HAZARD…Waterspouts, wind gusts in excess of 50 knots, and small hail.

    SOURCE…Radar indicated.

    IMPACT…Waterspouts can easily overturn boats and create locally hazardous seas. Boats could suffer significant structural damage in high winds. Small craft could capsize in suddenly higher waves.
    The severe thunderstorm will remain over mainly open waters.


    Move to safe harbor until hazardous weather passes.

    Thunderstorms can produce sudden waterspouts. Waterspouts can easily
    overturn boats and create locally hazardous seas. Seek safe harbor

  7. Ken in Wood Village says:

    I’m back home. I drove I-5 South from Longview to my home. There was a really bad accident just before Woodland, WA. Traffic was back-up for at least a mile. The after the accident, the right lane was blocked because a tree branch fell onto the bridge.

    The wind was really gusty all the way home and still is. What I’ve seen in the past with windstorms is when the clouds start to clear, the wind starts to pick up. Not saying it will happen this time but it’s a possibility. I think this was a decent storm. Winds were good at the beach and seeing multiple severe thunderstorm warning in the month of October I think is amazing.

  8. Mountain Man says:

    Quite a thunderstorm here. Recoded a 62 mph gusts and some hail and several fir branches flying through the air landing 200 feet from the trees and pelting my roof. Picked up a half inch in 15 minutes too, bringing October to 8.5 inches on the month, my average with a week to go.

    • PhilGil says:

      Pretty intense (but short-lived) here in St. Helens. Strong winds, near continuous thunder, torrential rain. Lasted, maybe, 15 minutes from beginning to end.

  9. Anonymous says:

    Lol what pathetic storm. Nearly a dud. Got 15 minutes of heavy rain and wind gusts now it’s calm and sunny. I’m calling this a complete bust.

  10. Anonymous says:

    The Dome is in the warning zone!

  11. Anonymous says:

    Was up at bald peak, some decent wind but nothing crazy.

    In Tualatin it’s dry and a mild breeze. I’m going to laugh if this storm is a dud given how much hype there’s been

    • Roland Derksen says:

      It’s a bit too early to say that yet- but so far, where i am (in BC) it’s been somewhat similar; a few showers this morning, and breezy, but not gale force. I’ve even seen a few breaks in the clouds. However, the barometric pressure continues to drop, so I’m going to wait.

    • Opie says:

      Looks like the center of circulation has just parked itself off our coast.

  12. Ken in Wood Village says:

    I decided to drive to the Coast. It’s a once in a lifetime to experience a bomb cyclone weather conditions. I’m in Cannon Beach area. The winds are picking up really good. The surf is a surfer’s dream…lol. I went onto the beach but forgot when the wind blows, the sand gets picked up and it feels like your being sandblasted…lol. It’s not raining at the moment but it looks like that will change soon…lol. I’ll post a little later to tell you about my experience…lol.

  13. Anonymous says:

    When is this thing supposed to hit the valley? I was expecting an active morning but it’s very calm out right now.

  14. Hank says:

    Winds have finally started to pick up in Salem!

  15. Ken in Wood Village says:

    Crown Point just had a Wind Gusts at 55 mph 🌬🤗

  16. tim says:

    Pressure is dropping rapidly.

    • Ken in Wood Village says:

      I’ve seen the East winds ramp up really quickly at my place. They were dead calm one minute then up to about 15 mph (or more). This is going to be fun…lol.

    • tim says:

      This is one of the most active falls we ever experienced in our life time let’s hope it continues into the winter before it burns out.

    • yigablademaster says:

      Must be too many Yiga’s around.

  17. tim says:

    Cpc is trending warmer and dryer long rang, which is fine by me lots of leaf raking in the next couple of weeks, those big maples are sure a mess.

  18. …meanwhile, forecast winds here in the Grande Ronde Valley are gusts to 60-70 with sundays fun….

    • Jake says:

      An impressive storm it is bombing past the Columbus Day Storm then weakens to what we see any day of November as it pushes 30ft+ waves. By all accounts a windstorm if you have to travel in the PNW. There’s a reason our ancestors settled in valleys since history was recorded

      I think as climate change moves along we’ll see more of these bombing lows.

  19. Karen says:

    Hank, do you sell propane and propane accessories? Everyone please make a burner account so everyone feels safe 😂😂

  20. Hank says:

    From all this impersonation stuff, I suggest everyone to make a WordPress account (I’m going to later!) No clue who’s doing it, but if you make a Account, we can see If its you or a Impersonation.

  21. Mountain Man says:

    What’s all this impersonation crap about? No one better do that to me! Still waiting because anything that might be a windstorm is always wrong in the models until under 24 hours.

  22. Ken in Wood Village says:

    I was looking at the 18Z GFS and saw something interesting (again!!). I really don’t think it will happen just because it’s at the very end of the run (which is Nov. 8th). If your not able to look at it, it has a big Low coming out of Alaska which is bring a whole lot of cold air. I did a cross section of the air in Alaska, most of the temps are in the teens. I just thought I would point it out. Again, I really don’t think this will happen, just because it’s in la la land.

    But it is interesting 🙂

    • K700 says:

      If this does actually happen, I think that would make you either 3/3 or 4/4 of spotting weather events first that come to fruition.

      • Ken in Wood Village says:

        LOL, thanks…hehe. I’m going to put it on my calendar so if it happens, then I say I was right…lmao 😉

    • Anonymous says:

      I love la la land. Never stop!

  23. Karen says:

    Well, if you like wind it looks like this event is a dud. Well at least Longview south, it’s early in the season so maybe we get another chance.

  24. Billy says:

    Hey weather enthusiasts, I’m looking for advice:

    Regarding this off coast storm and associated rain and wind, how are conditions going to be on Sunday morning and afternoon along I5 between Portland and Seattle? Between Mark’s post and Cliff Mass recent update, it’s still not clear to me how much wind and rain we can expect inland. Is travel on I5 going to be safe, or not at all recommended? Is the wind going to throw the car around and coupled with rain make visibility terrible, or is this just going to be typical winter conditions? Should I postpone Sunday travel on I5 or just take it slow and it will be fine?

    • Ken in Wood Village says:

      It really depends on the time you are leaving? If you are leaving at 6am, you should be fine going all the way up to Seattle (I highly recommend leaving close to 6am). If you leave say 10am, the weather conditions will be changing a lot. The big factor will be the rain. You’ll have some windy conditions going up there even if you leave at 6am. When you throw in the rain, there is a bigger chance you will have driving issues. I have drove up to Seattle with both those conditions before and it was white knuckle driving all the way. I don’t think you really want to go through that like I did.

      I hope that helped a little. It’s really up to you on when you want to leave. One advantage with leaving so early is less cars on the road. That will help with driving a little faster up to Seattle. 🙂

    • Anonymous says:

      we still aren’t about the wind speeds since wind is pretty unpredictable, but Ken’s suggestion

  25. Anonymous says:

    Kyle, yiga, karen, nate’s mom, John, the impersonations, and I bet any other new name suddenly coming out of nowhere are all the same person it seems.

    Mark needs to make somebody here (someone impartial) a moderator of this blog so we can get this type of stuff under control.

  26. Ken in Wood Village says:

    I’m wondering if someone has time to track the storms location and compare it to the models to see if the low is actually on track or if it’s not. This could give us a better idea if the low is moving closer to Oregon and Washington. Thanks 😊

    • Karen says:

      It’s a wrap Jen, maybe next storm will bring some excitement. Thunderstorms possible at the coast tomorrow at least.

  27. Ken in Wood Village says:

    I just looked at the 06Z GFS and all I could do was laugh 🤣🤣 I would disregard the run. The main reason is because the bomb cyclone moves from one spot to another spot in the next frame and it does it multiple times. Were it moves East then West then East again. If you look at the model run, you’ll see what I’m talking about…lol.

  28. yigablademaster says:

    How can I email Mark to get the other account stopped? I forgot that was still even there! I mostly just lurk now unless something exciting happens.

  29. kyle says:

    Seems like an interesting concept. Better get my volleyball “Wilson” like when Tom Hanks gets stranded on the desert island. You’re gonna be out there for a long time on those open waters!

    • yigablademaster says:

      Actually don’t get it. The third review down says it’s just the 2nd version of an earlier game screwing customers over with boats that should have been a DLC collection.

      Esail the competitor you can at least change time of day and weather settings so I’ll look into that.

      • Hank says:

        Kyle your talking to yourself, GET BACK ON YOUR MEDS IMMEDIATLY, This time something seems seriously wrong, what in the actually heck!

        • yigablademaster says:

          I’m not talking to myself. I’m logged in actually. I am not sure who uses my name anymore to be honest. I forgot I still had it till YOU borught it up!

        • yigablademaster says:

          How can I block the other person using my old account?

  30. Roland Derksen says:

    The lowest barometric pressure i ever recorded was 28.60 inches back in January 1980. Oddly, there wasn’t a lot of wind with that event in my area, probably because of the direction track that storm had. So it’ll be intresting to see what happens this Sunday!

    • yigablademaster says:

      If you have a Steam account this sailing sim is suppose to reflect real time weather over the world’s oceans. I wonder if it would do this upcoming cyclone storm where you could watch your Yacht get bounced around like peas in a frying pan?

      This is the one where you can sail when your not playing it due to it’s real time distances! 😲🤣

      “Sail around the world
      In Sailaway, the oceans of the planet are simulated with unparalleled accuracy at actual scale. A trip across the Pacific will take months, just as it would on a real boat. With a persistent online world, adjust your settings and your boat will continue to sail even if you aren’t online.”

  31. tim says:

    King 5 news said it’s very rare to get a big windstorm in a la Nina year, neutral years are the ones we need to worry about so with that said I’m not expecting any damaging big windstorms this fall/winter season for seattle.

  32. Karen says:

    I’m not buying this, Mark already said go away wind😂

  33. Jake says:

    At this point it is better to call that we’re seeing some level of a windstorm than not:

    Most ensembles put us over 40mph with a few past 55mph. That can change quickly either way. What alarms me is Cliff Mass stated clearly of giving an update today. Never seen him do that and despite his fan fanning he’s usually spot on about forecasts for Washington.

    That’s been pushed to tomorrow and rain amounts are climbing across all ensembles. This thing, also appears to be getting even stronger. I’m expecting it to pull back on that but 945 ~ 950mb is deadly any small craft out there would be effectively sunk.

    I disk like windstorms neighbors house and cars were crushed by a noble fir as a child. I recall my Dad going to see it as a child up the street and the wind having to hold onto his hand. Don’t want to see this happen but here we are

    • Jake says:

      I wanted to show this to those that don’t know. This is why these storms get this way. Think of the Western Pacific as a large bay for these storms relative to their size. You can see how BC curves NW toward Alaska hugging and guiding the Jet stream that goes East to West.

      The storms come brawling out of the Bearing Sea as it is, a powerful Jet Stream catches them, and feeds them, the remnants of a tropical storms, or hurricane around Japan, then they have this massive ocean.

      Land geographic topology (the West is very Mountainous relative to the rest of North America) and Jet stream temperature differences do the rest to feed on further as they’re brought ashore.

      This is why they bomb and I have neighbors that moved from the Coast to the Willamette valley because they couldn’t handle the constant storming of Winter storms there and driving rain:

    • tim says:

      High wind watch for wa coast and nw interior nothing for seattle thanks to the Olympics safe and sound in Puget sound.

    • Karen says:

      He is just pumping his podcast and book. It’s clickbait 😂

      • Hank says:

        Karen I Don’t think Cliff is the type of guy to do clickbait, He gets no profits off of his Podcast so I don’t think he would clickbait for that either.

        • Karen says:

          Thanks Hank, I did not know that. Guess I should investigate before whistle blowing 😂

        • yigablademaster says:

          I can see why you would think so. Nintendo news has been 90 percent rumors and 10 percent actual products when you calculate the rumor to fact ratio.

        • yigablademaster says:

          In other words it’s easy to assume Cliff Mass would be the weather version of the Nintendo rumors of this collection or that collection,etc.

        • kyle says:

          Yigablademaster is right. We have to look at the entire ensemble, not just the individual runs. Otherwise you get EURO trash

    • yigablademaster says:

      There was a Yacht Sailing Simulator on Steam once where it was set in the real world which you could actually keep going when your not playing the game bar any outside forces. Yes it had a real time weather simulator where storms especially like what you are describing would be accurately simulated in detail.

      I just don’t remember the name. I THINK this is actually it!

  34. W7ENK says:

    Sunday’s low must be slipping closer to the coast in the models…

    248 PM PDT FRI OCT 22 2021

  35. Weatherdan says:

    If AMS would have held the Winter conference in person as they should have tomorrow, we could have talked about Sundays storm with the pros. As it is we will be able to hear Mark talk about it in person on next years wrap up. Peace.

    • Tanis Leach says:

      There is still the facebook live chat. I will be on it, but I’ve actually not been focusing on the windstorm so far this week.

  36. Zach says:

    Todays 12z GFS has 8″ of rain in Portland over the entire run. Won’t verify but still insane to see.

  37. JohnD says:

    Yes indeed. I’m a hardened “wishcaster” from way back. And burst balloons are not fun. I never pull for big wind events though. I’m an older guy who remembers the Columbus Day storm when I was a boy like it was yesterday. No one can sanely want a repeat of that. So much destruction.
    Count me on board for snowstorms though. Every time. Can’t resist the excitement and transforming enchantment.
    This may be our year! OK here I go with the wishcasting again!

  38. Andrew says:

    Mark seems certain this will not amount to much and while I occasionally question his use of declarative statements (see above: “No, there is not a mega-storm on the way for the region”), I also recognize that he’s trying to reach those who see these sensationalist headlines and overlook the critical details. Plus, he’s virtually always right. They mainly just annoy me when they involve popping the snow balloon. but hey, can’t fault the messenger. 🙂

  39. Matt in Keizer says:

    Thanks for the very informative windstorm post Mark. I and most others on here hope that 943mb monster stays right out there where it is forecasted to stay and gets no closer to us. To put it in perspective central low pressure’s of 920-944mbs are classified as category 4 hurricanes in hurricane territory!! I was a 10 yr old in 1962 and experienced the terrifying -(to a 10 yr old)- wind gusts of the 960mb Columbus Day Storm from 90-100mph in the Willamette Valley and caused major damage to our house and property+no power for 2-3 weeks+impassable rural roads for 1-2 weeks. I for one hope I never have to go through that again.

  40. Nate’s Mom says:

    Thank you for the update, Mark. I was worried we may have been in for a big storm and I would need to have my son Nate come over quickly and get the house and yard ready for the storm. He’s always so busy with his weather group friends, and I hate to bother him. The rain has been nice this evening, and everything has really greened up quick.

    • Hank says:

      A big Storm still can happen Monday, prepare for the worst, And 40 MPH Gusts will be the heaviest wind since the Ice storm, Luckily by now we have cut most of the Damaged/weak branches off of the trees, But there is Definitely Going to be some big branches knocked down. And the thing about windstorm’s, Never be certain about a forecast, because it can’t really be predicted till the night before.

  41. Raw Courage says:

    Honestly it makes sense to have a record bomb storm run up our coast line 50miles off shore. Might as well get it done with we got the record heat wave now let’s do the wind 2 big meteorological records in 1 year. Buckle up!

  42. W7ENK says:

    Still something to keep a close eye on. 50 miles either way could make all the difference, and there’s still 3 days to go…

    • Nate’s Mom says:

      Didn’t you read the blog? Mark says you are wrong, as does my wonderful and knowledgeable son, Nate.

      • Ken in Wood Village says:

        Hi Nate’s Mom 🙂 I have been watching models for years and one thing I have learned is things can change in just a couple of hours. As much as the models try to tell you were the low is going, mother nature has other plans. W7ENK is right, the low can move move closer or further way from what the models show. If it’s closer, then we will see more gusty winds and if it’s further away, then we don’t see any wind.

        The only thing I can say is, just be prepared for the worse. I’m not saying it will happen, I’m just saying if you are prepared, then you won’t have to scramble to get things down at the last minute.

        I’ll look at the models a little later this afternoon. This morning model shows a secondary low forming from the bomb cyclone and coming South of the Portland area. It something to look at because if we have a strong secondary low, that means we will see some strong winds.

        Anyway, I need to get ready for work. Have fun 🙂

        • Hank says:

          I Agree with what your saying Ken (like always), Prepare for the worst. and I think she Seems over confident in Mark’s forecast, Never base your life off of one Forecast, especially with windstorms.

        • yigablademaster says:

          Username checks out! ✔

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