Current Wind Patterns from Japan to the United States

My friend, Gary Bender, sent me this.




It is the jet stream pattern for today. It seems to indicate that if radiation were to enter it now, it would arrive in the middle of the United States very quickly.

James Pilant

74 thoughts on “Current Wind Patterns from Japan to the United States

  1. Michele

    How quickly would it take the winds from Japan to reach the U.S in the event the Nuclear reactors blew?

  2. Josh

    How long would it take to travel to Uraga, Japan? Which is located south west but still on the east side of Japan?

    1. I think I was a little too cocky with my last response. There are so many “ifs.” The biggest if is “if there is a major meltdown will the radiation rise to the level of the jet stream?” If is does that, it will arrive in the United States very quickly withing a few day. If it does not rise that high, it becomes a matter of what the weather patterns are.
      James Pilant

    2. Uraga, Japan. That’s really interesting. The winds this time of the year tend to go west. So, that’s sort of good. Unfortunately, “tends” is not the optimum answer. My understanding is that it is a tough winter in Japan, that would suggest a northern wind pattern. According to today’s weather map, the wind is indeed blowing Northwest. However, the wind will reverse tomorrow and the will flow directly Southeast and as it shift it will change direction gradually. So, the wind on Tuesday is not on Uraga’s side. The wind on Wednesday according to the weather map will blow West. So, timing is everything. Go here for wind pattern –

  3. Don Bad Moccasin

    How is Hawaii sitting as far as the winds coming from Japan? And worse case scenario, how many days to get there?



    1. The maps I’ve seen would suggest that the jet stream is running far north of Hawaii. I’ve seen no maps whatever that suggest, that state would be struck by radiation from Japan. Of course, I might have missed a map but that’s what I’ve seen.
      James Pilant
      (the estimate of time for such an event was two days)

  4. Historically the jet stream runs further north during the winter months – the Pacific Northwest, but during the Summer months as far South as Oklahoma.
    James Pilant

  5. Jon

    Is the radiation from the winds going to hit south western part of Pennsylvania and when is it going to arrive?

  6. That’s almost perfectly opposite Japan on the Globe. I don’t think the jet stream runs that far East.
    Based on what I know you are very safe.

  7. JD

    Hey, first off thanks for all the info…any idea about Kyushu and Kagoshima in particular? There have been very strong winds here (like a typhoon coming) since last night…I wonder which direction they are going in and the vulnerability of this area.

    1. Kagoshima is a good distance South of Tokyo and right now the wind there is blowing Southwest. That’s good. But the extended forecast indicates that the wind will start blowing South in the next few days. Sorry, but the distance is a good factor in Kagoshima’s favor. The further down, the greater the radiation dispersal. The wind direction in the hours after a meltdown will be one of the critical factors. Not where Kagoshima is but on site. Kagoshima’s weather becomes interesting once you’ve got stuff in the air.

    1. I went back and looked at my answer and thought to myself, “that was kind of flippant.” Sorry, once you get in from the coast and you’ve got the Rocky Mountains involved, the weather patterns become very difficult to predict. The coast is easy because water is flat and has the same general temperature. The further you go inland the trickier it gets. Go to the dispersion map for Chernobyl and you’ll see that the local weather patterns drove it in many random directions. So, I can’t give you a very good answer.
      James Pilant

  8. eddie

    More importantly, in worst case, what kind of microseverts per hr would worst impacted parts of USA recieve?

  9. That’s a tough one. The thing you would have to know before you could make a really good guess would be how many of the plants melt down and how close together. jp

    1. eddie

      WORST CASE. As in all 3 reactors completely melt down, explosive release, strong jet stream, no rain along the way to USA. I mean just the WORST POSSIBLE. What kind of microseverts/hr? Are we talking like 10? Like 100? Like 10,000? What would worst possible case range be?

  10. I’m guessing. If the winds are at their most direct and the radiation gets into the jet stream and there a simultaneous meltdown in a minimum of three plants, I would GUESS abut 400. From the NRC I get the idea they are expecting around 10. I think it will be worse than that but I’m more worried about month’s long radiation burn from a number of plants. Nobody has ever seen one burn out of containment. So, it’s something of a mystery. jp

      1. becquerel (Bq)
        The SI derived unit of activity, usually meaning radioactivity. One becquerel is the radiation caused by one disintegration per second.
        I’m sorry I meant becquerel. I was using the baseline of 4,000 Becquerel at the United Kingdom after Chernobyl.

        I’ve been responding to a lot of e-mails and I was trying to convey my answer in Becquerels and I didn’t specify that I was not using micro sieverts. I’m sorry.

      2. Eddie, it’s obvious you’ve got some good knowledge, why don’t you keep an on my stuff and keep me straight? I don’t mind and I’m definitely not the repository of all knowledge, so I do have a certain degree of humility. I’d appreciate it.
        James Pilant

  11. ryan

    How will Taiwan? I am living in Taiwan (Changhua) but have family in the Bay Area. What location would be safer.

    1. eddie

      TW is westerly from Japan, seems rather unlikely anything would go that way, but not totally impossible. USA is 100% certain to be in the “path”, but distance makes dosing likely to be low…is my 2 cents worth

      1. Very good, Eddie. I just answered by amount of radiation. I was uncomfortable with making a wind prediction (I was just looking at the monsoon patterns on the web).
        Please come in anytime and give some advice. I’m cool with that. Maybe between us we can figure some stuff out.

    2. That sounds like an essay question in a meteorology class!
      Well, this is what anybody who does a little research will tell you and that is – that Taiwan is not that far from Japan and is much more likely to catch more fallout from a meltdown than any place in California.
      James Pilant

      1. eddie

        Thanks JP. Well Im an airline pilot, so winds aloft and geography are some areas I know about. A little about “normal” levels of radiation. Hence my thoughts are TW has little risk. Though it is relativly close to Japan, the wind simply doesnt blow that way (normally…hey, nothing is impossible).

        If your measurments of 10-400 BQ in USA compared to 4000 in England after Chernobyl is correct, that seems very minimal. Wouldnt recomend sleeping on the beach and doing deep breathing excercises either. But normal outdoor required activity (get to car, go to work, ect ect) shouldnt be impactfull. That being worst case. Which is far from whats going to happen at this point.

        As for the comment about “ongoing” and “waves” of radiation…worst case is a meltdown. Chernobyl was a melt down. It didnt spew “ongoing”. It melts, it leaks, it would be capped…damage done, but not like it will sit smouldering and spewing for years. From continental USA standpoint, the worry should be low. Not zero. But low.

        Excuse any miss spelling, its late here in San Francisco

  12. becquerel (Bq)
    The SI derived unit of activity, usually meaning radioactivity. One becquerel is the radiation caused by one disintegration per second.
    I’m sorry I meant becquerel. I was using the baseline of 4,000 Becquerel at the United Kingdom after Chernobyl.

      1. I agree. I think it will be unremarkable. But I also think and I believe you understand from reading my stuff that we are in totally uncharted territory. I thought about it as hard as I could based on my historical knowledge and came with a very low number but if you change just a few factors, the possibilities can get scary. Hey, you gave me an idea, I’m going to go check something. jp

  13. Diane

    Worst case would not be 3 reactors. Even though the last 3 are shut down, if no one tends to them and the other reactors meltdown and fuel rod fires occur, then the other reactors will slowly heat up and send a 2nd wave through. More importantly, the initial release will be on-going and will not stop; it will just slowly lessen over time (i.e. months or years). I don’t think we can all stay indoors that long…

    1. My wife is predicting six. I’m predicting four nuclear plants will melt down. You’re right, three is too few. I caught an internet rumor this afternoon that there are five more reactors in Japan that are having difficulty. I’m getting run kind of ragged here, so I haven’t had a chance to look.

      1. Diane

        Well now, here is the real problem…

        The Japanese govt is asking US military and experts now, too late, for advice. No one, at this point, is going to be able to stop this, except the military. They have the only item that could, at least, end the atmospheric release, but it would be last resort.

        They could bomb the reactors. It would mean the entire county of Japan would be contaminated and neighboring countries would not be happy, either.

        Also, regardless, if everyone leaves Japan, the rest of their other nuke plants will also run amok since even while shutdown, they still require maintenance too.

  14. robertak

    Thank you for all this information. I’m learning all that I can so I’m not stuck in fear & misinformation, so can someone tell me: I live in Southern California, in a beach city. If things did blow this way, how much disintegrates on the way here? Is rain & cloud a factor (its supposed to very cloudy/overcast the rest of this week then rain through this weekend. Or does it matter if its this close?). Also what’s the warning time for radiation to travel here — hours? a day? a few days? What’s best and worst case examples? I know its all a guess, but just trying to sort out options. Thanks!

  15. Southern California is a great place to be right now. I was looking at the National Post (Canada) and they feel the jet stream is a dagger aimed at them. So, you’re really far South of the current path. A lot will disperse on the way there. Absolutely, clouds and rains do have an effect. Rain takes the particles right out of the air. As for warning time I have “heard” everything from 14 hours to five days. The funny thing is “I’m beginning to suspect that different kinds of particulate matter may have different flight times.” I was looking at some maps of the dispersions from Chernobyl and they showed different kinds of radiation so I’m going to be thinking some more about that. I think you’re going to be okay. If radioactive material falls there, the basic precautions, stay indoors, take your potassium iodide and go out once the particles disperse, I think you’ll be fine. But of course, that’s my untrained opinion. jp

    1. eddie


      Just one thing: potassium iodide is for one type of radiation, for one small body part (thyroid), and most effective on children. Hence, essentially worthless as radiation comes in different types, effecting the whole body, and all ages. Wouldnt bother with it personally. Limiting outdoor activity would be far more effective.

      1. Laura

        I would be interested to know more about the different types of rays and how far they can travel. It seems from all the reading I have done there are 2 things to watch out for: 1. Penetrative things like gamma and neutron rays. 2. Alpha and beta particles. The particles generally do not penetrate much on their own (alpha particles stopped by sheet of paper, beta particles stopped by plexiglass) but are super dangerous if they manage to enter the body either through ingestion (food) inhalation (breathing) or direct absorption (via cut on the skin). The gamma rays and neutron rays are the things that are stopped by lead & super thick concrete but – how far can they travel? I can wrap my mind around something like a radioisotope traveling via the air jet stream because it is a particle, but how far can a gamma ray travel – it is in wave form?! Thanks for any insight you can offer.

    2. robertak

      Thank you! Great info. I’m actually from Canada originally and have family there on the West Coast still. I was thinking of flying up there should things fall out down here… but perhaps I am safer here then! Last question: if it does come this way, how long are you supposed to stay indoors? Days? Weeks? Months? And I’m confused how staying indoors helps. If radiation can penetrate any clothes or protection (from what I’ve read) how does staying indoors – which still has ventilation and openings to the outdoors – really help?

      1. eddie

        radioactive rays wil penetrate easily through most things. But they have short range. Rays come off particles. Keep the particles off your body, you will be much reduced exposure. Being inside, even with vetilation, will much reduce particles (compared to being outside). Sealing house off with plastic (remember those recommendations to stock up on plastic and duct tape after 9/11?) will further limit paticles

        How long stay indoors…or more accurately limiting outdoors…depends on how long particles are blowing by. Listen to govt./civil defense warnings, they have the monitoring equipment

    3. Tommy

      Take into account that the Half-life of IODINE 131 is 8.04 days and the Half-life of XENON 133 is 5.43 days. By the time these radioactive ‘boogie men’ reach the USA they are almost inert.

  16. eddie

    Nuke/bomb the nuke? Whatwhat? Thats like saying lets get the flu over with by having someone with the flu sneeze on your face. Fully opening the reactor and expelling its contents to the stratosphere isnt a fix.

    1. Diane


      No one else can do anything else. No one is yet understanding the full dimensions of the release likely to occur. It will not just blow over and go away. Once it melts you can’t get close enough to smother it. The release will continue till all radiation decays down to safe level – will take years (decades?). Meantime it continues to go airborne. How long could we hole up in our houses?

      Best they could do now is remove the rods from all the other plants and dump them in a deep ocean trench while they have time.

      1. eddie

        Chernobly was complete 100% exposure…and they managed to get that sealed. Nothing is continuing to go airborn from there. So yes, they can be capped and sealed…once the damage is done.

        Bombing them just spreads contamination father wider and quicker. Keeping SOME of it on site is better the spreading ALL of it through a bomb. Getting it spread quicker is no fix.

        Removing the rods…wich if melting can be upwards of 2000 degrees…is impossible, until after its somewhat cooled down. Either after melting…or hopefully get the damn things under control. Lets remember, the containment vessels are still intact, so anything that opens the containment vessel and/or spreads about the contents is opposite of needs to be done. Even if it melts down, as chernobyl, it can be (at some point) capped and contained. Any containment is better the spreading contaimination

      2. Diane

        600,000 russians were used to build the coffin for Chernobly; and over months – not likely to happen here. Emergency help and military from other countries are very unlikely to be volunteered for that job. Massive amounts of sand, etc., was used. Who is going to supply that? Also, Chernobly was in a closed bottom which was not breached; here the melt will interact with land and water. This one plant will be worse than Chernobly given the number of reactors & pools. What about the other plants beginning to have problems.

        I was not suggesting removing the rods from these plants. I was talking about the other 50 plus reactors Japan has. Once you start a reactor, it doesn’t shut down till you decommission it and remove the rods from it. Otherwise, even when it is “shut down”, it is merely on pause.

      3. Laura

        Diane, your thinking just seems faulty to me. “Dump in a deep ocean trench” hmmm lets see – that puts radioactive waste closer to destabilization through intense heat coming out of the earth AND/OR through another seismic event that might create another earthquake. There is no away. WE all live downstream.

  17. I don’t think there is any way to predict what would happen if explosives were used in a reactor site although probably almost all of the results would be counterproductive.

    1. Diane

      Yes there is. It would pulverize and put it in the atmosphere all at once and then, after a relatively much shorter period of time, it would start to reduce much more sharply, instead of a massive, continuous, very, very, very, slow decline in amount of release from the reactors. I am saying that some people might even get the chance to outlive the cloud.

      Look at what happened with Hiroshima and Nagaski.

      1. Geekoid

        Using an explosive would put more debris higher up in the air and the contamination will be higher in volume and larger in area.

        A meltdown in these plants can be contained, but even if it couldn’t it would be better to evacuate the whole of Japan then to bomb the plants.

        Radiation doesn’t travel*, radioactive material does.

        *for sufficiently large definition of travel.

  18. eddie

    yes can remove rods from other reactors, sure

    But for the ones in danger of melt down, even a pile of molten uranium sitting there in the open is better then spreading the full amount in upper atmosphere…many thousands of times worse.

    600,000 Russians were used because labor and life there is cheap. Japan has things like….plows, trucks, ect ect, whatever they need to do the work to cover it up. Japan managed to rebuild nuked citied. Im sure they would cover the reactors if get to that pint. You expect them to leave them sitting in the open and abandon half their contry??

    Where will they get the sand?? Is that a real question? The entire coastline nearby is sand, the whole world is made of sand, sand is not a scarce comodotiy.

    The bottom of the reactor vessel in Japan is far stronger then the open pit chernobyl was built on. Till it actually burns through it, it is just guessing that it WILL do so. For now, all of the containment vessels are fully intact. The radiation is coming from an open spent rod pool…which is NOT a melt down and NOT the kind of exposure anyone is talking about from a melt down. But nuking the place would result in exposure far far far above and beyong any possible scenario for even multiple meltdowns.

  19. SFmomwith2kids

    After the leak happened a week ago, is it still safe at San Francisco now? It is raining these days. Do the raindrops contain radiation already?

    1. eddie

      SF has zero extra radiation. It would take full melt down for anything to reach SF. I also live in SF, I have no worry about going outside

  20. adam selon

    What are levels going to be like in Olympia Washington and when are they going to be worst? Is there a website that has radiation levels for the Northwest? It seems as if the jet streams go right up the coast of oregon and washington and it rains here constantly. I work with the homeless community and we would like to impart some helpful tips for avoiding exposure. So any specific info or generals for this area would be helpful.

  21. dave river

    when they talk about micro sieverts, is that the exposure by the hour ? they talk about 1000 siverts being acceptable for a whole year so the prospect of hundreds per hour sounds very disturbing. how does los angeles look to be affected,the jet stream seems to curve to the north west of the usa.
    but the jet stream is high level correct ? i assume these arent the only wind patterns on the pacific. thank you.

  22. Val Gand

    This may be helpful in the days to come since we can not really trust our government as they tend to lie softly in attempt to avoid public panic.
    There is a NON-Government group of people in the US that have home geiger counters, much like the ham radio bunch.
    If you go to this URL you can see and learn what may be coming for the US in the winds.

    There is also a nuke worker forum online that are very truthful with their posts at:

    And lastly you can keep an eye on the next few days winds coming from Japan to the US in an animated graphic at:

    Goodluck everyone!
    Cesium gets into the food chain so hopefully the California happy cows won;t eat the grass, so much for the wine industry too as I love California wines. :[

    1. eddie

      Got any sites that show measurments worldwide…oh I dont know, like around northern japan and Chernobyl?

      1. I’ve done some internet searching and I haven’t come up with any publicly reporting stations. I can find locations of some government and international stations but no measurements. I’m sorry I can’ find out more for you. James Pilant

  23. DMK

    Thank you so much for all the info…I live in Southern California and have two very young children so am concerned!! One more question: If the wind does carry radiation this direction ~ how long would it take to pass over us? Also, once it passes are we in the clear in terms of exposure? Thanks so much again.

  24. Jeff Douglass

    Thanks so much for the information. It helped me to feel a little in control, just to know someone is keeping up with this thing.

  25. Pamela

    I live in Southern California — Marina Del Rey to be exact. We also have a place in the San Bernadino Mountains below Arrowhead which is about 1.45 hours away from the house near the beach. From a radiation stand point is it safer to be in the mountains or at the beach when the plumes blow our way?

    1. Great question! And I don’t have a great answer. It seems to me that the weather volatility in the mountains would make it difficult for radioactivity to remain undispersed. Mountains tend to favor high winds and rapid wind changes (updrafts and downdrafts as well 2d directions). The weather at the beach in Southern California tend to be quite standard. jp

  26. Jocelyn

    I have a concern; my daughter and my husband are leaving the 26th of March on an exchange trip to China.Specifically Xian, Beijeng, Hong Kong, Guangzhou and Zhouzhang. I have been keeping current with wind patterns and potential radiation spread. I am just a mom; how safe can they be? I know there is no guarantee but your thoughts are appreciated.

  27. The wind especially the upper atmosphere winds tend to flow East. I’ve been looking at fallout patterns from U.S. tests in the fifties. They only went Northwest once on any of the maps I saw. All the locales you have listed vary from Southwest to South Southwest. The winter weather in Japan has resulted in a lot of wind changes but to travel that far would require consistent winds for several days. That is not likely. If my son and my wife were to have an opportunity to go, I would explain basic radiation facts to them and then send them.
    James Pilant

  28. C. CrescentWolf

    Anybody here now think nuclear energy is worth it? I sure don’t.

    Won’t it be lovely when a big earthquake hits California (they have reactors ON the fault) and one blows here in the states?

    Time to shut ’em down!

    1. eddie

      And are you ready to cut back your energy consumption? And when your chopping up your furniture to throw in fireplace for heat and eating your family pet for food, and billions of people are starving I suppose you will be sreaming bloody murder that your government did nothing to replace fossil fuel while there was a chance? If Saudi Arabia should shut down exports (like if they have uprising such as Libya, Egypt, Tunisia, Bahrain) you will see exactly that scenario. But by all means, keep driving as much as you like, turning up your heat to 75, and using energy like there is no end.

      1. Laura

        Eddie, while some of your points about energy consumption are valid, the assumption that nuclear is the only valid energy alternative seems faulty to me.

        Several interesting reports on this website that you might want to check out.
        “August 21, 2010: Nuclear Power’s Competitive Landscape. PDF New presentation from Amory Lovins of Rocky Mountain Institute showing why nuclear power cannot compete with micropower—efficiency, renewables, etc. Devastating analysis for new nukes.

        July 8, 2010. Solar power is now cheaper than nuclear power in North Carolina, and will gain even more cost advantage in coming years. New report for NC WARN by former Duke University Chancellor. PDF

        May 11, 2010. Major new report from Synapse Energy Economics for the Civil Society Institute: Beyond Business as Usual: Investigating a Future without Coal and Nuclear Power in the U.S. Press release. PDF Full report PDF.

        March 2009: Can we go carbon-free, nuclear-free! A resounding Yes! says a new report prepared for Greenpeace by German Aerospace Center (German counterpart to NASA). Energy [r]evolution: A sustainable USA concludes that a virtually carbon-free, nuclear-free energy future for the U.S. is possible by mid-century, at an acceptable economic cost. Download here. PDF

        May 27, 2008: An important new article from Rocky Mountain Institute: The Nuclear Illusion PDF by Amory Lovins and Imran Sheikh. “Nuclear power is continuing its decades-long collapse in the global marketplace because it’s grossly uncompetitive, unneeded, and obsolete—so hopelessly uneconomic that one needn’t debate whether it’s clean and safe; it weakens electric reliability and national security; and it worsens climate change compared with devoting the same money and time to more effective options.” Read this to understand the reality of energy in the 21st century, and make sure your elected representatives at every level of government read it too.”

        PS. By the way, I just want to say thank you for contributing your knowledge regarding wind patterns etc. I appreciate it.

  29. Christine

    I am from Germany and wanted to take a trip with my to little kids to Hawaii this month. How is the radiation there and is it safe for my children to go into the water ?

  30. The information before me suggests it is perfectly safe. There are some commentators who belief that wind patterns are carrying some radiation to the United States. However they are describing the Pacific Northwest. Hawaii is very, very far South of those states. My personal opinion and I am certainly not a scientist but a lawyer and a commentator is that I would have no qualms about taking my family there.
    You have my best wishes.
    James Pilant

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