Watch the ‘super-soaker’ pineapple express storm hitting California

NASA eyes Pineapple Express soaking California – video follows


NASA has estimated rainfall from the Pineapple Express over the coastal regions southwestern Oregon and northern California from the series of storms in February, 2017.

 IMERG rainfall estimates for the period from Feb. 15 at 00:30 UTC (Feb. 14 at 7:30 p.m. EST) to Feb. 23 at 23:00 UTC (6 p.m. EST). The initial surge was responsible for bringing part of the rainfall (up to about 2 to 3 inches) was seen over the coastal regions southwestern Oregon and northern California. CREDIT NASA/JAXA, Hal Pierce

IMERG rainfall estimates for the period from Feb. 15 at 00:30 UTC (Feb. 14 at 7:30 p.m. EST) to Feb. 23 at 23:00 UTC (6 p.m. EST). The initial surge was responsible for bringing part of the rainfall (up to about 2 to 3 inches) was seen over the coastal regions southwestern Oregon and northern California.

The West Coast is once again feeling the effects of the “Pineapple Express.” Back in early January one of these “atmospheric river” events, which taps into tropical moisture from as far away as the Hawaiian Islands, brought heavy rains from Washington state and Oregon all the way down to southern California. This second time around, many of those same areas were hit again. The current rains are a result of three separate surges of moisture impacting the West Coast. The first such surge in this current event began impacting the Pacific coastal regions of Washington, Oregon, and northern California on February 15.

The Integrated Multi-satellitE Retrievals for GPM (the Global Precipitation Measurement mission) or IMERG is used to estimate precipitation from a combination of passive microwave sensors, including GPM’s microwave imager (GMI) and geostationary satellite infrared data. GPM is a joint mission between NASA and the Japanese space agency JAXA.

At NASA’s Goddard Space Flight Center in Greenbelt, Maryland data from IMERG was used to create images and animations showing the rainfall. One image showed accumulated IMERG rainfall estimates for the period from Feb. 15 at 00:30 UTC (Feb. 14 at 7:30 p.m. EST) to Feb. 23 at 23:00 UTC (6 p.m. EST). The initial surge was responsible for bringing part of the rainfall (up to about 2 to 3 inches) was seen over the coastal regions southwestern Oregon and northern California.

The next surge of moisture began to arrive on Feb. 17 and brought moderate to somewhat heavy rain initially to parts of the northern Sacramento Valley and along and inward from the coast from about Big Sur southward to Los Angeles. It delivered even heavier rainfall farther southward along the coast into Baja California where up to 7 to 10 inches is estimated to have fallen (shown in purple and pink). This surge was also responsible for bringing moderate to heavy rains (about 2 to 4 inches, shown in yellow and red) to parts of Arizona.

The analysis showed rain rates derived from both the GMI microwave imager and dual-frequency precipitation radar or DPR, that were overlaid on enhanced visible and infrared data from NOAA’s GOES-West satellite to create a full picture. The image was taken on Feb. 17 at 21:03 UTC (4:03 p.m. EST) and showed a long plume of mostly moderate rain (green areas) streaming northward into the coast around Los Angeles in association with this second surge. GPM’s DPR can also provide details on storm structure. This third image shows precipitation top heights corresponding to the previous image. The storms tops are all relatively shallow (generally below 7 km, shown in blue) with the highest only reaching just over 8 km (shown in lighter blue). The bulk of the rain accumulation is due to the steady, non-stop nature of this relatively shallow, moderate rain and the effects of orographic enhancement and not to intense thunderstorm activity.

The final and most recent surge of moisture began making its way ashore in and around central California closer to the San Francisco Bay area on Feb. 20, bringing rain to the Bay Area as well as farther north along the coast and enhancing the rainfall totals over the Sacramento Valley and coastal northern California and southwest Oregon.


Another storm system is forecast to impact the San Francisco region over the weekend. To get updated forecasts from the National Weather Service, visit:

For a global animated view of the IMERG precipitation and GEOS water vapor during the first three weeks of February 2017, visit:


92 thoughts on “Watch the ‘super-soaker’ pineapple express storm hitting California

  1. It is clear how the USA mountain ranges force the water to fall out of the systems. Like a sponge!.

    It is this long slow mo collision. Great animation.

    • I don’t know about the sponge analogy (how does it get squeezed?), but you are certainly right about the video clearly showing how the mountains suck it out of the air as they force the air masses to rise over them. Back in the day when they actually taught climate science, I did a research project for a class in climatology tracking the change in forest type across the crest of the Cascade Mountains in Oregon. Very obvious changes within a mile or so of either side of the crest. Once the air summits the crest and begins to fall, you get the “rain shadow” on the lee side. Basic stuff, but now we have technology to illustrate it so dramatically.

      Quick edit: The radar is picking up falling rain. Once it is over the crest, there is still moisture in the air, but not as much (obviously) and it isn’t falling because the air mass is now descending. Watch how the squall line near the end that passes over Baja soon disappears, but later reappears right at the end in the mid-South. I’m guessing there it is hitting a front clashing with maritime air out of the gulf, not mountains sucking it out like over the Sierra Nevada range.

      • Condenses out, ‘cuz elevation lowers temperature, and the prevailing westerlies force the humid air up the mountains. It’s simple(heh) physics, not fake.

      • My experience wasn’t so scientific. I was east bound I-80 from the Tahoe area to Reno. I got a call from my wife. When I looked up the trees (Pine I assume) were mostly gone near the state line. I was thinking at the time that, wow, California keeps the good part and Nevada gets the rest.

      • I live in Reno. A good portion of the missing trees along I-80 have been burned off in recent summers, courtesy of drivers flipping cigarette butts out the window. One fire was started by a locomotive with a “hot” wheel bearing.

    • Two more thoughts..

      I see a Von Karman vortex street developed west to east.

      Also, the rain is what is on the radar and not just heavy humidity? OK. Then the reds disappearing must represent the precipitation cessation due to adiabatic cooling and deluges as system crosses the mountain ranges?

      • The sign of alternating vortices in a “Vortex Street” flip. When observing weather patterns on earth, low pressure systems exhibit the characteristic vortex pattern, whereas the high pressure systems do not. This is due to the precipitation that strengthens lows. (For example, a falling barometer is considered an indication of coming rain, whereas a rising barometer foretells clear skies.) On our rotating earth, lows are always counter clockwise in the NH, and so the Vortex Street analogy doesn’t hold, unless we were to observe them along the equator where SH lows would have the opposite spin. However, the spacing and scale of the low pressure systems in the NE Pacific do appear to have some regularity.

      • I guess the street lights were illuminated on only one side of the street. Thanks for the clarification Mr. Stewart.

    • I noticed that as well. Wow. Talk about a huge storm just stopping in its tracks repeatedly. You know these things because less rain falls the farther inland you go but to see it stop dead like that visually is very cool.

      Mountain range 1, storm 0 :)

  2. A lot of water which can be measured but also a lot of heat released at altitude skipping about half of the heat-blocking and evil ( in some eyes) carbon dioxide.

    • If you were to calculate the amount of heat vented by those systems it would show the hubris of climate ‘scientists’. The energy from nature dwarfs anything that humanity can do.

      The calculations you can use are shown here – remember these weather systems are much larger than hurricanes.

      • But do the models show this latent heat transport? This is graduate study housework..heat transfer with mass transport and phase change enthalpy.

        It is just darn hard to put a thermometer in a mesoscale convective system ;). Can be done with sounding rockets as long as the lightning doesn’t fry them.

      • So hurricanes are 0.25% efficient at turning heat energy into mechanical? Even open steam reciprocating engines are more efficient. But using Carnot Cycle efficiency, this is about par.

      • See

        for average rainfall on earth.
        1 cubic meter of water is 1,000,000 grams
        average annual rainfall is between 0.0829 meters and 0.123 meters, or between 1,000,000 *.0829 and 1,000,000* 0.123 or 82,900 to 123,000 grams
        it takes 2.257 * 10^6* 82,900 to 2.257*10*^6*123,000 or
        1.871*10^10 joules and 2.776^10^10 joules to evaporate the water that falls in rainfall.
        1 watt is 1 joule per second.
        In a year there are 31,557,600 seconds or 3.15576^10^7 seconds
        divide 18.71*10^9 3.15576*10^10 to get a lower bound of 59 watts
        divide 27.76*10^9 by 3.15576*10^7 to get an upper bound of 87.96 watts per square meter removed from the surface to a higher level.

        From Trenberth’s figures,

        we get an average surface flux of 493 watts, but 17 watts is taken up in convection, 80 watts from evaporation of water.
        That 80 watts is within the range of 59 watts t0 87.96 watts. Now you know where Trenberth gets that water vapor latent heat estimate. The earth’s average surface temperature would be about

        288 K * (493/396)*0.25 or about 31 C if not for the latent heat of convection and evaporation.

    • Good point. Tangentially, I’ve often wandered about whether average cloud-base level has changed over time. It seems likely that the UK Met Office might have this coastal/marine data from the shipping forecasts that they have broadcast since 1911. As far as I know, this is not available on a public database and may not have been extracted rom the raw data. It would be a pity if it has been lost.

  3. Its appropriate that something called the “Pineapple Express” should blow away the Gilligan’s Island episode of permanent drought. Question is will the latest fail of a big scary prediction by the elites cause the regular folks to ask hard questions. We can hope.

    • Each week on Gilligan’s Island the castaways would have some new chance or scheme for getting rescued which was inevitably foiled by Gilligan’s stupidity or clumsiness. Their hopes were dashed every time.

      Each failed climate prediction is like an episode of Gilligan’s island where we are the castaways. We get our hopes up that the climate devotees will open their eyes, and each time we’re disappointed. We should know better. It’s not falsifiable for them. No matter what we see in the data, they still have the cabal of “scientists”, politicians and celebrities with their all-subsuming theory that can explain away any new developments in real world weather/climate. The only way a majority of regular folks start to ask hard questions is if they begin to suffer, and suffer severely.

      I live in Ontario where our electricity prices have doubled in 7 years largely due to crony capitalist “renewable” power purchase agreements with the state-owned utility. Businesses are leaving the province and power bills were the #1 issue for Ontario voters in a recent poll, but that hasn’t swayed popular support for the church of climatology. Ontario is a Mecca of progressive smugness.

  4. Squall line on the 17th and 18th went all the way south into southern Mexico. I don’t think I have ever seen that happen before and I have been around a long time.

    • And that happened multiple times over the last 14 weeks. I have daily snapshots from earth.null showing how the AR flow would flow into California, and then drop down south before reestablishing a connection further north once again. It was as if there was someone with a giant hose watering the entire West Coast from north to south. Amazing to watch how it operates.

  5. The Permadrought is worse than we feared. Nature is simply tricking mankind into thinking it’s over. So Cal’s Governor Moonbeam needs to keep the drought watering restrictions, increased water fees, and water controls in place, just to be safe.

    Lesson: the Left once given a power over the people will always fight to hold onto the power and control, even when no longer justified. Another example: Cal’s temporary taxes to address budget gaps a few years ago will eventually be made permanent.

    • Then there was Guv Brown up in Oroville recently to show that he is concerned about the problems the north part of the state has faced. That was followed by the dreaded Kamela Harris yesterday getting in her photo ops as the new senator for the state. What a worthless piece she is. She gave some spiel about how some bureaucrats have appeared to have dropped the ball, but somehow she would address that problem so that it would not happen again.

      • She gave some spiel about how some bureaucrats have appeared to have dropped the ball …

        It’s possible that some bureaucrats dropped the ball. It’s also possible that politicians made it impossible for the bureaucrats to do their job properly. When things went awry, the politicians then threw the defenceless public servants under the bus. That particular scumbag trick is as old as the hills.

        I have always admired the candour of Harry S. Truman whose desk sign said The Buck Stops Here. The responsibility rests with the political masters not with the peons.

      • Not disagreeing completely, but whoever was in charge of dumping water out of the reservoir should have seen what was coming a week or two sooner, as the forecasters predicted the series of wet storms. The man had one overarching job: “Just don’t let that dam overflow.”

      • agree brians356. Current weather forecasting should be more than capable of publishing recommended discharge rates for individual dams based on precipitation forecasts a week or more out.

      • I am reminded they were dumping water, but stopped for a while when the spillway collapsed. However, they probably should not have stopped at all (they were forced to resume and sacrifice the spillway anyway) and if they had started sooner, they wouldn’t have had to discharge so quickly and might have avoided damaging the main spillway (doubtful.) Seems like they were discharging at 100k cu-ft/sec when it collapsed as I recall. I’m just saying the evacuation order could have been avoided if they had acted sooner and not tried to salvage the main spillway once had collapsed.

  6. Interesting analysis with a great animation.
    Last week I stated that “the reformed NASA’s responsibility to collect such (weather related) data at every spatio-temporal stage and wherever possible to postulate physics that define it.
    Of course all data with the associated narrative (methods, instrumentation, tolerances, various compensation factors etc. etc.) should be made available to NOAA or to any institution or individual, to re-analyse, question or use for whatever purpose.”
    Some of the readers disagreed; the above article may persuade one or two doubters to reconsider.

  7. Recent weather in California has very much weakened my assumption that heavy rain patterns in the West are associated with a strong El Nino, as it was in 1996-7. IIRC, the ENSO is approaching neutral.

  8. It’s been great for skiing. Squaw said they’ll be open on July 4’th and Mammoth says they’ll try to stay open all summer long.

    Squaw Valley has received over 560″ of snow at 8200′ which is about 1 month ahead of the 2010/2011 pace which ended at over 800″. Unlike some of the previous pineapple express seasons back in the 90’s, the snow levels have been relatively low and even at lake level (about 6000′) they’re running out of places to put the snow when clearing roads and driveways.

    • I don’t think the 2011 record will be broken. That spring Squaw received a lot of snow in March, April, May, and even 14 inches in June. On 1 March 2011, Squaw’s 8000-ft total was right at the annual average at 454″, so an additional 356″ fell after 1 March!

      They’d need 244 inches from the rest of this winter to reach 810 inches. But the pattern now looks like shifting north (as normal) and March (and beyond?) is looking “normal” in CA.

      • On the following link at the Mammoth Mountain website the have a spot to click for Extended Snow History just below the Daily Message snow report.

        After you click that and scroll down you will see a month-by-month snow total for Mammoth from the 1969-1970 see through the current season.

        I find it interesting that not only does it show the difference of snow depth from year to year but also how it changes so dramatically month-by-month. By just looking at the 100+ inches of snow months you can see when the Pineapple Expresses have hit that part of California.

        I see that the link from brians356 shows the detail from Squaw for the current decade and it would be interesting if other ski resorts have similar totals available.

      • That Mammoth Mountain matrix is quite useful. I recall well the flooding in Reno, and avalanches / mudslides around Tahoe, of ’82/’83, and sure enough, there are 4 months in a row (Dec – Mar) wherein Mammoth received ~100 inches each month.

      • Looking at the link for Mammoth history it shows Jan. 2017 set a record at 245.5″ breaking the record from Jan.1995 of 182″. Feb. 2017 at 160″ is only 8.9″ from breaking the Feb. 1986 of 168.8″ record with additional snow expected before the month ends.

        While backpacking across Duck, Purple and Virginia lakes above Mammoth in Aug. 1976 we received about a half a foot of snow from a summer storm that rolled in from the Pacific. That storm was rain only below 9500 ft. elevation.

      • Yes, the storm track has moved North and it looks like it will be dry for the next week or so, but if history is any guide, it’s going to drop back down. When the storm track gets stuck North of us, that’s when we see the droughts. This tends to happen when there’s not enough energy over the Pacific to push the ridge of high pressure out of the way, which doesn’t seem to have been a problem this year. What’s more impressive than the amount of snow that has fallen is the amount still no the ground, largely because we haven’t had many of those nice sunny days that defines Tahoe skiing. I’m at about 6000′ and the windows are completely blocked by about 10′ of snow. I haven’t seen this much snow at this elevation since I started skiing here around 1980 and others who have been here for much longer than I have say the same thing.

    • Most of the rants heaved up by the drooling crashers of Rep. Tom Cotton’s town hall meeting yesterday were about CAGW, and read from scripts. Some school children were given scripts to recite from.

      A local child psychologist with a radio show here says many of her young patients suffer anxiety over “climate change” which narrative they have been force-fed in school. Our teachers are poisoning the minds of our kids, and creating a generation of zombies.

      • Brian: Agreed. I noticed few days ago, local news gave extended coverage to local street theater stunt “looking for” our local rep. Spokesperson for circus says, “we’re here to talk to our rep., ask questions, let him know he represents us.” Next day, NPR covered a similar Utah event, spokesperson there said they were there to talk to their rep., ask questions, let him know he rep’s us, almost word-for-word repeat. NPR did it better, playing audio of 11 yr old girl asking Rep.Chaifez (sp?)(who wasn’t there), “don’t you believe in science, I do.” Then NPR said “Cong. staff says it was staged, some protesters paid outsiders.” Trying to cover both sides (not!), NPR then found three people who were there, all three lived in district (like a Lewandosky study, NPR didn’t say how many others were polled before narrowing field to 3). So here was my takeaway-local news merely provided coverage, treating street theater like real news. NPR much more sophisticated, pre-emptively attacking those who don’t accept left-wing stunt as the voice of the people. I’m overjoyed to see the right finally pushing back, but this will be a long slog. The progressive press is the opposition party.

      • Teachers have been poisoning the minds of kids since my daughters were in school in the 1970s and ’80s. Back in those days the teaching was that there would be a nuclear war and most life would be destroyed. One of my daughters told me that some of the boys in her high school class said that it didn’t make any difference what they did because everything would go down the tubes anyway.
        Nowadays it’s global warming that will ruin life. IIRC there were several dire scenarios being taught in schools between the supposed menace of nuclear war and that of global warming.

    • “In the future, children just won’t know what droughts are any more.”

      Only if it gets warmer. Warmer temperatures mean more evaporation and more rain which for some reason, consensus climate science seems to have backwards. But then again, they have almost everything else wrong as well.

  9. Something I don’t understand. The previous post was about a new scientific paper changing our understanding of Artic sea ice in the 1970’s. If “the science is settled” can’t we declare victory and stop the spending on research.

    Settled is settled. I have good jobs in manufacturing and warehousing waiting for displaced scientists. Comes with instant global warming of about 120 degrees at the presses. Free Gatorade.

  10. Good article and maps.
    The term “Atmospheric Rivers” is so appropriate.
    “Pineapple Express”, which we also get in Vancouver is not too descriptive of the main event. Which is water!
    The term I’ve been using is “Maui Monsoon”.
    Mo’ better.

  11. Thank you NASA for satellite data…now please STOP trying to forecast the Weather…Please pass the data to National Weather Service… who are the reference for big weather events… NASA, please go back to the business indicated by the acronym of your organization. Thank you.

  12. Let me guess — a new study will show effects of pollution are causing heavy rains which mask the effects of drought caused by climate change?

  13. Computer climate modeling is a tech start up. They spring from the same root. Tech start ups have a high failure rate even after having convinced sophisticated investors to part with millions. Why should NCAR be different.

  14. Is this the cause of the unusually warm weather in the Midwest? My guess would be that the combination of very moist air and high wind speeds have caused the atmospheric river to precipitate huge amounts of water leaving dry air to heat adiabatically on the leeward (eastern side), in effect a Chinook wind, that results in unusually warm weather further east in the path of the river.

    The two effects are directly related.

    This would also tie into the existence of the extremely dry Atacama Desert to leeward of the Andes, despite having huge rain forests on the windward side.

  15. Well California will get a chance to dry out and dig out after this weekend’s little storm. Looks like nothing for at least 10 days maybe longer with some very warm weather on the way.

  16. So it is agreed.
    The “Pineapple Express” does not deliver pineapples.
    The “Maui Monsoon” delivers precipitation.

  17. Well, at least up here in the SF Bay area we aren’t looking to get “slammed”. Calling for a few light showers. Will be lucky to get even 1 inch of rain over two days.

  18. Recent Scientific American and Science articles reviewed the history of these Atmospheric Rivers hitting California,
    Geologic evidence shows massive floods every 100-200 years caused by these “Rivers”.
    The last one, in 1861 (After 43 days straight), turned the central valley into an inland sea 20 miles wide and 300 miles long. (Atmospheric CO2 was 286 ppm; so we can’t blame AGW)
    Being the largest food producing region in the country, this may be our next Black Swan.

  19. Back in 1997, the Snake River valley experienced a similar situation. They couldn’t keep the water back. There were lots of very sensible, very intelligent people who claimed that the management team didn’t do their jobs by preparing. If you look at what the Bureaucrats did though, you find that they have every reservoir empty as far as possible. You could see the original river bed at the bottom of the reservoir all the way to the base of the dam 6 weeks prior to the flood. They kept the gates at flood level until they had to just dump. Nature did not cooperate that year. Things flooded. There was nothing to do but bag up…

  20. Super soaker came and went, and the reservoir got nowhere close to the emergency spillway. Now the outflow is shut off so the channels can be opened enough to restore power generation.

    Fears of doom turned out to be unfounded. Perhaps the operators know what they’re doing?

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