February 18, 2017

Will Seattle Beat the All-Time February Precipitation Record? Almost Certainly Yes

Sunday morning update:  SEA how has 8.01 inches,  1.10 inches below the record Feb total.

People love records.   And precipitation records are falling over the West Coast.

Here is Seattle, the record February precipitation is 9.11 inches, which fell in 1961.

As of midnight, Seattle Tacoma Airport had 7.85 inches so far this month.
Since then, Sea Tac got another .07 inches, so we are now at 7.92 inches or 1.19 inches behind the record.  A plot of actual (red) and average (blue) cumulative precipitation at Seattle shows the story...we are about 6 inches ahead of normal now.

Looking at the forecasts, we have a very good chance exceed this.   For example, here is the precipitation forecasts for Seattle from the European Center ensemble and high-resolution models.  1.3 inches for the ensemble and 1.7 inches for the high resolution forecast.   If true, the record is toast.

Or the UW WRF forecast for the 72 hr starting at 4 AM this morning. The purple color is more than 1.28 inches.... very close.  And there is more rain after that.

So the chances are very good that a new February rainfall record will be set at Seattle Tacoma Airport and a number of other western WA locations.

All this precipitation has caused our soils to become highly saturated, resulting in mudslides and slope failures, such as the one that closed down I-90 near Issaquah and another that closed I-5 near Woodlawn (see below).


Northwest Weather Workshop:  

The Northwest Weather Workshop, the big annual weather gathering in the Northwest, will take place on March 3-4, 2017 in Seattle (NOAA Sand Point Facility).   Everyone is welcome.  For more information and to register, go to https://www.atmos.washington.edu/pnww/


  1. Even more interesting,is will the Puget Sound get another shot of snow and cold weather by month's end,as the medium range models are now starting to indicate!

  2. Cliff -

    As you know, Seattle has been keeping weather records since 1870 (History of Weather Observations, Seattle, Washington 1870-1948 [Conner]. Previous to Seatac (which began in 1945) there were buildings downtown that collected weather information and were considered the official readings for Seattle.

    The “official” February precip record for Seattle, as shown on the rainfall.weatherdb.com website, is 11.19” (1902). But because it was not collected at Seatac, that is now considered inconsistent data, correct?

    But you also have made note, in your 2011 post about the 3rd runway boosting temperatures (and btw, the only meteorologist honest enough to discuss it) that, at Seatac prior to 2002, “there had been major moves/sensor changes in previous years”.

    So if they were moving the equipment at Seatac since 1945 – in a “major” way - what makes any of the Seatac data accurate enough to make comparable record claims? Add to that the technological upgrades that have taken place in that time frame to the collection equipment, and it seems a stretch to be comparing any of this, particularly in the context of scientific method. Which brings it back to: if we are going to compare it, why not use the 11" from 1902, which is technically the "official" record for Seattle?

    So maybe then this is more of a fun comparison, which is fine. But it does seem to me people should be told this information, particularly if it is going to be emblazoned across headlines.

  3. The nearby town related to the second picture is called Woodland, not Woodlawn.

    I need to find myself a decent rain gauge (the last one I bought cracked in its very first freeze), because I'm really curious to start tracking the difference between precipitation at my house versus the nearest NOAA station.

    For the 24 hours ending Thursday morning, for example, NOAA recorded 1.14 inches of rain - relatively heavy, but not unusually so. I woke up Thursday, however, to find our creek running higher than I've ever seen, actually beyond the capacity of the culvert a nearby pond drains through (I checked to make sure it wasn't blocked), so that it was overflowing the small earthen dam that holds the pond back - we had our own miniature Oroville situation brewing.

    24 hours later, with no further rainfall, and it had just gotten back down to the top of the culvert.

    It would have been interesting to be able to see if my local area simply got much more rain than the nearest station, or if the soil finally reached complete saturation so a much larger proportion of the water than usual was running off almost right away, instead of percolating through the soil.

    1. You can get a really great rain gauge at Cocorahs.com. It has a large cylinder that can be mounted on a post or pole that has a second cylinder inside that holds one inch and has marks on the side in.01 increment. There's a funnel that sits on top, directing the rain into the marked cylinder. If it rains more than one inch, the overflow goes into the outer cylinder which holds 10 inches. I've had mine for 3.5 years and has held up under many weather conditions. Extreme heat and cold in the North Cascades foothills. Cocorahs stands for Community Collaborative Rain, Hail and Snow network associated with Colorado State University. Check it out!

    2. Go to www.cocorahs.org to get a really sturdy rain guage that holds up to 11 inches. I've had mine for 3.5 years and it's held up nicely.

  4. Yeah. Looks like a relatively "cool" long wave pattern is settting in to round up the month. We stop thinking of snow this time of year in Eastern Washington let alone maybe chances on both sides of the Mts. Of the already harsh and solid winter we have had, much enjoyed, it wouldn't surprise me to see more. A couple winter records we could achieve is, longest amount of time we have had snow on the ground (dec 5th) & last day to have a high over 50 degrees is December 3rd and it looks to continue indefinitely.

  5. Unless my memory is faulty, was it not just a few weeks ago when some commenters were bemoaning how sparse the rain was in WA, compared to OR and CA? Funny how things can change so suddenly...or were things actually not that dry to begin with?

  6. The skiing is great. And more powder on the way for tomorrow. One man's Weather crisis is another man's joy.

  7. Wonder how a re-emerging El Niño will affect our weather here later in the year. Especially when it comes to precip. 15-16 was our wettest Winter on record and that occured during one of the strongest El Niños on record. Plus we no longer have "the blob" out in the Pacific.

  8. @sunsnow12, I just checked your source for February 1902, and it gives contradictory data. If you add up the daily rainfall numbers for February 1902, the total is 8.1". If you go to a separate area on the site, it shows 11.19" for February 1902. Looks like something's wrong with your source.

    Lower number:


    Higher number:



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