July 21, 2009

Drought and Heat

This morning, Mark Albright of the UW shared these numbers with me:

2009 is the driest 20May-19 Jul period on record using the combined SeaTac/downtown observations:

2009 60 0.24
1925 60 0.42
1938 60 0.57
1922 60 0.61
1945 60 0.67
1911 60 0.72
2003 60 0.77
1965 60 0.79
1926 60 0.83
1927 60 0.87

This is really an extraordinary drought we are in. And the surface "fuels" are tinder-dry in eastern Washington and in the Cascades.

Tonight we will have a minor onshore push of marine air. The pressure difference between Seattle and the coast is now 2.7 mb and southwest winds are pushing through Shelton. It got to 87F today at Sea-Tac--tomorrow should be in the lower 80s.

I took a look at the long-range forecasts and was shocked. The temperature climbs through the weekend...into the lower 90s on Sunday and mid 90s at least on Monday and Tuesday. Too far out to be sure now....but be ready for real heat.


  1. We expect air quality in the cascade foothills to degrade this weekend if the long range solutions pan out. Not too sure at the moment regarding the magnitude of the ridge in current model runs. Will be an interesting event to watch unfold. Our profiler at NOAA should give us a good view of the vertical conditions. Current U of WA WRF time height forecasts look very good! Watch ozone conditions on our website at www.pscleanair.org/airq/aqi.aspx
    Select "airgraphing tool" then select under parameters "ozone west" AQI is determined with an 8 hours average.

  2. Yuck. My garden is looking bad

  3. Hi Cliff,

    I've been curious about this for awhile. With the magnitude of how dry we've been, why would we still only be in "abnormally dry" category in the Drought Monitor? I realize that this morning's hasn't been released yet, but it's hard to imagine it being significantly different. I know it's the dry season here, but even this is much drier than normal (normal for that May 20-July 19 period is 2.61", so we've only had 9% of normal). Why wouldn't we be in a higher category?

    (I did find 0.87" instead of 0.42" for the same period in 1925 - 0.20" from May 20-31, 0.61" for June, including 0.42" total on June 2-3, 1925, and 0.06" from July 1-19, thus I have the 0.57" in 1938 as second driest over that period, but that's beside the point).


  4. We have had a dry period but not in consecutive months(10+). If we had a dry winter or even abnormally dry consecutive years on end then the drought could even be more sever. We keep talking about from May on. What about 1987 or 88. I don't know what the numbers are for those years as in a prolong period of drought. I am not saying its dry out but it could be worse. In fact as far as wildfires we have been unscathed so far. Though the one area national fire managers are worried about is......Eastern Washington....Large fire growth is possible. Just need a spark...


  5. I remember 87, but that started out dry early, as in January, and lasted into fall. It would seem hard to forecast a trend here. 1981 was a very hot summer too, which lasted into fall.

  6. The outer surface of the blazing hot sun has a temperature of 11,000 F. By the time heat from it reaches the Earth, it is still very hot. If that's not real heat, I don't know what is.

  7. lol. Actually I am curious if some of the weather-nerds could answer this one; Why is the spread on temperature forcasts from various sites so big? I have yahoo weather telling me 96 on Monday and accuweather.com with 87 for the same day. It seems to be a pretty wide range...

  8. Michael,

    Sites like Accuweather are probably using computer-generated forecasts. The following link will take you to the National Weather Service website. They're usually pretty good.


  9. Horizon Air flights in and out of the Tri-Cities Airport have resumed.

    Two flights from Seattle to Pasco were canceled Tuesday evening and three Pasco-Seattle flights were canceled early today because of problems with the airport’s automated weather reporting system, said Horizon spokesman Mike Rose.

    Horizon doesn’t fly its planes without getting critical weather data in advance, he said.

    I noticed the PSC Wx observations were missing all day yesterday and part of this morning.

  10. Cliff

    Awhile back you wrote a blog showing how on clear summer nights birds can picked up on the doppler radar when set to sensitive mode. Even to the point where you could see what direction they are flying. The past week or so on most days I have seen what looks like a line of showers in a line going from southwest to northeast but they don't move much at all, rather they look to just "flicker" as they change a bit in intensity. I have read before that sometimes the trees blowing in the wind can look like precip so I am wondering if this is the case recently. Thanks!

  11. Oh, I failed to mention that these radar returns are near Olympia and Shelton, and in a line nearly with the eastern edge of the Olympics.

  12. Yay for onshore flow - it was misting down heavily enough to leave a puddle on my patio this morning in Port Townsend. Welcome relief!

  13. Since the start of May was wet, the three-month average of May through July will be very close to average, but since none of the rain has fallen recently and hot weather is on the way, the fire danger will be higher than normal.

    People in the East think it always rains in Seattle--that's quite a weather myth, isn't it?


  14. Yea, it's one of the biggest myths I've ever heard...

  15. Re Accuweather, I've generally found that they're on the INaccurate side of things, though I've noticed stretches where they seem to be closer than many others.

    I completely agree about the "always rainy" myth about the I-5 corridor in WA and OR. Having said that, people sometimes get caught up in simply "volume" of rain over the course of the year, when a better gauge (no pun intended) is probably how many days a year it rains enough to generally prevent outdoor activities.

  16. I'm enjoying the deeper marine layer today, hopefully delaying a bit the heat wave. Might give me time to figure out how to cool down this terribly insulated, southwest facing, brick MCM house.

  17. Lindsey, it rarely rains enough here to generally prevent outdoor activities, so even with that measure, it would be a rather "dry" place.

  18. Many may agree with you, WIML. Still, the longer stretches of cool, cloudy & damp conditions west of the Cascades -- that tend to dampen spirits -- as compared to many other parts of the country do contribute to the "rainy" perception. This is particularly so the further north one goes in the Pac NW.

  19. So what's with our few days of "June gloom" here in late July? I'm not sorry about it -- in fact, it's a pleasure -- but I'm wondering how long it will last. I guess the 105 for Redmond this weekend that someone has called for is as unlikely as it seemed?

  20. Just to see how the initial forecasts work out, I posted the temperature forecasts (as of Friday morning) for Seattle on my blog: http://cloudyandcool.com/2009/07/24/seattle-forecasts-from-friday-morning/

    I have included 7 Internet weather providers, with forecasts from today through next Wednesday.


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