Monday, August 20, 2012

Midsummer Drought?

Your plants know it, and so will your water bills if you have a garden.  Over western Washington most places have not seen rain in roughly four weeks.

For Seattle, the last day of measureable precipitation (at least .01 inch) was July 22.
For Spokane and Wenatchee, its been dry since July 20th.

Are we in a drought now?  Lets check the latest U.S. Drought Monitor Information for Washington State.  No problem.  Most of the region is not in drought, with a little bit of dryness in a small portion of eastern Washington.

So how can this be?  No rain for a month and no drought?  Because this is pretty much normal for around fact, we are one of the driest places in the country from mid-July through mid-August.

And you know the reason:  the general lack of thunderstorms during our summer due to the cold, Pacific Ocean.

We have had roughly 30 days without rain by tomorrow...but that falls WAY short of the record at Sea-Tac:  51 days in 1951.  

How does this year compare to last year at the same time (4 weeks ending 20 August)?  Here is the comparison--but be careful..the scales are different.  The red light red lines show the climatological highs, blue lines climatological lows--which are the same, allowing you to compare. Both years were on average were close to normal if you average the entire period, but this year had WAY more warm days.
The sunny, warm conditions of late have done wonders for my tomatoes--quite a few red, ripe ones already.

So how does it look for the period until Labor Day?   I am afraid the models show a series of troughs, bringing cooler than normal conditions and a chance of a few showers--but drier than normal-- during the next week to 10 days.  Consistent with this is the latest NWS Climate Prediction Center forecast for 8-14 days:

The pattern do not look favorable for convection of the Cascades and eastern Cascade slopes...which is good for the fire situation.

Orcas Island Talk:
I will be giving a talk: Global Warming, Separating Truth from Hype at 5:30 PM on August 29th at the Orcas Center Madrona RoomI will review the basics about global warming, its implications for the Northwest, and some issues regarding media coverage and claims of groups on both sides of the opinion spectrum.

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