Monday, February 8, 2016

Mid-summer Air over the Northwest

The air above us is so toasty, that it is warmer than normal even for July!  And associated with this unusual warmth is an amazingly intense inversion--which in turn created some strange optical effects.

First, the high temperatures today.  Lots of locations got to 60F, but some places  in the western foothills of the Cascades and Olympics surged to 70F and more, as warm air aloft subsided and warmed by compression.


Like 80s?  No need to go to Mexico or Hawaii...a drive to the coastal foothills near Tillamook would have done it.

We broke some all time daily records for temperatures at 850hPa (around 5000ft) today. Here is the climatology of 850 hPa temperatures at Quillayute (UIL) on the WA coast for the 0000 UTC (4 PM PST) radiosonde launch time.  The grey dot is today   The top red line is the  DAILY record--we beat it.  The black line is the average.  Today, we were well above the average temperatures for mid-summer.   If there had been summer sun, we would have been in the 80s near sea level.

With warm air aloft, and residual cool air at the surface, there was a very strong inversion (temperature increasing with height) above us....here is the plot of temperature (degrees C) over NE Seattle this morning every hour from 4 AM to 10 AM.  Time are in UTC (the one ending in 18 is 10 AM).  Temperatures increased about 10C (or about 18F) between the surface and 800 m (about 2500ft).  Would have been fun to climb one of the foothills peaks this AM...the contrast would have been amazing.
Strong inversions can have optical effects, distorting visible light so that objects seem to loom in the vertical.    Richard Burte of Snoqualmie sent me this one, from a park at 600 ft there.  If you look closely,  you will see some strange distortions of the Olympics.  The work of the inversion.


Well, if you liked today, wait until tomorrow....the latest UW WRF hi-res model forecast for 2 PM suggests lots of 70s in the foothills.  Much cooler in eastern WA.

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Northwest Weather Workshop

The big local weather workshop is less than a month away (March 4-5, Seattle).  If you are interested in attending, the agenda and registration information can be found here.

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