Hazy and troughy

Lots of haze this morning as I am sure you are aware.   Not good.  The rising sun whitish-yellow color indicated that the particles over all, are quite large for aerosols.  This makes you think of dust.  But, it hasn’t windy around here or really anywhere else much.

So, where is the haze coming from?

Here is a backtrajectory plot ending in Tucson, last evening at 8 PM AST, for two levels, about 5,000 (red) and 9000 feet above sea level (blue), clearly levels that are impacted by this aerosol.  It seems doubtful that any of the aerosol came out of the eastern Pacific, so the 9,000 feet above sea level trajectory can probably be ignored.

The best answer seems to be from smoke and or dust along the Mexican west coast and over the Sea of Cortez. Below is the visible satellite image that shows a heavy concentration of aerosols in the southern Sea of Cortez, near Mazatlán, northward to Guaymas-Hermosillo, MX.  (You’ll have to click a couple of times to see this whitishness over the Sea of Cortez and get the largest image.)

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Cumulus clouds and isolated showers knocking at the door

In that visible satellite image you will see that there are Cumulus and other clouds at the SE AZ border.

The models are now indicating a crease between the upper low pressure area that is forming off San Diego today, and an upper high over northern Mexico that will allow a little rivulet of moisture to flood northward for a day or two.  Two different models now have scattered showers/thunderstorms in SE AZ, mostly tomorrow!  It is likely that bases will be high, and so with that comes strong downdrafts and not a lot of rain.  Still, a quarter of an inch might fall in isolated areas.

Of note, there has not been a day with measurable rain here in Catalina on June 15th or 16th in 35 years of record keeping!

Here’s our trough (green lines) as seen on a 500 millibar map from the U of Washington:

 

The End for now, anyway.



By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.