Sprinkles in area overnight!

Some sprinkles/radar echoes passed overhead early this morning.  Will check, as you will, for drop images in dust on solid outdoor surfaces to possibly report a trace due to drops that reached the ground.  Going out now with flashlight, to heck with that coyote over there.  Result:  looks like there were a few isolated, larger drops that fell last night.  Below, confirmation of echoes overhead from WSI Intellicast’s 24 h radar-derived rain for AZ:

Radar-derived precip ending at 5 AM this morning from WSI Intellicast
Radar-derived precip ending at 5 AM this morning from WSI Intellicast

Nice sunset with late sudden bloom after looking like there might not be any color at all.

6:54 PM. Mammatus shaped virga hangs down from heavy patches of Altostratus providi
6:54 PM. Mammatus -haped virga hangs down from heavy patches of Altostratus providing sunset highlights.  Dimly seen are flakes of Altocumulus clouds, as seen below as well.
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6:18 PM. Doesn’t look like much of a sunset will get through this solid-looking cloud cover of Altostratus, Cirrus, with flakes of Altocumulus below.
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10:13 AM. Bright patch of CIrrus is from an aircraft; the Altocumulus flakes with virga hanging down are natural. Only a greatest of the Cloud Maven Juniors would be able to make such a discernation, if there is such a word.
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10:12 AM. Over this way, a mix of Cirrocumulus and Altocumulus (larger globules).

 

Expect another middle to high cloud cloudy day with nice breezes.  Weak jet stream to south (see map below) as upper level trough passes today, the main criteria for cool season rain in AZ (some 90-95% of all measurable rain in AZ falls only when the jet stream in the middle troposphere (about 18-20 kft above sea level) is south of us.  However, while that criteria is met today, just not enough moisture has leaked in over the Baja and southern California mountains for clouds low enough to produce rain.  So while its a virtually necessary condition, its not always sufficient.

Forecast winds at 500 mb (18.5 kft ASL) at 11 AM AST.
Forecast winds at 500 mb (18.5 kft ASL) at 11 AM AST.  Strongest winds at this level coming onshore in Baja, Cal.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The End.

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.