Near miss on rain; pretty clouds and a nice sunset

Here are a couple of scenes from pretty yesterday, a day that the phony numerical models had rain predicted for us one to two weeks in advance, and then dried that system out as far as we here in Catalina are concerned as the days got closer.  This happens all the time in the models, so you would think I would develop a tough skin to these repeated disappointments, but I haven’t.  Oh, photos.  Here they are-the middle panel having a nice pancake-like stack of Altocumulus lenticularis clouds northeast of Charouleau Gap:

 

 

 

 

 

 

 

So what was the missing ingredient? Well, the core of the jet stream at around 18,000 feet above sea level, what we call the 500 millibar pressure level as well, stayed just to the north of us. If you have read this blog, you know that the core at 500 mb has to be over or to the south of us and that didn’t happen. Its a necessary condition in the cool season here, but not always sufficient. Shown below is last evening’s 500 mb map, courtesy of the University of Washington with station plots and infrared satellite imagery. Those two flags and a wind barb for our Flagstaff balloon site (“rawinsonde” site) shows that the core of the jet stream was just about right over Flagstaff at that time, and the wind was over 120 mph (105 knots)! Note that the wind at the same pressure height on this map is “only” 65 knots over Tucson.  By this morning, that core had settled a little more southward to between Albuquerquequeque and El Paso, and along with that the precip shifted a bit south as well.  Darn, had this happened 12 h earlier we likely would have gotten a small amount of rain.

If you look at a loop of the radar echoes during the late afternoon and overnight from IPS Meteostar, you will see that the precip is confined to near that jet stream location and northward.

Shown on the Washington Huskies loop is another powerful storm about to strike the West Coast.  THIS one WILL bring the jet stream core south of us as it passes over on Monday night-Tuesday morning, the 23rd-24th, and circumscribed inside that jet stream core will be moisture and clouds low enough to produce at least scattered showers, and may a nice rain band of a few hours duration.  So, maybe the rest of January won’t end up as rainless after all.

The best thing about this next trough is that it gets stuck as a cut off over west Texas and causes quite a bit of rain there in that drought stricken region for a couple of days.  Might have to drive over there and see how happy the people of west and central Texas are when the rains begin.

Don’t want to end this session without a long distance model teaser, “big storm” from IPS METEOSTAR as shown here valid on February 3rd at 5 PM AST.  Note how it resembles once again our early winter pattern of the isolated cut off upper low.  Hmmmm.   Maybe there will be something to this one because of this winter’s theme song of cut offs.

 

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.