Dawdling low to bring scattered showers for a couple of days in 10-13 days

We’re not into streamlined titles here.

In the meantime, before taking a hopeful look way ahead;  wind and dust.  Today begins the well-forecast model trough and low event from more than 10 days ago for the 17th, except its happening on the 15th and 16th.  It means afternoon dust and wind, wind and dust, followed by unusually cool air on the 17th.  No rain likely in this one, though, like the last dust event; just some scattered Cumulus on late on the 16th and 17th.

The weather way ahead: After the dust, idle speculations of distant rain

There’s a tiny low now east of Hawaiian Islands, that, models say, will dawdle around out there for awhile, but also be drifting eastward eventually, not being picked by the jet stream and Nike swooshed to the northeast as most such lows would be.  Just continues along at low latitudes until reaching us late on Thursday, April 25th.  Here it is in the NOAA spaghetti plots.  It would be astonishing if this itty-bitty low gets here, but, here’s the hopeful sequence in “spaghetti.”  This is only brought up because its the first model rain that has shown up for southern AZ in a long,  LONG time.

Valid last evening at 5 PM AST.
Valid last evening at 5 PM AST.
Five days from last evening,
Five days from last evening,
Valid at 5 PM AST. Friday, APril 225th.
Valid at 5 PM AST. Thursday, April 25th (00 Z 26th in Central Universal Time).  Note the green CLIM line, bulging toward the Equator where it crosses northern Baja.  This means over the decades, there is a tendency for a trough to be in our area.  This MIGHT explain why the chance of rain here in Catalina, while small at the end of April, does not decline during the last week or so.













In case you don’t still don’t believe me, here’s a colorful model loop showing that this is supposed to happen to that low east of Hawaii.   Further support can be seen in some green pixelation over Arizona from IPS MeteoStar’s rendering of our WRF-GFS model, our best, for the amounts of rain in the 12 h ending on the morning of the 26th.

2013041500_CON_GFS_SFC_SLP_THK_PRECIP_WINDS_276I hope you’re happy now.

The End.

PS:  Pretty happy myself, after learning through a bz website that this blog has value!  How much?  TWENTY-FIVE US dollars!  Thanks tremendously to both readers!

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.