20190816

Initializations
Arizona is dominated by westerlies at most levels.  Overnight, an MCS has been active over southern Sonora, and all initializations have a closed circulation in the mid-levels in the correct location.  Otherwise, no other upper-air features were noted.  All 12Z initializations had only minor PW errors.  Overall, all initializations look good, and model forecast confidence is high.

Day 1
Sonora has been quite active the past few days, and this has resulted in a weak gulf surge into southern Arizona.    Dewpoints have increased significantly over far southern Arizona with a 76F at Yuma.  However, as the Tucson sounding and PW data shows, the surge is quite shallow. Previous forecasts have indicated sufficient moisture is present for storms for parts of far southern Arizona today so let's hope that verifies.

The surge continues into the early afternoon with PW increasing into the mid 20mm range.

Central Pima and southern Maricopa Counties barely reach the10C Td 850mb threshold for convection this afternoon.

  The 12Z WRFRR is the odd man out as it restricts convection to mainly Santa Cruz County.  The slightly wetter WRFNAM and WRFGFS develop a few storms far south-central Arizona by mid-afternoon.  It will be interesting to see if the 15Z WRFRR comes around to this more active forecast.

What is the date, mid-September?   Sure looks like it from the afternoon forecast Skew-T for Tucson.  Westerlies dominate as well as a pronounced warm layer just above 500mb.  There isn't much CAPE either.  The only thing going for it is a well-mixed PBL.

A few showers and storms continue into the late afternoon.

There is a fairly pronounced inverted V profile s a few storms could have strong winds.

The 15Z WRFRR is now available, and it's no better than the 12Z run as storms form only along the border later this afternoon and evening.  Note the one orphan just south of Phoenix though.  All hope isn't lost!

Day 2
Looks like today's limited activity is going to be it for some time at least into the middle part of next week.  #nonsoon.

I'm waiting for the 15Z WRFRR to make it out until this afternoon so I thought I'd post an astrophoto that I've been working on for literally, years!  It is M16, which is a star cluster and nebula in Sagittarius, and a part of it  (centered) has a well-known feature called "The Pillars of Creation." Inside, new stars are in the process of formation but still obscured by surrounding gas and dust.  I've struggled to get good images as it's pretty low in the sky so may times bad seeing has blurred the images.  It's almost always cloudy this time of year, so opportunities to image it when it's at it's highest are not often.  It's a multichannel blend of HII, OIII, Luminance, and RGB, acquired by a Celestron C11.