Arizona WRF Discussion: 20160802

Previous Day
Various versions of the WRFRR worked out pretty well as they had only isolated activity over the lower deserts.

Initializations
Most model runs are going to be of little use today most places as the atmosphere is so wet and with ongoing showers and a few storms. The 12z WRFRR and 6z WRFNAM do have morning activity over south central Arizona so they might not be too bad.

Mid level flow is light and variable over Arizona while a weak 700mb IT is present over far SW Arizona and was initialized well by all the 12Z initializations. I just noticed a MCV over the bootheel of NM. This seems to be partially responsible for the morning activity around Tucson.

The 12Z NAM was somewhat too wet (if that is possible!) over Arizona. In general, it's going to be a very tough day for the various model runs as the atmosphere is very unstable as proof by the morning convection and CAPE around 1300-1500 J/Kg. I have no confidence in the 12Z WRFNAM or GFS. The WRFRR seems to be the only run that may be of any use and even that is debatable.

Day 1
500mb flow is mainly light and variable today while the weak IT continues over far SW Arizona. The IT looks very weak thus is unlikely to have much of an impact.

As Bob Maddox mentioned, record IPW this morning. Afternoon 850mb dew-points are in the 15-16C range and IPW is in the mid 50's around Phoenix and 50 at Tucson. Wow!

The WRFRR CAPE forecast has little or no CAPE for areas that had morning convection. It has the area of minimal cape a bit too far to the north as most of the morning activity has been across eastern Pima.

The story is those areas that see the sun will develop deep convection and obviously, these storms are going to produce very heavy rain as it's so wet and they aren't moving much.

There is some CAPE present at both Tucson and Phoenix during the late afternoon and evening. It won't take much to get deep convection at either location so a few storms could pop up overnight.