20160701

Previous Day
A tough day, but some parts of the forecast were pretty good.  There were widespread strong storms out along the Colorado River which were forecast OK by the model runs.  Also, some storms with very heavy rain developed across Cochise county which wasn't handled well.  The Tucson and Phoenix areas remained quiet, as expected.  Storms are developing this morning between Tucson and Phoenix which was also forecast.

Initializations
Another complicated situation with widespread clouds and precipitation across the eastern 1/2 of the state.   Same old story with the 12Z initializations as they don't have enough clouds or showers present.  The 6Z runs looked significantly better.  The 500mb circulation has opened up into a trough, located across northern Arizona.  A lower level circulation is present between Tucson and Phoenix.  6Z runs and 12Z initializations all have these features.   All also have IPW initialized quite well except for the 12Z WRFGFS where it is too dry in far western AZ.   As the 6Z runs have a better handle on clouds and showers, I'll use them for the majority of the forecast.  In any case, model confidence is again low.

Day 1
Plenty of moisture remains across all of the state which will again support scattered storms as 850mb dew-point temperatures continue above 12C.

CAPE also remains moderate over much of the state.

By early afternoon, the area of showers and weak storms moves into eastern Arizona and weakens while strong storms develop over southeastern Arizona.

Tucson is right on the edge of the SE Arizona activity and it could be an active day here.  (it already is as a flash flood warning just came out)

WRFGFS

Storms wind down over SE Arizona during the late afternoon while areas north and northwest of Phoenix remain active.

Phoenix continues to hold onto a moderate amount of moisture and CAPE into the early evening in spite of mainly westerly winds.  The PBL is mixed deeply with a weak inversion holding back convection so they are primed and ready to go.

The model runs disagree on timing and intensity, but it does appear Phoenix will see some (or a lot) of activity after 6pm.

 The 6Z and especially the 12Z WRFGFS runs have very strong storms in and around Phoenix later this evening as an organized line of convection move through.  Confidence for at least some activity is high as all runs are forecasting storms including the 12Z WRFRR-they just vary in timing and intensity.

12 WRFGFS

The 12Z WRFGFS is forecasting some very strong winds.

WRFGFS

Storms continue to move SE and weaken and are into the SE part of the state by early morning.

Day 2
Much less activity as drier and warmer air moves into much of the state.