20190923 Day 2

Day 2
The storms just keep coming.  As mentioned in Day 1, the focus shifts to southern Arizona overnight and into the morning hours, as the low continues to move south overnight.

CAPE becomes very high over southern Arizona and will support strong to maybe even severe storms.  CAPE is also more than sufficient to support continuing storms for Maricopa County too.

Storms are again moving into the Phoenix area during the early morning hours and beginning to develop over southeastern Arizona.

A surface low begins to form over the far northern Gulf of California which increases low-level moisture advection over far southern Arizona. 

Widespread storms continue to redevelop over many areas of southeastern Arizona around sunrise.

Moist and unstable air continues to feed into southern Arizona during the morning hours fueling thunderstorm redevelopment.  Note the strength of the surface low; I've never seen one this strong before.

Thunderstorms continue throughout the morning.  All the model runs are similar to this outcome, so I'm fairly confident it will happen.

The differences are in the amount of precipitation.  The WRFRR series have the most and if these verify, this is going to be a major flood event for parts of southeastern Arizona, including Tucson.  Here are the four runs from this morning:

Storms generally dissipate during the afternoon hours.  Some activity might be possible under the cold-core cutoff over southwestern Arizona as depicted by the WRFNAM.