Severe Storms Over Northwest Arizona Yesterday

Yesterday was hot and suppressed over most of southeastern Arizona. High temperature at airport was 107F - eighth consecutive day with highs over 100F. Dewpoint temperatures fell to 40F at the airport yesterday (making swamp coolers very effective), and PW dropped below an inch for the first time in many days. The water vapor image below (7 pm MST) shows very dry upper-level air continuing over southeast Arizona. At this point it is not clear what features will act to push subtropical moisture back into this part of the state, so it looks like the heat will continue.

The image above also indicates an MCS out over the northwestern part of the state. This thunderstorm system produced strong outflow winds that led to a number of severe wind reports (below from SPC). Power was knocked out in Kingman, and in several towns along the Colorado River. Given the desolate character of that region, severe winds were probably considerably more widespread than indicated by the SPC chart.

Above is an experimental, blended PW product for 6 am this morning, from CIRA at Colorado State University (red indicates PW > 50 mm and green indicates PW > 25 mm). Higher moisture values remain quite close, and it appears that central Pima County will be a battle zone, as the boundary pushes back and forth the next couple of days. Of definite interest to us in the Southwest is the evolution of Ernesto. the remains of once Hurricane Ernesto are going to move offshore from Mexico and into the Eastern Pacific. The NHC has identified an area of high probability for redevelopment - see below.