More Activity Today?

Yesterday was characterized by persistent debris cloudiness over much of southeastern Arizona. As a result, maximum temperatures were lower by around 10F than on Friday (only 95F at TUS compared to 104F on Friday). There may have been light precip at up to three mountain ALERT stations, but basically the entire Tucson metro area was suppressed with no storms yesterday.

Above image is WV satellite image from 8 pm last evening. Strong storms and MCSs continued in Mexico all the way south to the mouth of GoC. Dewpoints jumped back into the 70s early yesterday afternoon at Yuma, and have held high since, although precipitable water out there has increased only slightly. Precipitable water has continued to inch upward over southeastern Arizona. There is a considerable gradient in PW at north end of GoC and somewhere along the Borderlands - note that Guaymas and Hermosilla are reporting PW of a bit over 2 inches (see eastern Pacific blended PW image below)..

The Tucson morning sounding (above from SPC) appears considerably better for low elevations this morning wrt last several days. Even though 500 mb temps are warm, the increase in low-level moisture indicates that there is increased CAPE. High elevations will remain unstable, stormy, and with heavy rain threat increased today. Note that our atmosphere remains windless overhead through almost the entire troposphere. The 500 mb anticyclone now has three ill-defined circulation centers - southeastern US, southwest of El Paso, and west of northern Baja. The NAM forecasts continue to consolidate these into a single center by tomorrow somewhere over southern to western New Mexico.

The midnight run of the U of A Atmo, high-resolution, WRF-GFS model forecasts a considerable increase in storm activity, with some late afternoon storms moving down into Tucso metro area. The above graphic shows WRF-GFS forecast of total rainfall through midnight tonight. The 1200 UTC NAM lower-resolution forecasts this morning predict only very light, and high elevation, rainfall this afternoon across southeastern Arizona - so will have some interest in observing which model forecast is better this afternoon.