In contrast, the sounding at Winslow has become very unstable and with high moisture and very weak steering level winds, heavy rains and flash floods are a threat along the Rim from the White Mountains to Kaibab Plateau. Note that the water vapor loop shows a pronounced tropical wave moving westward into eastern Mexico near and south of Brownsville - this feature will bear watching during the next several days. Satellite imagery this morning, along with the Tucson sounding, seems to indicate a small residual vortex at 500 mb located just north of Tucson. I expect little with it since yesterday's spectacular eddy appeared to have almost NO affect, except for much diminished activity over the Sand Tank Mountains. P chart of the 12 UTC sounding from Luke Air Force Base on July 24, 1994.
Wind speeds are in knots.
The small box indicates the location of Phoenix, and the Salt and Verde River Basins are outlined. There were numerous storms over the mountains this afternoon and evening, with several storms, but little rain, over the Valley. The most impressive storms occurred along the rim and produced a strong outflow that moved across the Valley from the north. This outflow helped to trigger some high based convection over the Valley and Luke reported a dry thunderstorm. Outflow winds were generally 20 to 30 kts.