The synoptic pattern seems to favor both strong flow up the northern Gulf AND advection of this airmass toward the Valley - a small increase in mean moisture could dramatically destabilize the Luke sounding. Probably the next tropical feature of import is a developing tropical storm off the Mexican coast near Manzanillo - this disturbance will move northwestward along the Mexican coast. Outflows remain likely, even if storms do not make it into the deserts. The pattern appears to be evolving into a Type I setting for tomorrow and the outlook is for an increased chance of Valley storms and also at least a slight chance of severe. P chart of the 12 UTC sounding from Luke Air Force Base on August 6, 1994.
Wind speeds are in knots.
The small box indicates the location of Phoenix, and the Salt and Verde River Basins are outlined. Observed Weather Thunderstorms occurred this afternoon and evening along the Rim, over the western mountains and low desert, and over the White mountains. The storms on the Rim developed slowly southward and moved into the Valley around 7 to 8 pm with some light rain, frequent lightning, and strong to severe outflows. There was an intense storm in the desert just west of the metro area around 9 pm that the NWS issued warnings on and strong storms in Miami-Globe area led to flash flood warnings. Once again neither Luke nor Phoenix observed any precipitation, although there were a number of reports of very heavy mountain rainfalls.