Weak But Cool 500 mb Low Along Borderlands

EDITED TO ADD AFTERNOON UPDATE - Some thunderstorms around southeastern Arizona this late afternoon. View of Catalinas above is from 5:40 pm MST and CG flash density below (from weather.graphics and Vaisala) is for 6-hours ending at 5:15 pm.

This morning a weak 500 mb cyclone is centered between Tucson and Yuma, while heading southeast into northern Sonora (12 UTC analysis above is from NCAR). Temperatures are around -15 C in the core of this system, and the WRF-NAM forecast from 06 UTC at Atmo (below for 500 mb and valid at 5:00 pm MST) indicates cool temperatures over most of southeastern Arizona this afternoon. The hot and very deep boundary layer will, in conjunction with the cool air above, lead to a chance of high based thunderstorms and lightning strikes over the highest elevations of our part of the state.