Another Fast-Moving 500 mb Short Wave To Cross Arizona

The 500 mb short wave that is near San Francisco this morning (NAM 12 UTC analysis above), is forecast to dig southeastward and be nearly over Tucson by 12 UTC tomorrow morning (below)

This system, while currently producing considerable rain across California, is forecast to be fairly dry as it moves across southern Arizona tonight (23 January 2012). The early run of the WRF-GFS at Atmo forecasts only light sprinkles over southeastern Arizona at higher elevations - see below for the WRF precipitation forecast through noon tomorrow. So it looks like more clouds and some gusty winds this afternoon and tonight, and perhaps some spits of rain.

The system that moved across Arizona Saturday afternoon (see previous post) produced an unusual, January outbreak of severe thunderstorms and some tornadoes yesterday over the middle Mississippi Valley and parts of the Southeast - SPC storm reports are shown below.