Interesting Week Ahead For The Southwest

The coming week will first bring a significant warm up, as mid-level ridging builds into our area. This will bring another flirtation with our first 100 F day of the year. However, during the weekend a cold, 500 mb closed low will develop to our west. This will bring much cooler temperatures and perhaps even a chance of showers.

Shown here are the operational global forecasts from 00 UTC last evening for 168-hours, with a valid time of 05:00 pm MST next Sunday afternoon. The 500 mb ECMWF forecast (above) predicts the 500 mb low to be centered over California. The corresponding 850 mb forecast (below) indicates a VERY strong east-to-west temperature gradient across Arizona, with temperatures approaching 30 C over New Mexico and California having temperatures in the single digits. The same forecast for 500 mb from the GFS is at the bottom and is very similar to that from the ECMWF. Will certainly be interesting to watch how this all plays out in the real atmosphere.