ECMWF Changes Its Forecast

The 168 hour forecast of the ECMWF for 1200 UTC on January 20th is shown above. The ECMWF had been forecasting a fairly substantial cutoff at 500 mb to dig into the Southwest - this continued until two forecast cycles ago (0000 UTC) when the cutoff was no longer forecast to develop.

The current 120-hour ECMWF forecast valid at the same time forecasts a positively-titled shortwave to be crossing Arizona and the central US at 1200 UTC on the 20th. This is now similar to the GFS forecast valid at the same time - see below. This is the second time in the last couple of months that the GFS has been more accurate (I'm assuming) than the ECMWF at 168-hours. So, right now both models' forecasts indicate that precipitation at mid-week will remain north and east of most of Arizona. So it goes, as 2011 remains precipitation-free.

Meanwhile, it's about as nice a day here in Tucson as one could hope for in the middle of January.