Looking Forward

June is a tough month here in Tucson, with very hot and dry conditions sometimes prevailing through the entire month. The only weather hopes hinge upon the summer thunderstorms starting early. Before the storms begin, people who stay in town for the summer are eagerly awaiting higher humidity, storms, and the sweet smell of the desert after a rain. So, I took a look at the global model 10-day forecasts.

Here are the operational member, 500 mb forecasts that are valid at 00 UTC on the 15th of June (GFS above and ECMWF below). The forecasts are quite similar except that the west coast trough is deeper and more pronounced in the GFS forecast, and the ECMWF forecasts a deeper trough along the east coast. Both forecast an extension of the Atlantic subtropical ridge into the Southwest. The GFS has an anticyclone center over southwestern New Mexico, while the ECMWF forecasts a stronger anticyclone centered over the Oklahoma Panhandle. The main thing I can say about these forecasts is that they look promising. However, the GFS ensemble spaghetti chart for the same time (bottom) is less promising, with some members having the west coast trough more pronounced and extending into the Southwest. We'll have to wait and see what actually happens.