Was A Brief Respite From The Dry-Out

The subtropical low from Mexico moved quickly by Tucson yesterday morning, leaving us in the dry quadrant during the afternoon. Total rainfall at the house was only 0.17” and amounts were generally light except to the south and east where Art Douglas reported over two inches in Ash Canyon (southeastern flanks of the Huachuca Mountains). The Pima County ALERT network had rain at 37 of 93 gauges in the past 24 hours – most of the reports were over the south and east parts of the network and likely occurred before 1 or 2 pm (the special TWC sounding at 18Z indicated that the atmosphere had stabilized and there was no CAPE in that sounding).

Northwesterly winds prevail this morning but the morning soundings at Phoenix and Tucson have some residual CAPE – drying will restrict any storm activity to the eastern mountains and southeast borderlands. Expect that this dry-out period will continue into early next week.

Other miscellaneous – out in the Pacific, Guillermo has become a hurricane and is moving off toward the west. The NAM forecasts a substantial inverted trough will be moving westward across Mexico next Monda, and we’ll keep an eye on that. In the longer term, the GFS forecasts a significant hurricane in the Gulf of Mexico (see 10-day SLP forecast above). The model has been very consistent in predicting an Atlantic hurricane; however landfall has ranged from around New York to New Orleans.