More heat; Gulf of Mexico disturbance

The heat was unrelenting yesterday across the Southwest U.S., where most of California and Arizona set new high temperature records. The 99 degrees in downtown Los Angeles beat the old record of 96 set in 1960, and the suburb of Woodland Hills hit a record 119. All the cities in California's Central Valley set records: 109 degrees in Sacramento, 111 in Redding, and 112 in Red Bluff, Stockton and Modesto. San Francisco's 87 degrees easily beat the record of 81 for the date, set back in 1917.

In Phoenix, this morning's low temperature was 97 degrees, which broke the all-time record for highest low temperature ever recorded in that city (96, set on Jul 15, 2003). Tucson's low of 89 Saturday morning was its highest low temperature in recorded history, as well. The temperature topped out at record 116 in Phoenix yesterday, and 121 in nearby Gila Bend.

Tropical update
An area of disturbed weather continues over the southwestern Gulf of Mexico. Wind shear is over 20 knots in this region, which is too high to allow development today. Both the GFS and NOGAPS models are forecasting this shear to be 15 knots or higher over the next few days, and usually one needs wind shear to fall to the 10-15 knot range for development. However, the NHC is playing it cautiously and has put a Hunter airplane on call for Monday, if needed. I'll be surprised if this flight happens.


Figure 1. Preliminary model forecast tracks for the area of disturbed weather in the Southwest Gulf of Mexico.

Enjoy another quiet weekend in the tropics, everyone!
Jeff Masters