The pattern of warmer east and south, cooler west, continues. Above average to well above average conditions south and east of a line drawn from southern Vermont, through Chicago, southwest to eastern AZ. Cooler than average along the west coast as a typical seasonal high pressure area sits offshore and brings northwest flow onto the west coast. Cooler too for the Colorado and Wyoming Rockies as late season snowmwelt keeps temperatures limited. The drought areas of Texas are helping to maintain the warm bias not only over TX and the southern plains but over much of the east. When a severe drought dries up the soil and kills or damages vegetation, there is much more heat available to go directly into heating up the air, since there is little moisture to evaporate. The increased temperatures help to maintain high pressure system dominating the drought region, and this keeps a cap on rainfall. Prevailing winds then help shift this hot air toward the east.

This week through July 13th will see a build up of heat over the northern and central plains, and gradually increasing maximum temperatures over the NE. By the end of the week, daytime maximum temperatures will exceed 30C (86F) over all of the continental US except directly along the west coast, Maine, and the higher elevations of the cordillera. Any precipiation will be thunderstorm based mainly over the northern plains, Florida and the SE seaboard, and the tropics remain quiet.