Weather Underground midday recap for Sunday, June 30, 2013.
The West remained hot on Sunday, while showers and thunderstorms persisted in the East.
Out West, another extremely hot day developed across the Western states on Sunday as an expansive ridge of high pressure remained dominant over the Southwest and Great Basin. Temperatures in parts of California, the Desert Southwest, and the Great Basin rose past the well past the century mark, while 100 degree temperatures became possible in parts of the Pacific Northwest. Near-record breaking temperatures were possible again in the Desert Southwest and California valleys on Sunday. Excessive Heat Warnings continued from western Arizona through most of California and Nevada, as outside activities remained dangerous for the region. Heat Advisories were also issued for from areas of northwestern Nevada through parts of Washington, northern Idaho, and northwestern Montana. Hot and dry conditions in parts of the Great Basin kept fire danger high for parts of Utah through western Colorado and led to Red Flag Warnings through the day. Elsewhere in the West, just east of this ridge, limited moisture pooling along a nearly stationary frontal boundary and warm afternoon temperatures kicked up scattered storms from parts of eastern Colorado through western and southern Texas. The Storm Prediction Centered issued a slight risk of severe thunderstorm development for parts of the Central and Southern Plains with possible hail, locally damaging wind gusts, and tornadoes.
In the East, hot and humid weather conditions continued for the East as the region remained in between an upper trough of low pressure over the Great Lakes and a ridge of high pressure in the western Atlantic Ocean. Ample warm, moist flow streamed in from the south-southwest and poole along a lingering frontal boundary over the Eastern Seaboard, kicking up more showers and thunderstorms from the Mid-Atlantic states through the Gulf of Mexico. Meanwhile,behind this activity, areas of scattered thunderstorms remained possible across the Midwest, Ohio River Valley, and Northeast.
Temperatures in the Lower 48 states Sunday have ranged from a morning low of 37 degrees at Land O' Lakes, Wis. to a midday high of 107 degrees at Boulder City, Nev.