DISCUSSION: Over the past few days, a massive ridge over the West Coast has been dominating the weather stories in the region with the Pacific Northwest reaching near and above 100 degrees Fahrenheit including in Portland, Oregon. However, the massive ridge also brought moisture into California. The moisture slowly crawled up the state of California in the form of high clouds, thunderstorms, and rain. The monsoon made its first stop in Santa Barbara Coast especially where there was slight rain on Tuesday followed by thunderstorms on Wednesday.
However, the moisture wasn’t quite enough as the showers were generally hit and miss in some areas. For example, the San Francisco Bay Area had some locations with a few drops even enough to barely tip the bucket in some locations such as San Francisco and San Jose while some like Livermore had received about seven hundredths of an inch in a day. However, no real thunderstorms occurred in the San Francisco Bay Area as much of the convective activity was positioned just off the coast on the edge of the Eastern Pacific Ocean near Half Moon Bay. Also, there were thunderstorms over parts of the Sierra Nevada mountains as well as the San Joaquin Valley, especially where the Detwiler fire is burning. Also, there happened to be little to no Convective Available Potential Energy (CAPE), which is a measurement of buoyancy related to the updrafts of thunderstorms, according to the soundings at Oakland, Vandenburg Air Force Base, and San Diego while Reno had observed about 100-200 joules per kilogram. Another phenomenon that happened during this monsoon flow was a few heat bursts, which occurs on occasion after a thunderstorm dissipates; although not much is known about them. The heat bursts had occurred over some parts of the San Francisco Bay Area, including in the City of Oakland.
Chief Meteorologist A.J. Fox of KSEE 24 News in Fresno said that the cloud cover and humidity helped Fresno set a record with a morning low temperature of 85 degrees on August 3rd. Fox also mentioned that there were several grass fires in the San Joaquin Valley due to the lightning strikes affiliated with the monsoon as well as dried up grass. San Jose also had a very high low temperature of 74 degrees on the morning of August 4th. However, the extremely high low temperatures were short-lived as the temperatures dropped the next day according to the National Weather Service office in Monterey, California. This monsoon is a yearly event during the summer where moisture gets drawn up into California from Arizona.
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©2017 Meteorologist JP Kalb