Warnings for dryness, air stagnation increase.
As strong high pressure continued its reign across the western states, extreme dryness, gusty winds, and temperature inversions continued to mount an assault on much of the nation west of the Rockies.
Multiple surface highs—with intensities characteristic of polar or arctic systems, sat unmoved Tuesday over the Pacific Northwest, and over Utah and Colorado. Early Wednesday morning, twin 1041 millibar highs straddled northern California and western Idaho, while a 1038 millibar high sat over the Utah-Colorado border.
Besides generating gusty offshore/Santa Ana winds across California, the cold, stable air resulted in strong temperature inversions prompting air stagnation advisories across widespread areas of Oregon and Washington State. Similar conditions are expected to develop across Utah beginning today, specifically the Salt Lake City area.
Red flag fire warnings were expanded on Tuesday from southern California to include much the Sierra Nevada foothills and mountains, as well as areas both north and south of San Francisco. A few minor fires were reported up and down the state, but were knocked down and contained immediately by fire crews on high alert.
In southern California, high wind warnings continue today for most mountain areas in Ventura, Los Angeles, Orange and San Diego Counties. On Tuesday, temperatures were in the 80s, with single digit dew points—resulting in relative humidity values as low as 4%. A few trees were reported down near Cajon Pass in San Bernardino as winds gusted upwards of 40 to 50 mph. Extreme caution is urged due to the extreme dryness combined with lack of rainfall over the past 18 months.
The outlook isn't good, either. Long-range models offer little in the way of hope for any significant precipitation, instead continue to suggest a pattern of continuing dryness. High pressure, both surface and aloft continues to be modeled along and off the U.S. west coast, with only minor disturbances not likely to bring significant rainfall.