Excessive heat, dryness predicted through August.
On February 20th, NOAA's Climate Prediction Center released its latest long-range temperature/precipitation outlook for the continental United States.
For drought-stricken westerners, it doesn't look good.
Based on a number of scientific deductions, temperatures are expected to be much above normal beginning this spring and continuing through the summer into early fall.
Scientists blame it on a number of factors; the principal element continues to be unusually persistent high atmospheric pressure, which has prevailed along and off the U.S. west coast for the past six months or longer,. This pattern has continually blocked moisture-bearing Pacific storms to the far northwestern U.S. with the single exception of the recent four day storm which generated heavy rainfall for the entire state of California.
California is currently in a state of drought emergency, experiencing the driest year ever in its recorded history.
Cutbacks in water usage have been strongly urged, and water rationing isn't at all unlikely in the coming summer months. The Sierra snowpack, source of much of California's water was at only 12% of normal in January, and the most optimistic estimates place it currently at one-third of normal following recent storms.
Beginning in April, almost the entire western U.S. is forecast to experience above average temperatures, ranging from very much above for most of California and immediately adjacent areas to much above or simply above for virtually all areas west of the Rocky Mts. At the same time, precipitation is expected to be from below average to much below average in these same areas.
These conditions are expected to persist more or less through the entire summer, with some expansion/movement of maximum heating areas indicated slightly and gradually to the east and north from California as the summer progresses.
Moderate offshore high pressure normally provides cooling sea breezes along the west coast during summer months; this may be offset if interior (monsoon) high pressure develops and becomes persistent in mid-June or early July as is sometimes typical.
Ocean temperatures also play a role in western summer climate. Colder water which is usually present with the California current also serves to moderate summer temperatures especially for California. But if warmer water more tropical in nature (low 70s water temp.) establishes itself offshore, conditions can become sticky, hot, humid and showery along the California coast in particular. This type of pattern would lend itself to enhanced development of tropical disturbances, which typically affect the southwestern U.S. in August and September.
These long-range forecasts are periodically updated if developments seem to suggest changes.