Special Weather StatementIssued by the National Weather Service at 9:40 PM PDT on May 12, 2008
... Hot weather on tap by midweek for much of southwestern California...
An upper level high pressure system will build off the central coast by Wednesday... then it will strengthen as the main core of the high becomes anchored over central and northern California Thursday through Friday. Weak to moderate offshore flow will develop by Tuesday morning... helping to warm temperatures to near normal for this time of year.
As the upper level high pressure system builds over California and weak offshore flow persists Wednesday morning... there will be additional warming across most areas on Wednesday... especially interior sections. Many valley... Lower Mountain... and desert locations will climb well into the 80s on Wednesday... with warmer locations soaring into the lower 90s. Onshore flow is projected Wednesday afternoon... which will help to moderate temperatures near the coast.
The hottest days will be Thursday and Friday as offshore flow becomes more pronounced and the boundary layer continues to warm with time. Temperatures will soar well into the 90s across most interior sections... with some of the hottest locations expected to climb to over 100 degrees. At this time... it appears that the offshore influence will affect portions of the coastal plain on Thursday and Friday. Areas near the immediate coast will likely climb into the 80s... while inland portions of the coastal plain will likely soar into the 90s. Some record high temperatures are likely Thursday and Friday.
During the hot spell... relative humidity levels will likely lower to around 10 percent in many valley and mountain locations... as well as the Antelope Valley. This could bring potentially dangerous fire conditions to many portions of southwestern California by Wednesday... with the threat continuing through at least Friday.
At this time... it appears that temperatures will continue to be quite warm on Saturday and Sunday. However... the upper high should weaken a bit... and there will be a quicker return of the seabreeze each afternoon... which should cool at least coastal regions. Inland temperatures will continue to be relatively hot... with highs in the lower to mid 90s in most areas. More significant cooling will likely occur early next week.
People planning outdoor activities later this week into the weekend should take into consideration the very high temperatures and adjust their activities accordingly. Wear loose fitting light weight clothing and drink plenty of water. Take advantage of shade and air conditioning if available.
Never... ever leave children... the elderly or pets in enclosed automobiles... even for the shortest time. Temperatures quickly rise to life-threatening levels... even if the windows are partially opened.
