A strong high-pressure system over the Pacific Ocean will expand over Southern California this week, weather forecasters said Sunday, bringing heat, low relative humidity and gusty winds to San Diego County, enhancing the wildfire risk.
High pressure began to influence the region Sunday, the first day of the big warmup that will affect Southern California through the week, the National Weather Service said.
On Sunday afternoon, forecasters in San Diego issued a heat advisory for Tuesday through Friday for the coast and valleys of San Diego County.
A heat advisory means that hot temperatures may cause heat illnesses to occur, the NWS said. Those without air conditioning will be especially vulnerable during this extended heat wave.
Coastal area high temperatures Sunday were 71-76 with overnight lows expected to be 55-62, the NWS said. Inland valley highs were 80-85 with overnight lows of 54-60.
Mountain highs were 75-83 with overnight lows of 49-59. Desert highs were 92-97 with overnight lows of 63-72.
Hot and dry will summarize the week ahead, forecasters said.
"An upper level ridge over the eastern Pacific will expand into Southern California and remain in place throughout the week," the NWS said. "The upper low now over Baja will meander and cut off. Global models show this feature moving back towards the northwest late this week, but consensus keeps this far enough off the coast for little relief from the heat."
The noticeable big jump in temperatures will occur on Monday as winds turn weakly offshore.
"We expect highs to reach well into the 90s inland on Monday and beyond this week with even some triple digits possible over the Inland Empire and perhaps at the hotter places in the San Diego County valleys east of I- 15," forecasters said.
Highs in the lower deserts will prevail at 100-105 this week with low- to-mid 90s for the high desert.
The beaches and mountain communities will be 75-85 degrees.
"Above normal temperatures and dry weather are likely into next week as well, just not quite as hot," the NWS said.
Fire weather conditions will be elevated through the week because of the hot and dry conditions along with gusty winds.
