High pressure aloft will maintain hot temperatures across inland regions through Wednesday, with the most intense heat occurring away from the coast. The weakening onshore flow reduced the marine layer depth. This hot air is significantly above the norm for this time of year.
Short-Term Forecast
Inland temperatures are expected to remain extremely high on Wednesday, reaching or exceeding 100 degrees, and will stay very warm on Thursday.
Coastal valleys will experience temperatures ranging from the upper 70s to near 90 on Wednesday. The marine layer will continue to protect coastal areas from the extreme heat affecting interior regions, providing night-to-morning low clouds and dense fog for some. Fog is anticipated to develop initially along the Santa Barbara South Coast and gradually extend up the coast to the west-facing parts of Santa Barbara County and ultimately San Luis Obispo (SLO) County. Due to the high pressure aloft, these low clouds should remain confined to beaches and adjacent areas. Consequently, beach temperatures are expected to drop slightly, with very near coastal valley temperatures remaining warm to hot away from the beaches on Wednesday.
A Heat Advisory has been issued for San Luis Obispo County Interior Valleys and the Southern Salinas Valley, effective from 10 AM Wednesday to 8 PM Thursday. Residents in cities such as Templeton, Shandon, Paso Robles, Creston, Atascadero, San Miguel, Lake Nacimiento, Carrizo Plain, and the Cuyama Valley can expect temperatures to soar up to 101 degrees Fahrenheit.
The National Weather Service warns that these hot conditions significantly increase the risk of heat-related illnesses, particularly for vulnerable populations such as young children, the elderly, and those engaging in outdoor activities. Authorities advise staying hydrated, limiting strenuous activities, and checking on at-risk individuals to ensure community safety during this heat event.
The main uncertainty in the forecast is the timing of the upper-level ridge moving east. Today's models suggest a slower progression, which could result in warm temperatures persisting a bit longer. There is also a need to monitor potential instability bringing mid-level moisture into Santa Barbara County on Thursday, which might cause a thunderstorm in the mountains, although the likelihood is low.
Long-Term Forecast
In the longer term, mid-range models do not indicate significant changes. Temperatures should start to cool, at least somewhat, with a more noticeable decrease likely in interior areas.
Stay tuned for updates and make sure to take necessary precautions during this heat wave.
