SAN DIEGO — A tropical storm off the coast of Baja California is causing a strange weather pattern blowing through the county. National Weather Service experts are warning of a heatwave posing fire threats, followed by possible flooding in the foothills.

“The door is open, and what I mean by that is the weather pattern is set up,” said Alex Tardy with the National Weather Service.

A regional heat wave covering the northwest is also threatening the power system with a possible flex alert, but San Diego is not expected to suffer like northern California and Oregon.

“Ongoing warm temperatures, fire weather threat but then it rains and the rain could be widespread. And yes, we are concerned with flooding, and we could see that as early as this weekend or next week,” said Tardy.

Cal Fire crews are now on standby to handle whatever is to come.

“We try to jump on these fires are quickly as we can. We send the full ground resources and full aircraft compliment, to try to keep these fires small and away from houses,” said Capt. Michael Cornett from Cal Fire.

Thursday is the turning point for weather and rescuers are at full staff to respond to fire or possible flooding.

“Details are unknown, how much rain, exactly when it will rain, how strong the rain will be, but the door is open for this tropical storm to come up from the south,” said Tardy.