A heat wave is headed this way and the National Weather Service has issued an excessive heat watch through the entire Sacramento and San Joaquin Valleys up to the Sierra crest.
Temperatures will be highest over the holiday weekend, with high to very high heat risk forecast for Sunday and Monday.
“The reason for this unseasonable heat wave for this time of year is the level of high pressure in the upper ridge is forecast to strengthen, the sinking air associated with that will cause temps to rise 15 to 20 degrees above normal for this time of year,” National Weather Service Meteorologist Scott Rowe said.
Today, the warming trend begins with highs around 90 degrees, 92 on Friday, 97 forecast for Saturday, 102 Sunday, and 99 Monday.
“It’s unexpected to see heat waves of this magnitude late in the season,” Rowe said. “We are in September now.”
“Looking ahead to the extended forecast, temps do tend to decline on Tuesday, when we start the new work week,” Rowe said.
Wildfire smoke wafting over areas of Northern California will also play a part in high and low temperatures, potentially keeping daytime highs from reaching their forecasted extremes.
“Smoke acts as a cloud,” Rowe said in reference to the ability for smoke to reduce high temperatures. “On the other hand, for the overnight lows, it would help keep temperatures in. It mutes the extremes a little in the end.”
Overnight lows are expected to stay in the upper 70s and low 80s, providing little overnight moisture recovery and increased wildfire risk.
A potential offshore north wind event is being eyed for Tuesday or Wednesday, though confidence at this point is low.
“We may be transferring from heat concerns to fire weather concerns rather quickly,” Rowe said.
“It’s still a little bit early to tell,” Rowe said of the potential north to northeast wind event. “It may be a little too early to discern. Depends on how cool it gets in the great basin.”
If the offshore wind event were to materialize, the weather service foresees anywhere from 15 to 20 mph winds on Tuesday or Wednesday.
“Going to have to get through the heat wave to see what kind of models we will have,” Rowe said.
With the holiday weekend coming up the National Weather Service wants to remind people to stay hydrated and take care of themselves in the heat.
“If folks do decide to go out on a hike or any trails or area waterways, there may not be that much relief from the heat for those coming up from the valley.”
To contact Multimedia Reporter Elias Funez, email [email protected] or call 530-477-4230.