A heat wave that brought record-breaking summer-like heat to Southern California in the middle of March is not a predictor of even worse summer temperatures, forecasters said.
Despite the intense heat of the last few days is not yet enough to bring drought to a region that was soaked by winter rain, but may make for a dangerous, fuel-heavy fire season, forecasters said Friday.
“Early season temperature spike like we saw doesn’t actually predict what we would see this summer,” NWS meteorologist David Gomberg said.
The record-breaking temps this week are a result of high-pressure systems, Santa Ana type conditions and a higher sun angle, which combined, created the “perfect setup for 90 to 100 degree temperatures,” Gomberg said.
“There’s not a specific reason that we’re just seeing a very anomalous heat wave this time of year and this isn’t really much of a sign of what we can expect during this summer, although because of anomalous sea surface temperatures on all of our coasts, if the sea surface anomalies remain above average then it is pretty likely that we get up in above average summer– at least closer to the coast,” NWS meteorologist Sebastian Westerink said.
The water year was off to a raging start with a series of rainstorms bringing much of Southern California to average or above average rain levels for the year in a period of just a few months.
The unseasonal heat this past week alone isn’t enough to push the state into drought conditions, that would require much longer periods of intense heat and a sustained period without rain. At this point in the year, it is unknown if Southern California will remain watered or moved towards drought.
The “odds are tilted” towards an El Niño year, according to the NWS’ longer term climate prediction tools. This pattern is characterized by wetter weather in Southern California, but is not a guarantee, forecasters said.
As spring comes, in April and May, ocean influence becomes more prevalent, with stronger onshore flows that bring the “May gray”, cooler weather, making heat waves in those months less likely, Gomberg said.
“If this trend were to continue for the rest of the rain season, into the next season, that’s when we start worrying about about actual drought… the more serious drought, it would take at least another year of anomalously dry conditions to put us back into a true drought condition,” Westerink said.
What is a worry, Westerink said, is the impact of a wet, rainy winter followed by a period of very high temperatures– the recipe for vegetation to grow at an increased rate, vegetation that will then dry out.
“I think that the main concern will probably end up being the fire threat because we did receive a lot of rain, especially early in the rain season, which means that there’s a lot of the vegetation growth… but because of the heat, a lot of it’s going to dry out pretty quickly, especially the finer fuels,” he said.
Some grasses have begun to dry out, and more vegetation will follow suit, at a faster rate when the weather is hotter.
“What we were thinking is, oh the recent rains that we had over winter, that might offset the fire season by a little while, but now, if we don’t get some more rain, things could start browning out more quickly than we were hoping,” Gomberg said.
On Friday, a grass fire broke out in San Luis Obispo County, the first of the season.
“It gives you the kind of indication that that potential is starting to get realized in some of those interior sections. They had about a 50 to 100 acre grass fire out there,” Gomberg said.
A small reprieve from the recent heat is inbound as temperatures are expected to drop a few degrees Saturday and Sunday. A heat spike is expected midway through next week when temperatures will be 15-25 degrees above normal, but this patch will not be as hot nor as long as what the region endured in recent days, Westerink said.
A heat advisory may come into place next week, forecasters said.
Coastal areas in Los Angeles will see the marine layer creep back in, making for much milder conditions, Gomberg said. Areas more inland that have been experiencing 90 to 100 degree temps will see a drop to the 80 to 90 degree range, which should feel noticeably cooler, he said.
On Friday, March 20, daily temperature records were broken in Downtown Los Angeles, where a temperature of 96 degrees was recorded, breaking a record of 93 from 1997. A 2004 record of 94 was broken in Woodland Hills, where a temperature of 100 degrees was recorded. At the Long Beach Airport, temperatures reached 91, just edging out a 1997 record of 90 degrees.
This heat wave brought the earliest 100 degree temperatures ever recorded in the San Fernando Valley’s Woodland Hills, according to the National Weather Service.
Across the four days of scorching temperatures, 40 daily high temperature records were broken, the NWS said.