Heat Wave

When and Where to Expect Record Highs During This Week's Heat Wave

Temperatures during the late-spring heat wave will peak Tuesday and Wednesday, but the rest of the week will still be hot.

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What to Know

  • Temperatures will peak Tuesday and Wednesday, remaining above normal for the rest of the week.
  • Triple-digit record temperatures are likely in the valleys and mountains.
  • The forecast raises the possibility of heat-related illnesses, strain on the power grid and brush fires that could quickly spread in the hot and dry conditions.

Summer is still days away, but record high temperatures are possible this week when a heat wave develops in Southern California.

Triple-digit record temperatures are likely in the valleys and mountains. Downtown Los Angeles could reach 100 degrees.

The forecast raises the possibility of heat-related illnesses, strain on the power grid and brush fires that could quickly spread in the hot and dry conditions. An excessive heat watch will be in effect from Tuesday morning through Wednesday evening along the Los Angeles County Coast, including downtown. An excessive heat watch through Friday night across the valleys and mountains.

In the Antelope Valley, temperatures might reach 113 this week.

Expect the peak of the heat from Tuesday through Thursday when highs between
100 and 110 and minimum humidities between 5 and 15 percent will be common over most mountains and lower elevations.

"The temperatures keeps climbing tomorrow," said NBCLA forecaster Belen De Leon. "That's when we could break some record highs."

Big Bear, Anaheim, Palmdale and Palm Springs are some of the locations that might reach record highs.

Monday night through Tuesday night is of particular concern, when north winds increase and enhance the warming and drying over the coasts and nearby valleys.

For interior valleys, hot, dry and breezy conditions could create critical fire danger. Red flag warnings will be in effect Monday evening through Wednesday morning along the south Santa Barbara County coast and critical fire weather conditions are also expected in southeastern California. 

Coastal areas will see relief a little earlier, with onshore flow expected to return by late Wednesday, bringing a return of the marine layer that will bring temperatures down.

"Thursday and Friday the temperatures start coming down, but it's still above normal," said De Leon. "This weekend for Father's Day weekend it's going to be a warm one."

Power Impacts

About 4,400 customers were without power in the Cudahy area late Monday morning, but it was not immediately clear whether the outages were heat-related. Most power was expected to be restored by midday.

The California Independent System Operator, which manages the state's power grid, released a statement saying the agency could take a number of actions to reduce demand and access additional energy.

The agency declared a restricted maintenance operation condition that will be in effect from noon to 10 p.m. Tuesday through Friday due to the forecasted high temperatures and demand. The declaration warns that all available resources will be needed to maintain supply, and calls on suppliers to defer scheduled maintenance on generators and transmission lines if possible.

"It is still too early to know the precise impact (the) high temperatures will have on the electricity grid,'' according to Cal-ISO. "But the ISO is closely monitoring conditions and the anticipated increase in demand for electricity and will issue additional public notifications as warranted.''

If necessary, the ISO could issue a Flex Alert, which is a voluntary call for residents to conserve power during peak hours to reduce strain on the grid.

About Your Health

The South Coast Air Quality Management District issued an ozone advisory Monday through Saturday, predicting increased likelihood of poor air quality in many areas. Levels of ground-level ozone -- the predominant summertime pollutant -- are likely to reach unhealthy or higher air quality index levels throughout most of the Southland.

And, the Los Angeles County Health Officer issued a Heat Alert starting Monday and ending Wednesday for West San Fernando Valley, East San Fernando Valley, East San Gabriel Valley, Santa Clarita Valley, Antelope Valley and San Gabriel Valley -- reminding everyone in those regions to take precautions to avoid heat-related illness, especially older adults, young children, outdoor workers, athletes, and people with chronic medical conditions.

Public Health issued the following recommendations to stay safe during high temperature days:

  • Drink plenty of water throughout the day;
  • Plan your day to avoid going out during the hottest hours, and wear sunscreen. 
  • Wear lightweight, light-colored clothes, and wear a hat or use an umbrella.
  • Never leave children or pets in cars and call 911 if you see a child or pet in a car alone.
  • Beware of heat-related illness, like heat stroke and call 911 if you or someone you know is experiencing high body temperature, vomiting, and pale and clammy skin.
  • Check on those at risk, such as those who are sick, older adults, pregnant women, and children, and those who live alone.
  • If you are wearing a mask, avoid strenuous workouts wearing face coverings or masks not intended for athletic purposes.
Copyright CNS - City News Service
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