Mud and debris as atmospheric rivers dumped rain in Studio City, Calif., in 2024. Forecasting heavy rain requires measurements from satellites, doppler radar, ocean buoys and other instruments, most of which are operated by the federal government.
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Marcio Jose Sanchez
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Topline:
Millions of Americans rely on weather forecasts every day. How are these forecasts made and where does the underlying information come from? We break it down, and explain how some of that weather information might be interrupted this year.
Satellites and radars: Basic measurements about the weather are the fuel for accurate forecasts. One of the most powerful ways to collect global data about the weather is through satellites and Doppler radar towers. Satellites offer big-picture information. For example, weather satellites can track hurricanes as they move across the ocean, and wildfire smoke as it spreads across large swaths of land. Weather satellites also measure lightning activity, cloud cover, the temperature of the ocean surface and humidity in the atmosphere.
Measuring the atmosphere: Balloon data, and other aerial measurements from planes, are the single most impactful source of data for weather forecasting computer models. In addition to providing real-time information about what's happening in the atmosphere, forecasters rely on balloon measurements to calibrate satellite data. Without balloon measurements, satellite measurements are less useful.But multiple National Weather Service offices have cut back on balloon launches this spring because of staffing shortages. The Trump administration has moved to lay off hundreds of weather workers and left hundreds of other critical forecasting positions vacant after workers retired.
You're about to walk your dog, but the sky looks ominous. You pull out your phone, open your favorite weather app, and see that it's about to pour. You wait for the rain to pass.
Or maybe you planned a summer vacation at the beach. A week before you're supposed to leave, you hear a weather alert on the radio in your car. There's a hurricane headed toward the coast. You have plenty of time to make new plans — and spend your vacation out of harm's way.
Millions of Americans rely on weather forecasts every day. And accurate weather forecasts have never been easier to access. Hourly outlooks and severe weather warnings are available on smartphone apps and weather websites, TV and radio broadcasts and in newspapers.
But how are these forecasts made? Where does the underlying information come from?
We break it down, and explain how some of that weather information might be interrupted this year.
Weather forecast Step 1: Make lots of measurements
Basic measurements about the weather are the fuel for accurate forecasts. That includes information about how fast and in what direction the wind is blowing, where it is raining or snowing and how much precipitation is falling, what the barometric pressure is and whether there are clouds.
And accurate weather forecasts require data from all over the world, says Alex Lamers, Forecast Operations Branch chief for the National Oceanic and Atmospheric Administration's Weather Prediction Center. "Weather happens in the atmosphere, and the atmosphere is connected globally. It doesn't happen in isolation over one specific location," he explains.
One of the most powerful ways to collect global data about the weather is through satellites and Doppler radar towers.
A satellite image of an atmospheric river moving in on Northern California and the Pacific Northwest in November 2024. Satellites operated by NOAA and NASA provide crucial, round-the-clock weather data for the United States.
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Satellites offer big-picture information. For example, weather satellites can track hurricanes as they move across the ocean, and wildfire smoke as it spreads across large swaths of land. Weather satellites also measure lightning activity, cloud cover, the temperature of the ocean surface and humidity in the atmosphere.
The U.S. government, through NASA and the National Oceanic and Atmospheric Administration (NOAA), operates multiple weather satellites and makes all the data they collect available to the public for free. Private weather forecasting companies, like the ones that operate weather websites and smartphone weather apps, use that data to inform their weather forecasts.
"Whatever weather app you might have on your phone, the view of clouds and precipitation from Doppler radar, that's probably NOAA data," Lamers says.
A NOAA weather satellite known as GOES-17 is prepared for launch in 2018. The satellite continuously measures weather conditions for an area that includes the West Coast of the United States.
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The National Weather Service also operates more than 150 Doppler radar towers across the country and shares the data with the public for free. Like satellites, Doppler radar collects big-picture information about rain, snow, sleet and hail, wind speed and direction and the clouds associated with thunderstorms. It can also detect debris in the air from tornadoes, which is very helpful for tracking where a tornado is and where it's going.
Having continuous information from radar and satellites is crucial during storms, including severe thunderstorms, tornado outbreaks and atmospheric rivers, Lamers explains. "That's really important for us to monitor storms as they develop," he says, "[to] be able to monitor the current state of the storm, where the most intense parts are, and be able to monitor that around the clock."
In an open letter in May, all five living former weather service directors expressed concern that those radar installations could be impacted by the Trump administration's federal hiring freeze and budget cuts, because radar instruments require maintenance by highly skilled technicians and there are many vacant positions.
The proposed White House budget would slash funding for NOAA by about a third and virtually eliminate weather research, ocean observations and work on new satellites.
A truck-mounted radar instrument called the Doppler On Wheels near Amanda Park, Wash. Scientists at NASA and the University of Washington used the radar instrument to validate satellite measurements of rain and snow. Permanent Doppler radar installations across the country, operated by NOAA, provide crucial real-time measurements about precipitation, tornado debris and hail.
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Many of those measurements happen at automated weather stations. NOAA runs about 900 weather stations all over the country. You might have seen one at an airport or next to a government building. One of the most obvious instruments is a rotating wheel with little cups on the end that measures wind speed.
Ocean information is also important because a lot of dangerous weather systems, including hurricanes and atmospheric rivers, form over the ocean before they affect the U.S.
But operating weather-monitoring instruments in the ocean takes a lot of work, because the conditions on the open sea are so harsh. The federal government maintains about 200 ocean buoys, as well as gliders and other instruments that can measure what's happening below the surface of the ocean. Research ships, military vessels and some cargo ships also contribute weather data for the public.
"Obviously we cannot cover the entire globe, the entire surface of the Earth, with all these instruments, so we have to be smart," says Vijay Tallapragada, a weather modeling expert for NOAA's Environmental Modeling Center. For example, weather sensors are strategically located in parts of the ocean where severe weather is more likely to form.
A NOAA ocean buoy is deployed in the Pacific Ocean in 2022. Ocean buoys measure wind, water temperature and other conditions on the open ocean. Because many weather systems form over the water, such data is important for accurate weather forecasts for the U.S.
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The last, and arguably most crucial, piece of the puzzle is information about the atmosphere. Every day, employees at the National Weather Service launch weather balloons with sensors attached to them. Until recently, that was happening at least twice a day at 90 locations across the country, and more often in places that were expecting severe weather such as tornadoes.
But multiple National Weather Service offices have cut back on balloon launches this spring because of staffing shortages. The Trump administration has moved to lay off hundreds of weather workers and left hundreds of other critical forecasting positions vacant after workers retired.
The weather service addressed such disruptions in a written statement. "The National Weather Service is adjusting some services due to temporary staffing changes at our local forecast offices throughout the country in order to best meet the needs of the public, our partners and stakeholders in each office's local area," the statement says. "These adjustments are also temporary and we will continue to fulfill our core mission of providing life-saving forecasts, warnings, and decision support services."
Tallapragada says balloon data, and other aerial measurements from planes, are the single most impactful source of data for weather forecasting computer models. In addition to providing real-time information about what's happening in the atmosphere, forecasters rely on balloon measurements to calibrate satellite data. So, without balloon measurements, satellite measurements are less useful.
"We definitely know that aircraft measurements and balloon data have the largest impact on the forecasts," Tallapragada explains.
A National Weather Service weather balloon launches in Bismarck, N.D., in June 2017. Weather balloons go up more than 5 miles into the atmosphere and transmit measurements back to the ground continuously as they fly.
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Weather forecast Step 2: Put all the data into a weather supercomputer
A weather forecast is basically the solution to a really complicated math problem. Supercomputers can solve that problem. They take all the information about what's going on in the atmosphere and oceans and use it to predict and track weather that will happen in the coming weeks.
The supercomputers doing this task for the U.S. are run by NOAA.
Those computers run multiple weather models, tailored to different types of weather. For example, hurricane models to predict when and where hurricanes will hit land, and how damaging they will be when they arrive.
Developing and running the computer models is quite labor-intensive, Tallapragada explains. "Each of these models require continuous improvement and maintenance," he says.
The incoming weather information changes all the time. Instruments on buoys and planes are replaced or recalibrated. Old satellites are decommissioned and new ones are launched. Private companies and weather services for other nations agree to share data, or change which data they're providing. Every little change must be accounted for in the computer models.
"So we need people to process, understand, calibrate and characterize those datasets so they can be assembled and used in a meaningful way," Tallapragada says.
Robert Fraser surveys damage to a warehouse after a tornado passed through an industrial park in Jeffersontown, Ky., in April. The National Weather Service provides real-time warnings about tornadoes across the country, which show up on cellphones, weather apps and websites and play on the radio and broadcast television stations in affected areas.
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Weather forecast Step 3: Translate the forecast from computer-speak to human-speak
The supercomputer is great at math, but it's not great at communicating with humans. When it is done crunching the numbers, it spits out a forecast result that's still mostly math.
Human forecasters then have to interpret the result and translate it into an actual weather forecast. For example, a string of numbers and probabilities becomes a map showing how much rain is expected to fall over a certain area in the next three days, and what the temperature will be each hour.
That work is done by professional weather forecasters, including meteorologists at more than 100 National Weather Service offices around the country. Local National Weather Service offices provide free, detailed local forecasts every few hours.
Meteorologists at private companies, including those who work for TV, radio and newspaper outlets, also rely on public weather model information to inform their local weather forecasts.
And if there's severe weather headed your way, like a hurricane, heavy rainstorm or tornado, the local National Weather Service office will put out a warning. That warning automatically shows up and makes an alarm sound on all the smartphones in the area. Warnings also play on the radio and on local television news stations, and they show up on weather apps and websites.
In their open letter this spring, former weather service directors warned that severe staffing shortages at local weather service offices could lead to less accurate and detailed forecasts this summer.
"Work is underway to restore services at local forecast offices around the country," according to a statement from the National Weather Service.
The summer and fall months are a busy time of year for severe weather in the U.S., from heat waves and hurricanes to heavy downpours and hailstorms. And climate change is causing dangerous weather to get more common.
Copyright 2025 NPR
O.C. Japan Fest, corgi beach day, the grunions are back, a new play festival, a talk with Sen. Cory Booker and more of the best things to do this weekend.
Highlights:
Experience sakura season without leaving the area at the O.C. Japan Fair, featuring 250 vendors, craftspeople, food booths, art activities and more, all celebrating Japanese culture.
Check out readings of five new plays – all for free! – at the Play L.A. New Works Festival, put on by Stage Raw and the Greenway Arts Alliance along with a number of L.A. indie theater powerhouses.
Spend Friday night with New Jersey Senator Cory Booker, whose new book, Stand, tells stories from his political life that aim to share “actionable insights” to help preserve democracy in these challenging times.
I hope you had luck in securing the first round of LA28 Olympics tickets — and that you’re not still waiting for page refreshes this morning! We’ve got all the info on how to get your tickets and why you shouldn’t fret if it doesn’t work out on this first try.
LAist’s Mariana Dale went to Hollywood High School this week to see how students and teachers felt about Mitski bringing a concert to the historic space. Seems like no one was missing class since perfect attendance meant a shot at tickets.
No matter your music taste, there’s a show for you this weekend. It may not be the height of summer yet, but things will be heating up at the Hollywood Bowl as Ben Platt and Rachel Zegler reunite for their concert performance of Broadway hit The Last Five Years. Plus, Licorice Pizza recommends Mercury Prize-winning London rapper Dave at the Palladium, St. Paul & the Broken Bones are at the Belasco, Calum Scott plays the Wiltern, and there’s a really cool First Fridays night at the Natural History Museum with dub legend Adrian Sherwood. Saturday has pop trio LANY at the Intuit Dome, Lamb of God slaughtering the YouTube Theater, SoundCloud rapper Rich Amiri at the Fonda, post-hardcore band Hail the Sun at the Wiltern, pop sensation Nessa Barrett at the Masonic Lodge, and another rising pop star, Alexander Stewart, at Chinatown’s cool new venue, Pacific Electric.
Experience sakura season without leaving the area at the O.C. Japan Fair, featuring 250 vendors, craftspeople, food booths, art activities and more, all celebrating Japanese culture. From sake tastings to sushi-making workshops to musical performances and kimono try-ons, the annual event is one of the largest Japanese cultural fairs in California.
Play L.A. New Works Festival
April 3-4 Greenway Court Theatre 544 North Fairfax Ave., Mid-City COST: FREE, MORE INFO
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Check out readings of five new plays — all for free! — at the Play L.A. New Works Festival, put on by Stage Raw and the Greenway Arts Alliance, along with a number of L.A. indie theater powerhouses. This year’s plays are Stonewall’s Bouncer by Louisa Hill, produced by The Victory Theatre; At Olduvai Gorge by India Kotis, produced by The Odyssey Theatre Company; Ghost Play by Mathew Scott Montgomery, produced by InHouse Theatre; The Incident by Rachel Borders, produced by The Road Theatre Ensemble; and Three Dates by Erica Wachs, produced by IAMA Theatre Company. Go see one, or go see them all!
SoCal Corgi Beach Day
Saturday, April 4, 10 a.m. to 3 p.m. 21351 California 1, Huntington Beach COST: FREE; MORE INFO
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Head to Huntington Beach for the cutest event of the year, the annual SoCal Corgi Beach Day. This year’s theme is "Tiki Beach Pawty," because of course it is. Honor Queen Elizabeth II’s favorite pets and spend the day at the beach with these short, stout, snuggly friends while they frolic and compete in events like — I am not making this up – Corgi Limbo.
Plaza Mexico Celebrates Easter
Sunday, April 5, 12:00 p.m. to 4 p.m. 3100 E. Imperial Highway, Lynwood COST: FREE; MORE INFO
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You have your pick of Easter Bunny photo ops and egg hunts around town, and Plaza Mexico would be a great one with the family. Meet and take a picture with the Easter bunny, enjoy kids' arts & crafts, family activities, vendors and sweet treats.
Writers Bloc: Cory Booker
Friday, April 3, 7:30 p.m. John Adams Middle School (JAMS) Performing Arts Center 2425 16th St., Santa Monica COST: $33; MORE INFO
NEW YORK, NEW YORK - FEBRUARY 05: Senator Cory Booker attends PBS' "Black & Jewish America: An Interwoven History" Screening With Henry Louis Gates, Jr. And Conversation With Sen. Cory Booker at 92NY on February 05, 2026 in New York City. (Photo by Jamie McCarthy/Getty Images)
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Spend Friday night with New Jersey Senator Cory Booker, whose new book, Stand, tells stories from his political life that aim to share "actionable insights" to help preserve democracy in these challenging times. The conversation with Writers Bloc will be hosted by Sean Bailey, the former head of Walt Disney Studios Motion Picture Production for 14 years and the current CEO of the new multi-platform production company B5 Studios. The event is sold out, but there is a waitlist available.
Behind the Canvas — An Exclusive Art Talk with the Jurors of A Woman's Place: Framing the Future
Saturday, April 4, 11 a.m. Ebell of Los Angeles 741 S. Lucerne Blvd., Mid-Wilshire COST: FREE; MORE INFO
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Have coffee and doughnuts with the curators of the Ebell’s Women’s History Month exhibit, "A Woman’s Place: Framing the Future." You can catch the show before it closes and see work from women artists exploring new interpretations of womanhood, feminism and art.
Grunion Run
Saturday, April 4, starting at 10:30 p.m. Venice Breakwater Ocean Front Walk, Venice COST: FREE; MORE INFO
Thousands of grunions on the shore.
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I have lived in Venice for more than 20 years and never actually seen a grunion, despite efforts, but that doesn’t mean it’s not fun to see all your neighbors scouring the beach by moonlight on a Saturday night. The Venice Oceanarium folks always organize an educational tent with lessons on how these unique fish show up on our shores to reproduce, and maybe you’ll luck out and time it right this year.
She’s Auspicious
Saturday, April 4, 7 p.m. Broad Stage 1310 11th St., Santa Monica COST: FROM $40; MORE INFO
L.A. native Mythili Prakash takes the Tamil dance form Bharatanatyam to new heights as a choreographer and performer. Her short dance film Mollika, commissioned by Sadler’s Wells Digital Stage in London, was nominated for a 2025 National Dance Award for Best Short Dance Film. She’s Auspicious, her latest production, "blurs the line between goddess and woman, exploring the dichotomy between celebration of the goddess versus the treatment of women in society." It was nominated for an Olivier Award in the category Best New Dance Performance in the U.K., and lucky for us, is on for one performance only at the Broad Stage in Santa Monica.
Julia Barajas
explores how college students achieve their goals, whether they’re fresh out of high school, pursuing graduate work or looking to join the labor force through alternative pathways.
Published April 2, 2026 5:00 AM
Cal State Long Beach is one of the 23 CSU campuses where Teamsters-represented workers held a strike last month.
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Topline:
The California Public Employment Relations Board (has issued a formal complaint against California State University trustees over the system’s alleged refusal to give raises to trades workers. The complaint follows a statewide strike earlier this year, in which workers at every campus walked off the job.
Why it matters: Teamsters Local 2010 represents 1,100 plumbers, electricians, HVAC techs, locksmiths and other building maintenance staff who work across the CSU system. A formal complaint from the Public Employment Relations Board means the two parties must resolve the dispute in a formal hearing process.
The backstory: According to Teamsters Local 2010, union members won wage increases in 2024 “after nearly three decades of stagnation.” That year, the union was on the verge of striking alongside the system's faculty, but it reached a last-minute deal with the CSU. The union has filed an unfair labor practice charge against the system, arguing that the CSU refused to honor contractually obligated raises and step increases for its members.
What the CSU says: The CSU maintains that conditions described in its collective bargaining agreement with the union — which “tied certain salary increases to the receipt of new, unallocated, ongoing state budget funding” — were not met.
What’s next: In an emailed statement, spokesperson Amy Bentley-Smith said the CSU welcomes “the opportunity to present the facts of this case before an administrative law judge.” After the formal hearing, the state board will propose a resolution to the dispute.
If you're enjoying this article, you'll love our daily newsletter, The LA Report. Each weekday, catch up on the 5 most pressing stories to start your morning in 3 minutes or less.
Wind moves palm trees on Monday, Dec. 29, 2025, in Stanton.
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Mel Melcon
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QUICK FACTS
Today’s weather: Mostly cloudy then sunny
Beaches: mid to upper 60s
Mountains: mid 60s to around 70 degrees
Inland: 64 to 71 degrees
Warnings and advisories: Wind advisory
What to expect: A mostly sunny afternoon with temperatures sticking to the low to mid 70s for most of Southern California. Breezy conditions will pick up in the afternoon for some valleys and mountain communities.
Read on ... for more details.
QUICK FACTS
Today’s weather: Mostly cloudy then sunny
Beaches: mid to upper 60s
Mountains: mid 60s to around 70 degrees
Inland: 64 to 71 degrees
Warnings and advisories: Wind advisory
The cool weather continues for one more day in Southern California. Later this evening, strong winds will kick in for some mountains and highway corridors ahead of a Santa Ana wind event slated for Friday.
Temperatures at the beaches are going to stick around the mid to upper 60s, and around 70 degrees more inland.
Coachella Valley, San Bernardino and Riverside County mountains will continue to see gusty winds until tonight.
At noon, the Antelope Valley will be under a wind advisory, with winds expected to reach 20 to 30 mph, and some gusts up to 50 mph. Wind advisories will also kick in for the 5 Freeway corridor, Ventura County mountains and the Santa Susana mountains, where gusts could reach 45 mph.
Libby Rainey
has been tracking how L.A. is prepping for the 2028 Olympic Games.
Published April 2, 2026 5:00 AM
The official Olympic flag returns to Los Angeles for the first time in 40 years.
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Dania Maxwell
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Topline:
One or two line overview of the story, should be sharp and to the point. If it's the only thing they read it should still give them good info.
{ERASE ME — some possible lead ins, please change/add/delete what makes sense for story}
Why it matters:
Why now:
The backstory:
What's next:
Go deeper: {if you have stories you want to link add them here}
A key agreement outlining what city services Los Angeles will provide for the 2028 Olympic Games and how the cash-strapped city will be reimbursed for its extra work is now six months late.
High-stakes talks over that agreement between the city and the private Olympics organizing committee LA28 have dragged far past an Oct. 1 deadline, sparking concern from city officials and observers that taxpayer dollars could be on the line.
City Controller Kenneth Mejia, who audits and scrutinizes city finances, called the delay "deeply troubling."
"The City needs a guarantee from LA28 that they will not go over budget and will pay for all of the additional security, sanitation, transportation, administrative, and any other costs associated with the Games," Mejia said in a statement to LAist. "The preparation and execution of these events should not come at any cost to Los Angeles taxpayers."
The 2028 Olympics are intended to be privately financed, and an existing city agreement with LA28 states that the Olympics organizers, not L.A., will pay for extra costs for public services in support of the Games – like policing and traffic control.
But the nuts and bolts of that arrangement have not been finalized, and if the agreement leaves L.A. exposed to unexpected or additional expenses, taxpayers could end up paying many millions.
Hosting the Games is already an enormous financial risk for Los Angeles. The city is the financial backstop for the Olympic Games, meaning if the organizing committee runs into the red, L.A. will pick up the bill, along with the state of California.
The extra staff and resources the city will dedicate to the Games represents another area where L.A. may end up with surprise costs.
Why is the agreement delayed?
Neither the city nor LA28 have shared publicly what's holding up the deal.
Past public meetings and comments indicate that the two sides may disagree over the scope of LA28's obligation to cover city expenses.
At a December city council meeting, the city administrative officer and council members discussed the boundaries of where LA28's responsibility for a service like traffic control ends and the city's responsibility begins.
The city's Chief Legislative Analyst Sharon Tso, who is leading negotiations with LA28 along with the City Administrative Officer, told LAist in an email Wednesday that the city is still discussing the terms for things like cost estimates, service levels, and timelines for repayment.
"We continue to work diligently with LA28 to finalize the agreement," Tso wrote. "I do not have an anticipated completion date at this time."
Jacie Prieto Lopez, Vice President of Communications and Public Affairs for LA28, said in a statement provided to LAist that the organizing committee was working with city leadership to finalize the agreement.
"We remain engaged in good faith negotiations and look forward to our continued partnership with the City of Los Angeles," she said.
Once the agreement is completed, it will be submitted to the city council and mayor.
LA is counting on federal funding
LA28 isn't the only entity expected to pay L.A. for Olympics-related costs. The city also is banking on money from the federal government, which has allocated $1 billion for security costs.
The city administrative officer told the council last year that city spending on security at the Olympic venues, like for local police, should be covered by those funds.
