California's latest storm brought pretty much exactly what forecasters expected: heavy bands of rain that caused intermittent flooding to Southern California.
As predicted, Santa Barbara and San Luis Obispo counties were the hardest hit, and though Los Angeles and other counties to the south look like they'll be spared from the worst, flood watches remain in effect until late Friday.
Due to the storm's impact on California, Governor Gavin Newsom declared a state of emergency across 34 counties. President Joe Biden approved an emergency disaster declaration, making federal resources available for both immediate response and recovery.
The storm's been a bit more intense in counties north of L.A.
The heaviest precipitation has been in San Luis Obispo County, which saw more than 10 inches of rain in one remote location.
There's been flooding in Cambria, as well as along the Los Salinas River in Los Padres National Forest. One road in Paso Robles was destroyed. A flash flood warning is in effect for the area and will remain in place until at least Friday night.
PASO ROBLES - Chimney Rock washout - we’re assessing this site and will follow up when we know more. This is a severe storm. Take warnings to stay home seriously. #storm2023 #stormdamage #slocounty @slocountyoes @CountyofSLO pic.twitter.com/bdFAnCnRhx
— County of SLO Public Works (@SLOCountyPWD) March 10, 2023
Santa Barbara – another area of concern according to the National Weather Service – also saw a bit of action, with flooding in northern parts of the county, and mudflows shutting down the 101 North in Los Alamos.
As the rain moved south throughout the day, Ventura also had some issues.
Mudflows impacted homes and a large sinkhole opened up.
#TruenoSinkHole VCFD crews are on scene in the 700 block of Trueno Ave. active sinkhole approximately 30’ by 30’ between two homes on Grada Ave. 16 individuals evacuated. County geologists is on scene. Crews are sandbagging to divert water from the sink hole. #vcfd pic.twitter.com/tkzPPAnYJ1
— VCFD PIO (@VCFD_PIO) March 10, 2023
The storm is expected to wrap up by early Saturday, however there are flood watches in place from Ventura to San Diego. As usual, be careful driving (or don't drive at all) as streets can easily flood, especially when storm drains back up.
Moderate to brief heavy rain will continue to move over Ventura and Los Angeles Counties thru the early evening hours. Minor flooding is likely to occur in urban areas along with small stream flooding. Rainfall rates of 0.30-0.50 inch per hour will be common. #TADD #CAwx #LArain pic.twitter.com/j1zU0h93Kw
— NWS Los Angeles (@NWSLosAngeles) March 10, 2023
Further inland, evacuations orders have been issued for lower lying areas of Kern County due to major flooding.
🚨 HAPPENING NOW 🚨 Recent video sent to us from Kernville, CA. Please stay away from fast moving rivers, creeks, and all flood waters! A sudden rise in water can sweep cars away and knock over an adult with less than 12 inches of water. All residents are https://t.co/bdzTK6DFHn… https://t.co/0464hN8OOl pic.twitter.com/5PeZP6bNFQ
— County of Kern (@CountyofKern) March 10, 2023
A "Pineapple Express" is a strong atmospheric river that pulls moisture up from the tropics, making it warmer than, say, an atmospheric river that comes down from Alaska, like what happened in late February. As a result, more the precipitation falls as rain, though we can see snow at higher elevations.
The current storm's main energy is coming over from the northern Pacific, but the jet stream that's fueling it is bringing up tropical moisture from below Hawaii.
The two are combining off the west coast of North America and slamming into us, as you can see here:
The warm rain brings with it a whole different set of hazards, especially to areas recently deluged by snow.
When it comes to snow-covered mountain communities, warm rain is a concern because it's awfully effective at melting snow and creating all sorts of flooding issues.
In addition to that, it adds to the weight of the snow already piled up on peoples roofs, making them more susceptible to collapse. You can learn about that here: New Storm, New Danger For Mountain Communities Watching For Roof Collapses And Flooding
That said, snowpack at higher elevations is so deep and this rain is likely light enough, that it should just get absorbed into the snow over the next 24 hours. Lower elevation snow that's been sticking around in our foothills will likely melt away.
The warmer weather is also going to increase the risk of avalanches at elevations above 5,000 feet — and, wind gusts up to 40 mph can send things flying.
La Niña is now officially over, according to NOAA. The climate pattern — indicated in part by cooling waters in the equatorial Pacific — is often associated with drier conditions in Southern California, though this winter it clearly was not.
Our snowpack is at nearly 200% of normal across the Sierra and L.A.’s gotten drenched with 184% of the rain we’d expect in an average year. All the precipitation has now had a significant effect on longstanding drought conditions in the state.
The climate patterns known as El Niño and La Niña can have substantial impacts on weather in California. They tend to develop some time around March, with one or the other coming along every three to five years, according to the National Oceanic and Atmospheric Administration.
But what's the difference between them? Here are the basics:
El Niño
La Niña
NOAA also explains that we could see El Niño start to shape up in time for our next rainy season, though it’s a bit far out to say for sure. If it does, that could theoretically mean wetter conditions than normal (what it’s often associated with), though the last time it came around in 2018, we didn’t see much standout precipitation.
The bottom line is this: Save as much water as you can, because besides hotter temperatures, we don’t know what kind of weather the next year is going to bring.
Roadway safety experts advised motorists to:
State law requires residential units to have heating systems that can keep indoor temperatures at a minimum of 70 degrees. That means every dwelling unit and guest room offered for rent or lease should offer heating equipment, usually central air conditioning (A/C) or a wall heater. — Caitlin Hernández
Use heat smartly to save money: Cranking things like the A/C and wall heaters can be expensive. If money is tight, be judicious about how and when you use your utilities. For example, only use heaters at night or only set the thermostat to around 70 degrees.
Open and close those vents: If you have central A/C, look at where the vents are around your home. Are any open in places where you don’t stay long? Practice opening and closing those so warm air only goes where you need it (most vents should have a small toggle lever). Humidifiers can also help you warm things up — and it’s useful to add moisture into our dry air.
Adjust your wall heaters: If you have a wall heater, you can change the output by adjusting the knob (usually at the bottom). Since wall heaters can only warm the areas where they’re placed, it’s essential to close doors to rooms you won’t be in so hot air doesn’t get wasted.
Turn on your ceiling fan (really): If you have a ceiling fan, try turning it on. This sounds counterintuitive, but there’s science behind it. The direction a fan turns can push air in different directions, and since hot air floats up, you’ll want to move that around. Your fan should spin clockwise to create an updraft to circulate. Not all fans will have this option, though.
Here's what you need to know when storms hit Southern California:
