NOAA’s hurricane hunters are now targeting the West Coast’s atmospheric rivers
Editor’s note: A version of this article originally appeared in the weekly weather bulletin, CNN Weather Brief, which is published every Monday. You can sign up here to receive them weekly and during major storms.
NOAA’s hurricane hunters can be just as busy now as they were during hurricane season. However, it is not the hurricanes they are flying through, but the atmospheric river systems that have been plaguing California since Christmas week.
Atmospheric rivers may not make headlines in the same way as hurricanes, but they can have extreme consequences.
“Atmospheric rivers can stretch across the Pacific. They’re long and narrow, but they’re much bigger than hurricanes,” said Atmospheric River Discovery Coordinator Anna Wilson.
They are crucial for the West Bank. Half of the rain and snow the West receives comes from atmospheric rivers, which are plumes of moisture coming from the Pacific Ocean. And they cross an area with very few observation sites, making them challenging to predict.
Until recent years, forecasters had to rely only on satellites and forecast models to predict atmospheric rivers, which can get very muddy without really knowing what’s going on inside storms.
The University of California-San Diego, the Scripps Institution of Oceanography and the Center for Western Weather and Water Extremes have teamed up with NOAA’s Hurricane Hunters, which are able to drop instruments called “dropsondes” inside an atmospheric river, to broadcast live correct. weather data. The information is instantly fed into weather forecast models, which dramatically improves forecast accuracy.
“With the drops released by the hurricane hunters, we get profiles of humidity, temperature, winds, in the lower atmosphere, which are really critical to understanding the atmospheric structure of the river,” Wilson said.
The information not only improves general knowledge of what atmospheric rivers are capable of doing, but improves immediate forecasts.
“NOAA aircraft are flying into these weather systems and validating the models,” Capt. Jason Mansour, pilot and commander of the NOAA Gulfstream IV Hurricane Hunter aircraft. “Then the NOAA National Weather Service is better prepared to predict where and when these systems will have impact and how much impact it will have.”
Mansour is a seasoned veteran of hurricane hunters. He says the ride may be a little less bumpy for atmospheric rivers, but the mission is the same.
“We are effectively part of the early warning system for atmospheric rivers across the board,” Mansour explained.
Parts of California have seen nearly a foot of rain since Christmas weekend. San Francisco received more than nine inches of rain, while Lake Tahoe saw more than 11 inches. Even at the highest elevations, the snow totals have been staggering. Parts of the Sierra have more than double the snow they would normally see this time of year. Mammoth Mountain has seen nearly 120” of snowfall since December 26th alone. And that’s not all.
This week will begin the fourth straight week of rain and snow for California. The series of atmospheric river events, occurring in rapid succession, are being referred to by experts as an “atmospheric river family”.
“Which basically means a series of them back to back with maybe a day or so in between,” Wilson explained. “If it came on its own, it wouldn’t have much of an impact, but because it came after the other three, it has much higher hydrological impacts than it would otherwise.”
The West has been at the forefront of hydrological problems. Experiencing severe drought, resulting in dry lakes and river beds, intense fires, and possible water shortages. The pendulum has now swung and California is now facing extreme drought and extreme flooding simultaneously as the current rainfall will not solve California’s drought.
“What we need to get out of the drought is not an extremely wet month where a lot of that water won’t be stored because of runoff,” Wilson explained. “What we need is a few sustained wet years and it’s coming in a way where more of it can seep into the ground.”
Wilson added that she has seen the pendulum swing many times in California, but not like this.
“The swing back and forth is potentially getting wider and wider,” Wilson said. “California is known for its erratic weather swings, but it seems like the last few years it’s been, like right now, we’re going from this new dry record to this new wet record.”
Rain will continue this week for the West, with no real closure of moisture available in the near future.