KEESLER AIR FORCE BASE, Miss. —  With Hurricane season just barely finished, members of the 53rd Weather Reconnaissance Squadron started the new year off on their way out to fly Atmospheric Rivers missions as a part of the unit’s role in the National Winter Season Operations Plan.

1st Lt. Tim Viere, pilot for the 53rd Weather Reconnaissance Squadron at Keesler Air Force Base, Miss., steers a WC-130J “Hurricane Hunter” aircraft during an atmospheric river reconnaissance mission from Reno-Tahoe International Airport, Nev., Jan. 31, 2021. The 53rd WRS is part of the Air Force Reserve’s 403rd Wing and is the only unit of its kind in the Department of Defense. (U.S. Air Force photo by Senior Airman Kristen Pittman)

“We already conducted two AR missions this season,” said Lt. Col. Ryan Rickert, 53rd WRS aerial reconnaissance weather officer. “These two missions were back in November.”

The Air Force Reserve began flying the Atmospheric Rivers missions in 2016, 2018 and 2019 as part of a research-based project, with flights added each year, until it became integrated into the NWSOP in 2020.

The winter storm season for the 53rd WRS begins Nov. 1 and ends March 31, with dedicated AR mission support along the Pacific Ocean Basin starting in January until March. The 53rd WRS fly these missions in support of the National Centers for Environmental Protection.

“Coordination for all winter season weather reconnaissance flights include several organizations including NCEP and the National Weather Service,” said Maj. Chris Dyke, 53rd WRS ARWO. “The ARs are a specific type of weather system in which we partner with the Scripps Institute of Oceanography to assist in identifying when and where weather data collection will contribute the most to improving forecast accuracy.”

The weather data collected during the AR missions helps build a vertical profile of the water vapor in the low-level jet stream.

“This data that we collect benefits in making the forecast models more accurate,” said Rickert. “The dropsondes we release collect temperature, dewpoint, pressure, wind speed and direction in the Atmospheric Rivers.”

Atmospheric rivers are rivers of moisture or water vapor that carry 25 times the water equivalent of the Mississippi River. Flowing at an altitude of about 10,000 feet, atmospheric rivers average between 100 and 500 miles wide and 2,000 miles long. When and where these ARs make landfall can be the determining factor of heavy rain, snow or it can lead to extensive flooding.

The weather data collected is used to improve forecast models for the West Coast and provide the critical knowledge needed to improve reservoir operations that can supply water during droughts and assist with the control of water levels during potential flood events.

“The impacts of knowing exactly where the AR is going to hit is important in determining reservoir management,” said Rickert. “Because having that information helps them make the decision on whether to release or hold the water in the reservoir.”