February 11, 2008
In an effort to improve forecasts released 12 and 72 hours before a winter storm, NOAA is flying its WP-3D “hurricane hunter” aircraft into severe weather over the Pacific Ocean from a temporary base in Portland, Ore. The aircraft is acquiring atmospheric data from severe winter storms originating over the Pacific Ocean that will affect the continental United States. The flights are in support of NOAA’s Winter Storms Reconnaissance program.
To provide full coverage of the Pacific jet stream that affects weather patterns over the United States, an Air Force Reserve WC-130 aircraft is flying missions out of Honolulu in conjunction with the NOAA P-3. Both aircraft are deploying dropwindsondes — small meteorological instruments that measure temperature, wind speed, humidity, and surface pressure. The information is relayed in real time to NOAA’s National Weather Service supercomputer, which incorporates it into the agency’s numerical prediction models.
“If you want to really know what the weather will be like two or three days ahead, you must get an accurate sense of what the weather is doing currently,” said Dr. Zoltan Toth, a research meteorologist at NOAA Environmental Modeling Center in Camp Springs, Md. “The net result of the flights is a 48-hour targeted storm forecast that is as accurate as a 36-hour forecast. The increased forecast lead time is crucial for residents living in the path of the storm.”
The aircraft are deployed from one to four days before a potential Pacific storm system that appears headed for the continental United States. “The NOAA P-3 and Air Force Reserve’s WC-130 will fly in tandem to capture data north and south of the jetstream simultaneously,” said Jack Parrish, meteorologist and program manager for the G-IV at NOAA’s Aircraft Operations Center in Tampa, Fla. “These flights provide the most comprehensive data coverage collected in the environment of winter storms.”
In its eighth year, the Winter Storm Reconnaissance Program has already seen up to a 20 percent increase in forecast accuracy on average. This year a new experiment — the Hydrometeorology Testbest (HMT) “Atmospheric Rivers” project — will be added to the aircraft’s mission. HMT will focus observations on low-level jets of high moisture within winter cyclones making landfall on the West Coast. In addition to causing flooding rains in the coastal mountains and playing a critical role in the global water cycle, atmospheric rivers are integral to water resource issues in the semi-arid West, where a majority of snowfall in the higher elevations provides year-round fresh water to the population.
The National Oceanic and Atmospheric Administration, an agency of the U.S. Commerce Department, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of our nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 70 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.