NOAA Study Seeks to Improve Accuracy of Winter Weather Forecasts
For people living in and traveling through the mountain regions in the western United States, winter weather can be unpredictable. This week, the National Oceanic and Atmospheric Administration (NOAA) begins a month-long research project to learn more about snow and rain in mountain areas with the ultimate goal of improving future winter weather forecasts.
The Intermountain Precipitation Experiment (IPEX) is a field project designed to improve the understanding, analysis and prediction of precipitation and precipitation processes in complex terrain. Thirty scientists from several NOAA organizations and the Universities of Utah and Oklahoma will gather data from Jan. 31 to Feb. 25 in the Wasatch Range of northern Utah based out of the National Weather Service (NWS) Forecast Office in Salt Lake City.
The major scientific objectives of IPEX are to understand the causes and variation in mountain precipitation and to study lake-effect precipitation downwind of the Great Salt Lake. The researchers will use the data they gather to validate precipitation estimates produced by Doppler weather radars located at high elevation. Ultimately, what the scientists learn during IPEX will be used to improve computer-based forecast models employed by forecasters in mountainous regions.
"During the past nine years, the fastest growing states have been Nevada, Arizona, Idaho and Utah. The steep terrain in this area makes it one of the most difficult places to forecast snow and rain," said project co-lead scientist Dr. David Schultz, research meteorologist with NOAA's National Severe Storms Laboratory in Norman, Okla. "Future analysis of the data we collect during IPEX should allow scientists to develop better understanding of the structure and evolution of these weather systems, eventually leading to better forecasts."
A variety of sophisticated atmospheric observing platforms will be used during the experiment. The NOAA P-3 research aircraft, equipped with meteorological instrumentation and radars, will fly into the storms. On the ground, scientists will release instrumented weather balloons from two NSSL mobile laboratories. Three mobile Doppler weather radars and a stationary microwave radiometer will be deployed throughout northern Utah to map areas of clouds and precipitation.
Weather balloons will be released three to eight times a day at National Weather Service sites near Boise, Idaho; Grand Junction, Colo.; Salt Lake City; Elko and Las Vegas, Nev. These measurements will enhance an existing surface observing system known as the Mesowest Cooperative Networks coordinated by the University of Utah.
The impact of IPEX will be far-reaching.
"The results from IPEX will have positive scientific and socio-economic benefits for the intermountain west, including Salt Lake City, host of the 2002 Winter Olympics," said Dr. James Steenburgh, meteorology professor at the University of Utah and IPEX co-lead scientist. "Local forecasters will use the data on a real-time basis during the experiment and the results will be used in future weather forecasts."
IPEX is lead by Schultz and Steenburgh; Dr. Jeff Trapp, NOAA/NSSL, Boulder, Colo.; and Dr. David Kingsmill, Desert Research Institute, Reno, Nev. Organizations collaborating on the project are the University of Utah and the National Weather Service Forecast Office in Salt Lake City; National Severe Storms Laboratory and Storm Prediction Center in Norman, Okla.; the NWS Hydrometeorological Prediction Center in Camp Springs, Md.; and flight crew members from NOAA's Aircraft Operations Center at MacDill Air Force Base in Florida. The scientists will be joined by 20 meteorological students from the Universities of Utah and Oklahoma.
Additional funding for the project was provided by the Utah Department of Transportation to purchase surface observing systems for IPEX observation sites.
For more information, visit the IPEX Web sites:
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The Intermountain Precipitation Experiment (IPEX) is a field research program to improve the understanding, analysis, and prediction of precipitation in the Western United States, in particular, Northern Utah.
The project involves 30 scientists from the University of Utah and the National Weather Service Forecast Office, both located in Salt Lake City; National Severe Storms Laboratory and Storm Prediction Center, both located in Norman, Okla; the NWS Hydrometeorological Prediction Center, Camp Springs, Md. and flight crew members from NOAA's Aircraft Operations Center at MacDill AFB, Fla.. The scientists will be joined by 20 meteorology students from the Universities of Utah and Oklahoma. The field phase is scheduled to be held January 31 through February 25, 2000 with operations based out of the NWS Forecast Office in Salt Lake City.
IPEX is lead by Dr. David Schultz, NOAA/ NSSL, Norman, Okla., Prof. James Steenburgh from the University of Utah; Dr. Jeff Trapp, NOAA/NSSL, Boulder, Colo., and Dr. David Kingsmill, Desert Research Institute, Reno, Nev.
The major scientific objectives of IPEX are:
• to understand the causes and variation in mountain precipitation within the steeply sloped Wasatch Range of northern Utah.
• to study lake-effect precipitation downwind of the Great Salt Lake;
• to improve computer-based forecast models used in regions of complex terrain; and
• to validate precipitation estimates produced by Doppler weather radars located at high elevation.
IPEX will involve flights into the storms using the NOAA P-3 research aircraft. On the ground, scientists will release instrumented weather balloons from two NSSL mobile laboratories. Three mobile Doppler weather radars and a stationary microwave radiometer will be deployed throughout Northern Utah to map areas of clouds and precipitation. Supplemental NWS balloon releases will take place three to eight times a day at sites near Boise, Idaho; Grand Junction, Colo.; Salt Lake City; Elko and Las Vegas, Nev. These platforms will enhance an existing surface observing system known as the Mesowest Cooperative Networks collected by the University of Utah.
The results from IPEX will also have positive scientific and socio-economic benefits for the Intermountain West, including Salt Lake City, host of the 2002 Winter Olympics. Local forecasters will use the data on a real-time basis during the experiment and the results will be used in future weather forecasts.
For more information about IPEX, see http://www.met.utah.edu/jimsteen/IPEX. Scientists will be posting experiment progress reports periodically to this page.
For further information:
Keli Tarp NOAA/NWS Public Affairs PH: (405) 366-0451
Marilu Trainor NOAA/NWS Public Affairs PH: (801) 524-5692 Ext 226
David Kingsmill, Ph.D.
Assistant Research Professor
Atmospheric Sciences Center, Desert Research Institute, University of Nevada at Reno, NV
Dr. Kingsmill has participated in numerous field experiments including most recently the California Jets Experiment (CALJET) during the El Nino winter of 1998. His expertise lies in the structure, dynamics, and microphysics of severe thunderstorms and winter storms using Doppler radar and direct measurements collected by aircraft. He received his undergraduate (1984), masters (1987) and doctorate degrees in meteorology (1991) from the University of California Los Angeles.
David Schultz, Ph.D.
NOAA/National Severe Storms Laboratory and Cooperative Institute for Mesoscale Meteorological Studies, Norman, Oklahoma
Dr. Schultz has been at the NSSL since 1996. He is also an Adjunct Professor at the University of Oklahoma, an Associate Editor of Monthly Weather Review, and a contributor to the Weather Watch column in Canoe & Kayak magazine. He obtained his undergraduate degree in Earth, Atmosphere, and Planetary Science from MIT in 1987, his M.S. in Atmospheric Sciences from the University of Washington in 1990, and his Ph.D. in Atmospheric Science from the University at Albany in 1996. He has published scientific research on midlatitude cyclones, fronts, forecasting techniques, and weather in complex terrain such as Central America and western North America.
James Steenburgh, Ph.D.
Department of Meteorology, University of Utah, Salt Lake City, UT
Being an avid back country skier fuels Prof. Steenburgh's research interests on understanding the complex weather patterns around mountain ranges like the Cascades of Washington State, the Rocky Mountains of the United States, the Wasatch of northern Utah, and the Sierra Madre of Mexico. Prof. Steenburgh received his B.S. degree from Pennsylvania State University in 1989 and his Ph.D. from the University of Washington in 1995. He has been a professor at the University of Utah since 1995. His interests are lake-effect snowstorms of the Great Salt Lake, mountain meteorology, and weather prediction in regions of complex terrain.
Jeff Trapp, Ph. D.
NOAA/National Severe Storms Laboratory and Cooperative Institute for Mesoscale Meteorological Studies, Boulder, CO
Dr. Trapp has been at NSSL since 1994. Currently, he is a Visiting Scientist at the National Center for Atmospheric Research in Boulder, CO. He obtained his undergraduate degree from the University of Missouri-Columbia in 1985, his M.S. from Texas A & M in 1989, and his Ph.D. from the University of Oklahoma in 1994. He has prior field experience with the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX) in 1994 and 1995. He has performed research on the dynamics of tornadoes, analysis of radar data, and the small-scale structure of winter weather systems.
Other IPEX Team Members
James D. McFadden, Ph.D.
Manager Aircraft Programs, NOAA Office of Marine and Aviation Operations, Aircraft Operations Center, MacDill AFB, FL
NOAA has employed Dr. McFadden for over 30 years where he has specialized in the management of airborne research programs in which the agency participates worldwide. With a B.S. in geology, and a Ph.D. in meteorology with an oceanography minor, he has managed a variety of environmental programs for NOAA involving hurricanes, global climate, oceanography, air chemistry and mountain meteorology. These projects have taken him from the tropical regions of Guadalcanal in the Solomon Islands to the northern winter climates of Alaska, Iceland and Norway. He currently has 430 hurricane missions.
William J. Alder/
Meteorologist in Charge, National Weather Service Forecast Office (NWSFO) Salt Lake City, UT
William ("Bill") Alder has been with the National Weather Service since 1963 and at the Salt Lake NWSFO since 1965. He obtained his B.S. (1964) and M.S. (1966) in Meteorology with a minor in Air Pollution Science from the University of Utah. He was Principal Assistant at the Salt Lake Office from 1977-79 and promoted to the Meteorologist in Charge in 1980. Bill was awarded the Department of Commerce Silver Medal in 1984 for "...his acts in the protection of life and property of Utah residents, before and during the disastrous Spring floods of 1983 and 1984." He is a member of the American Meteorological Society and the National Weather Association. He co-authored a book in 1996 on Utah's Weather and Climate with local television (KSL-TV) meteorologists Dan Pope and Clayton Brough.
Lawrence B. Dunn, Ph.D.
Science and Operations Officer, National Weather Service Forecast Office, Salt Lake City, UT
Dr. Dunn received his undergraduate degree in Meteorology from the University of Utah in 1979, his M.S. in Atmospheric Sciences in 1982 from the University of Washington, and his Ph.D. in Meteorology from the University of Utah in 1993. He has served as a forecaster in Salt Lake City, Utah and Denver, CO. He has also been a member of the Scientific Services Division of the NWS Western Region Headquarters in Salt Lake City. Dr. Dunn has published articles on forecasting. He has received numerous awards including the prestigious Department of Commerce Gold Medal in 1996 and a NWS Modernization Award in 1996. He serves on committees for the American Meteorological Society.
All forecasting for IPEX will be conducted from the IPEX Forecast and Operations Center at the National Weather Service Office at Salt Lake City.
From 8 a.m. through 12 noon, forecasters will prepare outlooks for potential storms for the next two days. At noon, forecasters will brief the scientists on their forecasts, after which, scientists will decide on possible deployments of the field resources (mobile laboratories, mobile radars, supplemental NWS weather balloon launches, P-3, etc.) for the next two days. If deployments are possible, then an Intensive Operations Period (IOP) will be declared. The field resources will be readied for deployment, pending the onset of the storm.
During IOPs, forecasters will shift into a mode called nowcasting, anticipating changes in the weather for very short time frames (less than three hours). The Operations Center will be staffed by the Mission Director (the chief scientist involved in making decisions during IOPs), the Operations Director (the scientist in charge of communications between the different field resources), and at least one nowcaster.
Nowcasting will be necessary to track the rapidly changing weather systems often seen in northern Utah. For instance, if a lake-effect snowband changes orientation, the nowcasters and the Mission Director will confer on possible redeployments of the mobile radars to capture the evolving storm. The Operations Director will communicate this information to the mobile radar operators, who will then move the radars to the new locations. As the weather starts to subside, the Mission Director will declare the end of the IOP and all facilities will stand down and scientists will return to Salt Lake City.
THE NSSL MOBILE LABORATORIES
The NSSL mobile laboratories are state-of-the-art atmospheric observatory and research vehicles, which served as the basis for the research vans in the movie Twister! Two such laboratories will be present during IPEX, operated by NSSL staff and University of Utah students.
Converted 15-passenger vans, the mobile laboratories are capable of measuring surface weather (pressure, temperature, wind, humidity) at locations where weather data is presently not being reported. In addition, one of the laboratories has the ability to measure surface electric field, to examine the potential for lightning in these storms. Both laboratories are equipped with instrumentation to release and track instrumented weather balloons, which rise to heights of 40,000 feet or more, measuring the properties of the atmosphere above the earth's surface. One of the ballooning systems will be capable of measuring the electric field as the balloons rise. The location of the balloons as they rise are reported using G.P.S. technology.
The mobile laboratories will be essential to the IPEX mission for taking vertical profiles of the atmosphere in remote areas, such as the north and west sides of the Great Salt Lake. Soundings in these areas will help scientists observe the atmospheric structure upstream of the Great Salt Lake, giving them a better picture of the state of the atmosphere.
DAILY WEATHER BALLOON SOUNDINGS
NOAA and other organizations launch instrumented weather balloons at over 100 selected sites across the United States and thousands of sites across the world simultaneously two times every day. This gives a vertical profile of the atmosphere and, combined with other stations, provides a map of the upper levels of the atmosphere. An instrument called a radiosonde is carried aloft by a helium-filled balloon measuring temperature, pressure, winds, and humidity. The data is transmitted back to computers on the ground. When the balloon bursts, the instrument floats earthward via a parachute. If you walk the woods and farmlands, it is possible that one day you will come across a radiosonde instrument. When you find one laying around, return it to the NOAA because it can be reused. The data is sent to supecomputers in Washington, D.C., where computer models of the atmosphere are generated for as many as 10 days in the future.
SUPPLEMENTAL WEATHER BALLOON SOUNDINGS DURING IPEX
During IPEX, the nearest locations that will release weather balloons are Salt Lake City, UT; Grand Junction, CO; Boise, ID; Elko and Desert Rock. (near Las Vegas), NV.) Sometimes the weather patterns evolve significantly within the 12-hour period between sounding times or have important structure in between sounding locations. In these situations, the standard NOAA soundings provide a blurred picture of the real structure of the atmosphere. During Intensive Observing Periods, five sites will be taking additional soundings, as often as eight times a day, to enhance the IPEX team's ability to observe and forecast the developing storms.
Two of the world's premier research aircraft, the NOAA WP-3D Orions, support a wide variety of national and international meteorological, oceanographic and environmental research programs. In the United States, the aircraft are widely recognized for their use in hurricane research and reconnaissance for NOAA's National Hurricane Center, National Weather Service and the Hurricane Research Division, Office of Oceanic and Atmospheric Research.
Obtained as new aircraft from the Lockheed production line in the mid-70's, these robust and well maintained aircraft have led this nation's effort in monitoring and studying hurricanes and severe storms, the health of the atmosphere, and various climate trends. The P-3s provide highly reliable access to the lower and middle troposphere with large payload, large fuselage volume and extended duration and range.
There is occasional confusion on the role of the NOAA P-3s and the USAF C-130s, both of which fly into hurricanes. With their sophisticated scientific instruments, the P-3s can conduct both hurricane reconnaissance and research; the USAF C-130s, with significantly less modifications to the airframe and supporting research instrumentation, provide only reconnaissance support. Also, the P-3s routinely penetrate the hurricane eyewall at much lower altitudes than do the C-130s. For research purposes, the closer to the water surface, the better. The C-130s do not fly over Cuban airspace whereas the P-3s do; flying over Cuba is especially important when a hurricane approaches Florida from the south as Hurricane Georges did in 1998.
These versatile P-3s are equipped with an unparalleled variety of scientific instrumentation, radars and recording systems for both in-situ and remote sensing measurements of the atmosphere. Aircraft instrumentation includes flight-level data sensors, airborne Doppler radars to determine wind intensity, cloud physics instrumentation (including electric field measurements), remote sensors for surface wind and rainfall estimation, dropsondes, AXBTs, drifting buoys and an aircraft-satellite data link for near real-time transmission of data. Some equipment, such as that for remote sensing of sea-surface conditions or for atmospheric electricity measurements, is unique to these aircraft.
In addition to the hurricane research mission, for which they were originally procured, these aircraft support diverse national and international programs throughout NOAA and other Federal agencies. With its world-wide operating capability, they have participated in numerous research experiments from the Arctic to the Indian Ocean, from Australia to Europe, and throughout the United States and the Caribbean.
In 1998 alone, both aircraft have already participated in Hurricanes Bonnie, Danielle, Earl and Georges accumulating over 200 hours for hurricane research and reconnaissance. Overall, both aircraft have made well over 2,000 hurricane eyewall penetrations in more than 60 hurricanes in the past 20 years.
The WP-3Ds are managed by NOAA's Aircraft Operations Center, MacDill Air Force Base, Tampa, Florida. For more information, contact the Office of NOAA Corps Operations at (301) 713-1045 or visit the Web site at http://www.omao.noaa.gov.
WP-3D Aircraft Specifications
Crew: 18 crew and scientists
Wing Span: 99' 77"
Cruising Speed: 325 knots
Takeoff Weight: 135,000 lbs
Range-Low Altitude: 2,250 nm
Range-High Altitude: 3,300 nm
Length: 111' 2"
Ceiling: 25,000 feet
Doppler Radar on Wheels
The "Doppler Radar on Wheels," dual high resolution Doppler radars mounted on flatbed trucks developed by researchers from the National Oceanic and Atmospheric Administration, the University of Oklahoma and the National Center for Atmospheric Research, will participate in the Intermountain Precipitation Experiment (IPEX) Jan. 31 - Feb. 25 in northern Utah.
The twin Dopplers on Wheels are unique truck-mounted research radars that can be positioned within a few kilometers of a storm to document wind speeds and structure in fine detail. Used to study severe weather, including tornadoes and hurricanes at landfall, the eight-foot diameter Doppler radars scan the entire storm every 90 seconds.
Quotes From Participants
Dr. David Schultz, Research Meteorologist, National Severe Storms
Laboratory, IPEX Principal Investigator
"Our computer models are the least skillful in producing forecasts of precipitation for the Intermountain West. Forecasters also find this area difficult to forecast because of the sparse observations of the atmosphere and the steep mountains that challenge our conceptions of the way we think the atmosphere works. Nevertheless, during the past nine years, the fastest growing states in the United States have been Nevada, Arizona, Idaho and Utah. Thus, imperfect forecasts have a much greater impact on the population than ever before.
The Intermountain Precipitation Experiment is a month-long field research program designed to improve the understanding of snow and rain in the Great Basin. Data collected during IPEX will provide unprecedented observations of these storms. Analysis of this data in years to come should allow scientists to develop better understanding of the structure and evolution of these weather systems, eventually leading to better forecasts."
Dr. James Steenburgh, Professor, Dept. of Meteorology, University of
Utah, IPEX Principal Investigator
"The cooperation between the different participants in IPEX will facilitate observations of snowstorms over the Intermountain West region that otherwise would not be possible. For example, the three mobile radars from the University of Oklahoma, the National Severe Storms Laboratory, and the Salt River Project/Radian Corporation will measure the precipitation and airflow in the lower atmosphere with greater detail in space and time than ever before. Also, the IPEX data collection effort leverages the 2,500-station surface data network assembled by the University of Utah, known as the Mesowest Cooperative Networks."
Dr. Jeff Trapp, Research Meteorologist, National Severe Storms
Laboratory, IPEX Principal Investigator
"Because the National Weather Service Doppler radar in northern Utah is situated atop Promontory Point for maximum radar coverage, observations of precipitation just above the valley floor are lacking. During lake-effect precipitation events, the mobile Doppler radars from the University of Oklahoma will be deployed along the south shore of the Great Salt Lake to maximize our ability to measure the processes occurring below the standard National Weather Service radar coverage."
Dr. James Kimpel, Director, National Severe Storms Laboratory
"NSSL's mission is to enhance the ability of the National Weather Service to provide timely warnings of hazardous weather, including heavy snow. NSSL's leadership and participation in IPEX underscores our lab's commitment to perform cutting-edge observational research on winter weather across the United States."
William Alder, Meteorologist in Charge, National Weather Service
Forecast Office, Salt Lake City, Utah
"I'd always love to make a perfect forecast, but with the state of the science we deal with, it's not easy sometimes, and the terrain of northern Utah complicates things even more. IPEX will study how the Wasatch Mountains affect the amount and distribution of precipitation."
Steve Vasiloff, Research Meteorologist, National Severe Storms
Laboratory/National Weather Service Western Region
"The vertically pointing weather radar at Snowbasin Ski Resort measures the height and snow content of the clouds. We're taking these measurements here to complete the data coverage of these important atmospheric conditions. The National Weather Service radar at Promontory Point is partially blocked east of Mount Ogden. So, the Snow Basin site helps the scientists get a more accurate picture of what is happening on both sides of the mountain."
Les Showell, Special Projects Consultant, National Severe Storms
"Data collected using the NSSL mobile atmospheric observatory will provide scientists and forecasters the first profiles observed of the atmospheric conditions upstream of the Great Salt Lake. This will allow us to measure the influence of the lake on supplying moisture to lake-effect precipitation."
Tom Blazek, University of Utah student and U.S. Air Force forecaster
"Winter storms in the Great Basin, from 1992 to 1998, caused $95 million in damage, more than twice the amount from tornadoes in Oklahoma. The large variation in snowfall over small distances, say 10 inches over ten miles, make forecasting in this area of the country extremely challenging."
John Horel, Professor, Dept. of Meteorology, University of Utah
"Students at the University of Utah will gain valuable experience with the meteorological instrumentation deployed during IPEX. Our students will help launch balloons, collect weather information and participate in weather briefings led by project scientists."
Craig Clements, Graduate Research Assistant, University of Utah
"The use of the mobile labs during IPEX gives students a ‘hands-on' research experience because there is quite a bit of team work involved getting the balloons launched."
Brian Olsen, junior, Dept. of Meteorology, University of Utah
"I'm really excited to participate in IPEX. This is the first time I've had the opportunity to gain hands-on experience with the specialized instrumentation used in the project."
Brooke Chisholm, junior, Dept. of Meteorology, University of Utah
"I am excited to work with a research team on IPEX. It will give me an idea of forecasting methods, especially in Salt Lake City, and research opportunities to help me decide what to do in my future."