NOAA 99-066
Jeanne Kouhestani
Barbara McGehan
Keli Tarp

Project is largest weather research project ever conducted in Europe

Scientists, a Doppler lidar, and a "hurricane hunter" aircraft from the National Oceanic and Atmospheric Administration have joined the largest weather research project ever conducted in Europe to study the effects on weather of wind flow over the Alps. Researchers from 11 nations hope to gain a better understanding of how this wind affects the weather, and to improve weather and river forecast models for mountainous areas, NOAA said today.

The Mesoscale Alpine Project (MAP), to continue through Nov. 15, is divided into "wet-MAP" and "dry-MAP" activities. Put simply, wet-MAP will study how wind flowing over the mountains affects precipitation and flooding. Dry-MAP will study how mountains produce clear-air turbulence and damaging surface winds. Researchers expect the data to improve computer weather and climate models that help predict the timing and effects of these events.

"We expect NOAA to benefit a great deal from the pooled resources and extensive scope of this massive project, which probably will never be duplicated. The Alps form a manageable natural research laboratory for the study of wind flow over mountains, and the knowledge we gain from this study will be directly applicable to our own mountain meteorological research effort in this country," said Jim McFadden, P-3 program manager and chief scientist with NOAA's Aircraft Operations Center in Tampa, Fla. "Gaining a better understanding of the ‘wet' effects will lead us to improved forecasts of deadly flooding events in the coastal mountains of California, Oregon and Washington."

The NOAA P-3, best known for penetrating the eyes of hurricanes, is a flying meteorological station and one of only three research aircraft in the world equipped with Doppler radar. NOAA scientists have used the unique capabilities of the P-3 in previous experiments to study severe convective storms that sometimes produce tornadoes in the central United States as well as land-falling storms and their interaction with steep coastal terrain. The P-3 is being used in the wet phase of MAP to study precipitation convection and storm areas.

Additionally, NOAA scientists, in cooperation with researchers from the University of Oklahoma and Princeton University, are directing the use of a portable "Doppler on Wheels" radar unit, known for its close-up studies of winds within tornadoes, to provide direct measurement of precipitation intensity and winds within several Alpine valleys that are too deep to be well sampled by radar-bearing aircraft flying overhead. The P-3 and Doppler on Wheels data will be used in conjunction with European ground-based radars.

The cooperative nature of the project allows U.S. scientists to gain a greater understanding of an important meteorological problem at a much lower cost than would be required for a project based in the United States.

"While the Alps are half a world away from North America, our involvement in MAP represents a good deal for U.S. taxpayers," said Dave Jorgensen, research meteorologist with the National Severe Storms Laboratory in Boulder, Colo., and MAP co-principal investigator. "Our unique contributions in observation of severe weather systems using Doppler radar-equipped aircraft are being leveraged by a great deal of complementary equipment and expertise offered by our colleagues in Europe."

The wet-MAP phase of the project deals with a study of the rain events that take place over Italy resulting from the lifting and funneling of warm, moist air that moves northward into the Alps and the Mediterranean and Adriatic Seas. Localized flash floods resulting from such events cause serious property damage and loss of life in the Alps, particularly in Italy, and gaining a better understanding of just how and why these episodes occur will lead to an improvement in their forecasts.

Dry-MAP deals with downslope windstorms (often referred to as "Foehn" events in Europe) - a wind phenomenon that occurs quite frequently in the American Rockies as well as in the Alps - as well as the prediction of clear-air turbulence caused when atmospheric gravity waves, which are formed as air flows across a mountain, break at high altitudes where commercial aircraft are often affected. The experiment will test recent results of weather prediction computer models that are showing promise of predicting such events. The research aircraft will be combined with unique measurements from a Doppler lidar deployed by NOAA's Environmental Technology Laboratory to measure airflow around the mountains in the absence of clouds and precipitation. It is hoped that such measurements will confirm the promising results of computer weather forecasts, and thus aid in developing better forecasts of damaging surface winds and clear-air turbulence.

NOAA's participation in MAP is being led by Jim McFadden of the Aircraft Operations Center in Tampa, Fla., and Dave Jorgensen (Boulder, Colo.) and Brad Smull (Seattle, Wash.) of the National Severe Storms Laboratory, for the wet phase; and Louisa Nance, Mike Hardesty and Martin Ralph of the Environmental Technology Laboratory in Boulder, for the dry phase. Other U.S. participants in the project are Robert Houze Jr. and Dale Durran from the University of Washington. ###

NOTE TO EDITORS: For further information about MAP, visit: The MAP Programme Office site at and NOAA's National Severe Storm Laboratory site at