Because for all that is known about El Ni o, that worldwide weather phenomenon tied to unusual warming of tropical Pacific waters, many gaps remain. A crucial question is why some storms defy the forecasters and dump huge, unexpected quantities of rain on land. It happened last week. Part of the problem for science is the sheer vastness of the laboratory. Weather satellites are useful to a point, but they can't tell forecasters enough about what's going on near the ocean surface - under the clouds.
Scientists think that area is a powerful engine in storm development.
Yet across the Pacific, there's no system to take consistent, detailed measurements of wind, temperature and humidity near the surface, ahead of storms. The NOAA flights are doing just that. Scientists are keenly interested in low-level jet streams that race immediately ahead of storm fronts a few hundred feet above the sea. Such streams are different from the massive, high-altitude polar and subtropical jet streams that are familiar on TV weather satellite images. Satellites can easily show meteorologists that the polar jet drops much farther south in an El Ni o year.