Weather balloons are launched into the atmosphere with an essential mission: to collect information about steering currents that can propel a hurricane toward land or nudge it out to sea.
But some National Weather Service offices aren't equipped to release balloons, leaving wide swaths of the atmosphere unmonitored even as hurricanes threaten.
And the offices that do launch them often find the 1950s-era equipment and computers broken for days, no parts to be found. The Weather Service admits 90 percent of the equipment is obsolete.
A plan to replace the weather-observing devices -- considered a primary building block to hurricane forecasts -- has been slowed by delays, officials said.
The breakdowns have long frustrated forecasters. Key West lost the use of its balloons for much of August 2004. When the equipment breaks in Tallahassee, hundreds of miles between Northeast Florida and Alabama are unmonitored.
''When we don't have it, there's a big hole in the atmosphere,'' said Paul Duval, the Weather Service's chief meteorologist in Tallahassee.
The observation gap is a particular problem in the Caribbean.
In a bilateral agreement with the World Meteorological Organization in 1968, the Weather Service agreed to provide support and equipment to struggling countries in the Caribbean. The idea was not only to protect the region, but give the United States an early warning as hurricanes form in the Caribbean's warm waters.
Yet countries including the Cayman Islands, the Dominican Republic, Colombia and Belize often fail to provide regular data during hurricane season, according to government records.
Belize and the Dominican Republic, for example, didn't post a single balloon reading during about one-fourth of the hurricane seasons from 2000 to 2004; the Cayman Islands missed almost half.
Sometimes the equipment breaks down. Other times, the balloons simply aren't launched.