Welcome Rains Soak Tampa Bay Area (Index) Suncoast rainfall for the period starting at midnight July 17 and ending at 5 PM July 20. At left: 500 millibar chart, 7 AM EDT July 18th, 2004. Note the unusually strong trough, for mid July, over the eastern U.S. Center: NOAA Geostationary Satellite (GOES) water vapor image, for the eastern two thirds of the U.S. Note the frontal zone moisture off the U.S. eastern seaboard, with tail extending into the central Gulf. At right: Surface chart, 7 AM EDT July 18th, 2004, with stationary front and broad low pressure area over the Southeast U.S. After a rather long dry spell to begin July for many along the immediate coast, as well as around portions of Tampa Bay, a fairly deep eastern U.S. trough (above left) for several days in mid July. At the base of the trough, west to southwest flow of air over very warm (upper 80s) eastern Gulf waters helped produce numerous showers and thunderstorms, each with brief torrential rains, for the coastal counties. For the 17th through 19th, the heaviest rains were generally from Tampa Bay north to the Nature Coast, shifting over and south of Tampa Bay by the 20th. Unlike the summer of 2003, when eastern U.S. troughs routinely dipped south into the eastern Gulf and Florida, this event broke the prolonged period of flat upper level ridging which had kept rainfall totals below normal for many coastal areas. Was this the beginning of a general pattern shift, or just a temporary aberration? Stay tuned. For a detailed rainfall summary, click here.