The Online News Station

...Several weather records broken Saturday in Jamaica Beach...

...Dangerous flash flood threat is becoming established across the region...

Saturday, July 1, 2006 was quite a weather day in Jamaica Beach and several new weather records were established at the Jamaica Beach Weather Observatory thanks to a torrential thunderstorm that developed in a very tropical air mass.

At 12:33 PM CDT Saturday, the Jamaica Beach Weather Observatory received a report from the owners of West Bay Bait & Tackle that three large waterspouts were sighted over the Gulf of Mexico just off the beach from the Escape Condominiums located on FM 3005 near 10 Mile Road on Galveston Island. No reports of damage or injuries have been received in association with these waterspouts.

The same thunderstorm that produced these waterspouts then moved NW over western Galveston Island including Jamaica Beach. A peak wind gust of 34 knots (39 mph) from SE was recorded at the Jamaica Beach Weather Observatory at 12:51 PM CDT. As colder air from the top of the thunderstorm mixed down to the surface with the thunderstorm downdraft...the temperature at Jamaica Beach fell

rapidly to a low temperature of 68º at 1:11 PM CDT.

The low temperature of 68º not only establishes a new record for the date breaking the old record of 74º set on July 1, 2003...it also establishes a new record for the lowest temperature ever recorded during the entire month of July since the weather station was established on December 1, 1990. The previous monthly record was 72º recorded on numerous dates and years but most recently on July 16, 2002.

Another record broken Saturday was the daily rainfall record. From Midnight to Midnight CST (1:00 AM to 1:00 AM CDT)...a total of 2.06 inches of rainfall was recorded at the Jamaica Beach Weather Observatory. This established a new record for the date breaking the previous record of 1.91 inches set on July 1, 2003. At one point, the rain was falling in such a torrent that 0.54 of an inch was recorded

in just a 5-minute period!

The weather was a little less dramatic at Scholes International Airport in Galveston on Saturday. The airport only recorded 0.44 of an inch of rainfall which was well below the daily record there of 6.96 inches set on July 1, 1903. Weather records in Galveston date back to 1871.

More heavy rainfall is expected during the next several days and it appears that a dangerous flash flood threat is becoming established across the region. A large area of disturbed weather over the western Gulf of Mexico is drifting northward toward the Texas and Louisiana coasts. This is bringing a very moist and unstable tropical air mass into the area with high precipitable water values. Accordingly,

showers and very heavy thunderstorms over the Gulf of Mexico will continue to move onshore in Texas and Louisiana. As this heavy rainfall "trains" over the same areas repeatedly, flash flooding could develop quickly due to several inches of rain in just a few hours time. The greatest threat will be along the coast and over the coastal counties during the overnight hours until about early afternoon while the threat over more inland areas will be greatest from mid-morning until early evening as the daily

"sea breeze front" moves inland from the coast enhancing thunderstorm development.

Along the coast, the extremely high dew points and relative humidity along with an abundance of towering cumulus and cumulonimbus clouds will favor the formation of tropical funnel clouds and waterspouts over the bays and offshore waters...particularly during the hours between sunrise and early afternoon. This will pose a significant hazard to small craft operators out on the water as well as along the beaches since waterspouts occasionally move briefly onshore where they are then classified as a

tornado. Winds in waterspouts are generally 40 to 60 knots but can be as high as 100 knots in some cases. Therefore, they should be avoided at all costs if possible.

Another significant hazard...on land and on the water...will be deadly cloud-to-ground and cloud-to-water lightning. Many persons are killed in the nation every summer, especially on the July 4th and Labor Day Holiday Weekends from lightning strikes. Most of these fatalities could have been avoided if persons had sought safe shelter at the first signs of threatening weather. Remember...if you wait until you hear thunder, it could already be too late. Lightning can strike many miles away from the parent

thunderstorm (cumulonimbus) cloud. There have been many stories of persons struck by lightning that never heard any thunder or thought they were well out of range of a nearby thunderstorm. If you are caught outdoors, never take shelter under trees or metal objects. If possible, curl your body up to make as small a target as possible and seek refuge in a nearby ditch or depression away from any tall objects. If indoors, stay away from windows and do not use electrical appliances or the

telephone during a thunderstorm.

Continue to monitor the latest weather forecasts and updates on this developing weather situation. Further statements will be issued as conditions warrant.

Jim O'Donnel

Jamaica Beach Weather Observatory