5:51 PM
Gustav Weakens Temporarily
judersonservices
Tropical Storm Gustav continues to weaken, and now winds are sustained at 50 MPH with higher gusts, and pressure has increased to 999MB. The high mountain ranges of Hispaniola hastened the weakening process of Gustav by disrupting the circulation. By disrupting the circulation, Tropical storm Gustav has a harder time building low level convergence, which is essential to a tropical cyclone. The residents of Haiti will continue to feel redundant heavy rain tonight, increasing the chance of lethal catastrophic mudslides. The death toll was 5 earlier today, and increased over four times to 22 this afternoon, and is expected to rise further. As Gustav slowly emerges off Haiti, it will be exposed to the warm sea surface temperatures near it. As Gustav moves back over water tonight, it is possible that it might strengthen. The sea surface temperatures near Gustav are a toasty 85+ degrees Fahrenheit, a sweet spot for tropical cyclones. During maximum diurnal phase late tonight, low temperatures are expected to be about 74-80 degrees, while the water temperature remains almost constant at 85 degrees, due to its higher thermal capacity or specific heat content. As a result air in contact with the water (air near the surface) will rise due to its lower density. As it rises, it will cool and condense forming vigorous cumulonimbus clouds. These massive cumulonimbus clouds acts as an efficacious upcurrent channel allowing more air to rise higher and faster. As the air reaches the apex altitude, it will then diverge, which decreases the pressure of the tropical cyclone*. A weak mid-upper level low about 100 miles north of Puerto Rico will further enhance the upper level divergence of Gustav. Due to the decrease in atmospheric pressure, the pressure gradient becomes steeper since Gustav's lower pressure than its surroundings will decrease even further. Subsequently, air will flow faster toward the low pressure center, and wind velocity will increase. The computer model tracks are in harmony with each other by taking this system to the Gulf Of Mexico. Residents in these areas must watch this system closely
A well defined area of low pressure about 200 miles northeast of the Lesser Antilles will have to be watched for potential development. The European model (ECMWF) develop this system into a substantial tropical cyclone
*I will post a special tutorial about how divergence helps cyclones sometime in the future.
A well defined area of low pressure about 200 miles northeast of the Lesser Antilles will have to be watched for potential development. The European model (ECMWF) develop this system into a substantial tropical cyclone
*I will post a special tutorial about how divergence helps cyclones sometime in the future.