NASA Satellites See Tropical Depression 11 Form in Western Caribbean

The eleventh tropical depression formed this morning in the far western Caribbean, and it is already forecast to make a landfall. NASA’s TRMM and Aqua satellites already noticed that there are some strong thunderstorms and heavy rainfall within Tropical Depression 11, and residents of eastern Nicaragua and eastern Honduras can expect those conditions.

At 1 p.m. EST the center of tropical depression eleven (TD11) was located near latitude 11.8 north…longitude 82.3 west or about 65 miles southwest of San Andres island and about 100 miles east of Bluefields, Nicaragua. The depression has maximum sustained winds near 35 mph, and may strengthen to a tropical storm later today. TD11 is moving west-northwest near 7 mph, however it is expected to slow down and move toward the northwest bringing its center near the east coast of Nicaragua this evening. The estimated minimum central pressure is 1006 millibars.

A tropical storm warning remains in effect for the entire eastern coast of Nicaragua and for the islands of San Andres and Providencia. A tropical storm warning means that tropical storm conditions are expected somewhere within the warning area within 24 hours.

Data from the Tropical Rainfall Measuring Mission (TRMM) satellite during the early morning hours of November 4 were used in making the rainfall analysis at NASA’s Goddard Space Flight Center in Greenbelt Md. The rainfall analysis showed strong thunderstorms with heavy rainfall, especially around the center of circulation. Looking at TRMM data, the forecasters at the National Hurricane Center noted that “The depression is expected to produce total rainfall accumulations of 5 to 7 inches over San Andres Island with maximum amounts of 12 inches possible. Rainfall accumulations of 15 to 20 inches are expected over eastern Nicaragua and eastern Honduras with maximum amounts of 25 inches possible. These rains could produce life-threatening flash flood and mud slides.”

NASA’s Aqua satellite captured TD11 on November 4 at 2:35 a.m. ET from the Atmospheric Infrared Sounder (AIRS) instrument. AIRS measures cloud temperature using infrared light. In NASA’s infrared imagery, the false-colored purple clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 Kelvin, or minus 27F. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone and Tropical Depression 11 has some high thunderstorms with temperatures as cold as minus 63 degrees Fahrenheit (F), especially near its center. That’s one indication that the storm may indeed already have strengthened to tropical storm status. Hurricane hunter aircraft from the National Oceanic and Atmospheric Administration will be flying over the storm today to confirm its strength.

The depression is currently in an environment with light wind shear and warm waters, which are helping to power it. In the meantime, residents of eastern Nicaragua and eastern Honduras need to prepare for flooding rains.