Tropical Storm Emily is an active Atlantic tropical cyclone that is currently threatening the northeastern Caribbean. The fifth named storm of the 2011 Atlantic hurricane season, it developed from a Cape Verde-type tropical wave tracking the open Atlantic for several days in late July. Throughout its journey, the wave remained fairly disorganized, lacking a defined circulation center. By July 31, it approaching the Lesser Antilles and became better defined, producing inclement weather over much of the area. Late on August 1, the National Hurricane Center issued the formation of Tropical Storm Emily just after it had crossed the islands.
Tropical Storm Emily
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| As of: | 7:30 p.m. AST (2330 UTC) August 1 | ||
| Location: | 15.2°N 62.0°W ± 30 nm About 50 miles (80 km) SSW of Dominican Republic About 350 miles (565 km) SE of San Juan, Puerto Rico | ||
| Sustained winds: | 35 knots | 40 mph | 65 km/h (1-min mean) gusting to 45 knots | 50 mph | 85 km/h | ||
| Pressure: | 1006 mbar (hPa) | 29.71 inHg | ||
| Movement: | W at 15 kt | 17 mph | 28 km/h | ||
| See more detailed information. | |||
Meteorological history
The cyclogenesis of Tropical Storm Emily was complicated, extending over several days from late July into early August. An easterly tropical wave—an equatorward trough of low pressure moving generally westward—exited the west African coast in the fourth week of July, at which point it became largely embedded within the monsoon trough.[1] Oriented north to south, the wave supported little to no precipitation for a day or two as it traversed the open Atlantic.[2] By July 28, a weak low-pressure center developed along its southern periphery, and over time clusters of moderate, albeit isolated convection increased around the broad wave axis.[3][4] Atmospheric conditions favored additional development into a tropical cyclone; an anticyclonic circulation soon formed over the system, creating a supportive upper-level environment.[5] It accordingly became better defined over the next couple of days, retaining unusually low surface pressures as well as concentrated showers and thunderstorms.[6] Following a retrace toward the west-northwest, the threat to nearby land became relative to higher chances of development, with several forecast models projecting a path directly into the northeastern Caribbean.[7]
During the morning of July 31, the large low markedly gained in organization, and the National Hurricane Center (NHC) noted it was close to becoming a tropical depression.[8] Later that day, however, the mean low-pressure envelope became increasingly elongated; its westernmost component promptly detached to form a separate tropical wave ahead. This new disturbance featured widely scattered convection, with rainbands briefly impacting the Lesser Antilles.[9] Meanwhile, a reconnaissance aircraft had been investigating the area, although loss of communication limited sufficient data reception. Despite this shortcoming, subsequent surface analysis and buoy observations indicated the disturbance lacked a closed circulation; as such, it did not yet meet the criteria for tropical cyclone classification at the time.[10] As the vigorous low closed in on the Leeward Islands, little change initially occurred in its structure the next day, though associated surface winds rose to near tropical storm-force.[11] A subsequent flight into the system finally revealed a well-defined circulation center near the deep convection mass, passing just to the south of Dominica. Consequently, the NHC marked the formation of Tropical Storm Emily around 2350 UTC August 1, as it accelerated toward the west in response to a mid-level high.[12]
- ^ Tichacek, Mike (2011-07-26). "Tropical Weather Discussion". National Hurricane Center. Retrieved 2011-08-01.
- ^ Tichacek, Mike (2011-07-27). "Tropical Weather Discussion". National Hurricane Center. Retrieved 2011-08-01.
- ^ Tichacek, Mike (2011-07-28). "Tropical Weather Discussion". National Hurricane Center. Retrieved 2011-08-01.
- ^ Formosa, Mike (2011-07-29). "Tropical Weather Discussion". National Hurricane Center. Retrieved 2011-08-01.
- ^ Huffman, Marshall (2011-07-29). "Tropical Weather Discussion". National Hurricane Center. Retrieved 2011-08-01.
- ^ Beven, Jack (2011-07-30). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2011-08-01.
- ^ Beven, Jack (2011-07-30). "Tropical Weather Discussion". National Hurricane Center. Retrieved 2011-08-01.
- ^ Berg, Robbie (2011-07-31). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2011-08-01.
- ^ "Graphical Tropical Weather Outlook". National Hurricane Center. 2011-07-31. Retrieved 2011-08-01.
- ^ Berg, Robbie (2011-07-31). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2011-08-01.
- ^ Stewart, Stacy (2011-08-01). "Graphical Tropical Weather Outlook". National Hurricane Center. Retrieved 2011-08-01.
- ^ Brennan, Michael (2011-08-01). "Tropical Storm Emily Discussion Number One". National Hurricane Center. Retrieved 2011-08-01.