The Life and Death of a Soaker: Tropical Storm Karen [image-51]
Tropical Storm Karen formed in the Gulf of Mexico during the federal government shutdown, so no NASA imagery was available. NOAA's GOES-East satellite continue to operate under emergency conditions and provided visible and infrared imagery of the storm as it formed and slowly made its way up the U.S. East Coast where it dropped a lot of rain.
Forecasters were watching Karen days before it developed when it was classified low pressure "System 97L." On Oct. 2 System 97L was centered near 16.7N 83.1W in the northwestern Caribbean Sea. The low moved into the southern Gulf of Mexico on Oct. 3 and strengthened quickly into Tropical Storm Karen by 9 a.m. EDT.
At the time of formation, it was located near 22.0 north and 87.6 west, about 40 miles/65 km northwest of Cabo Catoche, Mexico, and 500 miles/805 km south of the mouth of the Mississippi River. Its maximum sustained winds jumped to 60 mph/95 kph, and it was moving to the north-northwest at 13 mph/20 kph. Forecasters still on hand at the National Hurricane Center posted Hurricane and Tropical Storm watches. A Hurricane Watch was posted for Grand Isle, La. to Indian Pass, Fla. and a Tropical Storm Watch was posted for the area west of Grand Isle to Morgan City, La., metropolitan New Orleans, Lake Maurepas and Lake Pontchartrain.
Meanwhile, as Karen strengthened in the southern Gulf on Oct. 3, the National Hurricane Center noted that locally heavy rains could affect the Cayman Islands, parts of Cuba and the Yucatan Peninsula during the next day or two.
On Oct. 4, Karen was still a tropical storm with maximum sustained winds near 60 mph/95 kph. It was moving north-northwest at 10 mph/17 kph.
On Sunday, Oct. 6 at 11 a.m. EDT the National Hurricane Center issued their final advisory on Karen. Karen dissipated near 28.1 north and 89.9 west, about 85 miles/135 km southwest of the mouth of the Mississippi River. At that time, Karen's maximum sustained winds had fallen to 30 mph/45 kph and it was moving east at 13 mph/20 kph. The National Hurricane Center noted that the remnants would move to the east for the next couple of days.
Although Karen dissipated, the low pressure area was still causing localized local flooding along portions of the northern Gulf Coast. The remnants were also expected to produce between 1 and 3 inches of rainfall over the central Gulf coast and southeastern U.S. on Oct. 6 and Oct. 7.
By Oct. 8, Karen's remnants were crawling along the southern U.S. coast. On Oct. 9 and 10 the National Weather Service noted: The remnant disturbance from what was Karen this past weekend was located far enough south to not be picked up by the mid-latitude trough that moved thru the area. Jet streaks associated with this remnant low and northern jet stream trough becomes coupled...resulting in weak cyclogenesis (development of low pressure) near the southeast coast.
The low developed and brought clouds and rain over the southeast and Atlantic moisture was drawn inland on the northern side of the low. The low pressure area the contained Karen's remnants moved very slowly north and soaked the Mid-Atlantic coast for several days.
By Oct. 13, 2013 the low pressure area associated with the remnants of tropical storm Karen finally moved east of the mid-Atlantic, but not before that low dropped as much as 5 inches of rainfall in areas of Maryland, Delaware and the District of Columbia.
Text credit: Rob Gutro
NASA's Goddard Space Flight Center