NASA TRMM: Tropical Storm losing its strength

When TRMM passed over Tropical Storm Karina on August 19, there was an isolated area of heavy rain (red) in the western quadrant where rain was falling at a rate of 2 inches/40 mm per hour. 

Credit: NASA /SSAI, Hal Pierce

Tropical Storm Karina continues to weaken in the Eastern Pacific over open waters, and NASA data shows there's not much punch left in the storm.

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite can measure the rate of rainfall from its orbit in space and when it passed over Tropical Storm Karina in the Eastern Pacific it saw an isolated area of heavy rain remaining in the storm.

Tropical Storm Karina weakened during the overnight hours and by Tuesday, August 19, maximum sustained winds had decreased to near 60 mph (95 kph).

When TRMM passed overhead at 03:04 UTC (11:04 p.m. EDT, Aug. 18) on August 19, TRMM Precipitation Radar showed that there was an isolated area of heavy rain in the western quadrant where rain was falling at a rate of 2 inches/50 mm per hour.

Cloud heights in the area of the heaviest rainfall were just under 10 kilometers indicating that the uplift in the storm is weakening, as clouds reached greater heights earlier in the week.

Forecaster Berg at NOAA's National Hurricane Center (NHC) noted today "Water vapour imagery suggests that the outflow from Tropical Storm Lowell may be helping to produce southeasterly shear over Karina, and the low-level center is now exposed to the east of a small area of deep convection."

At 5 a.m. EDT on August 19, the center of Tropical Storm Karina was located near latitude 15.7 north and longitude 134.0 west, about 1,415 miles (2,275 km) east of Hilo, Hawaii. Karina is moving toward the west-southwest near 7 mph (11 kph) and is forecast to turn westward and slow down soon. The estimated minimum central pressure is 999 millibars.

Two computer models used by the NHC to forecast tropical cyclones: the Florida State Super ensemble and HWRF models, weaken Karina to a tropical depression in about 72 hours.