Doppler radar quick-looks from 2:00 AM P-3 flight into Tropical Storm Bertha, 5 August 2014

As Bertha weakened back to a tropical storm while passing southeast of Cape Hatteras, NC a NOAA P-3 mission collected airborne Doppler radar data to use in initializing and evaluating model guidance.  Included here you see images of the horizontal winds within 300 km of Bertha sampled from the tail Doppler radar on the P-3 aircraft during the early morning of 5 August 2014. These images are at three altitudes (1 km, 3 km, and 6 km) and are a composite of winds from the P-3 Doppler pattern around Bertha. Also plotted on each analysis are the locations of dropsondes deployed by the P-3 (plotted using standard station symbols). These analyses show that Bertha continued to weaken and it’s structure looked worse than the flight before with a very asymmetric distribution of precipitation at 1-and 3-km altitude, with the bulk of the precipitation east-southeast of the center. At 6-km altitude there was much less precipitation  surrounding the center with isolated areas east and well south of the center. There is indication of a circulation center at 1- and 3-km altitude, with a broad area of tropical storm force winds 50-60 km east-southeast of the circulation center, and a hint of a secondary wind maximum 170-180 km south-southeast of the center. At 6-km altitude it is very hard to discern a circulation center, with a trough embedded in southwesterly flow in the vicinity of the low-level centers indicative of the increasing southwesterly shear over the storm as it interacted with a frontal zone off the east coast of the United States.

All the Bertha radar composites at 0.5-km height resolution are available at http://www.aoml.noaa.gov/hrd/Storm_pages/bertha2014/radar.html