Doppler radar quick-looks from 4PM P-3 flight, 3 September 2010

As Earl continues to accelerate northeastward and weaken as it passes southeast of Long Island  (depicted by the black line in the upper left of the images)  the final NOAA P-3 mission into Earl collected airborne Doppler radar data to use in initializing and evaluating model guidance. Included here you will see images of the horizontal winds within the inner core of Hurricane Earl sampled from the tail Doppler radar on the P-3 early on 3 September 2010. These images are at three altitudes, 1km, 5km, and 10km, using a composite of winds from four legs oriented southwest-northeast, northwest-southeast, east-west, and south-north. Wind, temperature and relative humidity from GPS dropsondes dropped from the P-3 are also visible at 1 km altitude. Like in the previous mission the strongest winds are located on the southeast side of the storm at 1 km altitude, rotating only slightly clockwise in azimuth with increasing altitude until it is southeast of the center at 5 km. It is hard to tell what azimuth the peak winds are at 10 km because of the lack of scatterers at that altitude, indicative of weakening convection to loft precipitation to that altitude. This asymmetry in the wind maximum with increasing altitude is suggesting that Earl is encountering vertical shear of the horizontal wind over the vortex from the increasing westerlies aloft impacting the storm as it moves further northward. The peak winds continue to weaken and the radius of the maximum wind is continuing to increase, suggesting Earl is weakening rapidly as the vertical wind shear over the center continues and the storm accelerates northeastward. Other changes evident are a much more asymmetric wind field with stronger winds on the southeast side of the storm. These changes suggest the storm is likely becoming more extra-tropical in nature.