Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 9:07 PM GMT on September 08, 2005
The Air Force Hurricane Hunters sent in an eye report at 4pm EDT where they observed a central pressure of 985 mb and a surface winds of 70 knots (80 mph). Maximum flight level winds were 66 knots at 5000 feet altitude. This data suggests that Ophelia is at hurricane strength. The maximum temperature in the eye was 5C warmer than just outside the eye, which is a respectable temperature difference typical of a weak Category 1 hurricane. Doppler radar wind estimates also indicate hurricane force winds.
Figure 1. Wind speed estimates from the Melbourne Doppler radar. The dark red color on the south side of the eyewall indicate winds in excess of 64 knots (minimum hurricane force) blowing away from the radar. Because the radar uses the Doppler effect to measure wind speed, it cannot tell what the wind speed is when the winds don't have a component of motion towards or away from the radar, Thus, winds on the east and west eyewall are coded white (a speed of zero towards the radar) and the winds on the north eyewall are coded blue (blowing towards the radar).
Long range radar out of Melbourne FL, shows that a partial eyewall of 15 miles diameter, open to the northeast, has formed. The Hurricane Hunters also confirmed this. Satellite images show improving upper-level outflow in all quadants, and a modest increase in the size of the storm. Outflow and deep convection are still restricted on the southeast side, where strong winds of 10 - 15 knots continue to shear the storm.
No important changes to the environment have occurred or are forecast to occur, and Ophelia should continue to slowly intensify and sit in place the next 24 hours. After that, a slow northeast motion is likely as a weak trough pushes off of the east coast.
Comments will take a few seconds to appear.