Beryl Weakening Already?
July 19, 2006 - 01:05 AM UTC
Beryl is getting perilously close to tropical depression status this evening. I doubt that NHC would actually drop it to a TD the very next advisory after upgrading it for consistency's sake. That said, all signs point to Beryl weakening.
Thunderstorm activity has diminished greatly since 5pm. The U. of Wisconsin Dvorak intensity estimate has also been falling thoughout the evening. We are at the normal daily minimum for thunderstorm activity over the ocean, so perhaps this is the reason for the weakening. The hurricane hunters revisited the stronger southeast quadrant this evening and have found slightly slower wind speeds, although only by a few knots. Below, I have posted the two most recent infrared images and the most recent visible and water vapor satellite images, along with a superimposed tropical storm symbol for ease of recognizing the center of circulation. Notice on the two infrared images how thunderstorm activity has decreaed in size and intensity. On the visible (third) image, the center of circulation has become exposed. That would normally be a sign of shear affecting the system, but that isn't the case for this storm. It appears to me, the reason for the dwindling convection and exposed center would be dry air, which is apparent in the darkness on the west side of the storm on the water vapor (bottom) image. This dry air intrusion was mentioned by NHC in the last discussion. It appears this will be the limiting factor for further development........