WunderBlog Archive » Category 6™
Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.Alberto makes a comeback
Alberto survived some very strong wind shear last night, and is in much better shape this morning. Deep convection for all of Alberto's life had been confined to the storm's east side, but has now built westward and almost reaches the center. Spiral banding has appeared on both visible satellite imagery and the Tampa radar animation. The storm's central pressure was a very unimpressive 1006 mb last night when I thought the storm might get ripped apart, but has dropped to 1001 mb this morning, according to the latest 8am EDT Hurricane Hunters report. Peak winds are probably around 50 mph--buoy 42003 in the Gulf of Mexico measured peak winds of 43 mph earlier this morning as Alberto passed overhead.
Figure 1. Accumulated rain so far from Alberto, as estimated by the Tampa radar.
All this strengthening occurred in the face of strong wind shear of 20-30 knots. The shear has not changed much in the past 12 hours, nor is it expected to do so over the next few days. This should limit Alberto's intensification, keeping the storm below hurricane strength. In fact, the latest visible satellite imagery shows the shear once more blowing the deep convection away from the center, exposing the center once more. I expect Alberto will undergo some fluctuations in strength over the next day as the storm battles the shear. The most likely peak winds at landfall are in the 45 - 60 mph range. Alberto has about a 10% chance of reaching hurricane strength before landfall.
The major threat of damage with Alberto now appears to be storm surge, with a surge of 4 - 8 feet possible over portions of the west coast of Florida. The waters off the coast are very shallow for a long stretch, which allows a rather large surge to build up. Heavy rain will also be a concern, but as I discussed yesterday, this may be more of a boon than a bane given Florida's moderate drought conditions. Rain amounts of up to six inches have fallen in portions of the Keys and Naples, Florida.
We'll update this blog later today as conditions warrant.
Jeff Masters
Figure 1. Accumulated rain so far from Alberto, as estimated by the Tampa radar.
All this strengthening occurred in the face of strong wind shear of 20-30 knots. The shear has not changed much in the past 12 hours, nor is it expected to do so over the next few days. This should limit Alberto's intensification, keeping the storm below hurricane strength. In fact, the latest visible satellite imagery shows the shear once more blowing the deep convection away from the center, exposing the center once more. I expect Alberto will undergo some fluctuations in strength over the next day as the storm battles the shear. The most likely peak winds at landfall are in the 45 - 60 mph range. Alberto has about a 10% chance of reaching hurricane strength before landfall.
The major threat of damage with Alberto now appears to be storm surge, with a surge of 4 - 8 feet possible over portions of the west coast of Florida. The waters off the coast are very shallow for a long stretch, which allows a rather large surge to build up. Heavy rain will also be a concern, but as I discussed yesterday, this may be more of a boon than a bane given Florida's moderate drought conditions. Rain amounts of up to six inches have fallen in portions of the Keys and Naples, Florida.
We'll update this blog later today as conditions warrant.
Jeff Masters
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