FLHurricane.com: Is Bertha Bermuda Bound???

The answer is a somewhat qualified yes, however the real questions are 'when' and 'how strong'?

Hurricane Bertha's forward motion is beginning to slow down as she wobbles along to the west northwest to northwest (about 300 degrees) at 12 knots. Steering currents are becoming weaker, especially north of 24N, so a continued slowdown in forward speed is likely. Sea Surface Temperatures (SSTs) of 27C extend north and northwestward from her current position to about 31N - and this alone would suggest additional intensification - but maybe not.

The latest UKMET and CLP5 models indicate a storm track very much in line with the 07/15Z forecast - taking Bertha a little east of Bermuda late on the 12th, but the handles this storm quite differently with regard to timing and intensity. It is worth noting that he still has not initialized at all well with this system, however, it does maintain a storm track close to the consensus track for the first four days - but as a much weaker system. The then brings a weak Bertha to a stall in the vicinity of 26N 64w with a slow northward drift for a couple of days - and finally brings what is left of the system over Bermuda late on the 15th. So does Bertha pass east of Bermuda on the 12th as a 70 knot Hurricane, or does she drift over Bermuda as a minimal Tropical Storm, at best, on the 15th?

The answer is still an unknown, because the forecasted steering currents and wind shear are tied to the upper level forecasts. Current wind shear projections imply that Bertha will encounter about 20 knots of west southwesterly wind shear for the entire 24 hour period on Tuesday. The low-level shear actually decreases somewhat north of 29N, but the high-level shear actually increases. There are already some hints in the latest satellite imagery that upper level wind shear is beginning to impact the northwest quadrant of the cyclone.

Because the has not yet initialized properly on the strength of Bertha, its slower movement of a much weaker system does leave room for some doubt. However, if the shear zone does exist (and I think that it does), it becomes a question of just how strong is that windshear? There is not much data to glean from the central Atlantic (except for satellite interpretation) to determine a better answer, and until we get one, the folks in Bermuda need to remain vigilant (and I'm sure that they are).
Cheers,
ED