8:04 AM
As of 5 AM EDT, Bertha has upgraded to a category 2 hurricane with winds sustained 105 MPH with higher guts, and is moving to the northwest at 9 MPH. The storm seem better organized this morning as convection increased at southern quadrant of the storm, and the eye seems to be clearing. However, Bertha's intensity should continue to decrease as wind shear* (variation of wind velocity at different altitudes) increase over 20 knots over it, and sea surface temperatures cool will cool down as it heads north. Bertha should continue to moving towards the northwest, and eventually north as it trough of low pressure picks it up. Beyond Friday however, the cone of uncertainty of the National Hurricane Center's (NHC) forecast track broaden significantly. Thus, residents in Bermuda should indeed keep a close eye on this system. Regardless, if Hurricane Bertha makes landfall in Bermuda they will still somewhat feel the effects of this storm because the wind field increased with tropical storm force winds extending as far as 200 miles in radius, a 400 miles in diameter. In addition to that, residents of Bermuda will indeed feel the wave action caused by this tropical cyclone. Furthermore, the residents of Nova Scotia will need to keep a close eye on this because Bertha will be an enormous extratropical cyclone* by Wednesday or Thursday of next week. Extratropical cyclones have the propensity of having an immense wind field; for example, hurricane Noel's size significantly increased as it reached the northernmost regions of the Atlantic.
Possible Depression Next Week
For the past couple of days, the GFS, UKMET, and the ECWMF model have been forecasting a tropical depression to form early next week, and move towards the islands. This is worth keeping an eye on for now.
Wind Shear
*Wind shear is the variation of wind velocity at different altitudes. That is the easiest way to explain it, however, not everyone comprehends it. Variation means changing, velocity in physics is speed+direction, and altitude is height or elevation. So wind shear is when wind changes at both speed and direction at different heights. Now when the upper level winds blow at a high speed, it tends to remove the thunderstorm activity from the center of circulation, weakening the storm. However, wind shear is needed for dynamic storms such as tornadoes to form. I will eventually post a more detailed tutorial about wind shear.
Extratropical Cyclones
* A tropical cyclone transforms into extratropical cyclone when its core is cooled as it moves into cooler waters. Eventually, the storm will be like mid latitude storms that are associated with fronts, and that is how these storms gain their energy.
Forecaster Juderson
Forecaster Juderson