Igor barrels towards Bermuda as a high-end category 2 hurricane

Hurricane Igor

Latest visible satellite images reveal that Igor remains a very large and relatively powerful high-end category 2 hurricane. A microwave satellite image from a little earlier this morning concluded that Igor had begun an eyewall replacement cycle (EWRC). This can be noticed quite clearly on satellite imagery as there is a lack of an eye. The inner core of Igor has also slowly been eroding away, and although the microwave image only caught half of the circulation, all that there appears to be left of the inner core is a thin sliver around the western semicircle. As the inner core continues to erode away and eventually dissipates, it will be replaced by a much larger outer core. This outer core will then contract. By then, the EWRC should be complete. 

Figure 1. Latest visible satellite image of Hurricane Igor.

Igor has been moving towards the NW at around 12-13mph. This overall motion should continue as Igor is steered by a large deep-layer ridge/high to the east of him. It should then make a turn more towards the north and pass over or very near to Bermuda. The system will then meet the base of the westerlies and begin to make a turn towards the NE and then slowly make an extratropical transition...likely in about 60+ hours or so. The 12z dynamical model suite is in a good agreement with this scenario.

Upper level conditions are currently conducive for further restrengthening of the cyclone, however, since it is undergoing an EWRC, restrengthening may not happen. Upper level winds should then slowly become less conducive for strengthening due to southwesterly shear beginning to affect the system ahead of a shortwave trof. I do believe that Igor will be able to regain major hurricane status, but it will have to complete its EWRC quite quickly, and that may not happen. All in all, tropical storm force conditions will begin to affect the island of Bermuda tonight, with the worse of the weather appearing tomorrow on the island. All preparations should be complete by this afternoon. It is very likely at this point that Bermuda will at least get 3 or more hours of hurricane force conditions.

A hurricane hunter aircraft is currently en route to investigate the system.

Watches and Warnings

A hurricane warning is currently in effect for the island of Bermuda. A hurricane warning is an announcement that hurricane conditions (sustained winds of 74 mph or higher) are expected somewhere within the specified coastal area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.

Figure 2. A microwave satellite image overpass of Hurricane Igor from this morning.

Tropical Storm Julia

Northerly shear continues to affect Julia in association with the outflow of Igor. Latest visible satellite images reveal that the circulation is completely exposed to the NW of the deepest convective cluster. The combination of strong northerly shear along with continuously cooling sea surface temperatures should lead to the degeneration of this tropical cyclone. After the system becomes a remnant low, it will likely be absorbed by Igor, after it makes an extratropical transition.

Julia will likely continue to move off towards the NW as she is steered by the subtropical ridge to the east. Currently, she poses no threat to any landmasses.

Figure 3. Latest visible satellite image of Tropical Storm Julia.

The Remnants of Karl

Karl has degenerated into an area of showers and thunderstorms accompanied by an ill-defined mid-level circulation over the mountains of Mexico. Shower and thunderstorm activity associated with the remnants of Karl will likely be the hazard of this system as it moves generally towards the SW and into the eastern Pacific ocean. The NHC has stopped releasing advisories on this system.

This will be the last mention of Karl.

Invest 94L

A broad low pressure area accompanied by a decently organized cluster of shower and thunderstorm activity continues to get better organized as it drifts towards the WNW/NW. Further organization of this system is likely due to marginally conducive environmental conditions. Currently, I give this disturbance a 50% chance of developing into the next tropical depression.

This system should continue to move off towards the WNW/NW due to a weak subtropical ridge to the north. In a few days, the subtropical ridge is forecasted to strengthen, which in turn should cause the system to bend back towards the west. Whether or not this system does ultimately recurve will depend on how much it intensifies over the next few days. Since I do not anticipate much in the way of strengthening for the next 3 days or so, this system could eventually pose a threat to the Lesser Antilles, although way too far out to speculate.


Figure 4. Latest visible satellite image of 94L.

Elsewhere in the tropics

The GFS, CMC, and now the ECMWF continue to develop a tropical cyclone in the central/western Caribbean sea in about 7 days or so. Although far our, I will nevertheless continue to monitor the models for consistency.

The CMC has now begun to develop a tropical cyclone in the SW Caribbean sea in about 5 days. No other models have jumped aboard to this solution, however, conditions in the Caribbean are certainly conducive for something like this to develop.

Elsewhere tropical nor subtropical cyclone formation is anticipated through Sunday afternoon.

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