Rapidly deepening Matthew a possible long-term threat, but models far apart

Good afternoon.

While there is a major drought in New England and parts of New York right now, heavy rain is causing problems in parts of the southern coastal Mid-Atlantic. The upper level low may bring some relief to northern areas, but the impact there will be limited. What the upper level low is doing, however, is opening up a path for Hurricane Matthew. The storm rapidly intensified overnight and is now a category 4 hurricane, with further intensification likely. That will be very important as we move forward. Right now, Matthew is a potential long term threat to the entire east coast, but it is far too soon to pin down specifics.

Important points to make

Before I continue to analyze the situation and forecast, there are several key points that must be made. This is a fluid situation right now with great uncertainty.

1) Any impact to the Northeast or Mid-Atlantic, if there is any, will not be for at least 5 to 7 days and possibly longer. There is ample time for patterns to change even with the best models available.

2) There are still short term issues with the potential track of Matthew. The timing of the upper level low and position will be integral factors in determining where Matthew turns and who may be affected later.

3) Even though we are getting into the 7-day forecast range, models are still prone to large errors this far out. Much of the energy involving the blocking ridges and incoming troughs is still over the Pacific where observations are extremely sparse. The energy should reach the west coast early next week. It is likely that there will be additional weather balloon launches and more NOAA Gulfstream-IV flights next week.

4) This is likely to be a dangerous situation for parts of the Caribbean, particularly Cuba and Jamaica. It is quite possible that a major hurricane, possibly Category 4, may directly impact those islands by early next week. If you live there or have friends or family there, it is imperative that you let them know and tell them to prepare.

Current situation
Water vapor imagery of Hurricane Matthew at 4:15 pm EDT September 30, 2016. The eye is well defined with this category 4 storm located north of the Guajira Peninsula.

Water vapor imagery of Hurricane Matthew at 4:15 pm EDT September 30, 2016. The eye is well defined with this category 4 storm located north of the Guajira Peninsula.

Hurricane Matthew has rapidly intensified during the last 24 to 36 hours. The deepening has occurred despite moderate to strong wind shear which was expected to hinder the storm. It is moving west to west-southwest across the southern Caribbean Sea, between Haiti and Colombia. The latest data from the Hurricane Hunters suggest that maximum sustained winds are now near 140 mph, making it a category 4 storm on the Saffir-Simpson hurricane wind scale. The central pressure has fallen rapidly as well, deepening to about 950 mb. The central core has become much better defined today and a well-defined eye is now visible on satellite imagery.

Since Matthew has intensified rapidly in a less than ideal environment (although dry air is limited and oceans are very warm), I see no reason why it cannot continue to do so. As a result, I expect that Matthew will continue to intensify tonight and tomorrow. In my opinion, category 5 intensity is a reasonable possibility tomorrow. That said, eyewall replacement cycles and structural changes can affect the intensity and result in periods of weakening. In addition, conditions can change rapidly in the ocean, resulting in less (or more) favorable conditions.

Middle to long term

The models are quite consistent in Matthew slamming hard into Jamaica and/or Cuba (with some chance it may also make a direct hit on Haiti or the Cayman Islands) sometime early next week. The timing is different though and that will play a major role later. At this time, I see five possible scenarios.

Scenario 1: Matthew goes west (10% chance)

There is no major model support for this scenario, but I am not ready to rule it out.  Given the rapid intensification today, it is possible they aren’t capturing the overall atmosphere. Matthew would continue west or west-southwest, turning northward near 80°W. It would be a hard hit for western Cuba and the Cayman Islands, likely entering the southeastern Gulf of Mexico en route to landfall on the west coast of Florida or in the Florida Panhandle sometime next week. That path would be somewhat like Hurricanes Charley and Ivan in 2004.

It would likely be the best case scenario for the Northeast and Mid-Atlantic, other than the recurve, but would be disastrous for Florida if it makes landfall there at high intensity. The forecast intensities in the longer range are highly uncertain and dependent on land interaction and shear.

Scenario 2: Florida brush, southeast landfall or near miss (15% chance)
06Z GFDL model run from this morning showing Hurricane Matthew - at the time likely Category 1 or 2 - near Cape Canaveral early Wednesday morning.

06Z GFDL model run from this morning showing Hurricane Matthew – at the time likely Category 1 or 2 – near Cape Canaveral early Wednesday morning.

The GFDL and many GFS ensembles support this scenario. Matthew would likely make landfall farther west in central Cuba and perhaps in western Jamaica, then enter the Florida Straits. It would likely track just east of South Florida and continue northward probably on Wednesday or Thursday. Depending on latitude and timing, it may then make landfall over the Carolina coast before either merging with the trough or recurving out to sea. That would be quite similar to Hurricane Hazel in 1954 and Hurricane David in 1979.

It is unclear how this would impact the Northeast and Mid-Atlantic, but if it moved up the coast, it would likely weaken greatly. Nonetheless, heavy rain and strong winds may be possible for some late next week. Impact may be severe farther south, depending on the exact track and intensity.

Scenario 3: Race through Bahamas, beats trough (25% chance)
12Z CMC model run from earlier today for late next Thursday night. Hurricane Matthew is located off the Carolina coast, and with a weakness in the ridge to the east, manages to escape.

12Z CMC model run from earlier today for late next Thursday night. Hurricane Matthew is located off the Carolina coast, and with a weakness in the ridge to the east, may manage to escape.

This is supported by the CMC and earlier GFS runs (along with some ensembles). In this scenario, Matthew accelerates northward and plows through the Bahamas through the middle of next week. Afterward, it tracks roughly parallel to the Carolina coast. However, it manages to escape out to sea either because a new low opens up a weakness in the ridge or because the northern ridge cannot build in. In addition, the trough to the west cannot reach the storm in time. This is similar to Hurricane Joaquin last year.

This is probably our best case scenario, since Matthew would stay well off our shores. It is what we should hope for. Even still, it is a devastating situation for the Caribbean and may threaten Bermuda.

Scenario 4: Steady through Bahamas, trough captures (25% chance)
12Z GFS run from this morning showing vorticity potential next Saturday night (long range). The trough to the west begins to capture Matthew and bring it ashore as an intense storm.

12Z GFS run from this morning showing vorticity potential next Saturday night (long range). The trough to the west begins to capture Matthew and bring it ashore as an intense storm.

This is undoubtedly the worst case scenario for the Northeast and Mid-Atlantic. It is supported by the 12Z GFS, earlier CMC runs and many ensembles. The only difference between this scenario and the previous scenario is that Matthew is slightly slower and takes a day or two longer to reach off the Carolina coast. That is important since it allows the ridge to the east to rebuild. Concurrently, a trough to the west could reach near the east coast next weekend. That trough eventually “captures” Matthew and draws it into the coast, most likely in New England. This is similar to Hurricane Sandy in 2012 although such would likely take place farther north.

This is our worst case scenario. However, specific impacts certainly cannot be predicted this far out as it is at the outer limits of the long-range forecast.

Scenario 5: Slow movement stalls Matthew (25% chance)
12Z ECMWF model run from earlier today. Intense Hurricane Matthew - likely Category 4 or 5 - is blocked by a rebuilding ridge to the west as well as east. This is for next Thursday evening.

12Z ECMWF model run from earlier today. Intense Hurricane Matthew – likely Category 4 or 5 – is blocked by a rebuilding ridge to the west as well as east – it doesn’t move much for the next few days afterward. This is for next Friday morning.

This is supported by the ECMWF and that model has been consistent in showing this solution. Much like Scenarios 3 and 4, Matthew tracks across eastern Cuba or extreme western Haiti, but much slower. It takes until at least the middle of next week for it to reach the Bahamas. By then, the trough to the north gets blocked by a rebuilding ridge over the southeastern US. As a result, steering currents collapse and Matthew will likely stall out near or north of the Bahamas. This would be most similar to Hurricane Betsy in 1965 and Hurricane Felix in 1995.

Any future movements would be dictated by changes in steering currents as troughs in the future or weaknesses in the ridge develop. It is impossible to predict any impacts at this stage from this scenario.

Conclusion

Matthew rapidly intensified today into an extremely dangerous hurricane, and further intensification is likely. Any thoughts about Matthew’s future is pure speculation right now. That said, we are quite confident it will be a severe issue for parts of the Caribbean. Even the timing is uncertain, and that will play a big role in what might happen later. We will slowly learn more as the weekend progresses, but not until next week will we know more. It is impossible to predict impacts at this point since we don’t even know what Matthew’s structure or shape will be. Any threat to the Northeast and Mid-Atlantic is nearly a week away, if not more.

Enjoy your weekend, no matter what your plans are. Keep an eye on Matthew, but don’t let it get to you too much. We have a long way to go.

Forecaster Craig Ceecee – @Ceecee_Wx

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