Erika continues to surprise…where is it going next?

Good afternoon.

Unfortunately, Tropical Storm Erika has turned deadly in the Caribbean. At least four people are confirmed dead, and 25 to 30 more missing and feared dead, on the island of Dominica, and the damage there is catastrophic as a result of extreme flooding and mudslides. Puerto Rico also saw very heavy rain, but their impact was mitigated by a major drought that was ongoing there. It goes to show that even weak tropical storms can be deadly and very destructive and must always be taken seriously. It is just south of Puerto Rico now, with winds unchanged at 50 mph sustained, although flooding rains are ongoing and the greatest short-term threat.

Short Term: Does it survive Hispaniola?

The short term track is pretty much set in stone – it will likely make landfall this afternoon on the southern or eastern coast of the Dominican Republic, with little or no strengthening expected. It may even brush the islands to the south, but the highest mountains in Hispaniola are in the central and southwestern sections, with the peninsula in southwestern Haiti also very mountainous. Those are known to tear up even well developed hurricanes, let alone poorly organized tropical storms. It is certainly possible that Erika becomes an open wave or trough in the next 24 to 36 hours. I give that a 30% chance of taking place.

Regardless of structure or intensity, major flooding and landslides are certainly possible, and Haiti is known for weak storms or distant storms becoming catastrophic given the poor living standards there (even before the 2010 earthquake). In 1994, Tropical Storm Gordon killed over 1,000 people in Haiti, and in 2004, Hurricane Jeanne killed over 3,000 people, despite never making landfall. More recently, in 2008, Hurricane Hanna killed over 500 people in the country despite being weak and well to the north at the time, and four days before hitting the US East Coast, Hurricane Sandy also devastated the country despite making landfall in Jamaica and eastern Cuba. There have been many other very weak Haitian storms that have had death tolls rivaling (or exceeding) even Katrina since 1900.

Topographical map of Hispaniola (from Wikipedia).

Topographical map of Hispaniola (from Wikipedia).

Medium to Long Term: Still Clear as Mud

In the assumption that Erika survives the traverse of Hispaniola today and tonight, it should emerge near the coast of Cuba tomorrow, and then most likely to the south or southwest of the Bahamas. Eastern Cuba is not nearly as mountainous as Hispaniola, although some peaks as high as 3,000 feet do exist. The models have been slowly trending westward, but there is still no clear consensus. Nonetheless, some impact at least to Florida is highly likely as either a tropical storm or hurricane if Erika survives Hispaniola. There are 5 possible scenarios (with the sixth scenario being dissipation) as explained below.

Model forecast for the track of Erika. Notice the high concentration near Florida, but ensemble runs over a fairly large area. (Map from SFWMD)

Model forecast for the track of Erika. Notice the high concentration near Florida, but ensemble runs over a fairly large area. (Map from SFWMD)


Updated medium to long term track possibilities, as explained below. (My map)

Scenario 1: At sea, possible looping (5% chance)

This is now the least likely scenario of those still in play, despite having some ensemble support. In this scenario, a more likely stronger Erika would be attracted more to the incoming trough, and woulds start to track out to sea after impacting the eastern Bahamas. Once there, if the weakness remains, Erika would head out to sea, possibly after a close brush with Bermuda. However, if the ridge rebuilds quickly, Erika would likely begin a series of loops and erratic movements for the next few days to the east of the Bahamas, somewhat reminiscent of Hurricane Jeanne in 2004 and Hurricane Betsy in 1965 (also an El Nino year!), and Erika would likely strengthen in the process if it doesn’t run over its own upwelling. However, the fact that Erika is unlikely to intensify in the next 24 hours makes this scenario the most far fetched.

Scenario 2: Near or along the East Coast after missing Florida (15% chance)

This scenario is definitely still in play as well, as supported by the 12Z GFDL showing an intense hurricane off the North Carolina coast, and several ensembles suggesting this scenario as well. As a result, even in the Northeast we need to pay attention to later forecasts for Erika, although the shocking CMC model run yesterday is a highly unlikely scenario. More likely, Erika would be attracted to the trough and start to recurve over the central Bahamas, just missing the coast of Florida. The ridge would not rebuild in enough and would result in Erika moving up the coast, whether just offshore or just inland.

If the ridge rebuilt, the storm would likely begin erratic movements near the Carolina coast, like Diana in 1984 and Dennis in 1999, or it could just move westward and make landfall on the southeastern coast from the east between Myrtle Beach, SC and Jacksonville, FL. The Gulf Stream and weaker wind shear would likely help to allow Erika to maintain its intensity or strengthen in the Bahamas and hold the strength before its closest approach or landfall, although beyond Cape Hatteras water temperatures drop somewhat.

Scenario 3: Florida Peninsula impact (25% chance)

This is the official NHC forecast and is supported by the general model consensus. In this case, Erika would have a relatively short time over water before making landfall in South Florida or Southwest Florida, most likely as a tropical storm since it would have less time over water. It would most likely track along or near the spine of the Florida peninsula, possibly emerging over water on either side. The intensity would be limited by land interaction, although the marshy landscape of South Florida may limit weakening (remember Fay in 2008?). If the ridge can rebuild far to the west, an erratic movement may begin and Erika may be a problem for Florida for days to come.

Scenario 4: Eastern Gulf of Mexico (15% chance)

In this scenario, Erika remains weak and emerges off Cuba, too far west to directly impact most of Florida (although heavy rain and wind would still be likely there) by missing the trough. It would likely be a very weak storm in the Gulf initially, although some strengthening would be possible for sure if wind shear isn’t too high. It would likely round the ridge into the northern Gulf Coast roughly between Tallahassee and New Orleans. Many ensembles suggest this scenario, but none of them make Erika a strong storm in the Gulf. An alternate possibility is that the remnants of Erika, as an open trough, re-develop in this region en route for the northern Gulf coast.

Scenario 5: Western Gulf of Mexico (10% chance)

No models or ensembles support this scenario, but I am not ready to rule it out. Erika has had a clear right bias throughout its lifespan so far in terms of track, and this scenario continues it. In this case, Erika likely remains weak and tracks either on the southern edge of Hispaniola or misses it entirely like it missed Puerto Rico. It would then most likely track over or just south of Cuba, possibly with a window for strengthening in the Cayman Trench if it crosses over it. Since wind shear is expected to remain moderate to high in that region, any strengthening would likely be limited. If the trough departs, shear might decrease, however. Given its farther west location, it would likely make landfall on the western Gulf Coast between New Orleans and Brownsville.

How Erika has behaved so far relative to models and forecasts. Notice the models have been biased to the right for the entire lifespan. (Tweeted from John Morales)

How Erika has behaved so far relative to models and forecasts. Notice the models have been biased to the right for the entire lifespan. (Tweeted from John Morales)


The forecast is still very much up in the air. Erika has had a noticeable westerly trend relative to forecasts and models (thanks to John Morales for sharing the graphic), and that may continue. Land interaction will be a major factor as well. However, some models continue to show Erika reaching an area of development potential, so we need to continue to watch. The damage in the Leeward Islands, especially Dominica, should also be a reminder that even weak storms can be devastating.

Forecaster Craig Ceecee – @EternalWeather1

Featured image from Danielle Dozier – @DanielleDozier – earlier this morning.

Leave a Reply