Storm’s Slow Path Through Bahamas Bringing Category Four Hurricane Conditions for Almost 24 Hours

With the storm threat to the Mid-Atlantic Coast of the United States easing, the focus with Hurricane Joaquin has shifted to the impact the storm is having on the Bahamas.  The storm has been bringing hurricane conditions to the archipelago for the past couple days, and Category Four effects for close to the past 24 hours.  The combination of wind, rain, and surge with the storm’s slow movement (now to the Northwest at 3 miles per hour), has created significant damage in places such as San Salvador, Exuma, Long Island, and Inagua Island.

Since moving into the Bahamas earlier in the week, Joaquin has been plagued by slow moving steering currents.  On Wednesday, the storm has was moving to the Southwest at 7 miles per hour.  On Thursday, it slowed down some more, but began changing direction to the WSW at 5 miles per hour.  Now, it has begun the move toward the north with a NW trajectory at 3 miles per hour.  Slow moving hurricanes can cause extensive damage.  A classic example was Hurricane Frances to Florida in 2004.  A big part of the problem with slow moving hurricanes is the rain.

We saw this with both Hurricane Floyd (1999) and Irene (2011) here in New Jersey.  These slow moving storms dumped a lot of rain on the Garden State and caused significant inland and river flooding.  Tropical cyclones always bring with it a ton of moisture, and when it is moving at a slow rate, and encountering mountainous terrain that causes the air in the circulation to lift and condense, you have the situation like what is happening now in portions of the Bahamas were rainfall amounts could end up being anywhere between 12 to 18 inches with isolated areas receiving as much as 25 inches.  Other parts of the Bahamas further to the south along with the Turks and Caicos Islands, Haiti and the Dominican Republic, and Eastern Cuba could still see anywhere between 2 to 4 inches despite the fact that the center of the storm is many miles away.

Earlier this morning, I happened to see pictures posted on Facebook by Wayne Neely, a meteorologist in the Bahamas, who has written several books on hurricanes.  The pictures showed extensive damage to places such as Exuma, Long Island, and Inagua.  In addition, Jim Williams of Hurricane City reported on Thursday morning, that San Salvador was being hit hard by hurricane force winds.  These dangerous Category Four conditions are expected to continue over the Bahamas for several more hours, but the calvary is coming now that Joaquin has started to make that expected turn to the north.  The forecast is calling for hurricane and tropical storm force winds to continue in the Central and Southwestern Bahamas for much of today, but a northward turn is expected to continue with increased forward speed before Joaquin turns to the northeast and picks up more steam on Saturday.

As of the 8:00 AM Advisory from the National Hurricane Center, Hurricane Joaquin still had winds of 130 miles per hour with gusts at or near Category Five strength on the Saffir-Simpson Scale.  Barometric pressure has remained steady (only an increase of one millibar since last night) at 937 millibars, or 27.67 inches of Hg.  The latest forecast discussion calls for fluctuations in strength over the next 24 hours before a gradual weakening trend commences on Saturday.  The future track of the storm has it pulling away from the Bahamas, and becoming more of a threat for Bermuda, Cape Cod, Martha’s Vineyard, and Nantucket in Massachusetts, and Nova Scotia in the Canadian Maritimes.  However, the storm is one of several players affecting weather in the Mid-Atlantic right now.  In addition to Joaquin, there is strong high pressure moving down from Canada, and a storm system pushing in from the west.  These three will combine to create a pressure gradient that will produce a strong easterly fetch along the coast for several high tide cycles.

So for residents from the Carolinas into the New York/New Jersey Metro area, you can expect heavy surf from swells propagating out from Joaquin to begin arriving in your area over the next several days.  Expect heavy surf, dangerous rip currents, elevated water levels and coastal flooding for up to 6 high tide cycles.  Also, keep in mind that despite the fact that the model guidance has been showing more and more of an eastward track offshore and away from the United States coastline, there is still a possibility that the storm could change in direction and head for the coast.  Bottom line:  Don’t let your guard down yet.  Please continue to monitor reports on the storm from your trusted media sources, and be prepared to act if necessary.