GFS model forecasts storm to make landfall in South Carolina late Friday (WeatherBell.com)

Gusty winds, heavy rain, and high seas are likely for the coastal Carolinas late this week and this weekend as the first tropical cyclone of the Atlantic hurricane season has a good chance to form over the next 5 days.

The National Hurricane Center now says there’s a 60 percent chance a cyclone will form by the end of the weekend.  If it determines the storm has characteristics of a both a tropical and mid-latitude weather system and winds are at least 39 mph, it will technically be classified a “subtropical” storm.

Satellite imagery shows a large area of disturbed weather currently near the Bahamas very slowly congealing.  There is now a trackable low pressure area located just 40 miles off the coast of West Palm Beach, FL (identified as 90L).  However, the cloud cover and rainfall associated with it extend far from the center.


Visible satellite image from 8:15am EDT. The center of the surface low is marked with a red X. (NASA)

Impressively, a model analysis from 7 a.m. EDT also captured the weak nascent surface circulation:


Surface wind and pressure analysis from the 11Z RAP. (Univ. of Miami)

Not much has changed in terms of the forecast… this has all been very well predicted by several models, and they are in fairly good agreement on what is in store for the next few days.

The disturbance should continue its gradual pace of organization as it drifts north toward the Carolinas.  Coastal South Carolina and North Carolina will experience the worst weather on Friday-Saturday, including gusty winds (possibly gale-force), up to a few inches of heavy rain, and rough seas.


5-day rainfall forecast from the NWS Weather Prediction Center (WeatherBell.com)

However, it does not appear that this will intensify into anything beyond a  low-end tropical/subtropical storm.


Intensity forecasts from a series of dynamical and statistical models. (UCAR)

If this system gets named prior to May 9, it will be the earliest named storm since Ana formed on April 20, 2003.  As luck would have it, this storm’s name would also be Ana. The last storm to get named in May was Beryl 2012, and strangely enough, it looked a whole lot like today’s disturbance:

A visible satellite image of 94L (pre-Beryl) on May 24, 2012 looks very similar to 90L today. (NRL-Monterey)
A visible satellite image of 94L (pre-Beryl) on May 24, 2012 looks very similar to 90L today. (NRL-Monterey)