Tag Archives: Hispaniola

Chris Strengthens to a Hurricane Southeast of Cape Hatteras

Former Tropical Storm Chris strengthened to a hurricane southeast of Cape Hatteras on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Hurricane Chris was located at latitude 33.7°N and longitude 72.4°W which put it about 205 miles (330 km) east-southeast of Cape Hatteras, North Carolina.  Chris was moving toward the northeast at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 980 mb.

Hurricane Chris strengthened on Tuesday when it moved northeast of cooler water Chris had mixed to the surface while it was meandering off the coast of the Carolinas.  An eye with a diameter of 30 miles (50 km) formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in the eastern side of that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Hurricane Chris.  The strongest rainbands were in the eastern half of the circulation.  Drier air near the western half of the circulation was contributing to the weaker bands in that part of the hurricane.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away to the north and east of the hurricane.  Winds to hurricane force extended out about 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out about 95 miles (155 km) from the center.

Hurricane Chris will move through an environment favorable for intensification on Wednesday.  Chris will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough over the northeastern U.S. will produce southwesterly winds that will blow toward the top of the hurricane.  The winds speeds are similar at most levels and they will not generate a lot of vertical wind shear during the next 24 hours.  Hurricane Chris will strengthen on Wednesday and it could intensify rapidly.  Chris will move over cooler water when it gets north of the Gulf Stream and it will start to weaken when that occurs.

The trough over the northeastern U.S. will steer Hurricane Chris toward the northeast.  On its anticipated track Chris will move away from the coast of North Carolina.  Chris could be south of Nova Scotia in about 36 hours and it could be near Newfoundland in several days.

Elsewhere, the remnants of former Tropical Storm Beryl crossed Hispaniola and they were moving toward the southeastern Bahamas.  At 2:00 p.m. EDT on Tuesday the center of Former Tropical Storm Chris was located at latitude 20.1°N and longitude 72.6°W which put it about 40 miles (65 km) northeast of Port de Paix, Haiti.  It was moving toward the northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1013 mb.  A reconnaissance aircraft is scheduled to investigate the system on Wednesday if there are signs that it could be reorganizing into a tropical cyclone.

Tropical Storm Erika Bringing Heavy Rain to Hispaniola

Tropical Storm Erika is moving across Hispaniola and it is bringing heavy rain to parts of that island.  At 5:00 p.m. EDT the center of Tropical Storm Erika was located at latitude 17.9°N and longitude 71.2°W which put it about 95 miles (155 km) west-southwest of Santo Domingo, Dominican Republic and about 745 miles (1200 km) southeast of Miami, Florida.  Erika was moving toward the west at 21 m.p.h. (33 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1009 mb.  Tropical Storm Warnings have been issued for the southeastern Bahamas, the Turks and Caicos, for the Dominican Republic, Haiti, for the Central Bahamas including Cat Island, the Exumas, Long Island, Rum Cay and San Salvador.  Tropical Storm Watches have been issued for the northwestern Bahamas including the Abacos, Andros Island, Berry Island, Bimini, Eleuthera, Grand Bahama Island and New Providence, the Cuban provinces of Ciego de Avila, Camaguey, Las Tunas, Holguin and Guantanamo.

The circulation around Tropical Storm Erika is even less well organized today.  At times a small cyclonic rotation appeared on visible satellite images, while at other times Erika looked a lot like a very strong tropical wave.  Vertical wind shear caused by an upper level trough over the western Caribbean Sea has prevented thunderstorms from forming near the core of the circulation.  The lower part of the circulation will be significantly disrupted by the mountains of Hispaniola, but the middle portion may make it across the island.  If the middle level circulation is disrupted as well, then Erika will degenerate into a disorganized area of thunderstorms.  If the middle level circulation is still intact when it emerges west of Hispaniola, then it is possible that momentum could be transferred to the surface and a new low level center spun up.  Erika would most likely be a tropical depression at most at that time.  The water north of Cuba is very warm and if Erika still exists, it could intensify somewhat as it moves toward Florida.

The winds in the lower levels continued to push Erika toward the west-northwest on Friday and that general motion is likely continue for the next 12 to 12 hours.  Erika is getting closer to the western end of the subtropical high and it could turn more toward the north during the weekend.  On its anticipated track Erika or its remnants could be approaching the Florida Keys on Sunday afternoon.  At this time it is almost impossible to know how strong it will be at that time.  If Erika does start to reorganize when it gets west of Hispaniola, watches and/or warnings could be issued for parts of Florida.

Invest 96L

The circulation around the tropical disturbance designated 96L has been disrupted by the mountains on Hispaniola.  There a appears to be a broad low level center near the northern coast of Haiti.  There are several smaller vorticies rotating around within the broader area of low pressure.  The strongest winds are occurring north and east of the center and several reconnaissance flights found winds to tropical storm force north of the center.  The broad center appears to be moving toward the west-northwest at 10-15 m.p.h.   The area of low pressure has produced heavy rain on some of the islands of the northern Caribbean Sea.

It is still possible that 96L could organize into a tropical cyclone as it moves away from Hispaniola.  Once it gets away from the mountains, it will be easier for the flow to consolidate around one primary circulation center.  The Sea Surface Temperatures (SSTs) are very warm around the Bahamas and the upper level winds are not too strong.

There is a large amount of uncertainty about the future track of this system and that will continue until a well defined center of circulation exists.  It appears that the low has been initialized too far to the northeast in some runs of numerical models and that has produced some forecast tracks that are also too far north and east.  It is still possible that this system could head in the general direction of the southeastern U.S.

Development will possibly be slow to occur until the system becomes better organized.  Tropical cyclones can intensify rapidly over the Bahamas and people would be wise to monitor future developments with 96L.