Tag Archives: Dolly

Tropical Storm Dolly Forms over Atlantic

Tropical Storm Dolly formed over the Atlantic Ocean midway between Africa and the Lesser Antilles on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Dolly was located at latitude 13.6°N and longitude 38.7°W which put the center about 1555 miles (2505 km) east of the Lesser Antilles.  Dolly was moving toward the west at 24 m.p.h. (39 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1007 mb.

A low pressure system over the Atlantic Ocean midway between Africa and the Lesser Antilles strengthened on Thursday morning and the U.S. National Hurricane Center designated the system as Tropical Storm Dolly.

The distribution of thunderstorms in Tropical Storm Dolly was asymmetrical.  Thunderstorms were occurring in bands in the southern half of Dolly’s circulation.  Bands in the northern side of Tropical Storm Dolly consisted primarily of showers and lower clouds.  Storms near the center of Dolly generated upper level divergence that pumped mass away to the west of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the northeastern part of Tropical Storm Dolly.  Winds to tropical storm force extended out 60 miles (95 km) in the northeastern quadrant of Dolly’s circulation.  The winds in the other parts of Tropical Storm Dolly were blowing at less than tropical storm force.

Tropical Storm Dolly will move through an environment that will be marginally favorable for intensification during the next 24 hours.  Dolly will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the eastern side of a small upper level ridge.  The upper level ridge will produce northerly winds that will blow toward the top of Dolly’s circulation.  Since the winds in the lower levels of the atmosphere are blowing from the east, there will moderate to strong vertical wind shear.  Tropical Storm Dolly could intensify a little during the next 24 hours in spite of the moderate to strong vertical wind shear.  The vertical wind shear is expected to increase during the weekend.

Tropical Storm Dolly will move around the southern side of a high pressure system over the Atlantic Ocean.  The high pressure system will steer Dolly quickly toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Dolly will move toward the Leeward Islands.  Dolly could approach the Northern Leeward Islands by Saturday night.

 

Tropical Storm Dolly Develops Southwest of Newfoundland

Tropical Storm Dolly developed southwest of Newfoundland on Tuesday.  At 1:00 p.m. EDT on Tuesday the center of Tropical Storm Dolly was located at latitude 39.4°N and longitude 61.9°W which put it about 660 miles (1065 km) southwest of Cape Race, Newfoundland.  Dolly was moving toward the east-northeast at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (5 km/h).  The minimum surface pressure was 1002 mb.

Former Subtropical Depression Four strengthened on Tuesday and its structure continued to make a transition to a more tropical cyclone like appearance.  A band of showers and thunderstorms wrapped closely around the southern side of the center of circulation.  The strongest winds were occurring in that band.  Other bands of showers and thunderstorms were revolving around the center of circulation.  A scatterometer on board a satellite estimated that there were winds above tropical storm force and the National Hurricane Center designated the system as Tropical Storm Dolly.  The winds to tropical storm force extended out 65 miles (105 km) on the southern side of Dolly.  The winds in the other parts of the circulation were generally blowing at less than tropical storm force.

Tropical Storm Dolly will move through an environment that could be favorable for intensification during the next 6 to 12 hours.  Dolly will move near the northern part of the Gulf Stream where the water is near 26°C.  It will move around the southeastern part of a weakening upper level low.  The upper low will produce some vertical wind shear, but the shear will not be strong enough to prevent intensification during the next 6 to 12 hours.  Tropical Storm Dolly is likely to move north of the Gulf Stream on Wednesday.  When Dolly moves over colder water it will start to weaken.

Tropical Storm Dolly will move around the southeastern side of the upper low during the next few hours.  The upper low will weaken on Wednesday and both the upper low and Dolly will be steered toward the northeast by a larger upper level trough over eastern North America.  On its anticipated track Tropical Storm Dolly could bring gusty winds and rain to southeastern Newfoundland on Wednesday night and Thursday.