Hurricane Emily (1987) - Meteorological History

Meteorological History

Hurricane Emily originated out of a tropical disturbance, associated with the Intertropical Convergence Zone (ITCZ), that moved off the west coast of Africa on September 13. Tracking westward at a low latitude, the system fluctuated in organization, with the development and weakening of deep convection and weak outflow for several days. By September 18, the disturbance entered a region where there was sinking air, an inhibiting factor of tropical cyclone development. Two days later, the system separated from the ITCZ and quickly developed into a tropical depression, the twelfth of the season, while located about 605 miles (975 kilometers) southeast of Barbados.

Gradual intensification took place throughout September 20, attaining the status of tropical storm by 1800 UTC and received the name Emily. The storm tracked in a general west-northwest direction around the edge of a strong subtropical ridge. By 1200 UTC on September 21, the center of Emily passed directly over St. Vincent with winds of 50 mph (85 km/h). Situated underneath an anticyclone, rapid intensification took place as the storm quickly tracked towards Hispanola. In the 24-hour span between 1800 UTC on September 21 and 1800 UTC on September 22, the central barometric pressure of the storm dropped 44 mbar (hPa) to 958 mbar (hPa; 28.29 inHg) and winds increased to 125 mph (205 km/h), equivalent to a high-end Category 3 hurricane on the Saffir–Simpson Hurricane Scale. At the time of peak intensity, the hurricane hunters recorded flight-level winds of 155 mph (250 km/h) and unofficial pressure of 949 mbar (hPa; 28.02 inHg).

Slight weakening took place late on September 22 and early on September 23 as the hurricane neared landfall. Around 0300 UTC, the eye of Emily tracked onshore between Barahona and Bani, Dominican Republic as a strong Category 2 hurricane with winds of 110 mph (175 km/h). Within 12 hours of landfall, the hurricane weakened to a tropical storm and had emerged into the Atlantic Ocean near Haiti with winds of 65 mph (100 km/h). The storm significantly slowed while tracking through the eastern Bahamas as a quasi-stationary frontal system influenced Emily. Moving generally towards the north, the center of circulation passed very close to Inagua and Mayaguana on September 24.

By midday on September 24, the system became embedded within the mid-latitude westerlies and rapidly accelerated towards the northeast. The National Hurricane Center anticipated that Emily would undergo an extratropical transition within 24 hours at this point as they forecast it to merge with the frontal system to the northeast. However, the storm unexpectedly underwent a second phase of rapid intensification on September 25, at one point reaching the rate of explosive intensification with the central pressure decreasing at 2.5 mbar per hour. By 0600 UTC, Emily had re-attained hurricane intensity and at 1145 UTC, the center passed directly over Bermuda with winds of 85 mph (140 km/h). Soon after, the storm reached its secondary peak intensity with winds of 90 mph (150 km/h) and a minimum pressure of 974 mbar (hPa; 28.76 inHg).

Hurricane Emily continued tracking northeast throughout September 25 into the following day with increasing speed. By late on September 25, the forward motion of the storm had reached 50 mph (85 km/h). The storm now began to undergo an extratropical transition with forward speed peaking at 65 mph (100 km/h), the third highest forward motion ever recorded in a tropical cyclone. Interacting with a baroclinic zone, the hurricane completed its transition at 1800 UTC on September 26, resulting in the issuance of the final advisory on the storm.