Tropmet | Storm Chasing

During the latter half of September 1995 a tropical wave exited the west coast of Africa, crossed the tropical Atlantic and the Caribbean Sea, merging with a broad area of low pressure over the western Caribbean, before developing into a tropical depression southeast of Cozumel, Mexico on September 27th.

During the next several days, the depression meandered slowly across the Yucatan peninsula, before emerging over the Bay of Campeche in the southern Gulf of Mexico and reaching tropical storm strength on September 30, 1995. Over the next two days, Opal gradually strengthened with the system reaching hurricane intensity on October 2nd, about 150 miles west of Merida, Mexico.

Taking advantage of a well-established upper-level anticyclone, centered over the Gulf of Mexico, and very warm sea-surface temperatures, Opal underwent rapid intensification and by early on October 4, 1995 reconnaissance reports indicated that the hurricane had developed a pinhole eye, less than 10 nautical miles in diameter, with the minimum central pressure falling to 916 mb (27.05 in)**, and maximum sustained winds increasing to near 150 mph (130 kt), while about 250 miles south-southwest of Pensacola, Florida. At this time, Hurricane Opal was a high-end category four on the Saffir-Simpson Hurricane Wind Scale. During this period, Opal's motion had begun to accelerate towards the north-northeast and the northern Gulf coast.

During the following twelve hours Hurricane Opal underwent an Eyewall Replacement Cycle with the small inner-eyewall and eye collapsing and a much larger outer eyewall becoming dominant. The hurricane steadily weakened during this time, however, Opal was still a very large and powerful category three hurricane at the time of landfall, near Pensacola Beach, Florida on the afternoon of October 4, 1995, with sustained winds of 115 mph (100 kt), a minimum central pressure of 942 mb (27.82 in), and peak storm surge values near 15 ft. The highest officially recorded surface winds in Opal included a gust to 144 mph (125 kt) at Hurlburt Field, near Mary Esther, Florida (three miles west of my location), 115 mph (100 kt) at Eglin AFB, and 88 mph (76 kt) at Pensacola PNS.

During the afternoon and evening of October 4, 1995, my chase team intercepted Hurricane Opal at Fort Walton Beach, Florida. Highest winds at my location, during the peak of the eyewall, were sustained near 100 mph (85 kt) with gusts to 125 mph (110 kt). The peak storm surge at my location was approximately 13 ft, accounting for an 8-10 ft ground elevation, this resulted in a surge depth of 3-5 ft with higher waves. The eastern edge of Opal's eye passed over my location with a 30 minute lull, during which time sustained winds fell to 20-30 mph (15-25 kt). I recorded a minimum pressure of 960.3 mb (28.36 in) during this time.

Across all impacted areas, Hurricane Opal was responsible for 63 direct fatalities, and $5.14 billion (1995) in damage. Opal is ranked as the 14th costliest hurricane in U.S. history.

**Hurricane Opal retains the distinction of having the lowest pressure measured in an Atlantic basin tropical cyclone (916 mb) which did not reach category five intensity. Show less