Late November 1984 nor'easter

Late November 1984 Nor'easter

Image of the storm while at its most intense at 1 pm EST November 23, 1984. Its well-defined cold front is seen entering eastern Cuba at that time.
Storm type:	Nor'easter
Formed:	November 22, 1984
Dissipated:	November 29, 1984
Maximum amount:*	No snow or ice
Lowest pressure:	1005 mbar (hPa)
Damages:	$7.4 million (1984 USD)
Fatalities:	1
Areas affected:	Florida
^* Maximum snowfall or ice accretion

The Late November 1984 Nor'easter occurred on the United States' Thanksgiving Day, November 22, 1984. A deep extratropical cyclone located just off the shore of Florida led to significant beach erosion and the grounding of the freighter Mercedes I for several months along the coastal town of Palm Beach.^[1] It formed unusually early, and its effects were seen unusually far south into Florida.

Development of the cyclone

A cyclone aloft cut off from the main band of the Westerlies, it spurred cyclogenesis in the Florida Straits by November 22, which led to a nor'easter at an unusually southern latitude near the Bahamas. The surface cyclone slowly travelled from the Florida Keys up the Gulf Stream between Florida and the Bahamas before drifting back out to sea. The storm attempted to gain some central convection during several periods of its life cycle. It was at its most intense on November 23 and November 24, with a central pressure near 1005 hPa.^[2] The cyclone moved far enough to the east to allow winds and seas to subside on November 26. There is some evidence that it may have become a subtropical cyclone around November 28, while located in the vicinity of Bermuda.^[3]

Effects

Surface analysis showing the cyclone on the morning of November 23, 1984

Significant rainfall was recorded along the Palm Beach County coast between November 21 and November 26 during this event,^[4] with local amounts of up to 9 inches (225 mm) measured. Surface temperatures hovered in the middle 50s°F, or around 13°C, within the main region of impact. However, wind and high seas were the storm's main impact due to the strong pressure gradient between the cyclone's center and a 1040 hPa surface high over the Ohio Valley. Winds as high as 50 kts (90 km/h) with swells of up to 20 feet were reported by ships in the eastern Gulf of Mexico. Along the Atlantic coast, winds reached 50 knots (90 km/h) at Vero Beach, 48 kts (89 km/h) at Melbourne, 40 kts (74 km/h) at Titusville, and 38 kts (70 km/h) at Cocoa Beach. Offshore the Atlantic coast, seas also reached 20 feet (6 m). Coastal erosion took its toll between St. Augustine and Palm Beach during the three-day storm, which eventually subsided on November 26. About five-sixths of a new pier at St. Augustine was destroyed. Erosion from this cyclone would be the worst experienced in southern Brevard County until Hurricane Frances in 2004.^[5]

The storm dragged the 197-foot Venezuelan freighter Mercedes I ashore the coast of Palm Beach and through a seawall, where it remained in a socialite's backyard into early 1985.^[6] Once hauled out to sea, the vessel was sunk and became an artificial coral reef off Fort Lauderdale on March 30, 1985.^[7] A second freighter ran aground offshore Jacksonville. Damage from Vero Beach alone totalled US$3.4 million (1984 dollars). Martin County reported an addition US$4 million in losses (1984 dollars).^[8] One person perished.^[9]

Other significant Florida extratropical cyclones

The top three deadliest tornado outbreaks in the state's history occurred with extratropical cyclones in February 1998, March 1962, and April 1966.^[10] In 1989, a December cyclone spun up offshore northeast Florida, bringing measureable snow to Jacksonville and flurries across Sarasota in wast-central Florida,^[11] and some Lake Okeechobee-effect snows downwind of the lake. In 1993, the Storm of the Century brought an intense squall line, and winds gusting over 85 knots, to much of the Sunshine State during the early morning hours of March 13. Later that day, flurries were witnessed across the Florida Panhandle in its wake. A frontal wave which became a powerful Christmas 1994 Nor'easter moved across Florida, bringing windy and rainy conditions to the state.

See also

• Climate of Florida
• Cyclogenesis
• Extratropical cyclone
• Nor'easter
• Surface weather analysis

References

World wide web

1. ^ Vanderbilt University Television News Archive. Headline: Florida / Grounded Freighter. Retrieved on November 18, 2006.
2. ^ U.S. Department of Commerce. Daily Weather Maps: November 19- November 25, 1984. Retrieved on November 18, 2006.
3. ^ Danielle Manning and Robert Hart. Using ERA40 in Cyclone Phase Space to Refine the Classification of Historical Tropical Storms. Retrieved on November 18, 2006.
4. ^ Wossenu Abtew, R. Scott Huebner, and Violeta Ciuca. South Florida Water Management District. Chapter 5: Hydrology of the South Florida Environment. Retrieved on November 18, 2006.
5. ^ Florida Department of Environmental Protection. Brevard County: Hurricane Frances and Jeanne Damage Assessment Location Map. Retrieved on November 19, 2006.
6. ^ Marc Fisher and Mary Jo Tierney, Miami Herald. STORM CUTS SWATH OF DESTRUCTION ALONG FLORIDA COAST. Retrieved on November 18, 2006.
7. ^ Greg Johnston. Exploring Wrecks in Fort Lauderdale and the Keys. Retrieved on November 18, 2006.
8. ^ The New York Times. United Press International. AROUND THE NATION; Florida's Storm Ends, Leaving Damage Behind. Retrieved on November 18, 2006.
9. ^ National Weather Service Forecast Office, Melbourne, Florida. Martin County. Retrieved on November 19, 2006.
10. ^ Bartlett C. Hagemeyer and Scott M. Spratt. THIRTY YEARS AFTER HURRICANE AGNES - THE FORGOTTEN FLORIDA TORNADO DISASTER. Retrieved on November 25, 2006.
11. ^ National Weather Service Forecast Office, Melbourne, Florida. Cold Temperatures and Snow Flurries in East-Central Florida January 24, 2003. Retrieved on November 19, 2006.

Printed Media

• Weather Log, November 1984. Mariner's Weather Log. Spring 1985: pp. 91–92.

External links

• Florida Shipwrecks: Mercedes I