1956 Atlantic hurricane season

Westerlies too far south

Gordon Dunn, Walter Davis and Paul Moore called 1956 comparatively mild in the Monthly Weather Review. They counted eight tropical storms against a two-decade average of ten, and four hurricanes against a recent normal of five. None of the four was severe: one held hurricane force for only a few hours, Flossy for no more than a day, and Greta was as much extratropical as tropical. Only Betsy looked like a classic hurricane.

The authors found sea temperatures near or above normal through the summer and a normal number of easterly waves reaching the Antilles, though the waves were perhaps weaker than usual. They pointed instead to the westerlies, which from early July into early September ran south of their usual position, the reverse of 1954 and 1955. Following Jerome Namias, they argued that fast, low-latitude westerlies shrank the deep easterly current that hurricanes need. Many depressions formed under cold troughs aloft and never grew.

The site's archive counts 12 tropical storms, 4 hurricanes and 1 major hurricane, with an accumulated cyclone energy of 56.7. The Atlantic hurricane reanalysis by Sandy Delgado and Chris Landsea added four storms that the 1956 summary did not list as tropical storms: an early June storm off the Carolinas, two October storms and one in November. One of the October additions is the quasi-tropical low that crossed southern Florida on 15 October; the reanalysis lists a 50 kt landfall there.

June and July along the Gulf

A storm formed in the Bay of Campeche on 12 June and crossed the Louisiana coast just west of Grand Isle late on the morning of 13 June. The reanalysis puts landfall at 50 kt. Forecasters in New Orleans saw both tropical and extratropical traits. Grand Isle recorded 55 mph winds and 6.13 inches of rain, Biloxi a 4.7 foot tide. Four people drowned, three when a tug sank off Mississippi, and damage came to about $50,000; the rain ended a drought.

Hurricane Anna formed from a wave that crossed the Yucatán and strengthened in the Bay of Campeche. It moved inland south of Tampico on the evening of 26 July with a 70 knot wind reported, and forecasters thought hurricane force lasted only about three hours. The reanalysis gives a 75 kt landfall, matching the archive peak. Many houses in Tampico's poorer districts blew down, but no deaths or injuries were reported.

Hurricane Betsy across the islands

Hurricane Betsy was found by ships east of the Lesser Antilles on 9 and 10 August, and aircraft soon measured 120 mph winds around a 10 mile radar eye. It crossed Marie Galante and southern Guadeloupe about midday on 11 August. Reports gave 18 deaths there, about 1,000 dwellings badly damaged, half or more of the banana, breadfruit, coconut and papaya trees destroyed, and a preliminary damage estimate of $10 million.

Betsy came ashore in Puerto Rico near Arroyo around 1230 UTC on 12 August and crossed the island in about two and a half hours. The reanalysis estimates a 981 mb centre and 85 kt winds at landfall. San Juan recorded 73 mph sustained winds with 92 mph gusts, and Ramey Air Force Base gusts to 115 mph. The Weather Bureau counted 9 deaths on the island and $25,500,000 or more in damage, in 1956 dollars; the reanalysis notes these were the first hurricane warnings televised in Puerto Rico.

Betsy strengthened again north of Hispaniola. The archive gives its 105 kt peak, Category 3, at 06 UTC on 14 August, with the season's lowest pressure of 954 hPa. San Salvador in the Bahamas recorded 132 mph gusts on the evening of 13 August. Forecasters raised hurricane warnings for part of the Florida east coast that evening, then lowered them the next day as Betsy turned north. The Weather Bureau counted at least 27 deaths from Betsy and total damage of about $35,880,000.

Betsy also showed what new tools could do. The Navy's radar at Miami tracked its centre from 293 nautical miles out for 26 hours, and upper-air stations at Air Force missile bases in the Bahamas gathered rare data from the upper troposphere.

Carla, Dora, Ethel and Flossy

Carla formed near the Bahamas and drew strong northeast winds along the coast from Florida to New England as a polar high pressed south. Tropical Storm Dora reached Mexico near Tuxpan on 12 September; a landslide killed 13 people on a bus, and a later news report raised the storm's toll to 27. Ethel lasted about two days near the Bahamas, and the authors noted that without a research flight on 12 September nobody would have listed it.

Hurricane Flossy, the only hurricane to reach the United States in 1956, crossed the Yucatán into the Gulf on 21 September and turned east-northeast. It came ashore in the Mississippi delta between Burrwood and Venice around 10 UTC on 24 September. The reanalysis estimates 75 kt at that landfall, a Category 1, down from the Category 2 of earlier studies; the archive gives an 80 kt peak. Flossy then passed south of Pensacola and over Fort Walton.

Golden Meadow, Louisiana, recorded 16.70 inches of rain and Gulf Shores, Alabama, 16.30 inches, and the storm tide reached 7.4 feet at Laguna Beach, Florida. Damage in Louisiana, Florida, Alabama and Mississippi totaled $24,774,000, of which $15,204,000 was to crops. The Weather Bureau attributed 15 deaths to the storm, mostly in plane and car accidents.

Greta, a hurricane from a cold low

A quasi-tropical low crossed southern Florida on 15 October and moved north over the Carolina Capes. It dropped 6 to 20 inches of rain in a belt from Lake Okeechobee to Jacksonville, and flood damage, mostly around Kissimmee, came to about $3,000,000; two people drowned in the surf.

Hurricane Greta began southeast of Jamaica on 30 October as a cold-core low. Blocked by a large high off the Middle Atlantic coast, it looped and turned southeast, gained tropical traits, and reached hurricane force on 3 or 4 November, with aircraft reporting more than 100 mph and 970 mb on 5 November. The wide circulation between Greta and the high sent swells of 20 feet or more to Puerto Rico and Saint Lucia. Damage reached $1,170,605 on the Jacksonville beaches, 80 percent of the port installations at Basse-Terre in Guadeloupe were destroyed, and one person drowned in Puerto Rico.