Among the most unusual and unexpected hurricanes in United States history is the only hurricane to make landfall in the month of May. This recently rediscovered storm that struck northwest Florida on 28 May 1863 created a natural disaster in the area that became lost to history because it was embedded in a much larger and important manmade event—in this case, the U.S. Civil War. The authors document the arrival of this storm both historically and meteorologically and anachronistically name it “Hurricane Amanda” in honor of the Union ship driven ashore by the hurricane. The hurricane revealed deficiencies and strengths in combat readiness by both sides. Meteorologically, the storm nearly achieved major hurricane status at landfall and its absence from modern databases of tropical cyclone activity is a useful reminder to users of important gaps in our knowledge of tropical cyclones even in the best-sampled storm basins.

The year 1863 was a pivotal year in American history as major battles between Union and Confederate forces marked a gradual and inexorable shift of fortunes in favor of the Union. The American Civil War was in its third year and news of its battles constantly filled the columns of newspapers and magazines. More than 3,000 soldiers died in early May 1863 at the Battle of Chancellorsville. Hundreds more died in the early battles at Vicksburg in late May, adding to the accumulating Civil War death total already in the tens of thousands and unprecedented in American history at that time.

Amid the manmade carnage on land, a natural disaster brought a less extensive but locally severe tragedy of lost lives to the Florida coast. On 28 May 1863 an unprecedented hurricane made landfall in northwest Florida—the only landfalling hurricane now recorded in American history in the month of May. This unusual hurricane arrived in even more unusual times. The absence of any major effect on combat readiness and the relatively localized effects of the worst damage seems to have limited the duration of the memory of this storm even locally. This paper documents its rediscovery and the effects it had on the greater drama prevailing in the country.

We relied on the extensive series of official government documents that were printed in the late 1800s and early 1900s for written accounts of the storm. Union ship officers wrote to their superiors and to the board of inquiry investigating the storm concerning the loss of the USS Amanda, and there are other accounts from ships in the immediate area of the storm. These accounts provided details that are not available in the extant logbooks. The pertinent accounts were published in the 1903 volume ( U.S. Navy Department 1903 ). We also used the original logbooks of the U.S. Navy located at the National Archives in Washington, D.C. In addition, we made use of land-based weather records held in Records Group 27 at the National Archives in College Park, Maryland, which consists of U.S. Army fort records and cooperative observers of the Smithsonian Institution ( Fleming 1990 ). Newspaper accounts are from the U.S. Library of Congress Newspaper Library in Washington, D.C., and the newspaper microfilm collections at the University of Maryland in College Park. Online sources for newspaper records from Louisiana, Georgia, and Florida included the Jefferson Parish Library ( www.jefferson.lib.la.us/index.htm ), Georgia historical newspapers ( http://enquirer.galileo.usg.edu ), and the Florida Digital Newspaper Library ( http://ufdcweb1.uflib.ufl.edu ).

The following day the Chattahoochee was about to head back from Blountstown to the town of Chattahoochee because of low water in the river when the boilers exploded, killing 14 people outright; several more would die from their wounds soon after. [The gunboat sank and remained in the river below Blountstown until mid-August when the wreck was recovered and returned to Chattahoochee ( Watts et al. 1990 ).] It was not until about 12 hours after the midday boiler explosion on 27 May that another steamer arrived at the scene to transport survivors back to Chattahoochee. By that night heavy rain and strong winds had overspread the area, which would eventually lead to a rise in all the region's rivers. The Commander of the Confederate Navy Yard at Columbus wrote in a 15 June 1863 letter “The dead and wounded were taken on shore, where they remained until the next afternoon (May 28), most of the time a terrible storm raging” ( Campbell 2008 ). For the wounded, many lying in the open with little protection from the elements of a gathering hurricane, it was a miserable and painful experience with little medical care that could be provided to those scalded by the water from the boilers.

On 24 May, Union troops captured the schooner Fashion, loading cotton on the river north of Apalachicola, and towed it down to the Gulf of Mexico. News of its capture led to the decision to take the Chattahoochee down the river although it was in no position to directly challenge Union forces unless it could pass obstructions placed into the river to prevent Union ships from moving upriver (New York Times, 24 June 1863). On 26 May, the gunboat sailed down to Blountstown Bar and waited overnight for a possible rise in water ( Watts et al. 1990 ), the water being lower than normal at that season of the year following a drier than normal spring. Presumably, if the water level had been high enough the ship might have attempted to navigate around the obstructions to engage the Union fleet, but this can only be speculation at this point.

St. George Sound (Apalachicola Bay) is the waterway connecting the city of Apalachicola, Florida, to the Gulf of Mexico. The Apalachicola River empties into the sound and steamboats in the nineteenth century traveled as far north as Columbus, Georgia. This city became an important industrial center for the Confederacy during the Civil War and defense against possible Union incursions up the river led to the construction of warships for the Confederate Navy. The CSS Chattahoochee was constructed in late 1861 and 1862 and was finally delivered to the Confederate Navy from the shipyard in November 1862. By late May 1863, she was located at Chattahoochee, Florida, on the border with Georgia ( Turner 1988 ; Watts et al. 1990 ).

Map depicting the location and name of U.S. Navy ships blockading the Confederate ports along the Gulf of Mexico from Louisiana to Florida on 28 May 1863 for which logbooks are available and used in this study. The only nonextant logbook shown here is that of the Port Royal. The weather data from the logbooks from these ships, along with newspaper accounts and other sources, were used to reconstruct the track of the hurricane. Cities mentioned in the text and Fort Jefferson, where a weather record was taken and used in this study, are also included.

Map depicting the location and name of U.S. Navy ships blockading the Confederate ports along the Gulf of Mexico from Louisiana to Florida on 28 May 1863 for which logbooks are available and used in this study. The only nonextant logbook shown here is that of the Port Royal. The weather data from the logbooks from these ships, along with newspaper accounts and other sources, were used to reconstruct the track of the hurricane. Cities mentioned in the text and Fort Jefferson, where a weather record was taken and used in this study, are also included.

In late May 1863, the Gulf coast of northwest Florida was blockaded by the Union Navy's East Gulf Blockading Squadron, which operated from Pensacola eastward through the Florida Straits in an attempt to slow the flow of goods and war material in and out of Confederate ports ( Weddle 2002 ). At least one Union ship was posted for blockading duties in or near Hurricane Inlet (Panama City), St. Joseph's Bay, the West and East Passes of St. George Sound, St. Mark's, Cedar Key, Tampa Bay, and Port Charlotte. Navy facilities in Pensacola and Key West were also in Union possession. Figure 1 depicts these locations and the ships on station as well as those at sea on the morning of 28 May 1863.

The court also wrote “What took place subsequently on board the HH, on her spar deck and in the presence of all hands—see the record—(and which, under the precept, became a proper subject of enquiry) will go far to show the revising power the weight that was attached to rank and seniority in this instance, and it does not satisfactorily account for the reticence of Acting Volunteer Lt. Cate of assuming all his prerogatives, but will, to a certain extent, account for and palliate the only instance of insubordination reported on the part of a portion of the Amanda's crew” ( U.S. Navy Department 1903 ).

A court of enquiry held in June 1863 in Key West could find no corroborating evidence from any witnesses on either the Amanda or the Hendrick Hudson that any Confederate troops were seen at all. The court found that Lt. Welch's decision to abandon the ship was probably taken too easily and that Acting Volunteer Lt. Cate, of the Hendrick Hudson, as the senior of the two officers, also seemed to express little interest in overriding the decision to destroy the Amanda, a decision that rightly should have been of concern to him ( U.S. Navy Department 1903 ).

Acting Volunteer Lieutenant George E. Welch quickly, and controversially, ordered the abandonment and firing of the ship, as well as destroying the ships' guns, having claimed to see Confederate forces nearby and thereby considering the position of the Amanda indefensible ( U.S. Navy Department 1903 ). The focusing of the crew's attention on a feared Confederate attack and the firing of the ship can be seen in the subsequent log entries of the weather aboard the Amanda, which are less frequent and complete until the log ends later on the afternoon of 29 May. However, according to a note recorded at the bottom of the entry for 29 May the log entries for the last day were recorded from the log slate onto a sheet of paper, but this was lost in the confusion and recorded from memory after the fact. The poor agreement of the instrumental weather data with that of the collocated Hendrick Hudson logbook casts doubt to the accuracy of the other accounts of the ship's firing made from memory.

On the East Pass, off Dog Island, both the Amanda and Hendrick Hudson experienced even worse hurricane conditions. Figure 2 shows the Hendrick Hudson at anchor, taken sometime between 1862 and 1864. The Amanda initially grounded on the west point of Dog Island (where the sea made a complete breach and carried off all of the coal stored there). However, a shift of wind to the southeast drifted the bark into the sound and carried it on a northwest drift toward the mainland where she grounded in mud flats about 7 a.m. A sense of the confusion and danger that took place as the ship neared shore can be found in the original logbook of the Amanda, where the wind and weather data for the hours of 5 a.m. through 8 a.m. are mistakenly recorded as 8 a.m. through 11 a.m. This could be either an error in the original chalk slate log where the readings would normally be first recorded or in a transcription from the slate log to the logbook. A comparison of the nearly collocated Hendrick Hudson's logbook confirms the transcription error.

Four U.S. Navy ships were on station on either side of St. George Sound. The steam gunboat USS Port Royal and gunboat USS Somerset were stationed at the West Pass of the sound while the bark USS Amanda and the steamer USS Hendrick Hudson were stationed at the East Pass of St. George Sound. Ships at both locations experienced hurricane force winds for several hours and at West Pass it dismasted and drove ashore the barge Andrew Manderson onto Sand Island while the sloop Brockenburgh was driven ashore on St. Vincent's Island. Both the Somerset and Port Royal were able to ride out the hurricane, but not without difficulty ( U.S. Navy Department 1903 ).

Table 1 presents the noon temperature data recorded on 11 U.S. Navy ships from 26 to 30 May, centered on the date of the hurricane landfall on 28 May. Nonstandard thermometer exposure and thermometer type and an absence of metadata concerning thermometer calibration call for caution in the interpretation of the data. Data for the full month of May 1863 (not shown) suggest that the thermometers appear to be protected from direct sunlight and some may have been located below deck in the officer's cabins and work areas. Differences in temperatures between collocated ships are likely both random and systematic. The Hendrick Hudson consistently is one of the coolest and is an obvious outlier. Table 1 indicates that removal of the warmest and coolest ship each day makes little difference in the regional mean temperature. The higher temperatures in Louisiana and at Cedar Key may indicate thinner cloud cover at these times on either side of the storm center. The average temperature of 78.2°F (25.6°C) is consistent with the storm being tropical in nature. We also note that despite steady southerly winds on the day of the hurricane, ships in the area saw lower temperatures owing in part to less direct or indirect solar radiation and possibly owing to the wetting of thermometers. The remnant low later encountered a cold front in the Mississippi Valley and moved north and then northeast before being absorbed by an extratropical low. A proposed track of Hurricane “Amanda” is given in Fig. 3 .

Neither the Amanda nor the Hendrick Hudson experienced any diminished wind force during the hurricane. At 2 a.m. the pressure was 29.20 inches (uncorrected; 29.25″ corrected for elevation, gravity, temperature, and latitude; equivalent to ~991 hPa), and the wind from the southeast was at force “11+” with heavy rain. The written comments in the log also indicate that at 3:20 a.m. the wind hauled suddenly to southeast (from east-northeast at 1 a.m.) and the vessel then began to float off the west point of Dog Island to the northwest. The lowest pressure and strongest winds recorded in the Amanda's logbook were at 5 a.m. with an uncorrected reading of 28.74″ (28.79″ or 975 hPa corrected) and winds of force “12+” from the SSE. At 7 a.m. the pressure was up slightly to 28.80″ (28.85″ or 977 hPa corrected) with a south wind and at about this time the Amanda, which had drifted across the sound from the west end of Dog Island, was aground in mud flats on the mainland some three or more miles away from the Hendrick Hudson.

The hurricane moved due northward toward the Apalachicola area during the daylight hours of 27 May. Landfall on the barrier islands late that night and the mainland about sunrise 28 May ( Fig. 3 ). The western edge of the eyewall appears to have brushed the USS Somerset located off the west end of St. George Island in the West Pass of St. George Sound. A northeast hurricane began to moderate at 3:30 a.m. on 28 May and the wind went around gradually to the west; at daylight during the calmer weather the barge Andrew Manderson was spotted dismasted and ashore on Sand Island (at the tip of the west end of St. George Island) and the sloop Brockenburgh ashore on St. Vincent's Island. At 6 a.m. the wind again increased to a hurricane, the wind blowing from the west-southwest and the Somerset hove up all anchors and stood to leeward of Sand Island ( U.S. Navy Department 1903 ).

The storm came ashore on Thursday morning, 28 May, and reports of varying detail indicated a severe storm along the coast. In a letter dated 30 May from one of the editors of the Tallahassee Floridian to the editor of the Macon Daily Telegraph, it was stated “We have had a heavy blow here the past week—the heaviest I ever witnessed in Florida at this season of the year. From the coast there are various rumors of loss of life and property. I have just heard that from the Ochlockonee to Peurifoy's Landing, twenty-one bodies of persons drowned were recovered, and eleven from Goose Creek, making thirty-two” (Macon Daily Telegraph, 5 June 1863). At Tallahassee, it had rained more or less every day for the previous week and so severe a gale at the time of year was not within the memory of the oldest citizen. Wednesday night (27–28 May) the rain was literally pouring down and accompanied by a severe wind from the northeast, which shifted in the course of the night to the southwest with increased violence. (We note here that all of the available ship's log data and reports from elsewhere and the space–time continuity do not indicate that the southwest wind is representative of the prevailing winds and that it is either a simple error or associated with local convection.) The paper mentioned that at Dickerson Bay 19 persons were drowned and another 7 to 10 at Goose Creek (Florida Sentinel, 2 June 1863). These latter numbers are probably referring to the same deaths as communicated by the editor of the Floridian. His account of deaths “from the Ochlockonee to Peurifoy's Landing” would be inclusive of Dickerson Bay, which lies between the two.

Farther east, the salt works near St. Marks and Bayport were entirely destroyed. Large quantities of the salt were lost and 40 persons were drowned. The gale was said to be so strong as to have pushed the waters of the Gulf inland for several miles back into the country, inundating parts of the St. Marks railroad (Macon Daily Telegraph 5 June 1863, citing the Columbus Times of 3 June 1863). Railroad passengers arriving in Savannah reported houses blown down, fences destroyed, and, in some locations, total destruction of crops. One island in the vicinity of St. Marks was said to be submerged and a large number of persons drowned. Some of the names of the drowned were reported back to Savannah (Macon Daily Telegraph 5 June 1863, citing the Savannah News of 4 June 1863). Another letter published in the Macon Daily Telegraph of 5 June 1863, dated 3 June 1863 from Thomasville, Georgia, stated “the gale of Thursday is said to have done much mischief among the salt boilers on the Florida coast. One report says 150 lives were lost and many animals, much stock and salt. Hope it is not so bad; some, though, have certainly perished.”