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Preliminary Report
Hurricane Bertha
05-14 July 1996

Miles B. Lawrence
National Hurricane Center
9 November 1996

Tropical Storm Arthur
Hurricane Bertha
Hurricane Cesar
Hurricane Dolly
Hurricane Edouard
Hurricane Fran
Tropical Storm Gustav
Hurricane Hortense
Hurricane Isidore
Tropical Storm Josephine
Tropical Storm Kyle
Hurricane Lili
Hurricane Marco


[1996 Atlantic Hurricane Season]

Bertha was an early-season Cape Verde Hurricane that moved across the islands of the northeastern Caribbean Sea as a category 1 hurricane on the Saffir/Simpson scale and made landfall on the North Carolina coast near Wilmington as a category 2 hurricane. Bertha's one-minute winds reached their maximum value of 100 knots on 9 July, while located to the north of Puerto Rico. The last Hurricane to reach this strength, this early in the season, was Alma in 1966 (117K GIF) in the eastern Gulf of Mexico with 110 knots. Bertha is responsible for an estimated eight deaths and $250 million in U.S. damages.

a. Synoptic History

Bertha originated from a tropical wave which moved from Africa to the Atlantic on 1 July. A weak circulation was first detected on satellite imagery on 3 July, centered about 500 n mi south of the Cape Verde Islands in the far eastern Atlantic Ocean. The track of the circulation center begins on 5 July, when the circulation is believed to have reached the surface and become a tropical depression, in the central tropical Atlantic. This track is displayed in Fig. 1 (102K GIF) and listed in Table 1.

Bertha followed a fairly smooth curved path around the western periphery of the Atlantic subtropical high pressure ridge. This ridge changed little during Bertha's existence and a weak mid-level trough persisted in the western North Atlantic. For three days, the depression moved toward the west-northwest at the fast forward speed of 20 to 25 knots and strengthened to a hurricane with 1-min. maximum sustained winds of 75 knots on the 8th as the center moved across the Leeward and Virgin Islands of the northeastern Caribbean. The center moved between Antigua and Barbuda at 0600 UTC on the 8th, across St. Barthelemy, Anguilla, and St Martin, just north of St. Thomas, and over the British Virgin Islands by 1800 UTC.

The track gradually turned northwestward on the 9th and maximum sustained winds reached 100 knots at 0600 UTC. Bertha was centered 120 n mi north of Puerto Rico at this time, but earlier passed within 30 n mi of this island. The strongest winds were located in the northeast quadrant of the hurricane and most of Puerto Rico experienced only tropical storm conditions, except for Culebra, over which hurricane-force winds might have occurred.

Moving northwestward at a slower forward speed of 15 to 20 knots, the center of Bertha moved parallel to the Bahama islands, passing 40 to 60 n mi northeast of the Turks and Caicos islands, San Salvador, Eleuthera and the Abacos. Again, the strongest winds were located to the northeast of the center, but 65-knot sustained winds might have reached some of the above mentioned islands.

Continuing on its gradual turn, the track became north-northwestward on the 10th and 11th and the center moved parallel to the coast of Florida and Georgia at a distance of 150 to 175 n mi offshore. During this time, the forward speed slowed to about 8 knots. Moving northward and re-accelerating to a forward speed of 15 knots, Bertha made landfall at 2000 UTC on the 12th on the coast of North Carolina, with the center crossing the coast midway between Wrightsville and Topsail Beaches. The hurricane had been gradually weakening since its top speed of 100 knots on the 9th to 70 knots on the 11th. Then, in 12 hours just before landfall, the winds increased to 90 knots, which is the estimated maximum 1-min. wind speed at landfall. Bertha quickly dropped below hurricane strength when it moved inland over eastern North Carolina.

It then moved northeastward along the U.S. east coast, producing 40 to 50 knot sustained winds over land from northern North Carolina to New England and 60 knot winds over nearby Atlantic waters. Bertha was declared extratropical on the 14th when the center moved from the Maine coast to New Brunswick, Canada. The extratropical storm brought 40 to 50 knot winds to the Canadian Maritime Provinces and was tracked to just south of Greenland on the 17th.

b. Meteorological Statistics

Figures 2 and 3 (64K GIF) show a plot, versus time, of the various data used to estimate the minimum central sea-level pressure and the maximum 1-min. wind speed, 10 m above ground. Included are data from reconnaissance aircraft and satellite Dvorak-technique wind speed estimates. Table 2 lists selected surface observations of lowest pressure, peak wind, storm surge and rainfall values. Table 3 lists ship reports of 34 knots or greater that were associated with Bertha. The minimum pressure of 960 mb occurred at 0600 UTC on the 9th and is based on a dropsonde measurement. The best track maximum sustained wind speed of 100 knots at the same time is based on a 700-mb flight-level wind speed of 122 knots, measured 19 n mi east-northeast of the center.

Observations are incomplete from the Leeward and Virgin Islands, but because the circular eyewall was 20 - 30 n mi across, it is believed that hurricane conditions with sustained wind speeds to 75 knots, could have occurred on Antigua, Barbuda, Nevis, St. Eustatius, St. Bathelemy, Anguilla, St. Martin, and from St. Thomas northward through the U.S. and British Virgin Islands. Experience with Hurricane Marilyn in 1995 suggests that even higher sustained winds can occur over mountainous terrain as is found on many of these islands. Winds of 35 to 40 knots were experienced over portions of Puerto Rico as indicated by the San Juan observations in Table 2.

A reconnaissance aircraft flight level wind speed of 110 knots in the northeast quadrant of the circulation several hours before landfall is the basis for estimating sustained surface winds of 90 knots on the coast at landfall. The lowest sea-level pressure observed at landfall was 977 mb at Surf City, North Carolina and a value of 974 mb is assumed to be the minimum pressure at landfall.

Storm total rainfall amounts ranged from 5 to 8 inches along a coastal strip from South Carolina to Maine.

Coastal storm surge flood heights, from Florida through New England, ranged from 1 to 4 feet, but values to 5 feet were estimated on the North Carolina coast from Cape Fear to Cape Lookout. A storm surge of 6 feet or a little higher is indicated near Swansboro, where 5 to 6 feet of water was "inside of businesses on the waterfront".(from Newport, North Carolina National Weather Service Forecast Office Preliminary Storm Report).

Seven tornadoes have been confirmed, and these occurred during the passage of an outer rain band. There were five tornadoes in Virginia, one in North Carolina and one in Maryland.

c. Casualty and Damage Statistics

Twelve deaths have been related, in some way, to Hurricane Bertha. One, in Florida, was from an evacuating military jet crashing into a house. One death from an auto accident occurred in North Carolina and another drowned in rip currents. A surfer died in New Jersey. In Puerto Rico, two died in an automobile accident and another died while surfing. On the French half of St. Martin, one person was electrocuted and one fell off a boat.

The U.S. Virgin Islands, along with North Carolina, has been declared a federal disaster area. Surveys indicate that Bertha damaged almost 2500 homes on St. Thomas and St. John. For many, it was a second hit in the ten months since Hurricane Marilyn devastated the same area.

It is likely that there was beach erosion on the north coast of the Dominican Republic as Bertha passed to the north. The Bahamas were also affected by the weak side of the hurricane, but there are no damage figures available from either of these locations.

The primary effects in North Carolina were to the coastal counties and included storm surge flooding and beach erosion, roof damage, piers washed away, fallen trees, and damage to crops. A survey indicated over 5000 homes damaged, mostly from storm surge. A Federal Emergency Management Agency (FEMA) estimate of the number of persons in South and North Carolina who evacuated is 750,000. Minor wind damage and flooding also spread along the path of the storm all the way to New England.

The American Insurance Association reports an estimate of $135 million dollars in insured property damage, primarily along coastal North Carolina. A conservative ratio between total damage and insured property damage, compared to past land falling hurricanes, is two to one. Then the total U.S. damage estimate is 2 times $135 million or $270 million dollars. No figures are available from the Caribbean.

d. Forecast and Warning Critique

Bertha moved on a fairly smooth track. The average official track forecast errors for Bertha ranged from 80 n mi at 24 hours (32 cases) to 147 n mi at 48 hours (29 cases) to 224 n mi at 72 hours (27 cases). These errors are 15 per cent, or more, lower than the previous ten-year averages of the official track errors and are from 15 to 40 per cent lower than the CLIPER forecast errors for the same cases.

Overall, the track model guidance also performed very well. However, the 0000 UTC Aviation Model run on the 9th, when Bertha was located just north of Puerto Rico, (inexplicably?) showed the track recurving significantly further east than the previous run. All of the track guidance models that use the Aviation Model as a background environment also showed a similar track. This resulted in rather large official track forecast errors on the 9th, with a 613 n mi 72-hour error on the 1200 UTC forecast. The Aviation Model and some of the track guidance models recovered to an excellent forecast only 12 hours later. Fortunately, this guidance problem occurred three days prior to landfall in North Carolina and did not have a significant impact on U.S. warnings or on warnings for the Bahamas.

Table 4 lists the various watches and warnings that were issued. Hurricane warnings were issued from Sebastian Inlet, Florida to Chincoteague, Virginia as well as for the Bahamas and for the islands of the northeastern Caribbean Sea from Antigua through Puerto Rico. Tropical storm warnings were issued from Sebastian Inlet to north of Deerfield Beach, Florida and from north of Chincoteague to Watch Hill, Rhode Island. Almost all of the U.S. east coast was involved with some watch or warning and this is the result of the storm track's expected close passage to the southeast U.S. coast. The hurricane watch for the North Carolina landfall area was issued 65 hours before landfall and the hurricane warning was issued 47 hours before landfall. This is far more than the 36- and 24-hour lead times that the National Hurricane Center strives for and is the result of the forward motion decreasing at a faster rate than expected.

Table 1. Best track, Hurricane Bertha, 5 - 14 July, 1996 (updated 4 August 1996)
Position Pressure
Wind Speed
Lat. (°N)Lon. (°W)
05/00009.834.0100930 tropical depression
120011.039.0100735 tropical storm
1800 22.571.196790"
060036.777.099360tropical storm
1800 47.062.099550"
09/060020.367.7960100 minimum pressure
12/200034.377.897490 landfall * midway between
Wrightsville and Topsail Beaches

* The eyewall also passed over Antigua, Barbuda, St. Barthelemy, Anguilla, St Martin, St Thomas, and the British Virgin Islands and passed close to a number of other islands in the northeastern Caribbean Sea.

Table 2. Hurricane Bertha selected surface observations, July 1996 (updated 20 August, 1997).
(kt) a
(UTC) b
(ft) c
(ft) d
Antigua991 f08/060030 f 52 f08/0400   
Jacksonville1011.911/225622 (2 min)2711/1721   trace
Jacksonville Beach       2 
Sea Island       3 
St. Simon       3 
South Carolina:
Charleston Buoy
998.212/120039 5112/0800   
Charleston city office  36 5012/1130  0.94
Charleston harbor      2.7  
Charleston international airport1008.512/115530 (2-min.) 3912/0130  1.48
Cheraw        0.38
Cherry Grove pier  57 68   2.17
Folly Beach
1006.812/120034 (10 min) 5211/2100   
Garden City pier  4154     1.01
Loris        2.77
Myrtle Beach1003.712/1532314012/1512   2.40
Myrtle Beach, Sands Resort        4.73
Myrtle Beach Springmaid pier  40 (10 min) 5612/15003.3  
Myrtle Beach pavilion  43 52   1.64
Summerville        1.40
North Carolina:
Alligator River  48 f 56 f13/0300   
Beaufort Duke marine lab   82 12/22002.8  
Beaufort (MRH)  4256 12/2213   
Bath       6 
Bellhaven       7 
Bogue Field ASOS   71 13/0107   
Broad Creek        6.50
Brunswick       5 
Cape Lookout
(32 ft asl)
1002.012/2200 55 (10 min)7312/1837    
Carolina Beach       6 
Cherry Branch        5.09
Cherry Point (NKT)995.712/225547 6412/2304   
Diamond Shoals
(153 ft asl)
1007.713/0300 607912/2345    
1003.913/050045 5613/0500   
East Wilmington   70     
Elizabeth City (ECG)998.913/131339 4813/0055   
Englehard  28 f 43 f13/0300   
Fayetteville   38 12/2150   
Ft. Bragg   4013/0055    
Frying Pan Shoals
(145 ft asl)
977.512/1800 77 (10 min)10112/1610    
Greenville   76    4.11
Hatteras ASOS   56 12/2131   
Hatteras ferry ofice   63 13/0100   
Hatteras WSO1007.113/0130 53 12/2243   
Holden Beach   70 f 12/1630   
Kure Beach  4980 12/1835   
Lake Waccamaw        2.39
Lumberton (LBT)1003.112/215626 (2-min)3312/2325    
Manteo  4058 13/0345   
Newport994.312/2200 78    2.95
New Bern   6212/2208   4.56 e
New River (NCA)980.812/22007094 12/2021   
N Topsail Beach  67 f  12/2030   
Oregon Inlet  39 f 47 f13/0300   
Pongo River       4.5 
Seymour Johnson AFB986.312/23553352 12/2155  4.03
Snow Hill        5.44
S. Pamlico River       3 
Southport (Nixon)978.312/18355574 12/1703   
Surf City (Horodner)97712/2005       
Swansboro       8 
Topsail Beach  68 f  12/2000   
Williamston        4.10
Wilmington (ILM)978.712/202846 (2-min) 6112/19021.3 5.66
Wilmnington (Armquist)975.612/2000  63 f12/2200   
Wilmnington, Fig. Eight Is.    8312/1725   
Wilmington NC state port    77     
Wilmington port terminal980.112/1850 from NOAA ship Whiting, 34.2N 77.96W
Wrightsville Bch. Banks ch.    80    
Cape Charles   61 13/0330   
Cape Henry  40 f 6713/0600   
    40 f13/0900   
Chesapeake Light Stn.
998.913/080049 6313/0700   
Eastville, Northhampton Co.        7.00
False Cape Buoy
1004.113/090035 4313/0900   
Fenwick Is. Buoy
997.113/140041 4813/1300   
Ft. Belvoir1002.013/1055 35 13/1700   
Ft. Eustis993.113/0755 3413/0203    
Langley AFB993.513/0755 37 13/0215   
Newport News (PHF)993.113/07503038 13/0228   
Norfolk International airport995.113/07563142 13/0740  2.44
Norfolk NAS (NGU)994.413/07553042 13/0155   
Norfolk, Sewells Point      2.5  
Oceana NAS (NTU)997.213/0755 42 13/0615   
Pasquotank River       5 
Plantation Creek        7.20
Potomac river at Wisc. Ave.       5 
Wallops Island  3747 13/0605   
Washington Dulles airport   29 13/1218  1.12
Washington National airport1001.713/1221  3613/0639  1.24
Willis Wharf, Accomac Co.        5.80
Andrews AFB (ADW)1000.613/1155 35 13/0750  0.94
Baltimore Washington airport1000.313/1349  4113/0704  2.28
Nanticoke, Wicomico Co.        5.03
Patuxent River NAS (NHK)995.013/1100 42 13/0603  4.03
Salisbury995.213/1240      5.62
Thomas Point
998.813/12002939 13/1700   
Cape Henlopen  40  13/1335   
Lewes   4713/1250 1.58  
Wilmington998.313/1451 34 13/2051   
New Jersey
Atlantic City994.913/1554 37 13/11112.27 2.41
Avalon  35 13/1409    
Estelle Manor        6.59
Harvey Cedars   55     
Millerville995.213/1445 35 13/0950   
Newark airport996.613/190925 (2-min.)35 13/1521   
Teterboro airport997.313/194526 (2-min.)38 13/1547   
River Vale        2.17
West Milford        4.85
Philadelphia997.513/15512936    2.43
New York:
Ambrose Light Tower
994.513/190044 4813/1500   
Babylon Village, L.I.   64     
Brookhaven airport  2636 13/1947   
East Quogue, Suffolk co.        0.76
Fire Is. Buoy
995.413/20003341 13/1900   
JFK airport995.613/194231 (2-min.)37 13/1458   
LaGuardia airport995.913/195129 (2-min.)38 13/1518   
Mt. Sinai (New York City)        2.49
Ossining, Westchester Co.        3.09
Pomona, Rockland Co.        4.65
Westhampton Beach995.613/2045       
Bridgeport airport995.513/20542734 13/1547   
New Haven995.613/2145       
Preston   48     
Shelton        4.06
Vernon        5.50
Rhode Island:
Fox Point hurricane barrier      2.1  
Sachuest Point (Middletown)  54 6414/0010 e hand-held anemometer
Providence995.913/2336 4413/1926   5.41
Buzzards Bay Buoy
997.114/000037 4314/0000   
Goshen        5.70
Billerica        7.20
New Bedford  4576 13/20301.7  
Taunton ASOS995.614/0041       
Puerto Rico:
Lake Matrullas        3.02 g
Pueblito Del Rio        5.64 g
Quebrada Guava        6.84 g
Rio de la Plata        4.81 g
Rio Icacos        8.17 g
Rio Icacos Met Station        7.79 g
Rio Saliente        3.78 g
Roosevelt Roads992.008/19303852 08/1525  1.60
San Juan996.808/20564252 08/2110  1.56
St. Maarten985.608/0935 70 08/0900-
Virgin Islands:
Bonne Resolution Gut,
St. Thomas
        1.44 g
Cane Bay,
St. Croix
Coral Bay,
St. John
        3.00 g
St. Croix
  41  08/1918   
Mt Zion,
St. Thomas
        3.28 g
St. Thomas
        2.12 g

a Averaging period is 1 min. unless otherwise indicated.
b Date/time is for sustained wind when both sustained and gust are given.
c Storm surge is water height above normal astronomical tide level.
d Storm tide is water height above National Geodetic Vertical Datum.
e Top of rain gage blew off and "a lot of rain was sucked out".
f A more extreme value may have occurred.
g 24 hour total.

Table 3. Ship reports of 34 knots or higher wind speed, associated with Hurricane Bertha, July 1996.
ship namelatitude
wind dir/
speed (knots)
07/1200FORT ROYAL17.153.8110/39 1014.2
08/1800MAYAGUEZ21.664.3130/35 1013.0
09/0000SEALAND CONSUMER21.664.7080/036 1009.1
09/0300MAYAGUEZ20.064.6100/38 1007.0
SEALAND CONSUMER21.065.0100/481008.9
09/0600MAYAGUEZ16.965.1130/40 1007.5
SEALAND CONSUMER20.665.1130/481006.9
09/0900SEALAND CONSUMER20.465.3130/42 1009.0
09/1800SEALAND CRUSADER23.067.9 100/431012.0
11/1800KIRF27.877.8220/45 1006.2
SEALAND HAWAII28.578.8270/351006.0
NOBLE STAR30.879.9050/401010.0
DSR EUROPE32.472.6140/351022.5
12/0000C6YC28.374.8140/38 1017.5
NOBLE STAR30.880.1030/381004.7
12/0600DSR EUROPE30.774.7140/58 1019.0
SEALAND ATLANTIC31.376.5130/451008.0
12/0900SEALAND ATLANTIC30.876.4150/55 1007.3
12/1200BELGRAND28.679.7270/34 1015.5
SEALAND ATLANTIC30.476.4150/431008.8
12/1500DSR EUROPE30.077.3180/39 1015.0
12/1800DSR EUROPE30.178.1210/47 1015.5
ESSO CORAL GABLES33.873.9140/341017.8
13/0000EXPORT PATRIOT32.775.2180/35 1022.2
ESSO CORAL GABLES33.675.1170/381012.2
13/0600KAIJIN32.273.7180/37 1017.0
ESSO CORAL GABLES33.376.0200/381013.3
13/1200ZIM CANADA39.373.9140/60 1006.0
BREMEN EXPRESS37.973.2150/401008.1
13/15003FEB536.569.9180/40 1019.6
BREMEN EXPRESS37.673.9210/441006.5
ZIM CANADA38.774.1160/601000.0
13/18003FEB536.070.0170/37 1017.9
BREMEN EXPRESS37.374.8210/621009.6
ZIM CANADA38.174.3210/401005.0
SONG OF AMERICA40.672.4170/401004.0
14/0000PHAROS39.669.5210/47 1009.8
14/0900A.S.L. SANDERLING45.060.4170/35 1011.4
14/1200TRITONHIGHWAY37.466.5230/39 1022.0
ALFRED NEEDLER43.362.6230/501007.0
KASUGA 143.961.3180/481007.8
A.S.L. SANDERLING45.259.4170/35 

Table 4. Watch and warning summary, Hurricane Bertha, July 1996.
06/1500hurricane watch Antigua, Barbuda, Nevis, Montserrat, St Kitts, Anguilla, Saba, St Eustatius, Dominica, and Dutch St Maarten
06/2100hurricane watch Guadeloupe, St Barthelemy, French St Martin, U.S. and British Virgin Islands
07/0300hurricane warning Dominica northward to Anguilla and St Maarten
07/1200hurricane watch Puerto Rico
07/1500hurricane warning U.S. and British Virgin Islands and Puerto Rico
08/0000tropical storm watch Dominican Republic from Isla Saona to Cabo Frances Viejo
08/0300hurricane watch Dominican Republic from Isla Saona to Cabo Frances Viejo
08/0900hurricane watch Turks and Caicos Islands
08/1200hurricane warning Dominican Republic from Cabo Caucedo to Monte Cristo, southeastern Bahamas
08/1500hurricane warning discontinued Dominica
08/1800hurricane watch Haiti from St Nicolas to border of Dominican Republic
hurricane warning discontinued Leeward Islands south and east of St Eustatius
08/2100hurricane warning Turks and Caicos Islands and southeastern Bahamas
hurricane warning discontinuedLeeward Islands
hurricane watchcentral Bahamas
09/0100hurricane warning discontinued U.S. and British Virgin Islands
09/0300 hurricane warning discontinuedPuerto Rico
tropical storm warning Haiti from St Nicolas to border of Dominican Republic
09/0900hurricane warning central Bahamas
hurricane watchnorthwestern Bahamas
09/1500watches and warnings discontinued Dominican Republic and Haiti
09/2100hurricane warning northwestern Bahamas
10/0300tropical storm warning north of Deerfield Beach, FL to Brunswick, GA
hurricane watch north of Brunswick to NC/VA border including Pamlico and Albemarle Sounds
10/0900hurricane warning discontinued Turks and Caicos Islands and southeastern Bahamas
10/1500hurricane warning Sebastian Inlet, FL to Cape Romain, SC
10/1800hurricane warning discontinued central Bahamas
10/2100hurricane warning Cape Romain to NC/VA border including Pamlico and Albemarle Sounds
tropical storm warning discontinued south of Sebastian Inlet, FL
11/0300hurricane watch NC/VA border to Chincoteague VA including southern Chesapeake Bay
11/0600hurricane warning discontinued northwestern Bahamas
11/0900hurricane warning discontinued south of Brunswick, GA
12/0900hurricane warning discontinued Savannah, Ga southward
12/1500tropical storm warning NC/VA border to Chincoteague, VA including southern Chesapeake Bay
12/1900hurricane warning discontinued Cape Romain, SC southward
12/2100hurricane warning NC/VA border to Chincoteague, VA including the Hampton Roads area
tropical storm warningnorth of Chincoteague, VA to Watch Hill, RI including the lower Delaware Bay
tropical storm watch east of Watch Hill to the Merrimack River, MA
13/0300 hurricane warning discontinuedsouth of Topsail Beach, NC
hurricane watch discontinuedlower Chesapeake Bay
tropical storm warningall of Chesapeake Bay and the lower tidal Potomac River and all of Delaware Bay
13/0700hurricane warning to tropical storm warning Topsail Beach, NC to Chincoteage, VA including Albemarle and Pamlico Sounds
13/0900 hurricane warning discontined NC/VA border southward
13/1200tropical storm warning discontinued south of Fenwick Island, DE
13/1500tropical storm warning discontinuedsouth of Brigatine, NJ and Delaware Bay
13/2100tropical storm warning discontinued south of Fire Island, NY
14/0000tropical storm warning discontinued south of Watch Hill, RI
14/0300tropical storm warning discontinued remainder of U.S east coast

Brian Maher
Jack Beven

Last updated December 28, 1998