South Carolina Department of Natural Resources
Land, Water and Conservation Division
South Carolina State Climatology Office
Compiled by Mark Malsick
List of Figures:
Figure 1. Initial Wave disturbance.
Figure 2. Tropical storm Tammy.
Figure 3. Tammy at landfall 06 October, 2005
Figure 4. Tammy overland, prior to frontal absorption.
Figure 5. Surface synoptic situation 12Z 05 October, 2005.
Figure 6. 300 millibar streamlines 00Z 05 October, 2005.
Figure 7. 300 millibar divergence 00Z 05 October, 2005.
Figure 8. 500 millibar streamlines 00Z 05 October, 2005.
Figure 9. 850 millibar streamlines 00Z 05 October, 2005.
Figure 10. 1000 millibar streamlines 00Z 05 October, 2005.
Figure 11. Estimated October 2005 South Carolina rainfall distribution.
Figures 12a-b. Edisto Beach damage.
Tammy began as a weak easterly wave that tracked slowly across the Atlantic and became a persistent quasi-stationary wave over the Bahamas until the US Navy issued a Tropical Cyclone Formation Alert (TCFA) for the disturbance at 23oN 074.5oW. This disturbance had menaced the Bahamas for the previous 48 hours with 30 knot winds (Fig. 1). Early in the morning of October 5, 2005,National Weather Service Radar and 30 knot buoy observations indicated a rapidly developing, well-defined surface circulation in a broad tropical disturbance 40 miles east of Melbourne, Florida, that was quickly upgraded to Tropical Storm Tammy based on 35 knot winds embedded in deep convection contained in the northeast quadrant (Fig. 2.) of the season's twenty-first storm. Coastal proximity (<50 nm) of a rapidly developing Tammy forced the accelerated classification of this new storm.
Figure 1. Initial wave disturbance that became Tropical Storm Tammy.
Figure 2. Tropical Storm Tammy.
Tammy rapidly moved north, parallel to the Florida coast, at 14 knots passing over NOAA buoy 41009 which measured a central pressure of 1004mb.Tammy's asymmetrical convection hindered accurate center fixes, which complicated the track forecast. Aircraft recon later on the 5 measured peak fight level winds of 53 knots 150 nautical miles northeast of Tammy's center. This measurement and 50-55 knot visual estimates supported surface wind estimates of 45 knots. Motion estimates of Tammy were now 330 at 12 knots.
Tammy quickly made landfall by 9 PM October 5 in the vicinity of Mayport, Florida, with 35 knot winds and heavy rain, particularly in the northern semi-circle (Fig. 3). Tammy rapidly lost intensity while over south central Georgia as it slowed and spread heavy tropical rain bands into the Georgia coastline and South Carolina. Tammy was downgraded to a Tropical Depression at 11AM October 6 as it lurched slowly westward into southern Alabama where Tammy was absorbed within an cold frontal boundary. This frontal boundary sheared Tammy rapidly and spread a large plume of heavy tropical convective debris that would affect South Carolina and other coastal states northeastward into New England with deadly and devastating flooding.
Figure 3. Tammy at landfall 06 October 2005.
Figure 4. Tammy overland prior to frontal absorption.
Tammy was a surprising, short duration coastal storm that intensified from a persistent tropical wave into a minimal storm between an upper level low over the eastern Gulf of Mexico and the southwestern boundary of the Atlantic sub-tropical high. These synoptic features provided a lively north-northwesterly steering along the Florida coast on the morning of October 5 until landfall. (Fig. 5) Strengthening of the sub-tropical high provided a more westerly component for Tammy's track until Tammy was absorbed by an approaching frontal boundary.
Figure 5. Surface synoptic situation 12Z 05 October 2005.
The rapid intensification of Tammy can be attributed to Florida's warm, coastal waters,abundant low level relative vorticity associated with the disturbance lingering over the Bahamas prior to October 5 and upper level divergence at 300mb (Figures 6 and 7). A large 500mb cyclone (Figures 8-10) over Arkansas provided the shallow mean level steering, forcing Tammy quickly inland.Persistent upper level shear prevented Tammy from intensifying above Tropical Storm strength during its short life over warm Florida waters. Upper level shear was also responsible for Tammy's asymmetric circulation and deep convection concentration in the northeast semi-circle.
Figure 6. 300 millibar streamlines 00Z 05 October 2005.
Figure 7. 300 millibar divergence 00Z 05 October 2005.
Figure 8. 500 millibar streamlines 00Z 05 October 2005.
Figure 9. 850 millibar streamlines 00Z 05 October 2005.
Figure 10. 1000 millibar streamlines 00Z 05 October 2005.
Figure 11. Estimated October 2005 South Carolina rainfall distribution.
Figure 12a. Edisto City Beach damage.
(Photo by Delaine McJunkin)
Figure 12b. Edisto City Beach damage.
(Photo by Delaine McJunkin)
Gusty winds blew down 30 trees in Beaufort County. Scattered tree damage was reported along the coast. No tornados were reported during the passage of Tammy's convective debris.The South Carolina Emergency Operations Center was not activated for Tropical Storm Tammy.
Edisto Beach (NWS site) 59 MPH...51 Knots Folly Beach (C-Man buoy FBIS1) 54 MPH...47 Knots Edisto Buoy (41004) 54 MPH...47 Knots Port Authority Crane (CharlestonCounty) 50 MPH...44 Knots+++ Downtown Charleston (CHL) 49 MPH...43 Knots Ravenel Bridge (Charleston County) 48 MPH...42 Knots+++ Fripp Island 48 MPH...42 Knots Downtown Charleston (Coast Guard Station) 47 MPH...41 Knots Ben Sawyer Bridge DOT sensor 47 MPH...41 Knots Folly Beach City Hall 47 MPH...41 Knots Hilton Head (Salty Dog Cafe) 45 MPH...39 Knots Charleston (KCHS) 42 MPH...36 Knots Goose Creek High School 42 MPH...36 Knots Burke High School (Charleston County 41 MPH...35 Knots Savannah (RAWS site Jasper County) 41 MPH...35 Knots Beaufort (Media MESONET) 39 MPH...34 Knots Rivers Middle School (CharlestonCounty) 38 MPH...33 Knots Beaufort (NBC) 37 MPH...32 Knots Hilton Head (HXD) 35 MPH...30 Knots Isle of Palms 35 MPH...30 Knots Lambs Elementary School (Charleston County) 34 MPH...29 Knots Mitchell Elementary School (Charleston County) 32 MPH...28 Knots+++ Observation estimated at about 200 feet.
Precipitation Totals:
Division Name: Mountain
Precipitation (inches)
Obs 1-Day Max Date
Caesars Head 3.15 1.32 10/6
Hunts Bridge 1.67 0.84 10/7
Travelers Rest 3.90 1.90 10/7
Division Name: Northwest
Anderson County Arpt. 3.58 2.71 10/6
Clinton 7.48 5.68 10/8
Gaffney 6.31 4.38 10/8
Greenville-Spartanburg Arpt. 4.12 2.13 10/7
Laurens 6.70 5.35 10/8
Lockhart 3.90 2.90 10/8
Pickens 2.07 1.50 10/7
Sandy Springs 3.28 1.85 10/7
Union 4.11 2.67 10/8
Walhalla 3.02 2.12 10/7
West Pelzer 3.49 1.76 10/8
Division Name: North Central
Chester 2.77 0.93 10/8
Fort Mill 2.86 1.18 10/8+
York 3.86 2.37 10/8
Division Name: Northeast
Andrew 11.51 7.60 10/7
Cades 4.81 2.98 10/7
Cheraw 3.41 2.42 10/7
Dillon 3.70 2.50 10/7
Effingham 4.45 2.81 10/7
Florence 3.84 2.91 10/7
Florence Regional Arpt. 3.17 2.14 10/6
Georgetown 14.88 6.98 10/7
Hartsville 3.10 1.83 10/7
Hemingway 9.40 6.75 10/7
McColl 5.32 3.01 10/6
Mullins 4.20 2.85 10/7
Division Name: West Central
Aiken 5.25 2.61 10/8
Calhoun Falls 3.51 1.63 10/7
Chappells 5.44 3.51 10/8
Clark Hill 5.97 2.48 10/7
Johnston 3.52 1.14 10/8
Saluda 3.95 1.80 10/8
Division Name: Central
Bishopville 1.98 0.61 10/6
Cedar Creek 1.46 0.58 10/6
Columbia Metro. Arpt. 2.45 1.09 10/6
Columbia USC 1.07 0.73 10/6
Sandhill Research 1.88 0.75 10/6
Sumter 2.34 0.83 10/7
Division Name: Southern
Beaufort WWTP 4.23 2.20 10/6
Charleston City 3.44 1.56 10/7
Charleston Intl. Arpt. 3.65 1.44 10/5
Givhans Ferry 3.13 1.44 10/6
Jamestown 8.60 4.20 10/6
Santee COOP Spillway 4.07 2.14 10/6
Sullivans Island 3.70 1.53 10/7
Flag Information:
+ = indicates extreme also occurred on other dates (last date listed)
Special thanks to the National Oceanic and Atmospheric Administration and its many divisions for the wealth of weather and climate data made available too prepare this report. Specific thanks to:
Additional thanks the Naval Research Laboratory Monterey's Marine Meteorology Division for the well cataloged library of satellite imagery used for this report.
Figures from the Plymouth State College and the UNISYS web sites were also used for this report.
