Spatial Distributionof

Tropical Cyclone-Induced Precipitation:

Operational Applications in South Carolina

Jason CaldwellSouth Carolina State Climatology Office

PAMS Mini-Technical ConferenceMarch 11, 2005

Atlantic Ocean

Gulf of Mexico

Appalachian Mountains

Geographical Influences on Tropical Precipitation

UPSLOPE FLOW ENHANCEMENT

MOISTURE SOURCE

MOISTURE SOURCE

TROPICAL STORM STEERING MECHANISMS

SURFACE:

Central Atlantic Sub-Tropical HighExtends E-W with weakness SE US

500 MB:

Westerly Flow East Coast

Mid-Level Ridge over Central Atlantic

250 MB:

Trough over Midwest and Great Lakes

SOUTH CAROLINA TROPICAL STORMS

CLIMATOLOGICAL RECORD (1871-2004)

TOTAL STORMS: 145

PERIOD CONSIDERED: 1950-2003

TOTAL 1950-2003: 70 STORMS

SELECTED TOTAL: 54 STORMS

SELECTED TROPICAL STORM TRACKS AFFECTING SOUTH CAROLINA

1950-2003

Division 1Division 2Division 3Division 4Division 5Division 6Division 7Division 8

COOPSite County Lat LonAiken Aiken 33.61 -81.69

Anderson Anderson 34.53 -82.67Beaufort Beaufort 32.4 -80.7

Blackville Barnwell 33.36 -81.33CalhounFalls Abbeville 34.09 -82.59

Camden Kershaw 34.25 -80.65Chappells Newberry 34.21 -81.89Charleston Charleston 32.9 -80.04

Cheraw Chesterfield 34.7 -79.88Chester Chester 34.72 -81.22

Columbia Lexington 33.95 -81.12Conway Horry 33.83 -79.06Florence Florence 34.19 -79.73FortMill York 35.02 -81.01Gaffney Cherokee 35.09 -81.58

Georgetown Georgetown 33.36 -79.22Kingstree Williamsburg 33.65 -79.82

Orangeburg Orangeburg 33.49 -80.87Walhalla Oconee 34.75 -83.08

Walterboro Colleton 32.88 -80.68

SITE SELECTION

• 20 DAILY SITES

• SPACING: 50-75 km

DIVISION 1Offshore Track

Helene 1958 Ginny 1963 Amy 1975 Arthur 1996

4 STORMS

DIVISION 2East Florida LandfallSouth Carolina Track

Cleo 1964 Dora 1964 Dawn 1972 ST 3 1976 David 1979 Isidore 1984 Chris 1988 Jerry 1995 Kyle 2002

9 STORMS

DIVISION 3West Florida Landfall

Offshore Track

Donna 1960 Gladys 1968 Dennis 1981 Ana 1991 Irene 1999

5 STORMS

DIVISION 4Panhandle Florida Landfall

Inland/Coastal Track

TS 7 1953 Florence 1953 Flossy 1956 TS 1 1957 Brenda 1960 Alma 1966 Alma 1970 Agnes 1972 Kate 1985 Allison 1995 Josephine 1996 Earl 1998 Gordon 2000

13 STORMS

DIVISION 5Gulf Coast/Panhandle LandfallTrack East of Appalachians

Hilda 1964 TS 1 1965 Babe 1977 Marco 1990 Helene 2000

5 STORMS

DIVISION 6Gulf Coast/Panhandle LandfallTrack West of Appalachians

Danny 1985 Andrew 1992 Alberto 1994 Beryl 1994

4 STORMS

DIVISION 7Direct Landfall South Carolina

Able 1952 TS 3 1953 Hazel 1954 Cindy 1959 Gracie 1959 Hugo 1989

6 STORMS

DIVISION 8Direct Landfall North Carolina

Connie 1955 Diane 1955 Ione 1955 TS 6 1961 Diana 1984 Bertha 1996 Bonnie 1998 Floyd 1999

8 STORMS

Division 4 MeanObserved Precipitation

TROPICAL STORM BONNIE

* Used Panhandle/Inland-Coast Track (Division 4)

HURRICANE CHARLEY

* Used Direct Landfall SC Track (Division 7)

Observed Precipitation Division 7 Mean

Observed Precipitation Division 6 Mean

HURRICANE FRANCES

* Used Gulf Coast/W of Appalachian Track (Division 6)

Observed Precipitation Division 7 Mean

HURRICANE GASTON

* Used Direct Landfall SC Track (Division 7)

Observed Precipitation Division 6 Mean

HURRICANE IVAN

* Used Gulf Coast/W of Appalachian Track (Division 6)

Observed Precipitation Division 2 Mean

HURRICANE JEANNE

* E Florida/SC Track (Division 2)

BONNIE

GASTON

FRANCES

JEANNEIVAN

CHARLEY

ERRORS ASSOCIATED WITH CLIMATOLOGYObserved – Climatology = ERRORS

RANGE-4.60 (over-predicted) to +7.10 (under-predicted)

AVERAGE ERROR 2004-2.11 (Camden) to +0.56 (Calhoun Falls)

CONCLUSIONS AND FUTURE WORK------------------------------------------

UNDER-PREDICTS PRECIPITATION IN UPSTATE FAVORED UPSLOPE FLOW AREAS & ALONG TRACK; OVER PREDICTION MORE SPORADIC

ADDITIONAL STATIONS ADDED TO ACQUIRE MORE COMPLETE DISTRIBUTION (REMOVE WALTERBORO, CAMDEN)

COMPARISON OF CLIMATOLOGY TO HPC FORECASTS

PREPARATION OF MAX/MIN DISTRIBUTIONS FOR FLOOD FORECAST ENHANCEMENT

POTENTIAL WORK WITH SERFC

STATISTICS, STATISTICS, STATISTICS ……

15th CONFERENCE ON APPLIED CLIMATOLOGY (SAVANNAH, GA – JUNE 2005)