1. Weather Patterns Associated With Florida Rip Current Deaths
Charles H. Paxton1,2, Jennifer M. Collins2, Kortnie J. Pugh1,2
1. National Weather Service, Tampa Bay Florida 2. University of South Florida, Tampa, FL
INTRODUCTION AND METHODOLOGY
Rip currents pose a significant threat to swimmers in ocean waters. Table 1 shows that Florida had more rip current victims than any other state. Rip current death and injury reports from were collected from Storm Data (NCDC 2010). Sea level pressure (hPa) and wind (ms-1) mean and anomaly patterns were examined using NCEP reanalysis data (Kalnay et al., 1996). The data were plotted from day 0, the day of the event to day -3 which is 4 days before the event to examine precursor patterns. The state was divided into four regions (Fig. 1) The panhandle region stretches from the Florida border to the Suwannee River where 87 deaths and 106 injuries occurred. The Gulf coast region stretches from the Suwannee River to Flamingo with 19 deaths and 3 injuries in this region. The shallow water of Florida Bay and protective outer reefs of the Keys greatly reduce the threat for rip currents in that region. The Southeast coast stretches from Key Largo to Jensen Beach where 70 deaths and 70 injures occurred. The East coast area from Jensen Beach north to the Florida border had 59 deaths and 20 Injuries reported.
RESULTS AND CONCLUSION
Most rip current deaths and injuries in Florida occur during the warmer months. At panhandle beaches from March, April and May (MAM) a southerly wind anomaly begins to increase over the southwest Gulf of Mexico at day -3 and moves toward the panhandle. For June, July, August, and September (JJAS) the wind anomaly develops over the western Caribbean and translates north to the panhandle. Along the gulf coast during MAM, a southerly wind anomaly develops and persists becoming west on day 0. During JJAS a persistent southwest wind anomaly increases over the east gulf by day 0. Along the east coast during MAM a long northeast anomaly develops and increases by day 0. For JJAS the pattern is weaker with a more easterly anomaly. Along the southeast coast a wind max anomaly develops east of the Bahamas and translates west. For JJAS a similar but weaker pattern develops. The results from this study are intended to provide a guide for issuing rip current alerts several days in advance of the events.
Top 5 States
Deaths
Injuries
Florida
234
199
California 43 97
N. Carolina 36 14
N Jersey 22 27
Alabama 23 2 1
Table 1.Top five states with rip current deaths and injuries (Storm Data ).
87/106
70/70
19/3
59/20
Panhandle
Gulf Coast
East Coast
Southeast
Jun-Jul-Aug-Sep
Mar- Apr-May
Jun-Jul-Aug-Sep
Mar- Apr-May
Jun-Jul-Aug-Sep
Mar- Apr-May
Jun-Jul-Aug-Sep
Mar- Apr-May
Fig. 5a. Sea level pressure day 0
Fig. 5b. SLP anomaly day 0
Fig. 5c. Surface wind vector day 0
Fig. 5d. Wind anomaly day 0
Fig. 5e. Wind anomaly day -1
Fig. 5f. Wind anomaly day -2
Fig. 6a. Sea level pressure day 0
Fig. 6b. SLP anomaly day 0
Fig. 6d. Wind anomaly day 0
Fig. 6e. Wind anomaly day -1
Fig. 6f. Wind anomaly day -2
Fig. 6c. Surface wind vector day 0
Fig. 6g. Wind anomaly day -3
Fig. 8a. Sea level pressure day 0
Fig. 8b. SLP anomaly day 0
Fig. 8c. Surface wind vector day 0
Fig. 8d. Wind anomaly day 0
Fig. 8e. Wind anomaly day -1
Fig. 8f. Wind anomaly day -2
Fig. 8g. Wind anomaly day -3
Fig. 7a. Sea level pressure day 0
Fig. 7b. SLP anomaly day 0
Fig. 7c. Surface wind vector day 0
Fig. 7d. Wind anomaly day 0
Fig. 7e. Wind anomaly day -1
Fig. 7f. Wind anomaly day -2
Fig. 7g. Wind anomaly day -3
Fig. 2a. Sea level pressure day 0
Fig. 3a. Sea level pressure day 0
Fig. 4a. Sea level pressure day 0
Fig. 4a. Sea level pressure day 0
Fig. 2b. SLP anomaly day 0
Fig. 3b. SLP anomaly day 0
Fig. 5b. SLP anomaly day 0
Fig. 4b. SLP anomaly day 0
Fig 1. Coastal divisions with rip current deaths and injury numbers (deaths/injuries).
Top 5 Florida Counties
Deaths
Injuries
Broward 32 41
Escambia 31 46
Miami-Dade 20 13
Walton 1
St. Johns 19
Fig. 2c. Surface wind vector day 0
Fig. 3c. Surface wind vector day 0
Fig. 4c. Surface wind vector day 0
Fig. 5c. Surface wind vector day 0
Table 2.Top five Florida Counties with rip current deaths and injuries (Storm Data ).
Fig. 2d. Wind anomaly day 0
Fig. 3d. Wind anomaly day 0
Fig. 4d. Wind anomaly day 0
Fig. 5d. Wind anomaly day 0
Fig. 2e. Wind anomaly day -1
Fig. 3e. Wind anomaly day -1
Fig. 4e. Wind anomaly day -1
Fig. 5e. Wind anomaly day -1
Fig. 2f. Wind anomaly day -2
Fig. 3f. Wind anomaly day -2
Fig. 4f. Wind anomaly day -2
Fig. 5f. Wind anomaly day -2
Table 3. Rip current deaths and injuries by month (Storm Data ).
Fig. 2g. Wind anomaly day -3
Fig. 3g. Wind anomaly day -3
Fig. 4g. Wind anomaly day -3
Fig. 5g. Wind anomaly day -3
Fig. 5g. Wind anomaly day -3
Fig.6g. Wind anomaly day -3