- The National Weather Service confirmed a peak storm surge of 7-12 feet was recorded during Hurricane Idalia.
- Numerous homes within the surge zone suffered significant damage.
- Waves on top of the surge were around 3 feet high.
NATIONAL WEATHER SERVICE STATEMENT:
Hurricane Idalia made landfall at 745 am ET on Wednesday, August
30th near Keaton Beach, Florida with maximum sustained winds of
125 mph. The hurricane produced a devastating surge along coastal
communities in Taylor and Dixie Counties within our county warning
area. The peak surge values observed were from Dekle Beach in
Taylor County southeastward to Horseshoe Beach in Dixie County.
Surge heights in this area along the immediate coast were within
the range of 7 to 12 feet above normally dry ground. Lower values
of up to 6 feet above normally dry ground were noted south of
Horseshoe Beach near the community of Suwannee.
Storm surge is measured above normally dry ground. Numerous homes
within the surge zone suffered significant damage or had water and
debris marks on them where survey field crews could make a
determination of both the still water and wave water level. It is
important to stress that field crews work to differentiate
between the still water level, that is the water level rise above
normally dry ground, which is storm surge, and wave action. Wave
action, on top of the storm surge, is also measured. In this
event, wave action was generally found to average around 3 feet on
top of the peak storm surge.
It should also be noted the storm made landfall around the time of
low tide. Had the storm made landfall 6 hours later, around the
time of high tide, peak water level values could have been between
3-4 feet higher.
Aside from field observations on numerous structures within the
surge zone, live video from Steinhatchee helped confirm water
levels around the time of the peak surge. Additionally, a Suwannee
River Water Management gauge located just over 2.5 miles upstream
from the mouth of the Steinhatchee River near the Captain Chad
Reed Memorial Bridge, reported a river height of 8.03 ft mean
higher high water, a datum used to approximate water rise above
normally dry ground along the immediate coast. This value was 0.97
ft above the value recorded during Hurricane Hermine in 2016. The
gauge also recorded just over a 6 foot rise in water level in 1
hour. Note that this gauge has a short period of record and does
not extend back to the 1993 “storm of the century.”
In the process of the high water mark surveys, interviews were
conducted with several residents that lived in the area during the
“Storm of the Century,” a non-tropical system that affected this
portion of the Florida coastline on March 13, 1993. All of these
residents interviewed from Keaton Beach to Horseshoe Beach
indicated water levels that rivaled or exceeded those experienced
in the 1993 “Storm of the Century.” Moreover, Dixie County
Emergency Management noted that the inland extent of the storm
surge from Hurricane Idalia moved much further inland from
Horseshoe Beach than observed in “The Storm of the Century.” We
greatly appreciate these interviews and are continuing to compare
these statements with the high water marks collected from
Hurricane Idalia with the storm surveys completed following the
1993 “Storm of the Century”. It is still too early to definitively
state whether the surge from Hurricane Idalia exceeded the 1993
“Storm of the Century”. That determination will be made at a later
date.
The heights reported in this statement are considered preliminary
with final values available in the official Tropical Cyclone
Report for Idalia that will be issued by the National Hurricane
Center next year. Additional analysis of the storm surge will
continue in the mean time as further data is collected and
received. The National Weather Service in Tallahassee would like
to thank The National Hurricane Center’s Storm Surge Unit, The
Florida Division of Emergency Management, Florida Fish and
Wildlife Commission, Suwannee River Water Management District,
Taylor County Emergency Management and Dixie County Emergency
Management for their assistance in conducting these high water
mark surveys of the storm surge zone along with our own survey
crews from the National Weather Service in Tallahassee. In
addition to these field surveys, interviews and additional data
provided by residents surveying their homes immediately after the
water receded helped contribute to the finding of the peak surge
values.
The National Weather Service in Tallahassee would also like to
extend our thoughts and sympathies to residents impacted by this
record setting hurricane.
