Flood Potential Outlook
Issued by NWS
FGUS72 KTAE 051940
NATIONAL WEATHER SERVICE TALLAHASSEE FL
240 PM EST THU MAR 5 2015
...Spring Flood Potential Outlook for Southeast Alabama, Southwest
and South Central Georgia, and the Florida Panhandle and Big Bend...
...Above normal potential for river flooding this Spring...
In the Choctawhatchee Basin...
Rainfall since October 1, 2014 across Southern Alabama and into the
lower portion of the basin into the Florida Panhandle has been
slightly below normal with rainfall deficits between 2 to 3 inches.
However, with minimal departures from normal and surplus rainfall at
the end of the 2014 water year, moist ground conditions prevail
across the basin. Area streamflows along the Choctawhatchee River
and associated tributaries are at normal levels or slightly above
normal. Some storage capacity exists given the recent drier than
In the Apalachicola, Chattahoochee, Flint (ACF) Basin...
Rainfall over the last few months has been near normal across most
of the ACF basin, with some areas in Southwestern Georgia and into
the western Florida Big Bend receiving above normal rainfall. Moist
conditions from last year along with recent heavier rain events have
resulted in above normal streamflow conditions across the southern
portion of the ACF basin. With near normal precipitation amounts
further north across Central Georgia, incoming streamflows into our
portion of the ACF basin remain quite high, with associated
reservoirs at Lake Eufaula, Lake Seminole, and Lake Blackshear
slightly above normal pool levels. Retention ponds and smaller
storage systems across Southwestern Georgia are full, suggesting
that limited storage capacity exists for future heavy rains in this
In the Ochlockonee Basin...
Rainfall over the last few months has been well above normal in the
Ochlockonee Basin. From the top to bottom of the basin, rainfall
amounts in the last five months have been generally 4 to 6 inches
above normal with some areas as high as 10 inches above normal.
Though rainfall in the last 30 days has generally been near normal,
very moist conditions prevail across this basin. The Ochlockonee
River is well above normal at the first of March. In fact, in the
last 45 days, river forecast points above Lake Talquin have spent
the majority of the time above action stages. Below Lake Talquin,
flows remain above normal levels. As with the ACF basin, limited
storage capacity exists across this basin as suggested by pool
levels at Lake Talquin and many retention ponds being full.
In the Withlacoochee, Suwannee Basin...
As with the Ochlockonee River basin, rainfall over the last few
months has been well above normal in the Withlacoochee Basin and
upper portion of the Suwannee Basin. Rainfall amounts over the last
five months have been 3 to 5 inches above normal. Rainfall amounts
near normal have occurred in the Middle and Lower Suwannee over the
previous six months. Flows within the upper portion of the
Withlacoochee Basin remain well above normal and on March 1st were
near flood stage in Southern Georgia.
Flows across the Middle and Lower Suwannee are also running above
normal for this time of year, though flood stages have not been met
in this portion of the basin within the last six months. In the
lower portion of the basin, swampy areas and small lakes are nearly
...Long Term Precipitation Outlook...
The one month precipitation outlook for March indicates a greater
than 40 percent chance of above normal precipitation. This is
supported by numerical model forecasts which suggests the more
energetic pattern experienced in late February will continue into
much of the month of March. The longer range precipitation outlook
features near normal precipitation for the months of April and May.
The potential for heavy rainfall typically decreases after early
April as the region transitions into more of a drier pattern as
influences from frontal systems diminish.
...Spring Flood Outlook Summary...
Taking into account long term ensemble probabilities for
precipitation, recent rainfall, and current stream flows, there is
an above normal potential for river flooding across the region this
spring. This risk is maximized across the eastern half of our
region, which includes portions of the ACF, Ochlockonee, and
Withlacoochee Basins. In these specific basins, there is potential
for a high impact basin-wide flood event this spring should heavier
than normal rainfall occur, as storage capacity in the headwater
portion of these basins is especially low.
Should normal to above normal Spring rainfall amounts materialize,
the continued wet conditions will keep an increased flood risk for
our area rivers moving into hurricane season in June.