Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Sun Oct 6 2024
Day 1
Valid 12Z Sun Oct 06 2024 - 12Z Mon Oct 07 2024

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR THE MIAMI-
FORT LAUDERDALE METRO...

In coordination with the MFL/Miami, FL forecast office, a Moderate
Risk upgrade was introduced with this update.

A weak surface low is developing over the eastern Gulf well east of
T.S. Milton, but in the same plume of incredibly deep tropical
moisture. The low will drift southeastward toward south Florida.
This will increase the easterly flow over the Straits of Florida
between the Bahamas and Florida. This increased easterly flow in an
air mass with PWATs between 2.25 and 2.5 inches will both increase
the concentration and intensity of resultant thunderstorms over the
Gold Coast.

Portions of the Ft. Lauderdale and Miami metros saw up to 3 inches
of rain on Saturday. Rainfall amounts today and especially tonight
may accumulate to over 6 inches in that time. With saturated soils
and urban effects, the threat for ponding and flooding in the area
has greatly increased. Expect numerous areas of ponding and
flooding from today's rainfall, which necessitated the Moderate
Risk upgrade.

Elsewhere, the surrounding Slight Risk was expanded to include the
Gulf Coast from Tampa south and the Atlantic coast from Cape
Canaveral south. The aforementioned low will enhance rainfall rates
along much of the Gulf Coast from Tampa south, where heavy rainfall
Saturday caused localized flash flooding. This additional rainfall
on saturated soils will cause renewed flash flooding, mostly in
urban areas. Further north up the Atlantic coast, similar
convergence as further south is expected, but with lesser forcing,
resulting in lower rainfall amounts for the Treasure and Space
Coasts. Widely scattered instances of flash flooding are expected.

Finally, for the middle of the Florida Peninsula, the area will be
furthest from the strongest forcing, resulting in a local minimum
of rainfall. Since the area will not have tidal flooding concerns
and is somewhat less developed, only isolated flash flooding is
expected. The threat for heavy rainfall will continue up to the
Georgia coast however, where a local convergence zone may develop
as indicated in several of the CAMs. The Marginal was expanded
north to account for this possibility.

Wegman

Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt