Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
358 AM EDT Sun Oct 6 2024
Day 3
Valid 12Z Tue Oct 08 2024 - 12Z Wed Oct 09 2024

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE
FLORIDA PENINSULA...

The PRE (predecessor rain event) will enter its third and final day
over the Florida Peninsula on Tuesday. The trough that occasionally
spins up weak surface lows will remain in place across the
Peninsula. The circulation of what will then be Hurricane Milton
will make its approach to the Gulf Coast of Florida, likely near
Tampa very late Tuesday night/early Wednesday morning. At this
time, expect little of the rainfall directly associated with
Milton's core to yet impact the Florida Peninsula. Of course, with
future updates and forecast changes from NHC, this may change.
Given the inherent uncertainty with the track and speed of this
small hurricane, the Slight over the Peninsula was maintained,
albeit with some filling in in the middle of the Peninsula near the
Orlando area. There remains a bimodal distribution of the rain with
much more expected along the Gulf coast from Tampa down through
Naples, but with a secondary maximum for the Space and First
Coasts.

With the latest guidance, there is some offset of the axis of
heaviest rainfall ahead of Milton. The northward trend will reduce
amounts in portions of the hard-hit Gold Coast in favor of more
rain for the northern Peninsula towards the First Coast. By Tuesday
the greatest overlap will be over the Gulf Coast. It is here than
an internal higher-end Slight was introduced for the Tampa through
Naples area due to increasing amounts of heavy rain moving into the
coast, being moved along by the predominant southwesterly flow in
the trough ahead of Milton's core circulation. Heavy rainfall both
the past couple days as well as expected both today and Tuesday
should keep all of the soils on the Florida Peninsula at or near
saturation, resulting in nearly all of the rainfall converting to
runoff. Thus, progressively less rainfall will be needed to result
in flooding.

Despite Milton and directly associated rains largely holding to the
Day 4/Wednesday period, it appears that similar to Helene, most of
the rain over the Florida Peninsula will be associated with the
PRE, while the heaviest rain (as well as wind and storm surge) will
conclude the multi-day rain event with Milton moving through,
causing much more widespread flooding.

Wegman

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt