Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
637 PM EDT Mon Oct 5 2026
Day 1
Valid 01Z Tue Oct 06 2026 - 12Z Tue Oct 06 2026
...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
FL PANHANDLE & BIG BEND...
...Southeast...
The guidance maintains an 850 hPa circulation offshore the FL
Panhandle with the 850 hPa section of the front stuck ashore north
of Apalachicola overnight into the early morning, which maintains
a heavy rain risk for portions of the FL Panhandle and Big Bend.
Considering the rain that has fallen thus far, upgraded to a Slight
Risk for the region. The ingredients available support hourly rain
amounts to 3" with local totals to 5", which would be most
problematic in urban areas, where soils are saturating, and over
clay soils/hills. Heavy rainfall across portions of the FL
Peninsula caused by sea breeze circulations and the sagging front should
fade early on.
...Lower Texas Coast...
The heaviest rain has mainly been confined to far South Padre
Island leading to lower end and a very small scale threat for
flash flooding. A few cells may try to sneak in off the nearby Gulf
waters, so maintained the Marginal Risk. Both the 12z REFS and 18z
HREF keeps the possible threat going overnight which may edge more
ashore. Considering how much moisture and instability is closeby,
there's no reason to argue against the existing risk area.
Roth
Day 1 threat area:
www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Tue Oct 6 2026
Day 1
Valid 12Z Tue Oct 06 2026 - 12Z Wed Oct 07 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR MUCH OF
FLORIDA AND FAR SOUTHEASTERN GEORGIA...
A very slow-moving front will sag southward from Georgia and
Alabama into north Florida today. A very dry and refreshingly cool
air mass lies north of the front, while a very tropical, moisture-
rich air mass lies south of it. This large discrepancy between air
masses means the front is strong, and will effectively uplift the
tropical air mass, resulting in more of the same for north Florida.
Very slow-moving tropical showers with occasional embedded
thunderstorms will continue today. A widespread 1 to 3 inches of
rain is expected over much of north Florida. The flooding potential
remains Marginal. While soils are saturated from prior days' rains,
the flat terrain, generally low rainfall rates due to marginal
instability, and swampy areas should all continue to handle most of
the rain well. Thus, the isolated flooding threat is really
targeted towards urban and poor-drainage areas. Like yesterday,
there could be localized areas where heavier rain rates from
training storms could cause more widely scattered instances of
flash flooding, but those should be largely hit and miss.
Wegman
Day 1 threat area:
www.wpc.ncep.noaa.gov/qpf/94epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Tue Oct 6 2026
Day 2
Valid 12Z Wed Oct 07 2026 - 12Z Thu Oct 08 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE
FLORIDA PENINSULA...
The cold front sagging south into north Florida will stall out
near the Big Bend and the First Coast on Wednesday, becoming a
stationary front. The contrasting air masses on either side of the
front will remain extremely different, with dry air to the north,
and very soupy air to the south. Thus, the front will remain a very
effective boundary for the tropical air mass south of the front to
leverage to produce lift and locally heavy rain. The southward
progress of the front will allow the I-10 corridor to get a break,
relatively-speaking. While rain will the a threat there, the
amounts will be significantly lower than further south, as dry air
intrudes on north Florida. Meanwhile, on Wednesday the front will
more intensely target the I-4 corridor, especially on the Gulf
Coast side, where the heaviest rainfall amounts (1-3 inches) are
most likely. Meanwhile on the Atlantic side, expect a general 1-2
inches of rain. The format of the rain remains the same. Slow-
moving showers with embedded thunderstorms. Most of the time the
rain rates will be light, but where storms train, very localized
heavier amounts to 6 inches are possible. Flat terrain and sandy
soils, even if saturated, should limit the flash flooding threat
once again to urban and poor-drainage areas. The rainfall amounts
needed to get more significant flooding will be few and far
between.
Wegman
Day 2 threat area:
www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Tue Oct 6 2026
Day 3
Valid 12Z Thu Oct 08 2026 - 12Z Fri Oct 09 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR MUCH OF
FLORIDA...
The front that stalled across Florida on Wednesday will begin to
retreat northward as a warm front on Thursday. Thus, the swath of
heaviest rainfall will return to much of north Florida, though the
Panhandle may escape the heaviest rains for one more day. For the
most part, it's a rinse-and-repeat pattern. The front remains a
distinct dividing line between the soupy, tropical air mass to the
south, and a much drier one to the north. Thus, more of the same is
expected again on Thursday. Expect slow-moving showers and light
rain for most areas most of the time. However, there will be
embedded thunderstorms that if there is training or sufficient time
for a single cell to be parked over a given area, isolated flash
flooding is possible. Thus, the Marginal Risk remains in place,
much like the prior 2 days.
This will be the last day of this pattern, as the circulation
associated with AL92 begins to make its way northeast across the
Gulf from the Bay of Campeche. Thus will spur on a much more
widespread and significantly heavier rainfall threat into the Gulf
Coast for Friday into the weekend.
Wegman
Day 3 threat area:
www.wpc.ncep.noaa.gov/qpf/99epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Tue Oct 6 2026
Day 4 and Day 5
Valid 12Z Fri Oct 09 2026 - 12Z Sun Oct 11 2026
...A SLIGHT RISK OF EXCESSIVE RAINFALL ALONG PARTS OF THE NORTHERN GULF
COAST ON FRIDAY EXPANDS ACROSS THE LOWER MISSISSIPPI AND TENNESSEE
VALLEYS AND SOUTHEAST OVER THE WEEKEND...
The guidance is beginning to converge on a rather wet pattern
Friday into the weekend across central and eastern portions of the
Gulf Coast and areas inland across the Lower MS Valley, Lower TN
Valley, and Southeast. A big reason for this will be the possible
development and track of a tropical cyclone this week, though other
more synoptic-scale details will factor in as well. At this point
(4-5 days out), uncertainties (spatial and temporal) exist not
only with the possible tropical development, but also with the
possible interaction (and timing) of this system being absorbed by
the upper trough pivoting across the Lower MS Valley over the
weekend. The 00Z 10/6 operational ECMWF was faster than the GFS in
terms of this extratropical transition, while the CMC was slowest
and farthest west.
Given the timing and areal spread in the guidance, including
the AI models (00Z 10/6 EC-AIFS even faster than the operational
ECMWF), while we feel confident ramping up the ERO risk areas on
Days 4-5 (high-end Slight by Day 5), per collaboration with the
WFOs along the northern Gulf Coast, we opted to hold off on a
Moderate Risk at this point. This is consistent with the messaging
from the local WFOs as well as with the current Key Messages from
the NHC. Forecast confidence in a swath of at least 3-7" of
rainfall continues to grow per the latest global QPF trends, though
the potential for more (or less) will be highly dependent on the
speed of the Gulf system and extratropical transition with the
approaching upper trough. For further details regarding the
potential of tropical cyclone development in the Gulf, please
refer to the latest Tropical Weather Outlook from the NHC.
Hurley
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
430 AM EDT Tue Oct 6 2026
Day 4 and Day 5
Valid 12Z Fri Oct 09 2026 - 12Z Sun Oct 11 2026
...A SLIGHT RISK OF EXCESSIVE RAINFALL ALONG PARTS OF THE NORTHERN GULF
COAST ON FRIDAY EXPANDS ACROSS THE LOWER MISSISSIPPI AND TENNESSEE
VALLEYS AND SOUTHEAST OVER THE WEEKEND...
The guidance is beginning to converge on a rather wet pattern
Friday into the weekend across central and eastern portions of the
Gulf Coast and areas inland across the Lower MS Valley, Lower TN
Valley, and Southeast. A big reason for this will be the possible
development and track of a tropical cyclone this week, though other
more synoptic-scale details will factor in as well. At this point
(4-5 days out), uncertainties (spatial and temporal) exist not
only with the possible tropical development, but also with the
possible interaction (and timing) of this system being absorbed by
the upper trough pivoting across the Lower MS Valley over the
weekend. The 00Z 10/6 operational ECMWF was faster than the GFS in
terms of this extratropical transition, while the CMC was slowest
and farthest west.
Given the timing and areal spread in the guidance, including
the AI models (00Z 10/6 EC-AIFS even faster than the operational
ECMWF), while we feel confident ramping up the ERO risk areas on
Days 4-5 (high-end Slight by Day 5), per collaboration with the
WFOs along the northern Gulf Coast, we opted to hold off on a
Moderate Risk at this point. This is consistent with the messaging
from the local WFOs as well as with the current Key Messages from
the NHC. Forecast confidence in a swath of at least 3-7" of
rainfall continues to grow per the latest global QPF trends, though
the potential for more (or less) will be highly dependent on the
speed of the Gulf system and extratropical transition with the
approaching upper trough. For further details regarding the
potential of tropical cyclone development in the Gulf, please
refer to the latest Tropical Weather Outlook from the NHC.
Hurley
