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
637 PM EDT Mon Oct 5 2026
Day 2
Valid 12Z Tue Oct 06 2026 - 12Z Wed Oct 07 2026
...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR THE LOWER
TEXAS COAST, FAR SOUTHERN GEORGIA, AND MUCH OF FLORIDA...
20Z Update: Removed the MRGL risk across South TX as the setup
remains more prevalent for heavier convection offshore from South
Padre Island with the immediate coast the most notable area from an
impact standpoint. If trends move back closer to the Brownsville
area, then perhaps the MRGL returns, but the trends for less precip
inland to the urban centers lends to a removal with the mention of
the non-zero threat in far eastern Cameron and Willacy counties.
...Florida and Georgia...
20Z Update: Stalled front across FL will lead to a continued heavy
rain threat as pooling moisture and persistent convergence across
the Peninsula with modest instability will generate another period
of scattered convection for areas north of I-75 in South FL. Models
continue to converge on a signal that shows the greatest potential
located in-of the immediate coast, mainly for areas like
Tampa/Clearwater on the western coast, and the area between
Jacksonville to Port St. Lucie on the eastern side of the
Peninsula. The reasoning is just due to the frictional convergence
pattern along the coast with prevailing easterly winds near the
front itself, creating the threat for efficient rain makers
wherever they transpire. Models generally signaling locally 2-4"
with a threat for higher in any slow-moving thunderstorms that
linger over a given area. 12z HREF and REFS EAS fields overlap with
modest probs for >2" over the west-central coast of FL where each
ensemble depicts the location of the front for Tuesday afternoon
and evening. A little more discrepancy over the eastern FL coast
with the HREF signaling a threat closer to St. Augustine and the
REFS a bit further north into Jacksonville. Given the signal,
maintain general continuity in the MRGL risk inherited with just
some minor adjustments to the area of north-central FL between
Tallahassee and Jacksonville where guidance indicates an areal
minimum in the QPF distribution.
Kleebauer
Day 2 threat area:
www.wpc.ncep.noaa.gov/qpf/98epoints.txt
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
637 PM EDT Mon Oct 5 2026
Day 3
Valid 12Z Wed Oct 07 2026 - 12Z Thu Oct 08 2026
...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE FLORIDA PENINSULA, THE LOWER TEXAS COAST, AND SOUTHWEST TEXAS...
20Z Update: Removed the MRGL risks across both South TX and
Southwest Texas given the latest trends in guidance, and in
coordination with local offices. Both these areas will see an
uptick in the threat as we
16Z Update: Our cold front is making a bit more of a steady
southern progression this morning with the 12z surface analysis
depicting the front right along the FL/GA border with an
expectation for the front to bisect northern FL by later this
afternoon. The threat is dwindling for the northern extent of the
previous MRGL risk with the best chances for any locally heavy
rainfall occurring now into the early afternoon hours over southern
and eastern GA back into southern AL before ceasing by the evening.
Best signature for heavy rainfall and totals between 2-4" will
reside over the FL Panhandle between Destin to the Big Bend and up
through the interior, near and west of Tallahassee. HREF and REFS
EAS signatures for >2" are highest within that zone encompassing
the Apalachicola Forest and the coastal towns along US98, an area
that is traditionally hard to flood due to the sandier soils and
the necessity for fairly elevated rates >3"/hr, outside a few towns
like Panama City Beach and Apalachicola proper. The threat in those
areas remains lower end given the setup and the greatest ascent
lifting out of the region through the course of the afternoon. Some
indications that convection off the nearby Gulf this evening can
send an outflow or two towards land and create a localized area of
enhanced rainfall along the immediate coast. This signature is hit
or miss within the CAMs, but the threat is certainly non-zero for
something like this to occur. PWATs between 2.3-2.5" reside in this
area ahead of the cold front, so the environment is ripe for more
efficient warm rain processes and potential for locally >2"/hr. In
this case, the MRGL for the Panhandle area is more than sufficient.
Further east, frictional convergence along the front between
Savannah down through Jacksonville to St.Augustine will lead to
isolated flash flood concerns along the I-95 corridor as the
environment remains ripe with PWATs on the 12z KJAX sounding up at
2.44" this morning with a textbook tall, skinny CAPE signature that
correlates positively to heavy rain prospects. HREF and REFS
neighborhood probs for >5" are between 40-60% for that coastal area
between GA/FL but low EAS probabilities for >2" signal the threat
to be more isolated to widely scattered with the best risk tied to
those urban zones due to higher run off potential. Some convection
along the sea breeze further inland is also plausible with rates
between 2-3"/hr at peak intensity, but considering the pulse nature
of the convection, storms will have limited time before dwindling
in intensity, thus only generating short windows of opportunity to
promote flash flooding. The MRGL risk exists over northern and
central FL into eastern GA given all of the above. move later in the week, so be sure to
review the D4/5 ERO forecasts for each respective area.
Kleebauer
...Florida...
20Z Update: Little change to the previous forecast as the general
pattern and convective potential remain on track with run to run
continuity based on the latest guidance. Locally heavy rainfall
with the best threat along each coast (Tampa/Clearwater on the west
coast and St. Augustine to Port St. Lucie on the east coast) will
lead to isolated flash flood concerns as the environment in place
remains capable in producing rainfall rates between 2-3"/hr in any
given cell that initiates. The MRGL risk remains forecast for the
period.
Kleebauer
..Previous Discussion..
The front over the middle of the Florida Peninsula will end it's
slow southward movement on Wednesday and stall out over the area.
Fortunately, with the front no longer providing forcing for storms,
any rainfall will be driven by cold pools, proximity to other
storms, and localized pockets of higher instability. The point is
that there will be no organization to the convection, so the flash
flooding threat will remain Marginal, contingent on heavy rain
impacting an urban or poor
16Z Update: Our cold front is making a bit more of a steady
southern progression this morning with the 12z surface analysis
depicting the front right along the FL/GA border with an
expectation for the front to bisect northern FL by later this
afternoon. The threat is dwindling for the northern extent of the
previous MRGL risk with the best chances for any locally heavy
rainfall occurring now into the early afternoon hours over southern
and eastern GA back into southern AL before ceasing by the evening.
Best signature for heavy rainfall and totals between 2-4" will
reside over the FL Panhandle between Destin to the Big Bend and up
through the interior, near and west of Tallahassee. HREF and REFS
EAS signatures for >2" are highest within that zone encompassing
the Apalachicola Forest and the coastal towns along US98, an area
that is traditionally hard to flood due to the sandier soils and
the necessity for fairly elevated rates >3"/hr, outside a few towns
like Panama City Beach and Apalachicola proper. The threat in those
areas remains lower end given the setup and the greatest ascent
lifting out of the region through the course of the afternoon. Some
indications that convection off the nearby Gulf this evening can
send an outflow or two towards land and create a localized area of
enhanced rainfall along the immediate coast. This signature is hit
or miss within the CAMs, but the threat is certainly non-zero for
something like this to occur. PWATs between 2.3-2.5" reside in this
area ahead of the cold front, so the environment is ripe for more
efficient warm rain processes and potential for locally >2"/hr. In
this case, the MRGL for the Panhandle area is more than sufficient.
Further east, frictional convergence along the front between
Savannah down through Jacksonville to St.Augustine will lead to
isolated flash flood concerns along the I-95 corridor as the
environment remains ripe with PWATs on the 12z KJAX sounding up at
2.44" this morning with a textbook tall, skinny CAPE signature that
correlates positively to heavy rain prospects. HREF and REFS
neighborhood probs for >5" are between 40-60% for that coastal area
between GA/FL but low EAS probabilities for >2" signal the threat
to be more isolated to widely scattered with the best risk tied to
those urban zones due to higher run off potential. Some convection
along the sea breeze further inland is also plausible with rates
between 2-3"/hr at peak intensity, but considering the pulse nature
of the convection, storms will have limited time before dwindling
in intensity, thus only generating short windows of opportunity to
promote flash flooding. The MRGL risk exists over northern and
central FL into eastern GA given all of the above.-drainage area.
Wegman
Day 3 threat area:
www.wpc.ncep.noaa.gov/qpf/99epoints.txt
