No watches are valid as of Thu Oct 8 19:36:02 UTC 2026.No Mesoscale Discussions are in effect as of Thu Oct 8 19:36:02 UTC 2026.SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1123 AM CDT Thu Oct 08 2026
Valid 081630Z - 091200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
CENTRAL PORTION OF THE FLORIDA PENINSULA AND IOWA...
...SUMMARY...
Localized severe thunderstorms may occur across the central portion
of the Florida Peninsula and/or across Iowa tonight.
...Florida Peninsula...
Visible-satellite imagery shows a cloud shield generally near and
north of a residual frontal zone draped across the central portion
of the FL Peninsula. Filtered sunshine generally south of the I-4
corridor will contribute to weak destabilization in the presence of
a tropical airmass characterized by mid-upper 70s deg F surface
dewpoints. Model forecast soundings show moderate effective shear
(25-30 kt) and a veering wind profile through a deep layer. Given
the very moist boundary layer coupled with proximity to the frontal
zone and shear supporting potentially transient weak rotation, a
brief tornado or waterspout is possible.
...Iowa...
Isolated to scattered elevated thunderstorms are forecast
tonight in tandem with around 1000 J/kg MUCAPE developing as warm
advection and isentropic ascent increase to the northeast of a
northeastward-advancing warm front. With effective shear in the
cloud-bearing layer expected to increase to 40+ kt, the possibility
exists for a few elevated supercells late this evening into the
overnight, with a few instances of marginally severe hail possible.
..Smith/Jirak.. 10/08/2026
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0232 PM CDT Thu Oct 08 2026
Valid 082000Z - 091200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
CENTRAL PORTION OF THE FLORIDA PENINSULA AND IOWA...
...SUMMARY...
Localized severe thunderstorms may occur across the central portion
of the Florida Peninsula and/or across Iowa tonight.
...20Z Update...
The forecast remains on track, and no changes were needed with this
update. See the previous discussion below for details.
..Weinman.. 10/08/2026
.PREV DISCUSSION... /ISSUED 1123 AM CDT Thu Oct 08 2026/
...Florida Peninsula...
Visible-satellite imagery shows a cloud shield generally near and
north of a residual frontal zone draped across the central portion
of the FL Peninsula. Filtered sunshine generally south of the I-4
corridor will contribute to weak destabilization in the presence of
a tropical airmass characterized by mid-upper 70s deg F surface
dewpoints. Model forecast soundings show moderate effective shear
(25-30 kt) and a veering wind profile through a deep layer. Given
the very moist boundary layer coupled with proximity to the frontal
zone and shear supporting potentially transient weak rotation, a
brief tornado or waterspout is possible.
...Iowa...
Isolated to scattered elevated thunderstorms are forecast
tonight in tandem with around 1000 J/kg MUCAPE developing as warm
advection and isentropic ascent increase to the northeast of a
northeastward-advancing warm front. With effective shear in the
cloud-bearing layer expected to increase to 40+ kt, the possibility
exists for a few elevated supercells late this evening into the
overnight, with a few instances of marginally severe hail possible.
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1225 PM CDT Thu Oct 08 2026
Valid 091200Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE FRIDAY
THROUGH FRIDAY NIGHT ACROSS THE FLORIDA PANHANDLE/BIG BEND VICINITY
AND ADJACENT PORTIONS OF SOUTHERN ALABAMA/SOUTHWESTERN GEORGIA...
...SUMMARY...
A risk for tornadoes may develop across northeastern Gulf coastal
areas late Friday into early Saturday ahead of Isaias.
...Discussion...
Models continue to indicate substantive amplification of mid/upper
troughing within the mid-latitude westerlies, across British
Columbia through the Pacific Northwest Friday through Friday night.
As this occurs, downstream ridging is forecast to build a bit
further while translating east of the Canadian Prairies/northern
U.S. Great Plains through northwestern Ontario and the upper Great
Lakes by early Saturday. Farther east, large-scale mid-level
troughing likely will continue slowly across and east of the New
England/Canadian Maritimes vicinity. In lower latitudes, mid/upper
troughing forced southeastward within a weaker branch of westerlies
may contribute to a northeastward acceleration of Tropical Storm
Rachel across the lower latitude eastern Pacific. An upper-level
trough farther downstream is forecast to accelerate northeast of the
Texas coastal plain and contribute to the evolution of a mid-level
low across or just east of the lower Mississippi Valley, as it
interacts with Hurricane Isaias.
The spread concerning the evolution of the increasingly sheared
hurricane remains sizable, particularly as it progresses across and
inland of northeastern Gulf coastal areas. In general, it still
appears most probable that it will take a north to northwestward
turn after migrating inland near/east of Mobile Bay. This has been
preceded by an influx of dry/potentially cool boundary-layer air
across much of the northeastern Gulf Coast states through Carolinas,
which may be reinforced later today through Friday on the
southwestern flank of building surface ridging becoming centered
across the northern Mid Atlantic states.
...Northeastern Gulf Coast region...
The risk for tornadoes in association with Isaias remains unclear
for Friday through Friday night. Based on the forecast storm track
and speed, it appears possible, if not probable, that the favorable
right front quadrant (with respect to storm motion) forcing for
ascent and vertical shear will spread north-northwestward inland of
coastal areas before near-surface thermodynamic profiles
destabilize. As this approaches southwestern Alabama and western
Florida coastal areas prior to 10/00Z, supercell structures with
potential to produce waterspouts may impact offshore waters.
However, it is not clear that near-surface destabilization will
maintain intensity across the coastal waters and inland, prior to
the onset of mid-level warming and subsidence. Barring a
substantive change to the forecast track, it is possible that severe
probabilities could be reduced across this area in later outlooks
for this period.
Closer to the Tallahassee and Apalachicola vicinities, and eastward
across the Florida Big Bend, a gradual inland boundary-layer
moistening and destabilization appears possible later Friday evening
into early Saturday, to the east and southeast of the center of
Isaias. Coincident with the continuing presence of at least sizable
clockwise-curved low-level hodographs, forcing ascent to the east of
the developing dry slot may be sufficient to maintain a band or
bands of convective development, with transient embedded supercell
structures posing a risk for tornadoes.
..Kerr.. 10/08/2026
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