SPC Oct 18, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1114 AM CDT Sun Oct 18 2026

Valid 181630Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not forecast through tonight.

...Synopsis...
Tranquil conditions will exist across much of the contiguous United
States through tonight. Extensive surface high pressure influencing
much of the central and eastern U.S. will favor offshore flow into
the northern Gulf of America and feature a seasonably dry/stable
airmass. A few weak thunderstorms are possible over south FL and
the Keys to the north of a surface front undergoing frontolysis
across the southern Gulf and FL Straits. Farther west, an upper
trough migrating northeast across the Four Corners will be
associated with isolated showers/thunderstorms across parts of the
Southwest.

..Smith/Supinie.. 10/18/2026


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SPC Oct 18, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0730 AM CDT Sun Oct 18 2026

Valid 181300Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not forecast through tonight.

...Synopsis and Discussion...
Even with east-northeasterly low-level flow persisting to the north
of a remnant cold front, diurnal heating of a moist airmass will
support sufficient instability for isolated to scattered
thunderstorms across parts of south FL and the Keys today.
Occasional lightning flashes may also occur with convection across
parts of the Southwest ahead of a low-amplitude mid-level shortwave
trough. Weak shear across south FL and limited moisture/instability
over AZ/NM will hinder the potential for severe thunderstorms across
both regions. Dry and/or stable conditions will preclude
thunderstorms for the remainder of the CONUS through the period.

..Gleason/Kerr.. 10/18/2026


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SPC Oct 18, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 AM CDT Sun Oct 18 2026

Valid 181200Z - 191200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not forecast in the U.S. today or tonight.

...DISCUSSION...
A mid-level anticyclonic flow pattern, and an associated surface
high pressure system will be in place today over the central and
eastern U.S. Dry and cool conditions will be in place over much of
the nation, and thunderstorms will be unlikely. The exceptions will
be over south Florida and in the Desert Southwest where scattered
thunderstorms will be possible from today into tonight. No severe
threat is expected across the continental U.S. through daybreak on
Monday.

..Broyles/Chalmers.. 10/18/2026


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SPC Oct 18, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0754 PM CDT Sat Oct 17 2026

Valid 180100Z - 181200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected across the U.S. through
tonight.

...DISCUSSION...
At upper-levels, a trough and associated low will move eastward into
the western Atlantic tonight as a ridge dominates over the central
U.S. At the surface, dry and cool air associated with a large area
of high pressure will be in place over much of the nation. Moisture
and instability will be confined to south Florida, where isolated
thunderstorms will be possible this evening. Isolated storms may
also form over parts of southern Arizona this evening. No severe
threat is expected over the continental U.S. through daybreak on
Sunday.

..Broyles.. 10/18/2026


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