LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0658 AM CDT Sat Oct 17 2026
Valid 171300Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Organized severe thunderstorms are not forecast through tonight.
...Synopsis and Discussion...
Highly amplified upper troughing over the eastern CONUS this morning
will move eastward off the Atlantic Coast today, while a closed
mid/upper-level low eventually develops over the NC Outer Banks and
adjacent western Atlantic. An expansive area of surface high
pressure and related dry and/or stable conditions across much of the
central/eastern states will greatly limit thunderstorm potential
today, with two exceptions. One area will be across parts of the FL
Peninsula along/south of a cold front, where sufficient instability
may support isolated to scattered thunderstorms this afternoon in a
weak deep-layer shear environment. While gusty winds could occur
with the strongest cores that develop, overall severe potential is
expected to remain low. A second area of isolated thunderstorm
potential will exist across parts of southern AZ, on the northeast
periphery of a weak mid/upper-level low centered over the eastern
Pacific and Baja Peninsula.
..Gleason/Kerr.. 10/17/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVy6yx
Windy.com Temps | Gusts | WU KORD KPWK |
CLICK for this month's BIG night sky ... | RADAR FULL MAP SCREEN |
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MOBILE DEVICE? Turn sideways. Weather conditions directly above are near Lakefront. Top tabs refer to O'Hare (official).
Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.
CONVECTIVE | TORNADO | WIND | HAIL
O'Hare International Airport KORD
(Arlington Heights South)
Chicago Executive Airport KPWK
(Arlington Heights North)
Saturday, October 17, 2026
SPC Oct 17, 2026 1300 UTC Day 1 Convective Outlook
SPC Oct 17, 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
1214 AM CDT Sat Oct 17 2026
Valid 171200Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected today.
...Synopsis...
In the wake of a cold frontal passage, much of the CONUS will be too
dry and stable for thunderstorm development today. The front will
continue moving southward along the central/southern FL Peninsula,
where scattered storm development will be possible within a very
moist environment. Poor lapse rates and weak deep-layer shear should
limit organized severe potential, though localized strong gusts may
occur. Across the Southwest, sporadic lightning flashes may
accompany weak convection associated with a slow-moving mid/upper
low centered offshore of Baja California.
..Dean/Chalmers.. 10/17/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxyCF
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1214 AM CDT Sat Oct 17 2026
Valid 171200Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected today.
...Synopsis...
In the wake of a cold frontal passage, much of the CONUS will be too
dry and stable for thunderstorm development today. The front will
continue moving southward along the central/southern FL Peninsula,
where scattered storm development will be possible within a very
moist environment. Poor lapse rates and weak deep-layer shear should
limit organized severe potential, though localized strong gusts may
occur. Across the Southwest, sporadic lightning flashes may
accompany weak convection associated with a slow-moving mid/upper
low centered offshore of Baja California.
..Dean/Chalmers.. 10/17/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxyCF
Friday, October 16, 2026
SPC Oct 17, 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
0750 PM CDT Fri Oct 16 2026
Valid 170100Z - 171200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorm potential appears low through the remainder of
tonight.
...01Z Update...
Convection associated with a strong cold front has generally
weakened or moved offshore of the Mid-Atlantic and southern New
England this evening. Sporadic thunderstorm activity could persist
through the remainder of the evening across these areas, though the
generally post-frontal nature of the remaining convection should
limit severe potential. Otherwise, ongoing storms across the FL
Peninsula should generally weaken through the evening, though some
storm potential may persist overnight across the FL Keys and
near-coastal areas.
..Dean.. 10/17/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxrTs
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 PM CDT Fri Oct 16 2026
Valid 170100Z - 171200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorm potential appears low through the remainder of
tonight.
...01Z Update...
Convection associated with a strong cold front has generally
weakened or moved offshore of the Mid-Atlantic and southern New
England this evening. Sporadic thunderstorm activity could persist
through the remainder of the evening across these areas, though the
generally post-frontal nature of the remaining convection should
limit severe potential. Otherwise, ongoing storms across the FL
Peninsula should generally weaken through the evening, though some
storm potential may persist overnight across the FL Keys and
near-coastal areas.
..Dean.. 10/17/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxrTs
SPC Oct 16, 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
1129 AM CDT Fri Oct 16 2026
Valid 161630Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC INTO SOUTHERN NEW ENGLAND...
...SUMMARY...
Thunderstorms capable of producing damaging winds and perhaps a
tornado or two are expected across parts of the Mid-Atlantic into
southern New England, mainly this afternoon and early evening.
...Mid-Atlantic States/southern New England...
A large-scale positive-tilt upper-level trough will approach the
region, with a modest buoyancy/high-vertical shear scenario expected
to be favorable for low-topped/fast-moving storms capable of wind
damage near/ahead of a cold front. Such severe potential is expected
to maximize across the Delmarva and eastern Pennsylvania into New
Jersey and southern New York.
Stratus remains very prevalent across much of the region late this
morning, although visible satellite imagery reflects a rather quick
erosion south to north across southern Virginia, and this same trend
should continue for east of the Blue Ridge/Appalachians spine
especially across Virginia into eastern Pennsylvania and perhaps
nearby parts of New Jersey/Delmarva.
A related surface low over southern Ontario will develop
east-northeastward today into southern Quebec, as a trailing cold
front sweeps east-southeastward across the eastern states. Low-level
moisture is forecast to gradually increase ahead of the front
through the afternoon, and MLCAPE should gradually increase into the
500-1000 J/kg range, particularly where more cloud breaks occur.
But, lapse rates through low/mid levels are likely to remain quite
poor (reference BUF/PIT/IAD 12Z observed soundings). This should
temper overall updraft strength to some extent, and low-topped
convection which develops along/near the front may produce little
lightning, especially with northward extent into southern New
England.
Even with the potential thermodynamic limitations, favorable
deep-layer shear will support some updraft organization. Given the
strength of the low/mid-level flow, isolated strong/gusty winds may
occur. A low-topped convective line will further develop across
central into eastern Pennsylvania and southern New York this
afternoon. Convectively augmented wind gusts capable of producing
scattered damaging winds will likely be the main severe risk as this
activity spreads quickly eastward across the northern Mid-Atlantic
and southern New England through early evening. A few line-embedded
mesocirculations could also occur, which could yield a brief
tornado.
..Guyer/Karstens.. 10/16/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxkR2
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Fri Oct 16 2026
Valid 161630Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC INTO SOUTHERN NEW ENGLAND...
...SUMMARY...
Thunderstorms capable of producing damaging winds and perhaps a
tornado or two are expected across parts of the Mid-Atlantic into
southern New England, mainly this afternoon and early evening.
...Mid-Atlantic States/southern New England...
A large-scale positive-tilt upper-level trough will approach the
region, with a modest buoyancy/high-vertical shear scenario expected
to be favorable for low-topped/fast-moving storms capable of wind
damage near/ahead of a cold front. Such severe potential is expected
to maximize across the Delmarva and eastern Pennsylvania into New
Jersey and southern New York.
Stratus remains very prevalent across much of the region late this
morning, although visible satellite imagery reflects a rather quick
erosion south to north across southern Virginia, and this same trend
should continue for east of the Blue Ridge/Appalachians spine
especially across Virginia into eastern Pennsylvania and perhaps
nearby parts of New Jersey/Delmarva.
A related surface low over southern Ontario will develop
east-northeastward today into southern Quebec, as a trailing cold
front sweeps east-southeastward across the eastern states. Low-level
moisture is forecast to gradually increase ahead of the front
through the afternoon, and MLCAPE should gradually increase into the
500-1000 J/kg range, particularly where more cloud breaks occur.
But, lapse rates through low/mid levels are likely to remain quite
poor (reference BUF/PIT/IAD 12Z observed soundings). This should
temper overall updraft strength to some extent, and low-topped
convection which develops along/near the front may produce little
lightning, especially with northward extent into southern New
England.
Even with the potential thermodynamic limitations, favorable
deep-layer shear will support some updraft organization. Given the
strength of the low/mid-level flow, isolated strong/gusty winds may
occur. A low-topped convective line will further develop across
central into eastern Pennsylvania and southern New York this
afternoon. Convectively augmented wind gusts capable of producing
scattered damaging winds will likely be the main severe risk as this
activity spreads quickly eastward across the northern Mid-Atlantic
and southern New England through early evening. A few line-embedded
mesocirculations could also occur, which could yield a brief
tornado.
..Guyer/Karstens.. 10/16/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxkR2
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CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)
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