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
Windy.com Temps | Gusts | WU KORD KPWK |
CLICK for this month's BIG night sky ... | RADAR FULL MAP SCREEN |
|---|
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 0600 UTC Day 1 Convective Outlook
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
SPC Oct 16, 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
0742 AM CDT Fri Oct 16 2026
Valid 161300Z - 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 into Southern New England...
Recent water vapor satellite imagery shows a prominent and
positively tilted upper trough extending from eastern Canada into
the Upper Midwest. This upper trough will advance eastward while
amplifying over the eastern CONUS through the period, with enhanced
west-southwesterly low/mid-level flow expected to overspread much of
the Mid-Atlantic and Northeast. 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 with filtered
daytime heating. 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 lighting, 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 this morning with ongoing convection along/near the front
across western PA/NY, even though instability remains very limited.
Latest short-term guidance continues to suggest that a low-topped
convective line will further develop across central into eastern PA
and southern NY by 17-21Z. 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. The
greatest coverage of damaging winds should focus across parts of
eastern PA into NJ and southern NY, where locally greater
instability is forecast.
The potential for line-embedded mesocirculations is less clear.
While some low-level shear will be present, the enhanced low-level
flow is forecast to gradually veer to west-southwesterly through the
afternoon/evening, which may reduce effective SRH somewhat. Still,
at least an isolated threat for damaging winds and perhaps a tornado
should spread towards the coast before convection weakens this
evening due to marine layer influences and nocturnal cooling.
Overall, the ongoing forecast aligns reasonably well with recent
short-term guidance/observational trends, and therefore only minor
changes have been made to severe probabilities with this update.
..Gleason/Kerr.. 10/16/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxTzY
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Fri Oct 16 2026
Valid 161300Z - 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 into Southern New England...
Recent water vapor satellite imagery shows a prominent and
positively tilted upper trough extending from eastern Canada into
the Upper Midwest. This upper trough will advance eastward while
amplifying over the eastern CONUS through the period, with enhanced
west-southwesterly low/mid-level flow expected to overspread much of
the Mid-Atlantic and Northeast. 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 with filtered
daytime heating. 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 lighting, 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 this morning with ongoing convection along/near the front
across western PA/NY, even though instability remains very limited.
Latest short-term guidance continues to suggest that a low-topped
convective line will further develop across central into eastern PA
and southern NY by 17-21Z. 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. The
greatest coverage of damaging winds should focus across parts of
eastern PA into NJ and southern NY, where locally greater
instability is forecast.
The potential for line-embedded mesocirculations is less clear.
While some low-level shear will be present, the enhanced low-level
flow is forecast to gradually veer to west-southwesterly through the
afternoon/evening, which may reduce effective SRH somewhat. Still,
at least an isolated threat for damaging winds and perhaps a tornado
should spread towards the coast before convection weakens this
evening due to marine layer influences and nocturnal cooling.
Overall, the ongoing forecast aligns reasonably well with recent
short-term guidance/observational trends, and therefore only minor
changes have been made to severe probabilities with this update.
..Gleason/Kerr.. 10/16/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVxTzY
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SUNRISE AND SUNSET TIMES IN UTC (if you're not logged in to Google)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)




















