SPC AC 160556
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Fri Oct 16 2026
Valid 161200Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
MID-ATLANTIC INTO SOUTHERN NEW ENGLAND...
...SUMMARY...
Thunderstorms with wind-damage and localized brief-tornado potential
are expected across parts of the Mid-Atlantic into southern New
England, mainly this afternoon and early evening.
...Mid-Atlantic into southern New England...
A deep, positive-tilt mid/upper-level trough is forecast to further
amplify as it spreads over the eastern CONUS today. A surface low
initially near the lower Great Lakes will move quickly eastward
toward northern New England by evening. A trailing cold front will
sweep through the Mid-Atlantic and Northeast from this afternoon
into tonight.
In the wake of early-day clouds and precipitation, seasonably rich
low-level moisture and modest diurnal heating will result in
sufficient destabilization for storm development along the front.
Very weak lapse rates above 500 mb will constrain MLCAPE magnitudes
to the 500-1000 J/kg range, and result in rather low-topped
convection. However, in areas where temperatures can rise to
near/above 70 F, relatively robust buoyancy near/below 500 mb
(characterized by lifted indices in the -4 to -6 C range) will
develop prior to the frontal passage. This buoyancy will be
sufficient for development of occasionally organized storm
structures, in the presence of strengthening deep-layer flow/shear.
35-45 kt of flow in the 1-2 km AGL layer will support potential for
strong/damaging gusts with any sufficiently robust convection.
Generally front-parallel flow may result in a primarily linear mode
as convective coverage increases, though 40+ kt of effective shear
will support potential for embedded low-topped supercells. A
localized wind-damage threat may develop early this afternoon from
WV/western PA into southern NY, with initial frontal development.
The wind-damage threat is expected to increase through the afternoon
as storms spread eastward into a somewhat warmer and more unstable
environment across eastern PA, NJ, and vicinity. Rather strong
low-level shear will also support some brief-tornado potential with
QLCS circulations and/or embedded supercell structures.
Some wind-damage potential could spread into southern New England by
this evening, though marine-influenced low-level stability should
eventually constrain the eastward extent of the threat.
..Dean/Chalmers.. 10/16/2026
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
SPC AC 160524
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1224 AM CDT Fri Oct 16 2026
Valid 171200Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
No severe weather is expected tomorrow (Saturday).
...Synopsis...
Upper ridging and a surface anticyclone will overspread most of the
CONUS as an upper trough ejects into the Atlantic tomorrow
(Saturday). A relatively cool, stable airmass accompanying the
surface anticyclone will suppress thunderstorm development over most
locales. A surface cold front associated with the exiting upper
trough will sweep across the FL Peninsula during the day, providing
enough lift of a preceding moist airmass to support a couple of
thunderstorms. Scant buoyancy, driven by cooler mid-level
temperatures, will accompany a mid-level impulse over the Lower
Colorado River Basin, where enough lift may be present to support a
few lightning flashes.
..Squitieri.. 10/16/2026
WUUS02 PTSDY2
SPC AC 151904
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0204 PM CDT Thu Oct 15 2026
Valid 171200Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
No severe weather is expected Saturday or Saturday night.
...Synopsis...
An upper trough will eject into the Atlantic while an upper ridge
and accompanying surface high pressure/anticyclone overspreads most
of the CONUS on Saturday. Given the stability and subsidence
accompanying the broad surface anticyclone, thunderstorm development
should be limited across most of the CONUS. One exception would be
the central and southern FL Peninsula, where isolated thunderstorms
may accompany a sweeping surface cold front. The other exception is
the lower Colorado River Basin, where scant buoyancy, driven by
modestly cooler temperatures aloft, will accompany an approaching
mid-level impulse, fostering the potential for sparse lightning
flashes.
..Squitieri.. 10/15/2026
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
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