SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
0145 PM CST Sun Feb 27 2022
Valid 272000Z - 281200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for thunderstorms appears negligible across much of the
U.S. late today through tonight, but a few lightning flashes might
be possible in heavy snow squalls spreading into northern New
England and northern New York State late this afternoon.
...20Z Outlook Update...
...Upstate New York and northern New England...
A deep mid-level trough emerging from the Arctic latitudes continues
to dig toward the northern Atlantic coast, accompanied by strong
lower/mid tropospheric cooling and intensifying cyclonic mid-level
flow across much of the Northeast. One particular belt of stronger
low-level cooling (centered around the 850 mb level) is currently
spreading across and southeast of the St. Lawrence Valley through
the Lake Ontario region, and appears to be providing the primary
focus for weak boundary-layer based destabilization supportive of
bands of developing convection.
While some lightning has been observed across parts of southeastern
Ontario into southern Quebec, convection is rooted within a mostly
sub-freezing boundary layer, and low-topped, with equilibrium levels
peaking around 10-11,000 feet AGL. This is not expected to change
substantively while overspreading much of northern New England and
northern New York State through early evening, so probabilities for
thunderstorms still appear to remain less than the 10 percent
minimum threshold for a categorical thunderstorm area. However,
convection may still be impactful, accompanied by periods of heavy
snow squalls with strong wind gusts and sharply reduced
visibilities.
..Kerr.. 02/27/2022
.PREV DISCUSSION... /ISSUED 1014 AM CST Sun Feb 27 2022/
...Synopsis...
An expansive surface high will remain entrenched across the central
CONUS today, limiting the potential for deep convection for most of
the country. A weak cold front continues to push east/southeastward
across the southeastern U.S., and will eventually move offshore
later today. This may support a few offshore thunderstorms late this
evening off the FL/GA/SC coast. Across the Pacific Northwest,
onshore flow will continue to bring scattered precipitation to
western OR/WA, but both observed and forecast thermodynamic profiles
appear too marginal to support much lightning potential.
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