SPC AC 100650
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CST Sat Dec 10 2016
Valid 111200Z - 121200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
Thunderstorms may occur across parts of the lower and mid
Mississippi and Ohio Valleys Sunday. Showers and a few/occasional
lightning strikes may also occur over portions of the coastal
Low-amplitude cyclonic flow aloft will reside over virtually the
entire lower 48 states through the entire Day 2 (Sunday) period, as
an embedded short-wave trough moves quickly eastward across the
north-central U.S. and into the Upper Great Lakes region late.
At the surface, a developing low over the upper Midwest during the
afternoon should move northeast across the upper Great Lakes region
ahead of the aforementioned upper trough, while a trailing cold
front shifts eastward/southeastward across the
Midwest/Ozarks/southern Plains with time. Elsewhere, high pressure
will generally prevail.
...LOWER AND MID MISSISSIPPI/TENNESSEE/OHIO VALLEYS...
A strong (70 kt.) south-southwesterly low-level jet is forecast
ahead of the advancing upper short-wave trough, resulting in a broad
zone of warm advection roughly atop the surface frontal zone. As
the low-level theta-e advection permits eventual development of weak
elevated CAPE, showers and occasional/embedded thunderstorms are
forecast to develop -- mainly during the second half of the period.
Despite strong shear, weak instability should preclude appreciable
...PACIFIC NORTHWEST COASTAL AREAS...
Cold air aloft and strong west-northwesterly flow through the lower
half of the troposphere will support showers -- and likely
occasional lightning -- along windward slopes of the higher terrain
of western WA/western OR.
Showers are forecast to increase through the period along the
southeast U.S. coastal areas from FL to the Carolinas. While a
thunderstorm or two may also evolve across FL, most of the lightning
risk should remain offshore.
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z