SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1215 AM CDT Wed Apr 06 2022
Valid 061200Z - 071200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
THE SOUTHERN APPALACHIANS INTO THE SOUTHEASTERN U.S....
...SUMMARY...
Severe thunderstorms capable of producing swaths of damaging gusts,
severe hail, and several tornadoes are expected across a broad area
from parts of the southern Appalachians into the southeastern U.S.
this afternoon.
...Synopsis...
A robust upper-level wave is noted in early-morning water vapor
imagery over the northern CONUS. At the surface, an attendant
surface low is beginning to occlude over the upper MS river valley.
A progressive cold front arcing from the Midwest into the southern
Plains will continue to sweep east/southeast over the next 24 hours.
Ahead of this front, a diffuse warm front will advance north into
the Great Lakes region by the late afternoon, establishing a broad
warm sector from the Gulf Coast into the OH river valley.
...Middle TN into the OH River Valley...
Ongoing thunderstorms along the cold front in the mid-MS valley will
move into the middle TN/OH river valley through the day. Low-level
moisture will gradually increase as the warm front mixes north.
Dewpoints in the mid to upper 50s are expected as far north as
northern KY ahead of the front and will support MLCAPE values near
1000 J/kg. The upper-level jet streak overhead will support strong
50-60 knot effective bulk shear, and storm motions vectors near to
just off the cold front may support a mix of supercells and bowing
segments. Elongated hodographs in the 0-3 km layer will support a
tornado threat with any discrete cells.
...Southern Appalachians into the Southeast...
The cold front is expected to move across the lower MS valley
through the morning hours. Morning inhibition and weaker forcing for
ascent may limit storm coverage until the front reaches MS/AL around
early afternoon when diurnal heating/mixing can overcoming lingering
capping. Deep-layer shear will be more marginal compared to
locations farther north, but 30-40 knot in the 1-2 km layer will
still support a damaging wind threat with storms along the front. To
the east across southeast AL and southern GA, guidance suggests an
outflow boundary lingering from last night's MCS will lift through
the region. Thunderstorms will likely develop along this boundary by
late morning as inhibition erodes via insolation between cloud
breaks and low-level warm advection. Forecast hodographs show mid to
upper-level flow weakness, but low-level curvature will support
150-250 m2/s2 effective SRH across the region. This will support a
tornado threat, especially during the early afternoon when isolated
to scattered quasi-discrete supercells are most probable prior to
gradual clustering. While CAM guidance shows the highest
probabilities for convection across southeast AL into southern GA,
the exact location of convective initiation remains somewhat
uncertain.
..Moore/Smith.. 04/06/2022
Read more CHECK UPDATE ZOOM GRAPHIC
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