Valid 132000Z – 141200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS
INTO THE LOWER MISSISSIPPI VALLEY…AND OVER PARTS OF THE EASTERN
Isolated severe hail is possible from southeast Texas to the
Tennessee Valley, primarily after midnight. An isolated severe storm
is possible over the eastern Carolinas this afternoon.
A corridor of instability with MUCAPE of 1500-2000 J/kg exists ahead
of an ongoing cluster of storms from central SC into southeast NC.
This activity is primarily linear, oriented parallel to the
deep-layer mean wind. As such, a few strong wind gusts are possible
with any small bowing structures. While an isolated supercell with
brief tornado occurred earlier over Horry county SC, storm trends
suggest further storms of this nature are unlikely.
Elsewhere, no changes were made to the previous outlook. See
previous discussion for more information for east TX into the lower
.PREV DISCUSSION… /ISSUED 1006 AM CST Mon Jan 13 2020/
…East TX into TN Valley…
A partially modified air mass has returned to portions of the Gulf
Coast region with dewpoints in the 50s and lower 60s extending from
east TX into parts of LA/MS/AL. Scattered thunderstorms are ongoing
this morning over this area in weak low-level warm advection regime.
This activity will persist through the afternoon and lift northward
across portions of the MRGL risk area. While the overall
environment is not particularly good with these storms, one or two
cells might produce at least small hail.
Later tonight, midlevel lapse rates steepen across parts of east TX
into LA, where another round of widely scattered thunderstorms is
expected to form. These storms will be focused along a developing
low-level jet axis extending into AR and northern MS. Environmental
parameters will be more favorable for hail for these storms, with
MUCAPE values over 1000 J/kg and lapse rates over 6.5 C/km.
However, activity will be after midnight and CAM solutions suggest
that updrafts will struggle to intensify. Therefore, will maintain
only MRGL risk probabilities for hail at this time.