Severe Storm Outlook Narrative (AC)
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000
ACUS02 KWNS 100553
SWODY2
SPC AC 100551

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 AM CDT Wed Apr 10 2024

Valid 111200Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE UPPER OH
VALLEY AND PARTS OF THE SOUTHEAST...

...SUMMARY...
Severe thunderstorms with a few tornadoes, scattered damaging winds,
and isolated large hail are likely across the Upper Ohio Valley
vicinity, mainly during Thursday afternoon. Scattered damaging winds
and a few tornadoes will also be possible across southeast Georgia
into central Florida, from Thursday morning into the afternoon.

...Synopsis...
A full-latitude mid/upper trough will be centered near the MS
Valley at 12Z Thursday, comprised of two primary shortwave impulses.
The southern-stream impulse should pivot northeast and accelerate as
the northern-stream impulse becomes the dominant embedded feature. A
steadily deepening surface cyclone will track northeast from the
Lower OH Valley to the Lake Huron vicinity during the period.

...Upper OH Valley...
A synoptically favorable corridor for a few supercells and organized
clustering into short-line segments appears likely to develop east
of the gradually deepening surface cyclone track. This region should
have a period where an overspreading mid-level dry slot coincides
with the diurnal heating cycle, before afternoon convection develops
within the left-exit region of the strong mid-level jet across the
Southeast and southern Appalachians. MLCAPE should reach 500-1000
J/kg amid a meridional supercell wind profile, before low-level flow
becomes veered from the southwest. Consensus of 00Z CAM guidance
supports the potential for a few supercells, with some upscale
growth into a line segment as convection consolidates northeastward.
This may be relatively short-lived as convection outpaces the weak
buoyancy plume and likely weakens after dusk. A mesoscale corridor
of greater severe probabilities, seemingly in the form of damaging
wind, may be warranted in later outlooks.

...Southeast GA to central FL...
Extensive deep convection should be ongoing from north FL into GA at
12Z Thursday. The southern portion of this activity will have the
best chance to maintain a damaging wind and embedded tornado threat
during the late morning into about mid-afternoon as stronger
boundary-layer heating occurs across the FL Peninsula. Large-scale
ascent will subside with southern extent through the day given the
northeastward track of the surface cyclone, in addition to low-level
winds becoming more veered in time over the FL Peninsula.

...Carolinas and VA...
Overall severe threat appears rather conditional during the daytime
hours given extensive convection across at least north FL and GA on
Thursday morning. Diabatic surface heating should be quite limited
by abundant downstream cloudiness/weak convection north of the
deeper convection during the day. Consensus of guidance largely
attempts to destabilize on the backside of early-day convection
within a plume of at least mid 60s surface dew points. Overall
threat will probably consist of sporadic damaging winds and up to a
few brief tornadoes within lower-topped convection, mainly from
midday through Thursday evening. With the expectation for lesser
severe weather coverage relative to areas farther northwest and
south, have opted to highlight much of this region with a cat 1-MRGL
this cycle.

..Grams.. 04/10/2024

$$


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