SPC Aug 1, 2024 1630 UTC Day 1 Convective Outlook

[NorthGeorgiaWX]

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1130 AM CDT Thu Aug 01 2024

Valid 011630Z - 021200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MIDWEST/OHIO VALLEY...

...SUMMARY...
Severe thunderstorms will be possible today across parts of the
Midwest and Ohio Valley, with a threat of damaging winds, isolated
hail, and perhaps a tornado or two.

...Upper Midwest/Ohio Valley...
Primary upper trough located over the Upper Midwest late this
morning is forecast to develop generally east-southeastward across
the Great Lakes and OH Valley through the period. Multiple
convectively enhanced MCVs are present over the Midwest, along with
outflow boundaries from prior convection. These features will likely
serve as forcing mechanisms for additional robust thunderstorm
development across the OH Valley this afternoon and evening. One
such MCV located over far eastern MO into western IL should track
eastward through the day, while aiding a cluster of thunderstorms
that have already started strengthening across southern IL. The
outflow boundary extending across southern IN and vicinity will
likely serve as a focus for the subsequent MCS track, as the airmass
along/south of this boundary is rapidly destabilizing.

Given the mainly linear mode expected and sufficient deep-layer
shear present, scattered severe/damaging winds should be the main
threat. But, a line-embedded tornado or two may also occur,
especially near the outflow boundary. See recently issued Mesoscale
Discussion 1784 for more details. The northward extent of MCS
development into northern/central IN/OH remains uncertain given
lingering cloudiness and the outflow boundary remaining farther
south. Still, there may be additional strong to severe thunderstorm
development across these areas in association with another MCV over
northeast IL/northwest IN. Have therefore made no changes to the
northern edge of the Slight Risk in the OH Valley with this update.

Farther northwest, a separate area of strong to locally severe
thunderstorm development may occur closer to the mid/upper-level
cyclone across parts of WI into northern IL. Deep-layer shear is
forecast to remain modest, but moderate instability could support
isolated hail and damaging wind with the strongest cores.

...Mid-Atlantic into the Carolinas and Southeast...
Strong heating of a moist environment will result in the development
of moderate to locally strong instability from GA and the Carolinas
into southern parts of the Mid-Atlantic. Large-scale ascent across
this region should remain rather weak/nebulous. Accordingly,
thunderstorm coverage remains uncertain, and could be isolated to
widely scattered. However, robust thunderstorms may still form by
late afternoon into early evening, as lingering convective
inhibition erodes. Modest mid-level northwesterly flow in the wake
of the departing upper-level trough along the East Coast may provide
sufficient effective bulk shear for modest updraft organization,
with a threat of isolated damaging winds and perhaps marginally
severe hail.

...Southern/Central High Plains to the Mid-South...
The outflow-reinforced front has nearly stalled over the
south-central High Plains into northeast NM. Initial development may
occur near the Raton Mesa NM vicinity in a modest low-level upslope
flow regime, with more isolated development possible farther east
along the front into the OK/TX Panhandles, and potentially farther
east along the boundary into northern OK/AR and southern MO.
Low/midlevel flow will remain rather weak. Still, sufficient veering
of winds with height should support effective shear generally around
20-30 kt. This should be sufficient for some convective organization
with of moderate to strong instability present along/near the
boundary. Initially discrete thunderstorms could produce large hail,
but outflow and convective consolidation/clustering with the
well-mixed boundary layer should lead to an increasing threat for
isolated severe gusts later in the convective evolution.

..Gleason/Moore.. 08/01/2024

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