SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1210 PM CDT Thu Aug 08 2024
Valid 091200Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
PA...NJ...AND THE NORTHERN DELMARVA PENINSULA...
...SUMMARY...
There may be at least some continuing risk for damaging gusts
tornadoes in advance of the remnant low of Debby. Greatest severe
potential is expected from eastern Pennsylvania into New Jersey and
the northern Delmarva Peninsula.
...Synopsis...
A mid-latitude cyclone is forecast to begin the period over central
Ontario before shifting gradually throughout the day. Moderate to
strong flow is anticipated throughout the base of this cyclone,
spreading from the Upper Midwest across the Great Lakes and OH
Valley and into the Northeast as a shortwave trough progresses from
the Upper Midwest across the Upper Great Lakes into southwest
Quebec. Overall evolution of this cyclone and associated shortwave
trough will interact with Tropical Cyclone Debby, which may be in
its extratropical phase by early Friday morning. This interaction
will result in an accelerated northeastward progression of Debby,
taking it from its initial position near the WV/MD/VA border
vicinity quickly northeastward through the Northeast and into the
Upper St. Lawrence Valley by early Saturday.
Farther west, dampened upper ridging will persist across the
Southwest and southern Plains. A convectively generated,
low-amplitude shortwave trough is forecast to move through the
northern periphery of this ridging, from eastern CO into the
Mid-South. Another low-amplitude shortwave trough may follow in the
wake of the first, reaching the central KS/western OK by early
Saturday morning.
...Mid-Atlantic into the Northeast...
Robust low to mid-level flow is forecast to extend throughout the
eastern periphery of TC Debby, from eastern NC into southern ME,
early Friday morning. This strong flow will persist throughout the
day, gradually shifting northeastward with the parent system. The
strongest low/mid-level flow (i.e. 50+ kt at 850mb) will remain in
close proximity to the cyclone, spreading from far northeast
VA/central MD early Friday into eastern PA/NJ by the afternoon and
into southern New England by late Friday/early Saturday
Widespread cloud cover and limited heating is anticipated across the
region, but deep convection still appears possible amid the strong
warm-air advection. Buoyancy will be limited, likely tempering the
overall updraft strength within this convection. However, ample
moisture will be in place, which should combine with the strong
low-level shear to support some organized storm structures. Damaging
gusts will be the greatest severe threat, but embedded circulations
could be strong enough to produce brief tornadoes as well.
Highest severe potential is expected from eastern PA to the I-95
corridor in NJ, where the timing of the system allows for the best
overlap between the buoyancy/daytime heating and the low-level
shear. Strong forcing could still result in some damaging gusts
farther north into NY and western New England, despite very limited
buoyancy. Buoyancy will be greater farther south across eastern
VA/NC, but shear will be weaker, likely keeping the severe threat
isolated.
...Northeast NM/Southeast CO into TX Panhandle and Western OK...
Scattered showers and thunderstorms will likely be ongoing across
the TX Panhandle vicinity early Friday, with some potential that
this activity will persist downstream into western OK throughout the
day. Limited buoyancy and shear should keep the severe threat low.
Another round of thunderstorms is possible Friday afternoon,
beginning in the Raton Mesa vicinity and then continuing
eastward/southeastward through the evening and potentially
overnight, maintained by a moderate low-level jet across west TX. As
with the early morning storms, limited buoyancy and shear should
keep the severe threat low.
..Mosier.. 08/08/2024
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