Day 1 Severe Weather Outlook

Valid 131630Z – 141200Z


Scattered damaging winds, a couple tornadoes, and isolated severe
hail are possible across southeast Lower Michigan into northern Ohio
through about 9 PM EDT.

An upper low over northwest ON will evolve into an open wave while
moving northeastward towards James Bay, as embedded speed maxima
rotate around the southeastern periphery of the low. At the
surface, a cold front arcing into far southwest Lower MI to the
Wabash Valley will progress east across the rest of IN/Lower MI.
Thick overcast and residual stratiform rain have tempered
destabilization ahead of the front across most of Lower MI, except
across the southeast portion with nearly cloud-free insolation
occurring from there southward across much of OH and eastern IN.
Surface temperatures were already warming through the 80s and will
reach the low 90s across most of OH where surface dew points should
mix down into the low 60s. A confined corridor of upper 60s dew
points should remain near the front and where boundary-layer mixing
is not quite as pronounced across southeast Lower MI.

Scattered storms are expected to develop in the next couple hours
near the front, and then continue eastward across Lake Erie and
parts of northern OH into this evening. Despite being on the
southeast periphery of the Upper Great Lakes mid-level jet, largely
unidirectional/veered wind profiles should hold effective shear to
between 25-40 kts. The greatest potential for supercells will exist
across southeast Lower MI where the low-level hodograph should be
adequately enlarged, yielding a short-duration risk for a couple
tornadoes before surface winds veer. Modest mid-level lapse rates
will probably limit hail magnitudes. Scattered damaging winds should
be the primary hazard with this threat likely diminishing shortly
after dusk.

…Western NC into SC…
Strong surface heating and lingering low-level moisture along and
southwest of a reinforcing frontal surge could provide some focus
for thunderstorm development this afternoon. Thermodynamic profiles
will favor some risk for damaging downbursts given DCAPE values near
1000 J/kg. Minimal deep-layer shear will temper the potential for
organized clustering.

..Grams/Dial.. 09/13/2019


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.