Valid 131200Z – 141200Z
…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MI INTO
NORTHERN OH…
…SUMMARY…
Isolated severe thunderstorms are expected across portions of lower
Michigan into northern Ohio this afternoon.
…MI/IN/OH…
Notable short-wave trough will progress across the upper MS Valley
into the upper Great Lakes region by 14/00z while an associated
500mb speed max will translate downstream ahead of this feature into
northern lower MI by 18z. Early this morning, a considerable amount
of pre frontal convection is noted across WI into northern IL.
Latest model guidance suggests this activity will lift northeast
across Lake MI into northern lower MI early in the period, allowing
more moist/buoyant air mass to advance northeast ahead of the front
across IN into southeast lower MI. While mid-level lapse rates will
remain somewhat marginal across this region, if ongoing convection
evolves as currently forecast, boundary-layer heating ahead of the
front should allow a corridor of modest instability to develop from
IN into southeast lower MI. Forecast soundings suggest temperatures
will warm quickly into the lower 80s ahead of the front, allowing
surface parcels to reach their convective temperatures fairly early,
possibly by 18z. Scattered convection is expected to develop
along/ahead of the front shortly after noon and wind profiles
suggest some supercell potential. Locally damaging winds will be the
primary risk with this activity. Robust convection should shift into
southern ON and northern OH by early evening.
..Darrow/Dean.. 09/13/2019
$$