Discussion du SPC concernant le "setup" dans le Sud du Québec:
Northern ME...
Widely scattered to scattered thunderstorms are expected to develop
along/ahead of a cold front over southern QC, upshear from this
region, during the afternoon. Some of this activity may cross
northern ME before weakening, with the potential for isolated,
marginally severe gusts and/or hail. Forecast soundings suggest a
combination of diurnal heating and sufficient moisture (e.g.,
mid-60s F surface dewpoints) will offset modest mid/upper-level
lapse rates and yield around 1000 J/kg MLCAPE. Nearly
unidirectional deep-layer wind profiles will limit low-level shear,
but with strong flow in mid/upper levels, effective-shear magnitudes
around 35-45 kt reasonably appear in modeled wind profiles, prior to
convective influences. As such, organized multicells and isolated
supercells may occur.