Valid 270100Z – 271200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
…SUMMARY…
Low probabilities for thunderstorms will be generally confined to
the Pacific Northwest coastal waters this evening and the
northeastern Gulf coastal waters overnight.
…01Z Outlook Update…
…Ozark Plateau vicinity…
Sustained thunderstorm development the past few hours has been
focused across parts of northwest/north central Arkansas, near/east
of the Boston Mountains. This has been supported by a focused area
of forcing for ascent and destabilization beneath the cold core
(around -24C at 500 mb) of a compact mid-level perturbation digging
into the Ozark Plateau vicinity. With boundary layer cooling now
underway, lingering weak thunderstorm activity between Clinton and
Batesville AR seems likely to diminish by 01-02Z, if not earlier, as
the mid-level forcing progresses eastward.
…Pacific Northwest…
Mid-level cooling (500 mb temps of -28C or colder) associated with a
short wave troughing pivoting toward the Washington coast appears to
be contributing to a corridor of weak destabilization (most unstable
CAPE up to around 250 J/kg) offshore of the coast. Convective
development within this corridor appears to still be deepening, some
of which may become capable of producing lightning across the
coastal waters into immediate Washington/northern Oregon coastal
areas this evening. As the impulse progresses inland and mid-level
ridging begins to build into the Pacific coast, low thunderstorm
probabilities are expected to become increasingly negligible by
04-06Z.
…Northeast Gulf coast…
Large-scale ascent (largely due to low-level warm advection) and
destabilization, north/northeast of a weak eastward migrating
frontal wave over the northeastern Gulf of Mexico, might contribute
to weak thunderstorm development as far northeast as coastal waters
off the western Florida Panhandle by late tonight (toward 12Z
Monday).
..Kerr.. 01/27/2020
$$