Scientific Forecaster Discussion
fxus61 Kiln 251951
Area forecast discussion
National Weather Service Wilmington Ohio
351 PM EDT Fri may 25 2018
an upper level disturbance will approach overnight and move
through during the day on Saturday bring shower and thunderstorm
chances to the region, especially during the afternoon and
evening hours on Saturday. A few additional storms will be
possible Sunday and Monday with a warm and humid airmass
Near term /until 6 am Saturday morning/...
a few showers and isolated thunderstorms have developed near
Scioto County where there is better instability this afternoon.
Expect this activity to continue into the early evening hours
There will then be a brief lull in the precipitation before
additional showers and some thunderstorm activity begins to work
into the region as an upper level disturbance approaches the
region. The highest precipitation chances will be across
western and northwestern portions of the forecast area closer to
the disturbance. With the increase in cloud cover overnight
only expect temperatures to drop off into the 60s.
Short term /6 am Saturday morning through Saturday night/...
an upper level disturbance will move through during the day and
into the evening hours on Saturday. This will act as a focus for
thunderstorm development during this time especially during the
afternoon and early evening hours with peak daytime heating.
Expect most locations to see some precipitation at some point
during this time and therefore went pretty high on precipitation
chances. Guidance values support this decision as well.
Precipitation will keep temperatures a little cooler on Saturday
with high temperatures in the low to middle 80s.
Precipitation will begin to taper off overnight. With light
winds, a subtle surface boundary washing out across the region
Saturday night, and the recent precipitation that is expected
to fall during the day on Saturday, expect some patchy fog to
develop overnight Saturday night especially northwest of
Long term /Sunday through Friday/...
the period begins with a weak 500 mb trof over the nern U.S. On Sunday
500 mb ridging will start to build in from the mid MS valley. However a
weak boundary in Kentucky will keep the low level moisture pooling,
which could allow a pop-up storm to develop. Temperatures will
remain well above normal with highs in the mid to upper 80s.
By Monday, the models bring a tropical low into the nrn Gulf of
Mexico. Moisture on the nrn edge of this system could be enough for
a spotty storm to pop-up on Memorial Day, but overall dry conditions
are expected with highs in the upper 80s.
The 500 mb ridge continues to build over the region Monday night into
Tuesday, as the tropical low make landfall in the Gulf Coast states.
Kept Tuesday dry as capping looks to suppress and storm development.
Models begin to diverge for Tuesday night into Wednesday in their
handling of the tropical low and its pcpn. The European model (ecmwf) and Canadian
bring the low up over the region Wednesday night into Thursday,
while the GFS swings it to the south through Tennessee. Went with a blended
solution this far out, but leaned towards the European model (ecmwf)/Canadian
solution. Kept pops in the chance category for now. The rain chances
and cloud cover will hold temperatures down in the mid 80s on
Wednesday and the lower 80s Thursday.
By Friday, the center of the system is pulling off to the east, put
it has left NW flow over the Great Lakes, which keeps the chance of
storm development over the region.
Aviation /19z Friday through Wednesday/...
VFR conditions will start out the taf period. There will be an
increase in VFR clouds overnight and some MVFR cigs will be
possible by the end of the taf period on Saturday.
A few showers will be possible overnight and expect
thunderstorms to develop during the day on Saturday as an upper
level disturbance approaches the region. Added thunderstorms in the vicinity in for now,
however thunderstorms and rain will likely need to be added in future tafs.
Outlook...afternoon and evening thunderstorms are possible
Saturday and Sunday.