Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 191527
Area Forecast Discussion
National Weather Service Wilmington OH
1027 AM EST Thu Jan 19 2017
High pressure will move east today, while low pressure approaches
from the southwest. Expect widespread rain showers this evening
through tonight when the low is forecast to travel to northern
Ohio. Look for drier weather Friday and Saturday in the mild
southerly flow following the low.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --Low clouds continue to linger across the northern counties, but
waa is slowly eroding them from the south. The linger low clouds
have retarding the warming process, so bumped highs down a little,
especially across the north. Actually the high for the day could
occur towards 00Z. Highs will now range from the mid 40s in W
Central OH to the lower 50s in nrn KY.
Also, the latest mesoscale models are showing that the pcpn might
arrive a little later than earlier forecasts, so slowed the onset
of the pcpn by a few hours.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
Surface low will be traveling from Kentucky to Ohio tonight,
supported by a sharpening upper trough and carrying ample moisture
on the persistent LLJ. Showers will be widespread, with most
locations receiving one half to three quarters of an inch of
As the surface low lifts north to the vicinity of Lake Erie on
Friday, the area will be in a regime of reduced moisture and
forcing in the wake of the low. Under a weak ridge at the surface
and aloft, showers will diminish greatly in coverage, leaving most
sites free from precip by Friday afternoon. Similar mainly dry
conditions appear to be in store for Saturday in the slow to
Temperatures will be very mild for mid winter due to the southerly
low level flow coupled with above normal pressure heights aloft.
Forecast highs Friday are in the mid and upper 50s, with low to
mid 60s expected Saturday. This compares to normal highs in the
mid and upper 30s.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Low pressure moving into the upper midwest will be too far from
the region to provide strong forcing, but continued moist flow
will support the development of some precipitation by Saturday
evening and going into early Sunday morning. With as warm as it
may get, some very limited instability could develop, but thunder
will be kept out of the forecast until (and if) confidence
increases in this scenario. However, confidence continues to
increase in warm conditions for Saturday, and this forecast will
increase values by another degree or so. Record highs are in the
70s for all three climate sites, and these records appear safe.
A fast-moving upper level low pressure system is expected to move
across the southern tier of states on Sunday, with widespread
precipitation (and some heavy rainfall) expected to develop in the
Tennessee Valley region. On the northern periphery of this low,
precipitation is eventually expected to spread northward into the
Ohio Valley on Sunday, with another wave arriving on Monday as
precipitable water values continue remain high for January (near or
just under an inch). Overall, model differences are not large,
though the ECMWF is slightly faster with the progression of this
stacked low pressure system. Once the low has moved from south of
the region to southeast of the region, a switch to northerly flow
will allow for a gradual drop in temperatures through Monday and
Tuesday. Timing out the end of precipitation is uncertain, however,
as there is significant model spread (within GEFS members) regarding
how the mid-level low / trough progress northeastward on Monday
night into Tuesday.
Beyond the passage of the low and the arrival of a narrow ridge,
model solutions diverge significantly with regards to the next
system moving through the quick westerly flow. Thus, confidence in
specific temperature and precipitation details beyond Tuesday is
fairly low. However, a general warmer-than-normal trend is almost
certain to continue going into the rest of the week.
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
Low clouds with CIGS below 1000 feet will continue to slowly
erode from the southwest to northeast. High level clouds CIGS
this morning will thicken into the mid levels this afternoon in
advance of the next system.
Mid level flow backs to the southwest durg the aftn with embedded
shortwave and sfc low tracking northeast into the Ohio Valley by
Friday morning. As favorable isentropic lift develops, expect rain
to overspread the TAF sites around 00Z at KCVG/KLUK to 04Z at
KCMH/KLCK. Expect CIGS and VSBYS to drop into MVFR category this
evening and then IFR overnight.
OUTLOOK...MVFR/IFR ceilings possible through Friday, and then
late Sunday into Monday.