Area Forecast Discussion
Issued by NWS Wilmington, OH

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KILN 091143
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
643 AM EST Fri Dec 9 2016

.SYNOPSIS...
A cold air mass will remain over the region for the next several
days. Some flurries are expected this morning, before high
pressure moves into the region tonight into Saturday. A complex
low pressure system will affect the Ohio Valley Saturday night
into Monday, bringing a mix of snow and rain.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Below normal heights with a broad upper level trof centered over
New England. In w-nw flow regime Arctic high pressure to settle
into the lower Ohio Valley by late afternoon. Snow showers will
diminish to a few scattered flurries which will diminish this
morning. Expect some breaks but a good deal of clouds to linger
and then begin to diminish from the southwest as high pressure
noses in late in the day. Temp wise...mos appears too warm dealing
with arctic airmass and have lowered highs to upper 20s to near 30.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
West-northwest flow with surface high pressure settling into the
TN valley overnight. The low clouds will erode from the southwest,
but additional mid and high clouds will stream in from the west.
Expect lows generally in the upper teens.

Surface high pressure will build across the region on Saturday.
This high will provide dry weather and continued cold
temperature. Highs will range from the upper 20s across the north
to the lower 30s across the south.

Flow backs with s/w and associated surface wave ejecting from the
central plains to the Great Lakes on Sunday/sunday night.
Waa/isentropic lift pcpn develops in the form of snow across ILN/s
far northern counties late Saturday night. Trends look a little
further north and slower. Have a chance of snow from about I-70
north with perhaps an inch or two of snow across the far north
overnight. Lows Saturday night to range from the lower 20s far
north to the mid/upper 20s far south.

WAA pcpn continues to slide east across ILN/s nrn counties Sunday
morning with pcpn filling in across the south durg the afternoon
as favorable lift develops associated with 8H 55-60 kt low level
jet. Expect pcpn to remain snow across the far north with a snow
to rain/snow mix acrs the central and south. Eventually under the
influence of waa, the entire cwa turns over to rain Sunday night.
Several inches of additional snow accumulation are possible
Sun/Sun night prior to the change to rain across the far north.
Temperatures on Sunday look to warm to readings ranging from the
lower 30s far north to the lower 40s far south.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The upper level shortwave quickly exits east on Monday and
precipitation ends from west to east with high pressure building
in the Midwest. A broad trough will cross the northern Great Lakes
region Tuesday night and Wednesday with zonal westerly flow found
underneath it. GFS and Canadian models are sharper with the trough
and influences a lot more lift in the region on Wednesday while
the ECMWF is more muted and shifts the forcing off of the east
coast with very little precip in the Ohio Valley. Given the
precipitation was already in the forecast, continued the low
chances for the middle of next week and dried out the region on
Wednesday.

Models are in a sharply cool pattern for the end of the valid period
on days 5-7 but show a strong variability in the ensembles of 30
degrees or more in both daytime highs and nighttime lows. While the
model spreads for any period are large, the average of the runs and
the deterministic run are definitely on the colder side of the
ensemble members. Kept the cold pattern of the forecast but tried to
trend slightly warmer to account for the variability that in
inherent in the longer range forecast.

Precip on these days will likely see snow on Sunday, mixing with
rain along and south of the Ohio River. Temperatures will warm
overnight and the rain/snow line will lift to the I-70 corridor by
daybreak Monday. Precipitation on Tuesday at this moment in time
would start as a mix or plain rain in the southern half of the CWA
and then change to snow in the evening before ending overnight.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MVFR ceilings and snow flurries are lingering at most sites in a
cold cyclonic flow. Improvement to VFR has occurred at ILN and
DAY, but MVFR ceiling may fill back in at those sites by 15z.
All sites should see VFR about 01z with the arrival of high
pressure and a drier airmass. Winds will stay out of the west,
with speeds around 10 knots becoming light by the end of the
forecast.

OUTLOOK...MVFR/IFR ceilings and visibilities possible Sunday into
Monday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...AR
LONG TERM...Franks
AVIATION...Coniglio



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.