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Area Forecast Discussion (AFD)

Issued by Wilmington, OH (ILN)

FXUS61 KILN 212050

National Weather Service Wilmington OH
350 PM EST Thu Feb 21 2019

A ridge of high pressure in the northern Ohio Valley will 
keep a southern stream of moisture at bay through Friday night.
By Saturday, this high will have moved east of Ohio and a warm 
front will move south to north through the Ohio Valley. A steady
moderate to heavy rain will be possible Saturday until a cold
front brings drier air behind it when it crosses east through
the region Saturday night. 


High clouds will continue to work into the Ohio Valley from the
southwest, become overcast tonight. West winds over the northern
CWA 5-10 mph will lighten and then turn northeast overnight.

Temperatures tonight will range from mid 20s in the north to mid
30s in the south under cloudy skies.


Cloud cover will thicken through the day Friday and east-
northeast wind 5-10 mph will keep similar temperatures over the
region as was seen today, from the low 40s north to upper 40s
south. A few sprinkles cannot be ruled out for portions of
Kentucky early in the day, but the drier air will overcome the
threat of actual measurable rain in the CWA.

Models continue to push the northern edge of the precip shield
south on Friday and keep the CWA dry through the better part of
the overnight, ramping things up quickly late overnight and Saturday
morning from the south and southwest. 

Overnight lows will range from near freezing in the far northern
reaches of the CWA to the lower 40s over Kentucky. 


As close low becomes negatively tilted and lifts from the southern 
Plains into the Great Lakes over the weekend, a corresponding 
surface low will deepen as it passes west and north of the forecast 
area. Showers will increase across the area as a warm front 
extending from the low into the Tennessee Valley lifts across the 
region on Saturday afternoon/evening. Warm sector will be short 
lived as a cold front will come sweeping across the region Saturday 
night. Narrow axis of instability may be sufficient when combined 
with the high shear values to generate strong to severe convection, 
even if lightning might be limited. Looking like widespread heavier 
rainfall will be south of the area, but still could see some locally 
heavy rain, which with the saturated ground will keep an elevated 
flood threat. 

Cold air advection late Saturday night into Sunday will result in 
strong winds in the wake of this system with the peak wind expected 
Sunday morning. Gaining higher confidence that sustained speeds 
and/or gusts will exceed advisory thresholds with the potential of 
approaching warning criteria in northwest counties. Temperatures 
will fall well into the morning with little or no recovery Sunday 

Winds will diminish Sunday night with high pressure building across 
the area on Monday. 12Z runs continue to show discrepancies between 
ECMWF and other operational models. ECMWF has been bringing the 
center of an Canadian high further south which results in colder 
temperatures. Other models hanging up the colder air until after a 
short wave and weak low passes on Wednesday. Have opted to use a 
blend for now until a clearer signal becomes established. There is 
reasonable agreement with the short wave which will bring the next 
chance of precipitation. 


VFR conditions will prevail as a cirrus deck moves in and
thickens tonight and through the day Friday. West wind this
afternoon 6-8kt over DAY ILN and CMH/LCK will lighten and go
more variable tonight. These winds will shift east-northeast
and then increase to 6-8 kt Friday morning. 

OUTLOOK...MVFR conditions are possible from Friday night through
Sunday. There will be a chance of thunderstorms on Saturday
night. Strong winds are expected on Sunday.




NEAR TERM...Franks