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Area Forecast Discussion (AFD)

Issued by Wilmington, OH (ILN)

                            
000
FXUS61 KILN 141744
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
144 PM EDT Sat Sep 14 2019

.SYNOPSIS...
In the wake of a cold front which passed through the area
overnight, cooler and drier air will continue to filter into the
Ohio Valley today as high pressure moves in. The high will
continue to influence the region through Sunday with several
days of dry and somewhat cooler temperatures in comparison to
the past week, although highs will be in the 80s both days this
weekend. A weak front will slip quietly into the Ohio Valley on
Monday, but likely without precipitation. Temperatures next week
will once again be well above normal as the dry weather is
expected to continue.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A cooler and drier airmass is continuing to filter into the
region this morning in the wake of a cold front that moved 
through last night. We are see some lingering higher level 
clouds across the region but these should continue to shift off
to the northeast/dissipate as we progress through the afternoon.
Will range highs today from the upper 70s in the northwest to 
the lower 80s in the southeast.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
An extremely enjoyable early autumn evening is expected as winds
go light/calm as high pressure remains directly overhead with
clear skies. Given the very dry setup, expect a rapid
temperature fall through the evening, bottoming out in the mid
to upper 50s areawide. This will likely induce another round of
valley fog like we've seen most mornings in August and
September. 

On Sunday, as the thermal trough departs aloft and heights begin
rising, a subtle disturbance moving from MN/WI into Michigan
will combine with a ribbon of anomalous PWAT originating over
the western Corn Belt to drive a complex of showers and storms
Saturday night into the western Great Lakes Sunday morning as
it weakens and rapidly erodes. The boundary layer over the Ohio
Valley will still be heavily influenced by the surface high 
departing to the east, so this system's potential to impact the 
local area with any precipitation chances will be very low. 
However, remnant cirrus debris /which may be quite dense/ is 
likely to spread across Indiana and Ohio for parts of the day on
Sunday which may diminish the amount seen especially in the far
northern portions of the forecast area. Where sunshine is more
abundant, the departure of the thermal trough means
temperatures will again rebound quickly. As mentioned above,
with very dry soils, model 2m temps and statistical MOS is
getting more and more behind in keeping up with the heating
efficiency, so have once again sided on the very warm side of
guidance which yields temperatures into the 80s on Sunday
afternoon. Again there is potential for dewpoints to mix
considerably in the area given boundary layer remains very dry
and any moistening that occurs will be well aloft.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A mid level ridge will build northward into the middle/upper 
Mississippi River Valley Sunday night into Monday. As this occurs, 
northwest flow aloft will develop over the Great Lakes and the Ohio 
Valley. This will push a weakening frontal boundary southward across 
the region. Lack of strong dynamics and forcing should allow this 
boundary to pass through dry. Highs will mostly be in the mid and 
upper 80s.

For Monday night into Tuesday, under a northwest flow, surface high 
pressure will extend southwest into the area from southeast 
Canada/New England. This will bring drier air and a slightly cooler 
temperatures. Highs will be in the lower to mid 80s after lows in 
the 60s.  

Coolest temperatures will occur Tuesday night with lows in the upper 
50s to the lower 60s under mostly clear skies. Mostly sunny skies 
can be expected on Wednesday as the mid level ridge to the west 
begins to move east. Highs will modify slightly on Wednesday with 
mainly mid to upper 80s expected. 

For the remainder of the extended, have discounted the operational 
GFS which tries to push a weak cold front south on Thursday/Thursday 
night through the mid level ridge while the other operational models 
hold the ridge in place. There may be enough moisture and diurnal 
instability to allow for a slight chance of afternoon and evening 
showers and thunderstorms by Friday. Highs will continue to range 
from the mid/upper 80s with lows in the lower 60s.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A band of mid and high level clouds across the region should
gradually dissipate through the afternoon. This will leave 
mainly clear skies overnight as high pressure continues to build
into the region. Some river fog will be possible later tonight 
into early Sunday morning, mainly affecting KLUK. Otherwise, VFR
conditions are expected through the TAF period.

OUTLOOK...No significant weather expected.

&&

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

&&

$$
SYNOPSIS...Binau
NEAR TERM...JGL
SHORT TERM...Binau
LONG TERM...Hickman
AVIATION...JGL