874 
FXUS63 KLMK 192332
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
732 PM EDT Tue Oct 19 2021

...Updated Aviation Discussion...

.Short Term...(This evening through Wednesday)
Issued at 300 PM EDT Tue Oct 19 2021

A shortwave trough aloft within the main jet stream flow will 
provide enough lift to bring some increased high level cloud cover 
this afternoon through this evening before quickly moving eastward 
beyond Kentucky.  Otherwise, upper level ridge builds tonight into 
Wednesday to bring continued dry weather with mainly sunny skies. 
Low temperatures tonight warm slightly with the return of southerly 
flow to near normal into the upper 50s to lower 50s, which is closer 
to normal to slightly above normal for this time of year.  Some 
chances for minor fog again tonight along low lying river/stream 
valleys as mostly clear conditions will allow for good radiational 
cooling and low dew point depressions.

.Long Term...(Wednesday night through Tuesday)
Issued at 345 PM EDT Tue Oct 19 2021

Sfc wave over the Upper Midwest Wednesday night will cross the lower 
Great Lakes on Thursday. Precipitation chances increase out ahead of 
an approaching cold front during the early morning hours on 
Thursday. Went with widely scattered to scattered PoPs for the early 
morning hours across our western/central CWA with increasing chance 
PoPs to the east of I-65 and south of the Parkways during the 
afternoon. There is just a slight chance of embedded thunder in the 
afternoon across southern KY into the Bluegrass given the timing of 
the day and CAPE around 500J/kg. Winds will also be gusty as the 
front moves through with gusts between 20-25mph. Bulk of the 
precipitation exits central KY Thursday evening. 

Weak area of sfc high pressure works in behind the cold front Friday 
and settles in over central KY/southern IN. Colder air advects in 
over the region during the day with winds out of the west-northwest.
Highs will be in the low to mid 60s. There's a slight chance of 
showers across southern IN/north KY in the afternoon as an embedded 
shortwave and 500mb vort max cross the Ohio Valley along the base of 
an upper level trough over the region. 

Saturday remains dry as sfc high pressure remains over the area and 
the upper level trough flattens out and pushes eastward. It will 
remain cool with highs in the mid/upper 60s. 

High pressure will slide off to east-southeast on Sunday bringing a 
return flow that will advect warmer and moist air into the region. 
Quasi-stationary surface boundary will set up from the central US 
across the Ozarks into the Ohio Valley Sunday and Monday. The 
resulting southerly flow from the SE surface high will create weak 
isentropic upglide along this boundary. Increase PoPs with showers 
and a few thunderstorms are possible. Temperatures warm back to near 
70 on Sunday and low 70s on Monday.

&&

.Aviation...(00Z TAF Issuance)
Issued at 720 PM EDT Tue Oct 19 2021

VFR conditions are expected through the valid TAF period, with only 
few-sct cirrus. BWG and HNB could encounter some shallow ground fog 
around daybreak, but at this time not expecting any restrictions to 
vis. South winds dropping off to 5 kt or less as the boundary layer 
decouples this evening, then picking up again to near 10 kt by 
midday Wed.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&

$$

Short Term...MCK
Long Term...BTN
Aviation...RAS