197 
FXUS63 KLMK 091746
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
146 PM EDT Tue Oct 9 2018

.Short Term...(This evening through Wednesday)
Issued at 310 AM EDT Tue Oct 9 2018

Ridging over the eastern coast will continue to influence southern 
Indiana and central KY on Tuesday with temperatures much warmer than 
the climatological average for this time of year. A low level jet 
set up overnight will give way to gusty winds at times beginning 
late morning into early afternoon (15-20mph). Expect a dry day 
Tuesday with highs in the mid to upper 80s. 

The ridge will slowly recede from the region as a shortwave trough 
approaches from the west. Tightening gradient will allow for a 
strong low level jet to develop Tuesday night into Wednesday 
morning. Weather associated with the surface cold front should begin 
to make an appearance in southern KY as isolated showers early 
Wednesday morning. Low temps expected to range from mid to high 60s.

&&

.Long Term...(Wednesday night through Tuesday)
Issued at 306 AM EDT Tue Oct 9 2018

Wednesday will dawn with deepening low pressure over Iowa and its 
cold front dropping south to the Sabine River. By evening the low 
will lift into Wisconsin while the cold front swings into the lower 
Mississippi Valley. GEFS plumes, operational GFS, and SPC SREF 
suggest 500-1000 J/kg of CAPE in the lower Ohio Valley Wednesday 
afternoon/evening with enough shear to support thunder. Mid-level 
lapse rates look weak and stronger dynamics will remain off to our 
northwest and north, but there may be a short window of opportunity 
for a stronger storm or two Wednesday evening west of I-65 and north 
of the Natcher Parkway. FROPA will then take place Wednesday night 
accompanied by widespread showers and possibly some embedded 
thunder. Lingering showers will exit central Kentucky Thursday 
morning as the front continues to push to the east.

Canadian high pressure will then build in and cross the region 
Friday-Saturday. The center of the high will be just about overhead 
at 12Z Saturday. Went a bit below guidance for minimum temperatures 
Saturday morning, with the usual cold spots dipping briefly into the 
upper 30s.

Sunday-Monday we'll be in return flow behind the departing high and 
ahead of an upper trough advancing from the mid-Mississippi Valley 
to the Great Lakes, possibly along with far-removed remnants of 
Pacific Hurricane Sergio moving up the Ohio Valley. A complicated 
set-up, especially for so far out in the forecast period, but the 
bottom line is relatively high PoPs for Days 6-7.

&&

.Aviation...(18Z TAF Issuance)
Issued at 145 PM EDT Tue Oct 9 2018

Active weather is in the tail end of this forecast issuance as 
moisture and low clouds stream into the area overnight in advance of 
a cold front set to cross the region after 11/0000Z.  

Gusty surface winds to around 20kts this afternoon will drop off as 
thermal decoupling sets in by 23Z. The nose of an ill-defined low 
level jet is progged to move north through KY between 08-12Z, but 
with mesoscale model inconsistencies, have only introduced LLWS to 
KBWG, where there is more agreement on the strength of this feature.

Surface dew points currently in the 60s will linger overnight before 
returning back into the 70s prior to the FROPA occurring beyond this 
forecast period. This will help lower CIGs toward the end of the TAF 
period, at least in and near showers that are expected to move 
through primarily after 12Z.  While BR is not anticipated, VSBYs in 
any SHRA will likely drop to MVFR, and potentially IFR at KSDF in 
the planning period beyond 18Z.

&&

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

$$

Short Term...CG
Long Term...13
Aviation...JBS