070 
FXUS63 KLMK 200714
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
314 AM EDT Wed May 20 2020

.Short Term...(Today and tonight)
Issued at 314 AM EDT Wed May 20 2020

Stacked low pressure is centered over the TN Valley this morning, 
and deep/moist easterly flow continues over KY on the north side of 
the cyclone. SE 40 kt LLJ over eastern KY and WV is nosing into the 
I-75 corridor early this morning, fueling scattered light to 
moderate showers. Rainfall totals since midnight have been around a 
tenth of an inch or less with this activity so far. 

The current batch of scattered light rain will continue drifting 
northwest, mainly across the eastern portions of the forecast area 
through 12z. A lull in precip coverage is then likely during the mid 
to late morning hours as forcing diminishes. Diurnal heating this 
afternoon should be enough to help spark additional isolated to 
scattered showers over central KY, with SCT coverage south of a line 
from Frankfort to Bowling Green. Weak instability may support a few 
lightning strikes near and south of the Cumberland Pkwy in southern 
KY. Highs will likely stay in the low 60s in the Bluegrass Region 
today, with mid and upper 60s common further west. Areas south of 
the WK Pkwy near I-65 could hit 70. 

Tonight, the closed low moves northwest toward the KY/TN border, and 
the LLJ does intensify once again over Huntington, WV. Another batch 
of light showers looks likely, moving NW through eastern, east-
central, and northern KY. Basin average rainfall amounts over the 24 
hour period ending 12z Thu are expected to range from 0.10-0.30 
inches through the I-75 corridor. Given the scattered, light nature 
of the precip, will go ahead and cancel the Flash Flood Watch this 
morning. Lows tonight will drop into the low to mid 50s.

&&

.Long Term...(Thursday through Tuesday)
Issued at 250 AM EDT Wed May 20 2020

Thursday - Friday Night...

The closed upper low will wobble back northward over our CWA to end 
the work week, continuing to bring heavy cloud cover, scattered 
shower and storm chances, and below normal temperatures Thursday 
moderating by Friday. As mentioned in the previous discussion, pops 
should mainly follow a diurnal peak/valley as lapse rates steepen 
each afternoon. Models show pretty good agreement that the low will 
center along and west of the I-65 corridor as it works northward, 
which puts the best moisture feed to the east over our eastern CWA. 
Will continue highest coverage there, which is where we don't need 
any additional rainfall!

Look for highs in the upper 60s and low 70s Thursday, with lows 
Thursday night in the mid to upper 50s. As the upper low begins to 
exit the area Friday, we'll have a chance to get some more heating 
with highs back toward normal in the mid to upper 70s. Milder 
overnight lows follow Friday night in the upper 50s and low 60s.

Saturday - Tuesday...

The holiday weekend looks to feature a building upper ridge which 
will likely center just to our east over the mid Atlantic states. 
Meanwhile, central CONUS troughing looks to take hold. This upper 
pattern will allow for warmer temps with highs back in the 80s each 
day, and milder lows in the 60s. The pattern will allow for Gulf 
moisture to work between the two upper features into our area, which 
will help instability values and overall shower and storm chances 
each day. Looks to be a mainly diurnal type of setup at this point, 
so will continue to maximize pops each afternoon/evening. Repeated 
showers and storms each day may continue to agitate ongoing wet 
conditions, so may have to monitor isolated flood/flash flood 
potential into and through the weekend.

&&

.Aviation...(06Z TAF Issuance)
Issued at 155 AM EDT Wed May 20 2020

Stacked low pressure is slowly drifting southeast early this morning 
over the Tennessee Valley. Deep, moist easterly flow continues to 
advect moisture into the region. The primary concerns this TAF 
period are widespread MVFR ceilings and breezy easterly winds. 
Scattered light showers will also be possible through the period, 
especially at LEX. 

Ceilings are flirting with the IFR threshold currently at SDF and 
HNB. A band of low level moisture drifting westward looks to bring 1-
2 hours of IFR, with ceilings then likely lifting back to Fuel 
Alternate. Fuel alternate looks likely through the morning hours, 
with a brief improvement this afternoon. Breezy ENE winds are 
forecast today, with gusts 19-25 kts possible. Strongest gusts are 
expected at SDF and LEX, with slightly lighter winds further south 
and west.


&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...Flash Flood Watch until 8 AM EDT this morning for KYZ036-037-
     041>043-049-057.

&&

$$

Short Term...EBW
Long Term...BJS
Aviation...EBW