420 
FXUS63 KLMK 181509
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
1109 AM EDT Sun Aug 18 2024

.KEY MESSAGES...

*   Scattered showers and storms today. No severe weather expected. 

*   Dry weather is forecast for most of next week.

&&

.UPDATE...
Issued at 1108 AM EDT Sun Aug 18 2024

Upper low continues to slowly spin eastward over southern Ontario, 
with upper level shortwave energy rotating southeast over the Ohio 
Valley within the parent trough. SCT-BKN stratocumulus has blossomed 
since sunrise as low level moisture lifts into clouds. These clouds 
will continue to gradually lift into the afternoon, but expect skies 
to remain partly to mostly cloudy for much of the day. 

Have lowered PoPs a touch over the next few hours. Showers have been 
slow to develop thus far and will be diurnally-driven. Still 
expecting scattered showers and a few thunderstorms this afternoon, 
when cyclonic flow aloft combines with sufficient moisture and low-
level warming.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 324 AM EDT Sun Aug 18 2024

A subtle upper level disturbance over the Midwest this morning will 
slide southeastward between an upper trough over the Great Lakes/ 
Appalachians and upper ridging over the Plains/Front Range. This 
feature will move into the Ohio Valley this afternoon as convective 
temperatures in the lower 80s are reached and precipitable water 
values increase slightly into the 1.5-1.7" range. Instability will 
be fairly weak, but sufficient for scattered showers and a few 
thunderstorms to bubble up during the afternoon and early evening 
hours. Very weak shear, narrow positive area on sounding progs, and 
chaotic hodographs suggest poorly organized non-severe single cell 
thunderstorms. The main threat (other than lightning) should be sub-
severe wind gusts near the heaviest downpours.

High temperatures today will be tricky given clouds, showers, and 
northwest breezes behind last night's cold front. Will go for highs 
mostly in the lower 80s, though that may be optimistic.

Convection this afternoon and early evening will dissipate with the 
setting of the sun, leading to a mostly dry overnight under partly 
cloudy skies. With a light north breeze ahead of high pressure 
centered over Manitoba and Ontario, temperatures will fall into the 
lower and middle 60s.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 324 AM EDT Sun Aug 18 2024

The work week will begin with the axis of an upper trough centered 
over Appalachia as a huge upper ridge begins working into the Lower 
Ohio Valley. At the surface, high pressure centered over the Midwest 
will direct cold air advection over southern Indiana and central 
Kentucky. Not only will the northerly winds bring cooler air but 
also drier air to the CWA. There is a small chance for early 
lingering rain showers towards eastern Kentucky Monday, but the 
latest data looks pretty dry. Don't believe there will be any 
rainfall in the CWA, only some early morning cloud cover. High 
temperatures will be held to the upper 70s to low 80s on Monday, and 
with the continued northerly surface flow, Tuesday and Wednesday 
appear a couple of degrees cooler than Monday. 

By the end of the work week, the upper ridge won't move much as it 
will be blocked by the embedded low in the upper trough parked over 
New England. The upper ridge will have pushed the surface high to 
near the southern Great Lakes by Wednesday evening, and as this high 
works past the CWA, northerly surface winds will veer towards the 
east, killing cold air advection. Temperatures will begin warming to 
the low to mid 80s on Thursday before the upper 80s return on 
Friday. Then, as the high makes it closer to the coast, light warm 
air advection will help the low 90s return for the weekend. Skies 
will remain mostly sunny all week after the early cloud cover on 
Monday. Dew points for most of the week will remain in the 50s to 
low 60s.

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
Issued at 645 AM EDT Sun Aug 18 2024

Sub-VFR clouds are present from central Indiana to central Ohio, 
some of which are IFR. At this time it appears that some of those 
clouds will push south into southern Indiana and central Kentucky 
during the first half of the morning, but model guidance suggests 
ceilings will prevail MVFR. 

This afternoon showers and thunderstorms will develop, dissipating 
as the sun sets this evening. Severe storms are not expected, and 
conditions outside thunderstorms will be VFR.

&&

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

&&

$$

UPDATE...EBW
SHORT TERM...13
LONG TERM...KDW
AVIATION...13