798 
FXUS63 KLMK 111808
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
208 PM EDT Fri Oct 11 2024

.KEY MESSAGES...

*  Dry weather and seasonable temperatures through the weekend.

*  Turning cooler Monday into next week, with frost possible, 
   especially Tuesday night.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 319 AM EDT Fri Oct 11 2024

Synopsis...Presence of ridge building aloft and surface high 
pressure transitioning from Upper Ohio Valley to the Appalachians 
will keep the dry and sunny conditions across the region.   

Today...Current KY Mesonet observations show a well-defined 
dewpoint gradient associate with the diffuse front that came in 
yesterday. Lower dewpoints along with optimal radiational cooling 
conditions will favor cooler temperatures east of I-65 with some 
readings falling to the upper 30s in the Bluegrass river valleys. 
Also, satellite imagery reveal some patchy fog across the Ohio, 
Kentucky, and Cumberland river basins. Overall, winds will remain 
light and variable as high pressure center moves closer, although 
periods of southerly flow could be possible in the afternoon 
allowing subtle warm air advection. Last but not least, forecast 
soundings indicate the potential for some dry-air mixdown, so 
reduced dewpoints throughout the day to indicate this possibility.  

Tonight...Clear skies and dry airmass will support a large diurnal 
curve; however, surface high pressure in the southern Appalachians 
and low pressure wave over the Mid Mississippi will account for more 
established southerly winds through the forecast area. Therefore, 
lows will be a few degrees higher compared to Thursday night.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 319 AM EDT Fri Oct 11 2024

Low-amplitude upper ridging will persist for most of the weekend, 
and with low-level return flow finally developing, temps will push 
solidly above seasonal normals, especially for daytime highs. Look 
for Saturday to run just either side of 80, with Sunday in the lower 
to mid 80s. Dry air mixdown is in play either day, and could keep 
dewpoints in the upper 40s on Sat afternoon, but winds will remain 
light.   

By Sunday a northern stream upper wave will deepen as it digs into 
the Great Lakes, pushing a cold front toward the Ohio Valley. 
However, deep moisture is in short supply, so would not expect the 
front to light up until it moves into the higher terrain of eastern 
Kentucky. Still carrying a slight chance for showers in the 
Bluegrass region, but even that may be generous and what does fall 
will not amount to much. 

Broad eastern CONUS trof develops on Monday and will hang on for 
most of the week.  Strong cold advection on Monday as sfc high 
pressure builds down the Plains, with some bust potential in the 
temp forecast. Current forecast is in the lower/mid 60s with partly 
cloudy skies and a strong NW breeze, but the cyclonic pattern could 
make it difficult for some to get out of the 50s. Another 
disturbance dropping out of the Upper Midwest to reinforce the cold 
air mass limits confidence, and will also keep temps from tanking on 
Monday night. A few spots will likely drop into the 30s, but frost 
will be limited by clouds and mixing.  

Tuesday and Tuesday night are the coldest period with the low-level 
thermal trof overhead. Highs Tuesday will struggle to crack 60, and 
we could have widespread frost with some pockets of freezing temps 
on Wednesday morning. 

For the latter half of the week, temps will start to gradually 
recover as progressive upper ridging moves across the area Thursday. 
Temps remain below normal for mid-October, and still no rain in 
sight for the Ohio Valley.

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 207 PM EDT Fri Oct 11 2024

VFR conditions expected through this forecast period. Sfc high 
pressure continues to sink slowly south of the region. Light S or SW 
winds are expected through tonight, generally 5 kt or less. 
Tomorrow, sfc high pressure moves further south as a cold front 
advances southeast through the Midwest and central Plains. 
Southwesterly winds will increase to 5-10 kts Sat afternoon due to 
the tightening pressure gradient. We'll also see a band of non-
impactful high clouds spread southeast over the TAF sites from mid 
to late morning through the afternoon hours.

&&

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

&&

$$

SHORT TERM...ALL
LONG TERM...RAS
AVIATION...EBW