Area Forecast Discussion
Issued by NWS Louisville, KY

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697
FXUS63 KLMK 200049
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
849 PM EDT Thu Sep 19 2024

.KEY MESSAGES...

*  Mainly dry and hot weather through Sunday with highs each day near
   or above 90 degrees. Patchy fog possible in the AM.

&&

.UPDATE...
Issued at 849 PM EDT Thu Sep 19 2024

After afternoon highs in the low 90s, clear skies have allowed
temperatures to cool into the low 80s at this hour. Temperatures
will continue to fall through the overnight, reaching lows in the
low-mid 60s. Some fog is expected to develop in river valley areas
and the southeast portion of our region. Current forecast remains on
track.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 255 PM EDT Thu Sep 19 2024

Hot and quiet weather continues in the short term as strong upper
ridging dominates the pattern. High temperatures this afternoon are
still expected in the upper 80s and low 90s with light and variable
winds and a healthy diurnal cu field.

Look for a mostly clear and quiet overnight with some fog concerns
in spots. River valleys and our SE CWA will be the most likely
candidates for visibility restrictions.

Same upper pattern for Friday with low level thicknesses supportive
of another degree or so rise in temps. Dew points will remain in
check, so not worried about overall heat indices. However, still
pretty hot for this time of year as we get about 10-12 degrees above
normal values.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 255 PM EDT Thu Sep 19 2024

Friday Night - Sunday Night...

Looking for a continued hot and mostly dry weekend as a strong upper
ridge centered near the Rio Grande River Valley extends influence to
the NE over our area. With H85 temps near 20C and plenty of
opportunities for solar insolation, temps look to range in the upper
80s and low 90s each day. As mentioned before, overall heat indices
will be held in check due to dew points mainly in the low and mid
60s.

A very weak and moisture starved frontal boundary extending from a
northern Manitoba surface low will work into our area early Saturday
morning. This feature could bring a stray shower or sprinkle to our
northern CWA, but overall most of the moisture looks to be above 500
mb with drier air in place in the lower levels. Not worth mentioning
any measurable pops at this time for that feature, however if anyone
saw a light shower, it would likely be north of I-64 Sat morning.

By later Sunday, central CONUS troughing will impinge on the upper
ridge into our area, with more moisture possibly able to make it
into our northern CWA. Perhaps some isolated shower or storm chances
reach into our NW CWA by Sunday/Sunday night but confidence isn`t
real high. Not much of a focus for any real coverage, and our
antecedent dry airmass in place lowers confidence even more. Sunday
will be another hot day with highs in the upper 80s and low 90s. A
bit more cloud cover (across northern CWA) than previous days, so
this may keep temps a degree or two cooler than Saturday up there.

Monday - Thursday...

The upper ridge axis slides east through early next week, with
either SW or WSW flow aloft overspreading our area ahead of a
shortwave trough over the north central CONUS. This system seems to
have a decent amount of Pacific moisture with it, along with some
forcing ahead of the upper trough axis. Looks like enough
ingredients to at least warrant some scattered shower/storm coverage
through early to mid week. The front doesn`t make a whole lot of
progress eastward, and could lead to a bit more prolonged period of
at least some chance for rain each day. Right now, Tuesday looks to
carry the best chances, but overall pretty low confidence for the
Monday - Wednesday timeframe. Cooler temperatures do arrive by mid
week with highs back in the low to mid 80s under the upper
troughiness. May have a tropical system coming out of the Gulf to
watch for late week, but confidence very low in whether that would
have any impacts over our area.

&&

.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 702 PM EDT Thu Sep 19 2024

Clear and calm tonight, with some brief fog chances. Have mentioned
some TEMPO fog at BWG in the early morning hours. RGA and LEX could
see some thin fog, however at this time chances are very slim.
Surface winds will take a more consistent SW/WSW component tomorrow.
Still very light around 5 knots or so. FEW-SCT CU around 6kft will
develop in the afternoon.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Air Quality Alert from midnight tonight to midnight EDT Friday
     night for KYZ029>031.
IN...Air Quality Alert from midnight tonight to midnight EDT Friday
     night for INZ077>079-090>092.

&&

$$

UPDATE...SRM
SHORT TERM...BJS
LONG TERM...BJS
AVIATION...SRM