000
FXUS63 KLMK 230021
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
821 PM EDT Mon Apr 22 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*   Showers Tuesday night with rainfall around a quarter inch.

*   Lows in the 30s Wednesday night from southern Indiana into the
    northern Bluegrass region, and typical cold spots.

*   Warmer and more active weather late Friday through the weekend,
    but plenty of uncertainty in timing of any intervals of showers
    and thunderstorms.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 320 PM EDT Mon Apr 22 2024

Sfc high pressure currently centered over the Lower Mississippi
Valley will slowly work eastward tonight and be off the southeast US
coast tomorrow. This will continue to keep weather quiet and dry.
Upper Pacific moisture associated with the system working across
southern Canada just north of the US border will increase high
clouds over the region along with warm air advection (WAA) ahead of
an approaching cold front associate with the system. While
temperatures will be cool overnight falling into the low/mid 40s (a
few locations could drop into the upper 30s) it won`t be as cold as
this morning so frost is not a concern.

As the sfc low works across the Great Lakes during the day tomorrow,
it will work the associated cold front southward across IL and IN
during the day. Pressure gradient will tighten over the Ohio Valley
allowing for winds to increase out of the southwest with gusts of 20
to 25 mph towards the afternoon. The bulk of the day will be dry and
with increased WAA, even with high clouds, temperatures are likely
to warm to near 70. With Td in the low 40s/upper 30s we will have
dry low levels. While we have precipitation chances increasing late
afternoon/early evening across southern IN, the dry air may cause
the shower activity to hold off until tomorrow night.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 320 PM EDT Mon Apr 22 2024

Still on track for a rainy Tuesday night as a progressive upper trof
moves through the Great Lakes, driving a cold front through the Ohio
Valley. Instability is nil and moisture supply isn`t great, so
expect a few hrs of showery light to moderate rain and little or no
chance of thunder. QPF will be around a quarter inch along and north
of the I-64 corridor, tapering down to a tenth or less across south
central Kentucky.

Dry and seasonably cool wx is expected Wed-Thu with sfc high
pressure over the Great Lakes and NW flow aloft. Wed night could see
some of our traditional cold spots, especially in the northern
Bluegrass region, drop into the 30s, and therefore bears watch for
frost potential.

Upper pattern shifts toward the end of the week trofiness digging
into the West and the Plains, and an amplifying ridge along the East
Coast. Overall trend will be toward warmer than normal temps as S-SW
flow deepens, but how much more active the pattern becomes will
depend on the trajectory of disturbances kicking out of the trof out
west. At this point, would expect intervals of rain chances, but the
timing is too uncertain to do more than a broadbrush 30-40% POP for
most of the weekend and into Monday. The more favorable spot for
severe wx still looks to be across the Plains, but we`ll need to
keep an eye on any eastward expansion of that threat. Temps this
weekend will be solidly above normal in the southerly flow,
especially at night when clouds, higher dewpoints, and a mixy
boundary-layer could keep us in the 60s, with 80 being in easy reach
in the afternoon.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 821 PM EDT Mon Apr 22 2024

VFR overnight with light southerly winds and SCT thin cirrus.
Southwesterly winds will increase shortly after sunrise Tuesday,
becoming gusty after 14z. Gusts of 25+ kts are expected during the
afternoon hours, before cloud cover thickens in the evening.

Clouds will thicken and lower after 21z Tue, first over southern IN
and northern KY, as a Great Lakes low pressure system drags a cold
front into the area. Expect light rain in the SDF planning period
with ceilings dipping below 5 kft.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...RAS
AVIATION...EBW