Louisville, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

784
FXUS63 KLMK 241119
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
619 AM EST Sun Nov 24 2024

...Updated Aviation Discussion...

.KEY MESSAGES...

*  Patchy areas of fog will be possible this morning in low-lying
   and fog prone areas.

*  Rain showers are likely Monday with a cold frontal passage.

*  Another round of rain arrives later in the day on Wednesday.

*  Undesirable weather for Thanksgiving Day, with cold rain, and
   brisk northwest winds of 10-15 mph with gusts to 20-25 mph.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 328 AM EST Sun Nov 24 2024

Morning satellite imagery shows earlier low stratus continuing to
mix out across the region.  In its place, high level cirrus is
streaming into the region from the west/northwest.  Nighttime fog
imagery shows river valley fog in progress across the region.
Current data and indications suggest that the high clouds will keep
the fog from becoming more widespread.  However, some locally dense
areas of fog will be possible in the deeper valleys and typical fog
prone areas.  Temperatures across the region were in the upper 20s
to the lower 30s.  The exception was over the northeast Bluegrass
where the stratus has been slow to clear and temps were in the lower
40s.  Some localized areas of freezing fog will be possible across
central KY this morning, but no impacts are expected.  Overnight
lows will bottom out in the upper 20s to the lower 30s..

For today, look for fog to quickly mix out after sunrise.  We`ll see
wind shift from the southeast early in the day to a southwest regime
with increasing warm advection.  Partly to mostly sunny skies are
expected with highs ranging from the mid-upper 50s over the
Bluegrass to the upper 50s and lower 60s along and west of I-65.
Winds will pick up through the day as the pressure gradient
increases.  Look for winds of 5-10 mph this morning increasing to 10-
15 mph this afternoon with gusts of 20-25 mph at times.

Tonight, cloud cover will gradually increase as the next low
pressure system moves through the Plains and Midwest pushing a cold
front toward the region.  A southwest flow at the surface and aloft
will continue to provide warm advection across the region and will
keep temps from falling off too much.  For areas west of I-65, lows
will be in the upper 40s to near 50.  East of I-65 mid-upper 40s are
expected.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 328 AM EST Sun Nov 24 2024

===== Monday - Tuesday =====

It`ll be a very mild Monday morning, as we will be located in the
pre-frontal WAA airmass with increasing southwesterly flow and
underneath a deep warm cloud layer. An upper level shortwave, and
associated mid-level low, will be centered over the Manitoba/North
Dakota border, with upper ridging departing to our east. The
correlated sfc low will be near Chicago Monday morning, with the
trailing cold front riding down the I-55 corridor to St. Louis, and
extending through the rest of Missouri and into Oklahoma. Ahead of
the sfc front, the warm front will be located across southern
Michigan, so the entire Ohio Valley will be in the warm sector with
ample WAA. As a result, temps will be well above normal for this
time of year, with highs potentially reaching the lower 60s. We`re
not looking at any record-breaking temps, but at least 10 degrees
above normal is likely.

We`ll start off with an isolated rain chance Monday morning, but as
we get into slightly more favorable moisture transport, we should
have PWAT values briefly peak around 1.10". This would be around the
90th percentile for BNA 12z sounding climatology for Nov 25. Rain
chances will be the greatest right along the frontal boundary, which
will be during the afternoon and evening hours. Numerous to
widespread light to moderate showers will be possible during this
time. By Monday night, we`ll begin to see rain chances taper off
from west to east as the front slides east and drier air filters in.
Rainfall amounts with this event will not amount to much, with most
of the region expected to receive less than a quarter of an inch of
rain.

Clouds will linger Monday night and into Tuesday as the trough axis
lags behind the front. However, we should see at least partial
clearing in our western half of the forecast area as high pressure
builds to our west, resulting in slightly cooler morning low temps
west of I-65 from better radiational cooling. Light northwest flow
will allow for CAA on Tuesday, so temps will be much cooler than
Monday. Afternoon highs will peak in the upper 40s, but with
clearing skycover, can`t rule out seeing some spots hit 50. Tuesday
will be dry with the sfc high moving across the region by the
afternoon and evening.


===== Wednesday - Friday =====

Confidence is unfortunately slightly lower for the Thanksgiving time
frame, which is driven by a wide spread in guidance solutions and
timing for this period of the forecast. With that said though, we
are looking at another wave passing through, which will bring less
desirable weather to the area for the holiday.

We will start off with dry conditions for Wednesday, with the sfc
high sliding to our east, and zonal upper flow with a speed max
north of our area. However, we will be watching an upper shortwave
eject out of the Rockies and across the central US. Rain chances
will increase across our area by the afternoon hours as WAA and
isentropic lifting provides vertical ascent. However, model
soundings do show rather dry air below 700mb for the afternoon, so
onset of precip may end up being later than currently forecast. We
could see quite the temperature range that afternoon, with mid to
upper 40s for southern Indiana, to mid and upper 50s for the south-
central KY and Lake Cumberland regions.

Rain chances and coverage increase for Wednesday night and into
Thanksgiving morning as the shortwave pivots over the Ozarks and
associated vort max stretches across the TN Valley. While forcing
will be better than the Monday event, difference on the placement of
the LLJ and moisture transport axis is resulting in lower confidence
on precip coverage and QPF amounts. PoPs will begin to slowly
decrease by Thanksgiving evening as the system pulls away to the
ENE. Cold air wrapping around the backside of the system could pose
the chance for some brief changeover to light snow for Thursday
night. However, the better chance for accumulating snow is certainly
to our north across central IL/IN/OH.

Thanksgiving is looking to be a raw and nasty day, with temps
remaining in the 40s, cold rain, and brisk sfc winds. Sfc winds with
this system will make our apparent temperatures feel like we will be
in the 30s. Sfc winds will be from the northwest, with sustained
winds up to 10-15 mph, and gusts peaking in the 20-25 mph range.

Temperatures are then forecast to drop to near or below freezing by
Friday morning, and won`t budge much during the daylight hours.
Conditions may trend drier for Friday, but expect a chilly day with
highs in the mid to upper 30s. Some cold nights will then be
possible next weekend, with lows in the 20s.

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
Issued at 618 AM EST Sun Nov 24 2024

Morning satellite imagery shows high level cirrus moving through the
region this morning.  Some patchy ground fog will be possible very
early in the period, but will mix out by sunrise.  Look for surface
winds to start out of the southeast this morning at 3-5 knots. Winds
are forecast to shift to the southwest by mid-late morning and
continue through the afternoon.  Winds are forecast to back to the
southeast after sunset with VFR conditions expected overnight and
into Monday.

&&

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

&&

$$

SHORT TERM...MJ
LONG TERM....CJP
AVIATION.....MJ