Area Forecast Discussion
Issued by NWS Louisville, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KLMK 281914
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
314 PM EDT Thu Mar 28 2024

.KEY MESSAGES...

* Moderating temperatures for the remainder of the week and into the
  weekend.

* Stormy pattern setting up for late Sunday through Tuesday night.
  Most likely timing for strong/severe storms would be in the Monday-
  Tuesday time frame.  Confidence in storm evolution and timing
  remains lower than average.

* Colder weather arrives by Wednesday with the potential for some
  wintry weather across portions of the area.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 313 PM EDT Thu Mar 28 2024

High pressure over the region is leading to light winds, clear
skies, and dry conditions. Temperatures will peak in the upper 50s
this afternoon. In the overnight hours, high pressure will slowly
move off to the southeast of the region and southwesterly flow will
return to the Ohio Valley. At the same time, a weak shortwave will
move through central Indiana and southern Ohio bringing some
scattered clouds into southern Indiana and northern Kentucky.

On Friday, ridging will move over the region further enforcing dry
conditions and clear skies. Atmospheric mixing will build to 6-7kft
over the region in the afternoon leading to minimum relative
humidity in the 20-25% range and wind gusts up to 25mph.
Southwesterly flow and warm air advection will bring high
temperatures into the upper 60s and low 70s. Friday looks to be a
pleasant spring day to end the work week.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 313 PM EDT Thu Mar 28 2024

Friday Night through Sunday Night...

Low amplitude upper level trough axis is forecast to push into the
northern Ohio Valley and southern Great Lakes late Friday night and
into Saturday.  This feature may bring some showers to the region
late Friday night and Saturday morning.  Current model trends
continue to be a little drier for Saturday afternoon, but a surface
frontal boundary will sink into the region and may become a foci for
convective development Saturday evening into early Sunday morning.
Lows Saturday morning will be in the upper 40s/lower 50s with highs
Saturday warming into the lower-mid 70s.  Lows Saturday night will be
a bit warmer as we get into a southwest flow pattern.  Lows will be
in the mid-upper 50s.

For Sunday, surface frontal boundary is expected bisecting the
forecast area in the morning but lifting northward during the
afternoon.  With that front in the area, skies are likely to be
cloudy in the morning with perhaps a little clearing taking place in
the afternoon.  While the bulk of the expected precipitation will be
along and north of the retreating warm front, our area will become
solidly in the warm sector in the afternoon with temperatures
warming into the mid-upper 70s.  Depending on the amount of
clearing, model soundings show rather steep low-level lapse rates
with bulk shear values increasing through the day.  Synoptically, not
seeing any real areas of strong forcing for convection and model
soundings do show a decent temperature inversion setting up above
850 hPa which may effectively cap convective development.  Current
NBM PoPs for Sunday look a bit high and considering the 12Z Euro
trending drier, I think the later runs of the NBM will come down on
PoPs.  For now, slight chance PoPs seem warranted with the
retreating front, but the overall trend in the modeling suggest a
drier Sunday.  NBM PoPs continue to look too high for Sunday night
as the frontal boundary looks to set up along the I-70 corridor
across central IL/IN/OH and that might be where some convective
clusters move along the boundary.  Again, with later runs of the
NBM, we`ll probably continue to see a downward trend in PoPs here.
Lows will remain quite warm in the broad southwest flow.  Lows will
likely only drop into the upper 50s to the lower 60s.

Monday through Tuesday Night...

As we move into the new work week, the pattern looks to become more
active across the region.  On Monday, we look to start off dry in
the morning as we`ll be solidly in the warm sector again.  Not sure
how clean the warm sector will be, but I`d imagine we`ll have some
clouds around during the day.  Highs look to warm into mid-upper 70s
again.  During the afternoon, we should see instability redevelop
with the possibility of some isolated-scattered convection developing
in the afternoon.  Again, we`re not seeing any real areas of strong
forcing locally, but most of the forcing will be out across AR/MO
where an outbreak of severe weather looks likely.  Model soundings
across our area again show a temperature inversion above 850 hPa
which may supress convective development to some extent.

A higher chance of showers and storms is likely to impact the region
late Monday night and into Tuesday morning as a cold frontal
boundary pushes in from the west.  We`re still seeing some temporal
differences between the GFS and Euro here with the frontal timing.
The GFS is a little slower bringing the front through during the
afternoon within the realm of peak heating.  Given the thermodynamic
and kinematic profiles from the GFS, plenty of instability and shear
will be available for severe convection with all hazards in play. On
the other hand, the Euro is a bit faster bringing the front into the
region early Tuesday morning.  The Euro then suggests that
convective redevelopment would be more focused east of I-65 Tuesday
afternoon.  Euro sounding profiles here show plenty of CAPE/Shear
for organized severe weather with all hazards on the table
(primarily east of I-65).

In terms of confidence here, experimental signal analysis has been
targeting a signal passage in the Mon/Tue time frame since early
March.  Current machine learning output from CSU, CIPS analogs, and
SPC Chiclets support the idea of strong/severe weather in the late
Monday/Tuesday period. So the overall confidence in impactful
weather in the Monday night-Tuesday time frame is relatively high.
However, the timing of the frontal boundary through the region along
with the unknown evolution of the mesoscale features at this time
range results in a lower confidence on the severity of the
convection.  We`ll continue to closely monitor forecast trends over
the weekend.  Stay tuned.

Wednesday through Thursday...

After the front passes through sometime on Tuesday, a much colder
pattern will infiltrate the region on Wednesday.  Strong cold
advection within the mid-upper levels will result in steep lapse
rates across the region promoting light precipitation.  The depth of
the cold air may result in some wintry mixed precipitation across
the region on Wednesday and into Wednesday night.  A cool northwest
flow is likely on Thursday with skies slowly clearing through the
day.  Highs Wednesday look too warm in the NBM as it suggest highs
in the low-mid 50s.  It may end up being more in the upper 40s across
much of the region with lows Thursday morning dropping into the mid
30s. Highs Thursday look to warm back into the upper 50s to near 60.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 313 PM EDT Thu Mar 28 2024

VFR conditions will continue during this TAF period. High pressure
over the region is leading to mostly light and variable winds this
afternoon. In the overnight hours, high pressure will shift to the
southeast of the region and allow southwesterly flow to return to
the region. A weak shortwave trough will move through central
Indiana and Ohio, extending a marginal LLJ into southern Indiana
and northern Kentucky. This LLJ could lead to low-end LLWS over SDF
and LEX from 7-11Z. Confidence is low in this occurring, therefore
it has been left out of the TAFs at this time.

&&

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

&&

$$

SHORT TERM...SRM
LONG TERM...MJ
AVIATION...SRM


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.