LMK issues Area Forecast Discussion (AFD) at Nov 27, 9:49 PM EST815
FXUS63 KLMK 280249
AFDLMK
Area Forecast Discussion
National Weather Service Louisville KY
949 PM EST Wed Nov 27 2024
.KEY MESSAGES...
* Rain arrives late this afternoon, continuing through the
nighttime hours into Thursday morning. Rainfall amounts between
0.25-0.50" possible.
* A cool and dreary Thanksgiving Day is expected, with patchy
drizzle early in the day.
* Unseasonably cold temperatures are likely this weekend into the
first few days of December. There is a chance for minor snow
accumulations Saturday night.
&&
.UPDATE...
Issued at 949 PM EST Wed Nov 27 2024
Light precipitation, mostly in the form of rain, will continue to
move through the region overnight ahead of a 500mb shortwave trough
sweeping across the middle and upper Mississippi Valley. Banding has
been evident in radar imagery across central and southern Indiana
this evening, and this will continue to be the case overnight as the
precipitation shield swings through southern Indiana and north
central Kentucky. The greatest rainfall amounts are still expected
along and north of I-64, on the order of a third to a half inch.
Model soundings show plenty of moisture above the -4C height and
into the DGZ with a nearly isothermal layer around -1C to -2C down
to around 1-2k' above the surface late tonight. So, some wet
snowflakes may mix in with the rain in parts of southern Indiana and
far north central Kentucky. A heavier band may be able to produce
some slightly stronger snow/rain rates, but with near-surface T/Td
and surface temperatures above freezing and a wet ground, any snow
accumulation would be little more than a dusting on rooftops and
grassy areas, and wouldn't last long. Impacts would be few if any,
especially considering the most likely timing for any frozen
precipitation would be from 3am to 6am.
&&
.SHORT TERM /THROUGH THURSDAY/...
Issued at 224 PM EST Wed Nov 27 2024
Conditions are mostly cloudy early this afternoon, and we are
starting to see a few sprinkles reach the ground in some spots. The
day has been mainly dry up to this point, with recent SDF ACARS
soundings still showing a notable dry layer below 800 mb.
Temperatures have risen into the mid 40s to lower 50s, and readings
should rise just a touch higher through mid-afternoon.
A mid-level shortwave trough currently over Colorado is forecast to
swing east, reaching the Ohio Valley by 12Z tomorrow. Just ahead of
this wave, sfc low pressure currently over Oklahoma is forecast to
track ENE across Arkansas, Tennessee, and southeastern Kentucky this
evening and overnight. An inverted sfc trough will extend NE from
the sfc low into central KY this evening as strengthening
southwesterly 925-850 mb flow advects low-level moisture across the
boundary. Light rain will gradually increase in coverage late this
afternoon and evening as the lower levels saturate. Meanwhile, hi-
res guidance continues to point to a somewhat heavier mid-level
frontogenetical precip band setting up to our northwest across
portions of central IL/IN. Later tonight, this band will pivot
southeast over portions of southern IN and northern KY. This will
help boost the rainfall totals north of I-64.
The bulk of the rainfall with this wave is expected 00-12Z Thu.
However, steadier light rain will gradually wind down from west to
east between 06-12Z Thu. Lingering low-level moisture may be just
deep enough to produce some patchy drizzle a couple hours past
sunrise. Brief drizzle looks possible near and east of I-65 between
7-10 AM on Thanksgiving. After that, however, Thanksgiving Day will
be mainly dry and chilly. Total rainfall amounts through tomorrow
morning will likely be in the 0.25-0.50 inch range in most areas,
though the SW CWA near Bowling Green could see a bit less than a
quarter-inch.
As for temperatures, readings will dip into the 35-40 degree range
tomorrow morning. There is a slight chance (10-20%) for a very brief
changeover to light snow near (and mainly north of) the Scottsburg
and Madison areas in Indiana during the pre-dawn hours. But then we
lose deep saturation through the DGZ fairly quickly, and only brief
drizzle would then be possible around daybreak. Sfc temps will
remain above freezing.
Sfc winds increase to 10-15 mph out of the NW tomorrow morning
behind the departing sfc low. While much of the day looks dry,
Thanksgiving will be cloudy, gloomy, and chilly. Clouds and NW flow
CAA will really limit sfc warming. Afternoon highs will be limited
to the low to mid 40s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 224 PM EST Wed Nov 27 2024
Thursday Night - Saturday Morning...
We'll be in a post-frontal cold advection pattern with surface high
pressure steadily building into the region late week into the
weekend. Temperatures fall off pretty dramatically Thursday night
with lows dropping into the 20s to right around 30 for lows. There
is still some indication in the data that trapped low level moisture
may hang around into Thursday night, and if so, may still have to
carry some lingering drizzle or flurry mention (once it gets cold
enough). Drier air will be advecting in with high pressure becoming
more established, so any overnight lingering precip will likely end
before sunrise Friday.
Do expect to see plenty of sunshine on Friday as high pressure
becomes more established, however temps are only expected to climb
into the mid and upper 30s for most, possibly around 40 for our
southern counties. In addition, look for wind chills to mostly be in
the 20s through the day as a steady, to occasionally gusty, west
wind will be around. The cold really sets in for the weekend as
better radiational cooling conditions on Friday night allow for lows
in the teens and low 20s. The first part of Saturday starts off dry,
however we'll be looking upstream to an approaching clipper system
for our next weather maker.
Later Saturday - Saturday Night...
A weak clipper looks to quickly scoot through the region later
Saturday into Saturday night. This system doesn't appear to have a
whole lot of moisture with it, however it will have several
favorable factors for snow accumulations. First off, we'll have the
cold air in place with highs only in the 30s for most on Saturday
afternoon. By the time the dry low levels are overcome later
Saturday into Saturday night, we'll wet bulb down to a thermal
column supportive of all snow. We'll also see some healthy snow to
liquid ratios in the 12 to 15:1 range given the cold column. We might
even near 18:1 later in the event across our north, especially if
the event is deeper into the overnight hours. As a result, we should
be able to take advantage of what little moisture resides with this
system. Right now, amounts still look to be less than an inch, but
will monitor this system over the coming forecasts. Lows by Sunday
morning look to get down into the teens and low 20s once again.
Sunday - Wednesday...
Cold weather continues late weekend into early next week as a
reinforcing shot of cold air comes in behind the departing clipper.
We'll see dry NW flow and surface high pressure take over which
should result in mostly dry stretch, although a few passing
shortwaves could bring some light precip events at times. Not enough
confidence in timing/moisture depth for these features at that
range, but will monitor for the need for a couple instances of light
precip early week across our NE CWA. Otherwise, this should be a
mostly dry stretch, although we'll continue with the theme of highs
in the 30s and lows in the teens and 20s through Tuesday. We'll
start to see some moderation by Wednesday, along with some small
chances for precipitation as a passing frontal boundary scoots
through.
&&
.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 636 PM EST Wed Nov 27 2024
Starting to see lowering mid-level ceilings as the low pressure
system moves across the region. Ceilings will continue to fall to
MVFR/IFR in the first half of the overnight period. Light rain will
continue, with MVFR and brief IFR Vis possible in steady rain. Rain
will gradually wind down in the early morning, from west to east.
Ceilings will gradually improve back into the MVFR in the morning
over the western sites and early afternoon over the eastern
terminals. Winds will begin to back to a northwesterly direction by
day break.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...13
SHORT TERM...EBW
LONG TERM...BJS
AVIATION...SRM
Source:
LMK issues Area Forecast Discussion (AFD) at Nov 27, 9:49 PM EST---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
