LMK issues Area Forecast Discussion (AFD) at Dec 2, 7:00 PM EST015
FXUS63 KLMK 030000
AFDLMK
Area Forecast Discussion
National Weather Service Louisville KY
700 PM EST Mon Dec 2 2024
.KEY MESSAGES...
* Scattered light snow and flurries are possible this afternoon and
evening. Snow accumulations of a dusting to half an inch are
possible.
* Windy conditions expected Wednesday with gusts of 35-40 mph
possible.
* Cold wind chills in the teens Thursday.
* Light winds but cold temperatures Thursday night, with the
traditional cold spots dropping into the single digits.
&&
.UPDATE...
Issued at 700 PM EST Mon Dec 2 2024
Returns on radar have decreased over the past hour. Area
observations continue to report light snow with some reduced
visibilities, but heavier snow showers continue to move SE out of
our CWA. Have let the earlier SPS, addressing snow and visibility
issues, expire. KY Mesonet shows temperatures across the region well
below freezing, now in the mid 20s. Have gone ahead and issued
another SPS focusing on slick roadways, valid until 0500Z.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 254 PM EST Mon Dec 2 2024
A mid-level shortwave disturbance which can be seen on water vapor
imagery over central Illinois at this time will move from NW to SE
across the Ohio Valley and into the southern Appalachians this
afternoon and evening. Immediately ahead of this shortwave,
differential vorticity advection is promoting broad lift across the
region, which when combined with modest amounts of moisture, has led
to the development of areas of mostly light snow. While light radar
returns extend as far east as the I-75 corridor at this time, the
low levels of the atmosphere remain quite dry across much of the
area, with sfc dewpoint depressions of 15-20 degrees along and east
of I-65. However, across SW IN and western KY, moisture has begun to
approach the sfc, with dewpoint depressions generally less than 10
degrees. Traffic and Mesonet cameras as well as ASOS/AWOS obs show
flurries and light snow now reaching the western counties of the CWA.
As we head through the rest of the afternoon, continuing saturation
in the lowest 5-10 kft of the atmosphere should allow for light snow
showers to spread to the east. With the mid-level trough expected to
cross the region over the next 6-12 hours, support for rising motion
in the low-mid levels will be in place, with moisture being the main
limiting factor. BUFKIT soundings show at least a few hours this
afternoon and evening with saturation in the DGZ coupled with
negative omega, so occasional bursts of slightly heavier rates are
certainly possible. With that being said, total liquid equivalent
amounts should only range from a trace to a few hundredths of an
inch across the area. While snow will not accumulate across the
entire forecast area, those which see locally heavier showers could
pick up a quick dusting to as much as a half an inch. By the late
evening hours, deeper moisture will exit the region to the east,
bringing an end to the widespread snow chances. A few flurries may
linger east of I-65 until a few hours after midnight.
There is quite a spread in low temperatures tonight, primarily
dictated by uncertainty in how long low clouds linger. An earlier
clearing of clouds from north to south will allow temperatures to
plunge well into the teens, while more resilient cloud cover will
hold temperatures up in the low-to-mid 20s. Regardless, temperatures
will be cold enough that if there is any lingering moisture on
untreated surfaces, a few slick spots will be possible tonight into
tomorrow morning.
On Tuesday, sfc high pressure and ridging aloft will nose into the
region from the west and southwest. Any lingering cloud cover is
expected to exit the area by mid-morning, giving us mostly sunny
skies Tuesday afternoon. Temperatures will remain chilly, with highs
only in the low-to-mid 30s, although increased sunshine and light
winds will make things feel a bit warmer than today.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 254 PM EST Mon Dec 2 2024
High pressure over Tennessee and Georgia Tuesday night will give us
another dry, chilly night. As the high moves away, southwest
breezes will increase and cloudiness will begin to increase from
west to east by the pre-dawn hours ahead of the next system. So,
temperatures will likely reach their nadir in the low 20s shortly
after midnight and then steady out or rise a couple degrees by
sunrise.
Low pressure passing from Ontario to Quebec will swing a cold front
through the Ohio Valley Wednesday evening. Deeper moisture
associated with this system will remain to our north and northeast,
bringing the Great Lakes another round of locally heavy snow. In
southern Indiana and central Kentucky, moisture will be less
plentiful, with weak lift, so little if any precipitation is
expected beyond some sprinkles or very light rain, possibly ending
as scattered flurries. Temperatures will remain above freezing ahead
of the cold front, but cold air will quickly rush in behind the
boundary, forcing temperatures down into the 20s across southern
Indiana and much of central Kentucky north of the Cumberland Parkway.
Gusty winds can be expected ahead of this seasonably strong system
on Wednesday as a low level jet extends from Little Rock to Toronto.
Though mostly cloudy conditions are likely, gusts of 35-40mph still
look achievable into the evening hours.
Thursday will be a raw day as gusty northwest winds in a tight
pressure gradient between the departing storm system and high
pressure advancing from the northern Plains to the Midwest pull cold
air into the region. Though we should have mostly sunny skies, the
cold air rushing in is expected to limit diurnal temperature rises
to around 5-10 degrees, resulting in highs from the mid 20s to mid
30s. Wind chills will be in the teens. If the forecast pans out,
we'll see the coldest wind chills for the calendar date of December
5 since 2010 at BWG, 2008 at SDF, and 2002 at LEX.
The high to our west will pass overhead Thursday night and Friday,
decreasing our winds but also bringing cold temperatures under clear
skies. Lows Thursday night will mostly drop into the 10-15 degree
range, but given the perfect radiational cooling conditions expected
with the high right overhead at 12Z Friday, the usual cold spots
will slip into the single digits. Forecast lows at the main airport
climate sites are about 10 degrees above the record lows for
December 6.
Forecast confidence decreases over the weekend as model solutions
diverge. In general, it appears mid-week upper troughiness will push
off the East Coast and be replaced by weak ridging coming in from
the Plains by Sunday. Quick flow will then bring the next upper
trough into the Plains on Monday with a surface boundary possibly
reaching from the Great Lakes to the Gulf Coast by Monday evening.
As a result, will keep PoPs low Saturday-Sunday then ramp them up,
along with warming temperatures, by Sunday night into Monday (highs
in the 50s on Monday).
&&
.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 618 PM EST Mon Dec 2 2024
Impacts:
- Light snow showers bringing MVFR/IFR visibilities to begin the
forecast period (high confidence)
- MVFR ceilings lingering overnight into early Tuesday morning
(medium confidence on duration)
Discussion: Current radar continues to show light snow showers
moving through the region with area observations reporting MVFR to
IFR CIGS/VIS. Snow should begin to decrease in intensity at
beginning of TAF period, but covered any stray overachieving showers
with a tempo for reduced VIS. MVFR CIGs will linger overnight into
the morning hours accompanied by light WNW winds and possible light
flurries, especially at RGA and LEX. Expect VFR conditions to resume
by Tuesday mid to late morning for all TAF sites with light winds
backing to WSW.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...CG
SHORT TERM...CSG
LONG TERM...13
AVIATION...CG
Source:
LMK issues Area Forecast Discussion (AFD) at Dec 2, 7:00 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!
