LMK issues Area Forecast Discussion (AFD) at Dec 25, 1:00 PM EST151
FXUS63 KLMK 251800
AFDLMK
Area Forecast Discussion
National Weather Service Louisville KY
100 PM EST Wed Dec 25 2024
.KEY MESSAGES...
* Christmas Day will feature light rain showers and above normal
temperatures.
* Widespread rainfall, heavy at times, expected Friday - Sunday.
* Well above normal temperatures Thursday through the weekend.
&&
.UPDATE...
Issued at 1058 AM EST Wed Dec 25 2024
Weak warm front is situated to our north across central IN with the
bulk of the precipitation riding along this boundary from southern IL
and the Missouri Bootheel. While a few light rain
showers/sprinkles/drizzle pass just north of the Ohio River across
southern IN this morning, the rest of the CWA was mainly dry. This
Christmas morning will remain mild, temperatures were ranging from
the mid/upper 40s to the north and low 50s further south along the
KY/TN border. The boundary will eventually stall out and become
quasi stationary this afternoon. This will likely take and keep our
best precipitation chances to the north. Other than a few minor
tweaks to the PoP and Sky grids to better represent the current
weather better, no other changes were made. The overall forecast
today look to be in good shape.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 318 AM EST Wed Dec 25 2024
An upper level shortwave is over the Midwest this morning, with a
weak sfc front stretching across a portion of the Lower Ohio Valley
and Mid-Mississippi River Valley. Weak isentropic lift is supporting
some light showers this morning, which are expected to continue for
today as the sfc boundary gradually shifts northward. This push to
the north will not only keep our precip chances primarily north of
the Western Kentucky and Bluegrass Pkwys, but will also support
warmer temps for Christmas Day. Temperatures will range from upper
40s and low 50s north of the aforementioned parkways, and mid to
upper 50s to the south. This will place us somewhere around 5-10
degrees above normal for Christmas Day.
While PoPs will extend as far south as the parkways, the best
chances for any light measurable rainfall will be along and north of
the I-64 corridor. Rainfall amounts will be light given the weak
isentropic ascent and meager moisture convergence and transport. A
few hundredths of an inch are possible. With temps above normal
today, all precip will be plain rain.
Cloud cover will linger into this evening and tonight as the sfc
boundary will most likely be located to our north, possibly
extending from St. Louis to Indianapolis. Light rain will continue
for tonight, though chances will remain fairly low for areas south
of the parkways again. Best chances in our forecast area will be
across southern Indiana. Temperatures for tonight will remain mild
thanks to the cloud cover and southeasterly WAA flow, with most
areas remaining in the low to mid 40s.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 318 AM EST Wed Dec 25 2024
Thursday...
A potent upper level shortwave trough will swing east across the
southern Plains on Thursday, with downstream shortwave ridging over
the Ohio Valley. At the surface, high pressure will remain in place
over the Northeast with light southeasterly winds locally. This will
be one of the few mainly dry days in the medium range. Fcst
soundings reveal fairly dry air below 5 kft, but more mid-level
saturation will yield partly to mostly cloudy skies. Temperatures
will run 10-15 degrees above normal, with highs in the mid/upper
50s.
Thursday Night through Sunday Night...
Rain chances begin to increase Thursday night as the aforementioned
southern Plains low ejects northeast over the Ozarks. This is but
the first in a series of mid/upper level disturbances forecast to
rotate cyclonically across the Ohio Valley over the weekend.
Strong, deep ascent will be in place Friday morning as the upper
level shortwave moves over the Lower OH Valley. A 50+ kt southerly
LLJ will overspread KY and southern IN, just downstream of the low.
Favorable dynamics and very strong integrated water vapor transport
(IVT) will produce widespread rain showers. Model soundings reveal a
stable environment, so the thunder probability is low. Deep
southerly flow will produce continued mild conditions, with highs in
the mid/upper 50s.
The next upper level disturbance lifts just to our NW across MO/IL
Friday night, followed by a deeper upper level shortwave trough
forecast to approach the region Saturday before swinging overhead on
Sunday. Persistent deep SW flow and an anomalously moist airmass (PW
values near or exceeding 1 inch) will keep high rain chances in the
forecast Friday night through Saturday night. Of note, there is some
potential for enhanced rainfall totals Saturday afternoon into early
Sunday. This is also when thunderstorm probabilities are highest (20-
30%). Strengthening synoptic scale ascent (impressive jet dynamics,
sfc cyclogenesis/fropa) will interact with deep moisture to produce
swaths of moderate to heavy rainfall. There is a signal for weak sfc-
based instability, and any convective enhancement could certainly
boost rainfall totals as well. The severe weather risk still looks
fairly low, but will need to keep an eye on the destabilization
potential.
Rainfall chances will diminish from west to east Sunday or Sunday
night, but timing at this range is still somewhat problematic.
However, a dry period does look likely in the wake of fropa later
Sunday into Monday. Total rainfall amounts Thursday night through
Sunday of 1-2 inches are likely. Some localized totals of 2+ inches
are possible. Bottom line...a wet weekend ahead with heavy rainfall
and ponding at times. Localized flooding is a possibility, and we
can expect rises on rivers and streams to continue into next week.
Monday and Tuesday...
Monday still looks to be mainly dry in the wake of the weekend storm
system. A significant cool down is not expected, with temps
remaining solidly above normal into early next week. Yet another
storms system will bring additional rain chances for New Year's Eve,
though confidence in the details is very low at this time.
&&
.AVIATION /18Z TAFS THROUGH 00Z FRIDAY/...
Issued at 1259 PM EST Wed Dec 25 2024
Quasi stationary boundary is north of our area across central IN,
central IL back towards central MO. Bulk of the precipitation will
ride along this boundary but a few showers are possible, mainly for
HNB and SDF. BKN to OVC mid-level CIGS are likely through the
forecast duration with winds generally out of the east and less than
7kts. VFR will remain the flight category through the forecast.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...BTN
SHORT TERM...CJP
LONG TERM...EBW
AVIATION...BTN
Source:
LMK issues Area Forecast Discussion (AFD) at Dec 25, 1:00 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!
