Area Forecast Discussion Issued by NWS Jackson, KY
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000
FXUS63 KJKL 161637 AAC
AFDJKL
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1237 PM EDT Sat Mar 16 2024
.KEY MESSAGES...
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- Temperatures will remain about 5 to 10 degrees above normal
through tonight.
- A deep trough passing aloft brings a threat of some rain/snow
showers on Monday.
- Hard freeze conditions Monday night could kill any cold
sensitive vegetation that has emerged prematurely due to early
season warmth.
- Temperatures rebound back to near normal through mid-week, with
lower confidence in the next potential chance of precipitation
moving in towards the end of the work week.-- End Changed Discussion --
&&
.UPDATE...
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Issued at 1225 PM EDT SAT MAR 16 2024
Fog and stratocumulus has lifted and scattered out over the past
hour. Minor adjustments were made to grids to account for this as
well as trends in hourly observations for temperatures, dewpoints,
and winds. Overall, this led to no substantial changes at this
time.
UPDATE Issued at 1046 AM EDT SAT MAR 16 2024
Fog and sky cover grids were updated based on recent observations
and satellite trends. The fog was lifting and starting to dissipate
across the Dense Fog Advisory area and it was allowed to expire at
10 AM. The fog and lingering stratocumulus and stratus should
continue to gradually lift and mix out through midday to early
this afternoon.
UPDATE Issued at 715 AM EDT SAT MAR 16 2024
Touched up the fog in the grids and decided to expand the SPS to
the rest of the CWA as the low clouds break up down in the far
southeast. Did also include the latest obs and trends for the T/Td
grids. These adjustments have been sent to the NDFD and web
servers.-- End Changed Discussion --
&&
.SHORT TERM...(Today through Sunday)
Issued at 510 AM EDT SAT MAR 16 2024
08Z sfc analysis shows low pressure pulling away to the southeast
of the area while a cooler high is moving in from the west. This
is attempting to clear out the low clouds through eastern Kentucky
early this morning. However, the wet ground left from yesterday`s
rains is allowing fog to develop and become extra thick in the
deeper valleys where those clouds cleared earlier - mainly in the
western and northern parts of the CWA. For this reason, a Dense
Fog Advisory is in effect until 10 am EDT for our western and
northern counties with an SPS out for patchier fog elsewhere.
Currently, temperatures vary from the upper 30s in the northwest
parts of the JKL CWA to near 50 degrees in the far southeast.
Meanwhile, amid those light winds, dewpoints likewise vary from
the upper 30s northwest to the upper 40s in the southeast.
The models, and their individual ensemble suites, remain in good
agreement aloft through the short term portion of the forecast.
They all depict fast and nearly zonal flow at mid levels
downstream from a deep trough finally opening up over the Desert
Southwest. The flow remains quick and laminar, with limited
energy, packets over Kentucky into Sunday even as a very broad
and deep trough descends into the Great Lakes from Canada - though
starting to dig to our northwest late in the period. Given the
small model spread, have again favored the NBM as the starting
point for the forecast grids with mainly just some terrain
distinction added to the hourly temps and low temperatures
tonight.
Sensible weather will feature another day of slightly above
normal temperatures awaiting the initial (and mostly dry) cold
front arriving Sunday morning. Look for a mostly sunny day,
today, under the auspices of high pressure, once the lingering fog
and low clouds clear this morning. The approach of that boundary
tonight will keep the air more stirred along with some mid level
clouds limiting the radiational cooling, but still allowing for
some terrain differences to develop after dark. This front passes
through Sunday morning mainly pushing any return flow moisture
south of the state, keeping southern warmth at bay, and generally
acting as a reminder of the chilly start promised for the new
work week.
The main adjustments to the NBM starting point were to add some
terrain distinctions into low and hourly temperatures tonight.
PoPs were generally single digits from the NBM and kept there
through Sunday evening.
.LONG TERM...(Sunday night through Friday)
Issued at 546 AM EDT SAT MAR 16 2024
The models agree on an amplified long wave pattern to start out
over the CONUS through early next week. A progressive stout short
wave trough will move in from the western Great Lakes late this
weekend, establishing a deeper northern stream trough across the
East by Monday. The trough will pull off to the northeast and
broaden with time through the middle of next week. Meanwhile, a
closed low over the southwestern CONUS will gradually move east
and transition to more of an open wave. This feature will reach
the southern Plains by Thursday, and then at least the
middle/lower Mississippi Valley by Friday. Model agreement on the
details remain poor with this system, with the GFS slower with the
progression of the short wave, while the ECMWF is quicker and
keeps moisture shunted further southeast. Given the uncertainty,
stuck close with the blended guidance regarding the chance of
precipitation, with peak PoPs around 50%, generally a bit less
compared to yesterday.
The majority of the extended forecast will be dry across eastern
Kentucky, although with the passage of the deeper trough axis on
Monday, some rain/snow shower activity may occur during the day,
with highs retreating to the lower 40s for most locations. Model
guidance has trended less deep with the available moisture and
consequently PoPs for Monday. Confidence remains high on a hard
freeze for Monday night, with lows in the low to mid 20s.
Temperatures will then gradually rebound back to near normal
through mid-week, with dry weather hanging on through most of
Thursday. Precipitation chances then increase Thursday night into
Friday.
&&
.AVIATION...-- Changed Discussion --
(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1236 PM EDT SAT MAR 16 2024
As of midday, fog and stratocumulus was mixing out with any
lingering instances of MVFR or IFR quickly trending to VFR.
Overall, VFR prevailed in most places as of 1630Z. Winds will
become southwest to west early in the period in the 5 to 10KT
range through about 06Z. Then, as a cold front drops across the
are, winds will shift to the west and then northwest late in the
period again at 5 to 10KT. Despite the passage of a cold front, it
will be rather moisture starved and VFR will prevail through the
end of the period.-- End Changed Discussion --
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...GEOGERIAN
AVIATION...JP