324
FXUS63 KJKL 162015
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
415 PM EDT Thu May 16 2024

.KEY MESSAGES...

- After a lull in shower and thunderstorm chances for most places
  tonight, higher chances return to close out the week and carry
  over into Saturday and Saturday evening, before tapering off
  Saturday night into Sunday.

- High pressure brings dry weather back to the area Sunday night
  through Tuesday. Couple areas of low pressure will bring rain
  back to the area Tuesday night through Thursday.

- Near normal to slightly above normal temperatures are expected
  to continue into the weekend. A further warm up is then
  expected into the first part of next week.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 415 PM EDT THU MAY 16 2024

The models exhibited some differences today regarding sensible
weather across eastern Kentucky the next few days. The system that
will influence our weather Friday into Saturday looks to be a
developing storm system that will move out of the southern Plains
Friday and Friday night, and then across the lower Mississippi
Valley and Tennessee Valley. A few rain showers were popping here
and there is a few of our eastern counties this afternoon, and it
appears this activity will continue until the sun begins to set
this evening. After that, we should see dry weather through the
night. With none of the models showing any convection continuing
after dark in our area, decided to keep things dry after 23Z. The
NAMNEST, NAM12, and HRRR models were the most robust with shower
and storm activity around eastern Kentucky tonight through
Saturday. The upper pattern currently features a warm front now
situated north of the Ohio River, which was previously seen as a
trigger for convection in our northwest counties this evening, but
with this boundary now being analyzed well out of our area, it
does not appear the front will play a factor in convective
activity in our area this evening.

The latest model consensus seems to be pointing toward having the
first showers and storms moving into our northwest very late
tonight to around dawn on Friday, with activity gradually
spreading eastward and increasing in coverage through out the day
on Friday. A new wrinkle in the latest model data is the
production of a large and robust MCS far to our south that will be
moving across the southern portions of the states along the Gulf
of Mexico. The models, to varying degrees, have this southern MCS
cutting off the northward moisture off of the Gulf, thereby
decreasing the coverage of showers and storms across KY and TN
Friday and Friday night. The latest SREF runs took this scenario
to the extreme, and had very little precip affecting eastern
Kentucky on Friday, with scattered activity occurring early Friday
morning, but quickly dissipating by around 16Z, and having not
much else occurring until later in the day in our northern
counties and keeping Saturday almost entirely dry. That being
said, the solutions of the NAMNEST and HRRR runs seemed more
reasonable, as a moist air mass is already in place, and we should
see enough moisture return to support scattered to at times
numerous showers and storms around our area heading into the
weekend.

Temperatures still look to be quite warm on Friday, perhaps a few
degrees above normal, with mild lows on tap tonight and Friday
night. Winds should see be fairly light heading into the weekend
as well. No major weather concerns at this time, but there is a
small chance of excessive rainfall occurring with some of the
storms on Friday, or where multiple storms move over the same
areas repeatedly.

.LONG TERM...(Saturday through Thursday)
Issued at 415 PM EDT THU MAY 16 2024

Models are indicating an upper level split flow expected across the
CONUS at the start of the period, with the southern portion of the
flow having troughiness from the ArkLaTex region northeastward over
the Ohio Valley. A weak upper low is expected to be embedded in this
trough, but there is poor model agreement on its position. Ample
moisture should be present beneath and ahead of the upper trough,
allowing for precip. The regime will shift east with time, but the
aforementioned model discrepancies result in uncertainty down the
line as to how quickly it departs. A model blend being used for the
forecast continues to lack details, but has an overall decreasing
POP trend during the weekend, overlaid with diurnal tendencies. Dry
weather is forecast by late Sunday evening. Ridging at all levels
approaching and passing over from late Sunday night through Tuesday
will result in dry weather persisting during that time. Slightly
drier low level air should also arrive.

Beyond this, a shortwave trough aloft originating in the northern
part of the flow is expected to approach and pass over Tuesday night
and Wednesday, with the bulk of the wave to our north. This supports
a surface cold front which both the GFS and ECMWF pass through our
area on Wednesday afternoon or evening. The best upper level support
is weakening and shifting to our north as the system goes by. It
would also appear that the best moisture return ahead of the front
will be to our west and probably not make it here before cold fropa.
These considerations as well as models only generating light precip
here, will limit the POP to chance category.

By Thursday, the deterministic/operational ECMWF has deepened an
upper level trough over Ontario and the eastern CONUS much more so
than the deterministic/operational GFS. In terms of surface features,
this allows the ECMWF to take the cold front further south than the
GFS. The GFS`s stalling of the front further north results in
additional precip in our area on Thursday, compared to a dry ECMWF.
The GFS ensemble mean points toward more eastern CONUS troughing
than in the operational/deterministic run, lending some support
toward the ECMWF idea. That being the case, will go with POPs a
little below the values in the model blend on Thursday, with nothing
higher than slight chance.&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 142 PM EDT THU MAY 16 2024

Based on current trends, the TAF sites will continue to experience
BKN low level cover through around 0Z this evening, before the
clouds begin to scatter out a bit. VFR should be the rule at JKL,
LOZ, and SME, but SJS and SYM will continue to see MVFR CIGs of
around 2K this afternoon, before the clouds scatter and lift a bit
this evening. Winds should be generally light and variable through
out the period, but especially tonight. Clouds will be on the
increase late tonight, as an area of low pressure moves in from
the west, leading to periods of BKN clouds. A few showers and
storms could begin moving into the I-64 corridor in our
northwestern counties late this evening. The rain will continue to
advance slowly eastward overnight into early Friday, and could
begin to affect JKL, LOZ ,SME, and SYM toward the end of the
forecast period. MVFR fog will be possible again tonight as
moisture advects in ahead of the incoming storm system. LOZ and
SME might even see brief periods of IFR fog between 10 and 12Z on
Friday.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...AR
LONG TERM...AR
AVIATION...AR