-- Discussion containing changed information from previous version are highlighted. --
419
FXUS63 KJKL 020736
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
336 AM EDT Thu May 2 2024

.KEY MESSAGES...

-- Changed Discussion --
- Very warm with record or near-record highs this afternoon.

- Shower and thunderstorm chances return to the forecast Friday
  through Wednesday.

-Not as warm this weekend with highs generally near 80.
-- End Changed Discussion --

&&

.SHORT TERM...
-- Changed Discussion --
(Today through Friday)
Issued at 335 AM EDT THU MAY 2 2024

Satellite imagery as of this writing is beginning to show some fog
developing in the river valleys. This trend is anticipated to
continue until sunrise. Fog will not be nearly as widespread as it
was 24 hours ago. This, as we were able to mix out on Wednesday and
evaporate some of Tuesday`s rainfall.

Very warm this afternoon with near-record high temperatures. Some
spots could hit 90 degrees; this first 90-degree temperature would
be about 6 weeks ahead of average (at Jackson). Meanwhile, the
forecast high of 88 would break the record set in 2012 by 1 degree.
A high of 88 is near the climate record`s average first 88 degree
date. This heat is thanks to a towering 579dm ridge centered over the
Florida Peninsula. By Friday, this ridge gives way to an approaching
trough, currently over the Central Plains. Expect increasing clouds
late Thursday night and the chance of showers and thunderstorms
increasing after sunrise Friday. Instability is meager and upper-
level support is poor. Therefore, showers and any thunderstorms will
be rather disorganized Friday.

A word about the coming night`s low temperatures: Current forecast
lows are the coldest among model guidance with a forecast-area
average low of about 59 degrees. A 25th percentile forecast could be
closer to 62 degrees. Prior to clouds arriving, lows could quickly
drop towards dew points that will be in the 50s. However, should
cloud cover arrive quickly after sunset our existing forecast lows
would be too cold. I`ll pass this concern along to the incoming
shift for consideration.

.LONG TERM...(Friday through Wednesday)
Issued at 348 PM EDT WED MAY 1 2024

Core of westerlies remain to our north through the bulk of the
extended time frame, through the Upper Midwest and Great Lakes.
That leaves our area within weak flow aloft, with subtle
disturbances passing through the region at times during the
extended portion of the forecast. Low pressure drops out of the
northern Pacific and into the West Coast by this weekend. This
system then slides eastward over the Central Plains and eventually
noses its way into the Upper Midwest and Great Lakes regions by
the end of the forecast window. This will bring stronger winds
(core westerlies) across our region by the end of the period as a
broad trough is carved out over the lower forty-eight. In general
this will keep eastern Kentucky within the warm sector (south of
the polar jet) through the period. At the surface, and with little
or no support aloft, a cold frontal boundary appears to drop
southeast to the Ohio River by late Sunday, then stalls briefly
before retreating northward in quick fashion Monday. A cold
frontal system then approaches from the west by the end of the
extended. Several of the aforementioned disturbances will tend to
keep the threat of showers and thunderstorms in the forecast
during much of the extended, with a diurnal flavor to the
activity.

Sensible weather features seasonably warm temperatures running as
much as 5 to 10 degrees above normal. There will be at least a
chance of rain, or at least a climatological 30% or higher PoP
each day of the extended. A series of disturbances will pass
through the Ohio Valley during the period, the first roughly late
Friday into Saturday, with a second late Sunday into Monday and
then a third late Tuesday into Wednesday. The last disturbance at
the end of the period will be more closely associated with the
storm system approaching from the west. Other than thunderstorms,
not seeing much in the way of hazards through the period. QPF for
the extended does not exceed 1-1.5 inches in total, hardly enough
to be of concern at this time. We could experience some strong
thunderstorms, perhaps an increased potential for some severe
storms towards the end of the forecast window. Afternoon
instability increases each day, Monday through Wednesday, with
MLCAPES climbing from around 500 J/kg on Monday to close to 2000
J/kg by Wednesday. Only seeing marginal shear Monday at around 25
kts effective shear. That increases to around 30 kts by Tuesday
and then between 30 and 40 kts by Wednesday. Consequently,
thinking at this time is that a strong storm or two could not be
ruled out Tuesday, then some strong to a couple severe storm would
be possible by Wednesday with the approach of the storm system
from our west if current model solutions hold. Confidence is not
high due to the fact that this is still a week away. But NCAR
Ensemble C-Shield forecast would tend to support this line of
thinking.
-- End Changed Discussion --

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 123 AM EDT THU MAY 2 2024

Existing TAFs were in great shape; few to no changes needed. High
pressure centered over the AL-GA line provides calm weather
conditions through the TAF period. Some valley fog is expected
these next few hours, but not as dense as 24 hours ago.

&&

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

$$

SHORT TERM...BROWN
LONG TERM...RAY
AVIATION...BROWN