341
FXUS63 KJKL 161129
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
729 AM EDT Tue Jul 16 2024

.KEY MESSAGES...

- Hot and humid weather will bring heat index values ranging from
  the upper 90s to the lower 100s to many locations Tuesday.

- Showers and thunderstorms will impact the region late this
  afternoon through early next week.

- Thunderstorms this afternoon into the overnight will be capable
  of producing damaging wind gusts. There is also the risk for
  excessive rainfall through Wednesday from potentially repeat
  rounds of showers and thunderstorms, despite antecedent
  abnormally dry conditions for many areas.

- A welcomed relief from the heat follows the cold front for
  Thursday through this weekend, with temperatures averaging near
  normal to below normal Thursday into early next week.


&&

.UPDATE...
Issued at 729 AM EDT TUE JUL 16 2024

Debris clouds from upstream MCS activity overnight has started to
thin and diminish over eastern Kentucky. Have thus gone back and
lowered Sky coverage in the grids significantly from the last
update this morning. This yields higher confidence in achieving
today`s forecast highs in the lower to mid-90s, with associated
heat indices approaching 105 degrees in some of the warmest
locations. Also blended the current PoPs from the morning forecast
package with the latest 1-hr NBM PoPs and then smoothed somewhat
to blend with neighboring forecasts. Also used the latest
observations as the initialization for the update to the grids for
the next several hours.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 331 AM EDT TUE JUL 16 2024

Eastern Kentucky will see an increasingly active weather pattern
through Wednesday afternoon as the area comes under the influence
of increasing cyclonic flow aloft and a cold front approaches
from the northwest.

A large MCS continues to weaken upstream over the Midwest as it
approaches the area. Latest trends suggest little to no rain
reaching the area this morning, with some remnant outflow winds
possibly impacting areas especially north of Interstate 64. But
trends will need to be monitored as what is left of the MCS
approaches the area.

The remnant debris clouds left from the MCS will move over the area
this morning. This may prevent high temperatures today from reaching
their full potential this afternoon. The NBM has trended downward
a degree or two compared to 24 hours ago, but with lower to
mid-90s still expected. Humidity will also increase today as warm
advection continues to push moisture into the region. With the
question mark of cloud cover today and uncertainty with how
quickly dew points rise today, will cover the heat impacts with a
Special Weather Statement as we have been doing.

As for showers and thunderstorms, expect generally low chances until
late this afternoon into the evening as models depict moisture
advection fairly parallel with the mid- and upper-level winds
entering northern parts of the CWA by this evening. This
increases the chances of showers and thunderstorm activity
training across parts of the area, especially toward the
Interstate 64 corridor, which is why the Weather Prediction
Center has issued a Slight Risk for excessive rainfall. However,
given antecedent abnormally dry conditions it will take more rain
than usual to cause any significant flooding issues. Thus, have
decided to withhold any issuance of a Flood Watch at this time.

As disturbances move west to east across the area the approaching
cold front and upper level trough will gradually push shower and
thunderstorm activity south across the CWA through Wednesday.
Widespread categorical PoPs cover the area Wednesday during the
daytime period, which will bring badly needed rainfall for many
areas, though again will need to watch for the potential for
excessive rainfall with a Slight Risk continuing over eastern parts
of the forecast area.

.LONG TERM...(Wednesday night through Monday)
Issued at 418 AM EDT TUE JUL 16 2024

The extended period will start off quite active, as a cold front
moves through the region. The front will make a strong push out of
the Ohio Valley and across Kentucky Wednesday night and Thursday.
As the front pushes southeast, it will be slowed greatly, due to
persistent southerly flow around the western edge of the
subtropical high, which will be parked off the southeastern CONUS
throughout the period. The front should make it out of our area
early Thursday evening. After that, we should see a brief window
of dry weather Thursday night into early Friday morning, as the
front meanders about to our south. However, as the subtropical
high expands back westward, the front will make a push to the
northwest. By Friday afternoon, we will see isolated to scattered
showers and storms moving back into our southeastern counties, as
impulses of low pressure move along the incoming front. The rain
will become more widespread on Saturday, as a stronger wave of low
pressure moves from west to east along the stalled front, and
southerly flow around the off shore ridge pushes ample moisture
into the Tennessee Valleys. This pattern will repeat itself
through the weekend and into the first of the new work, as
multiple waves of low pressures move by just to our south, and
warm and moist air remains in place.

Temperatures during the extended will be much nicer than what
we`ve experienced over the past week or so, as much cooler air
will finally makes its way into the area behind the aforementioned
cold front. While warm and humid air will still be in place south
and southeast of the front, with clouds and precip persisting in
those regions, northerly flow will invade the area behind the
front. The convergence of the cooler northerly flow with the much
warmer and moist southerly flow south of the front, will be the
impetus for precipitation. Winds will eventually shift back to a
more predominantly southerly or southeasterly flow pattern over
weekend and into the first of next week, allowing temperatures to
warm to closer to normal values in the low to mid 80s. This will
be in contrast to the upper 70s and lower 80s we are expecting
Thursday and Friday.

We will monitor the potential for locally heavy rainfall,
especially Wednesday night and Thursday, as the cold front moves
slowly through the region. This will be the primary forecast
concern Wednesday night and Thursday. All in all, the models were
in pretty good agreement with the large scale flow pattern in the
extended across the CONUS and with the timing and evolution of the
front and waves of low pressure and ridging that will influence
the weather of eastern Kentucky.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 716 AM EDT TUE JUL 16 2024

VFR conditions are expected to prevail, with exceptions coming
with showers and thunderstorms later today, mainly after 21z,
producing sub-VFR conditions, and then later tonight with any fog
developing as a result of earlier rainfall and at least partially
clearing skies. Winds will generally be light and variable, except
becoming southwest at 5 to 10 kts in the afternoon before becoming
light and variable again around sunset. Gusty and erratic outflow
winds will be possible with thunderstorms, possibly extending a
considerable distance away from the storms themselves particularly
late this afternoon.

&&

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

$$

UPDATE...CMC
SHORT TERM...CMC
LONG TERM...AR
AVIATION...CMC