362
FXUS63 KJKL 210742
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
342 AM EDT Tue May 21 2024

.KEY MESSAGES...

- Dry weather is expected area wide through Wednesday morning.
  High temperatures may approach or exceed record levels this
  afternoon.

- There is a potential for showers and thunderstorms at times from
  Wednesday afternoon through Monday.

- Very warm temperatures will persist through Wednesday. An
  increase in clouds and the possibility of rain will bring
  somewhat lower temperature after that, especially Thursday and
  Friday.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 340 AM EDT TUE MAY 21 2024

Warm advection increases through the short-term period as a strong
cyclone grazes the Mid-Ohio Valley through early Wednesday evening.
With the mid-level jet stream remaining west and northwest of the
forecast area, however, shower and thunderstorm activity will
remain limited.

For today, near-record high temperatures in the mid- to upper 80s
are expected as southerly flow begins to increase (yet remains
light) near the surface and southwest flow increases aloft as upper
ridging remains just to the southeast over the Southeast US. There
appears to enough instability and moisture to justify PoPs of around
10 percent for this afternoon, not quite enough to warrant mention
in the official forecasts (15 is required) for almost the entire
forecast area.

Heading into tonight, a southwesterly low-level jet will impact
the Mississippi and Lower Ohio Valleys, including the Bluegrass
region, just grazing our western and northwestern counties in the
CWA. Therefore, warm and dry conditions are expected yet with
increasing high clouds. Lows will generally be in the upper 50s to
mid to upper 60s, coolest in the deeper valley locations.

Lower atmospheric winds increase Wednesday morning around or just
after daybreak ahead of am impinging cold front into the Midwest,
well upstream of the forecast area. This will help to increase
moisture and instability through the day, especially toward the
Bluegrass region. Have thus kept slight chance to chance PoPs (15
to 40 PoPs) for much of northern through southwestern parts of the
forecast area beginning in the afternoon and extending into the
early evening hours. Warm temperatures continue despite the
increasing warm advection and cloud cover with mid to upper 80s
expected once again.

.LONG TERM...(Wednesday through Monday)
Issued at 522 PM EDT MON MAY 20 2024

There is decent enough agreement with respect to the pattern aloft
among the operational models through Dy5, Saturday, then solutions
diverge from there with some of the more significant synoptic
features. Pattern is best described as being a broad zonal flow
across the eastern CONUS. Further west a few lows rotate in a circle
the wagons fashion across the northern Rockies and Canada`s BC with
a mean trough stretching down to the Baja. On occasion, short wave
energy shoots eastward from out of the mean trough sitting over the
West Coast and Rockies. Main challenge is the timing and strength of
each of the short wave disturbance as it tracks across the country
and into the Ohio Valley, or Commonwealth, particularly after Dy5
where there is less agreement in solutions. At the surface, a weak
frontal zone will sag southward across the region by Wednesday
night, providing a focus for mainly afternoon and evening diurnal
convection from late Wednesday through to the end of the forecast
window as a series of disturbances travel through the region.

Sensible weather generally features a warm and unsettled extended,
with daily high temperatures ranging from around 80 into the mid
80s, approximately 5 degrees above normal on average. Thursday and
Friday are our two coolest days with clouds and rain keeping
temperatures around 80 for highs each day. With extra cloud cover
overnight lows are expected to run generally in the 60s, though
guidance suggests some mid to upper 50s will be possible if there is
enough clearing that takes place on any given night. Should temps
dip into the 50s, one could expect valley fog to be a good bet,
similar to what we have experienced over the past week. Not seeing
much in the way of obvious hazardous weather threats. There are
periods of time where there is some marginal effective shear 30-35
kts to deal with. However, at this time not seeing any periods of
time where ample instability matches up with the necessary shear for
the more robust and/or organized convection. Overall this aspect of
the forecast is of a lower confidence with respect to the potential
of hazardous weather. Total rainfall expected through the period
from late Wednesday through Monday is generally around 1.5 inches or
less. The Weather Prediction Center does include portions of eastern
Kentucky in a Marginal risk of excessive rainfall for Day 5, Friday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 340 AM EDT TUE MAY 21 2024

VFR conditions will continue to prevail through the majority of
the period. The only exception will be some MVFR or lower fog that
will occur in the river valleys between 06Z and 13z. The fog is
expected to be more confined this morning compared to the past
couple of mornings. KSME and perhaps KLOZ and KSJS have a chance
to dip into the MVFR/IFR range at least briefly between about 06Z
and 12Z, and thus included TEMPO groups for these locations.
Winds will average around 5KT or less through 14Z, before becoming
south to southwest at less than 10Kt to end the period.

&&

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

$$

SHORT TERM...CMC
LONG TERM...RAY
AVIATION...CMC