JKL issues Area Forecast Discussion (AFD) at Jul 24, 7:51 AM EDT
410
FXUS63 KJKL 241151
AFDJKL
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
751 AM EDT Thu Jul 24 2025
.KEY MESSAGES...
- Other than the low chance of a popup shower or thunderstorm, dry
weather is expected through Friday as heat builds across our
region.
- Heat indices will approach 100 degrees in many places each day
through Tuesday, and could be in excess of 100 on the warmest
days early next week.
- Scattered showers and storms return for the weekend.
&&
.UPDATE...
Issued at 751 AM EDT THU JUL 24 2025
Another hot and increasingly humid day is ahead across the Eastern
Kentucky Coalfields and adjacent regions. Some consolidation in
the CAM solutions on the 00z and 06z cycles have been noted. This
has warranted the addition of isolated popup shower and
thunderstorm chances later today across the high terrain near
Virginia border where differential heating is greater and also
near/north of I-64 where PWATs will be surging higher this
afternoon. High temperatures are expected to range in the lower
90s for most locations but the rising humidity levels will make it
feel more like the upper 90s to lower 100s.
UPDATE Issued at 1206 AM EDT THU JUL 24 2025
There are no changes to the forecast with the midnight update.
UPDATE Issued at 951 PM EDT WED JUL 23 2025
Convection has diminished with the loss of daytime heating, and is
expected to remain that way through the overnight given a lack of
forcing mechanism. Adjusted hourly temperatures a bit for the next
several hours, using the most recent hourly observations as the
initialization for the forecast.
UPDATE Issued at 724 PM EDT WED JUL 23 2025
Lowered PoPs and confined them more to the TN border area,
particularly around Wayne County east to Whitley County, where a
few small showers have developed in the last hour or so. A few
sprinkles are possible extending northeast to near Breathitt and
Knott counties in the next hour or so, but overall the trend is
toward diminishing clouds and precipitation chances with the loss
of daytime heating and absent any other forcing.
&&
.SHORT TERM...(This evening through Thursday night)
Issued at 330 PM EDT WED JUL 23 2025
Thermometers range from 85 to 90 degrees across most of the area
this afternoon under mostly sunny skies. A few light sprinkles and
an isolated shower have briefly bubbled up on radar over far
southeastern Kentucky, but for most locations there have just been
some fluffy cumulus. Heat indices range from 95 to 100F at many
locations, thanks to dew points recovering back into the lower to
middle 70s. The latest analysis shows a weak surface trough
northwest of Pine Mountain under an axis of 500 to 1,500 J/kg of
MLCAPE. The trough intrudes into a broad area of surface high
pressure which is centered off of the Mid-Atlantic/New England
coast. Looking aloft, we find a parent 500 hPa ridge/high
extending from the Western Gulf Coast northeastward across Lower
Ontario and into Quebec, though a minor weakness in the ridge is
noted over Central/Southern Appalachians.
The upper level ridge will flatten out through the short term and
morph into a closed low along the North Carolina/South Carolina
coast as the associated surface high drifts into the Atlantic.
Through early this evening, the combination of continued strong
surface heating as well as the presence of weak convergence with
the surface trough and a weak vorticity max passing through the
500 hPa weakness aloft is expected to continue sparking additional
isolated convection into early evening before instability wanes
with the loss of diurnal heating. A few passing mid and high level
clouds are anticipated tonight as moisture levels continue to
rise amidst a south/southwesterly return flow on the back side of
the slowly departing high. While fog formation is likely in the
deeper, sheltered river valleys, modest flow just above ridgetop
level favors sufficient mixing to mitigate fog formation at closer
to ridgetop elevations and in more open areas. On Thursday,
another extensive cumulus field should develop, but given the lack
of any apparent forcing mechanism and little confidence where any
isolated activity is favored to develop, PoPs in the forecast
will remain too low to mention (less than 15%) at this time.
Conditions on Thursday night appear similar to the prior night.
In sensible terms, look for a hot and increasingly humid weather
pattern to continue. An isolated shower or perhaps a thunderstorm
is possible through early this evening from Wayne to Breathitt to
Letcher counties and south, but most locations will stay dry.
Thereafter, look for a mostly clear night with temperatures
settling back into the upper 60s to lower 70s. Fog is probable in
the typically favored sheltered river valley locales. On Thursday,
mostly sunny skies return with temperatures rising back into the
lower 90s for most locations. With humidity factored in, those
temperatures are expected to feel more like 97F to 102F. A very
isolated shower or storm cannot be ruled out (10% chance) but a
vast majority of the area will just be hot and dry. Thursday night
will see temperatures settling back into the upper 60s to lower
70s while fog is favored to develop once again in the sheltered
river valleys.
.LONG TERM...(Friday through Wednesday)
Issued at 637 PM EDT Wed Jul 23 2025
The long term forecast continues to be defined by atmospheric
ridging and hot sensible weather conditions. When the period opens
on Friday morning, the ridge will be centered over the southeastern
CONUS. As the weekend progresses, a series of shortwave disturbances
will propagate around its northern periphery. This should flatten
the ridge out and place Eastern Kentucky in a regime of weak, quasi-
zonal flow aloft. Thus, the surface frontal boundary associated with
these shortwaves is unlikely to progress south of the Ohio River.
The antecedent warmth and humidity will keep isolated to scattered
diurnal-type showers and thunderstorms in the forecast on Friday,
Saturday, and Sunday, with MaxTs in the low 90s and MinTs in the low
70s. This convection, and its related cloud cover, could work to
provide some localized relief from the heat through the weekend.
Heat indices are forecast to climb above 100 degrees in the deepest
valleys and in urban corridors during this time frame, but
confidence in reaching headline criteria is reduced by these rain
chances. With that being said, heat impacts are cumulative, and the
heat is likely to persist into the next work week.
Early next week, stronger ridging is expected to build to the
southwest of the forecast area. This orientation will shift the
winds aloft towards the north/west and allow some drier air to
advect into the midlevels. This favors efficient boundary layer
mixing and less diurnal precipitation coverage, which could allow
soils to dry out some. Such factors are climatologically known to
increase the likelihood of realizing forecast high temperatures
above 95 degrees in the forecast area, and the latest NBM guidance
for Monday and Tuesday has highs warming into the mid 90s across the
region. This actually appears feasible given the latest model data.
LREF probabilities of 850mb temperatures greater than 22 degrees C
continue to trend upwards in this time frame, giving further
credence to the notion that the heat early next week could be the
real deal. The stagnant surface pattern will keep the antecedent low-
level humidity in place as the other ingredients fall into place.
Collectively, this set up points toward forecast heat indices above
105 degrees in the valleys, in the Bluegrass, and in locations west
of I-75 on Monday and Tuesday. Forecast overnight lows above 70
degrees will provide little nocturnal relief from the heat, and heat-
related health impacts will become increasingly likely by the end of
the forecast period. The experimental NWS HeatRisk product visually
depicts this increasing risk, with much of Eastern Kentucky in the
Level 3/Major category on Monday, July 28th. Because of this risk,
the trends in this temperature forecast will need to be monitored
closely in the coming days. The current forecast grids flirt with
heat headline criteria, and regardless of eventual product issuance,
this heat is poised to be impactful.
Thankfully, some relief from this heat is expected to eventually
emerge within the extended forecast period. By mid-week, models
begin to point towards height falls and a shift towards more
persistent northwesterly flow. The guidance suite generally agrees
that broad troughing will dig into the NE CONUS as the calendar
turns to August, with ridging still in place over the Great Plains.
This favors the eventual advection of a relatively cooler/drier
continental airmass into the Ohio River Valley via more uniform NW
flow. Along these lines, the CPC 8-14 day outlook depicts a chance
for below-normal temperatures and near-normal precipitation after
July 31st. However, this northwesterly flow pattern can also lead to
ridge-riding mesoscale convective systems in our forecast area.
These MCSes are not resolved well within the coarsely-gridded long-
range forecast guidance, but SPC notes the potential for these low-
predictability systems to propagate towards the Ohio River Valley
next week in their Days 4-8 discussion. If such a system makes it
all the way to our forecast area next week, it could also "bust" the
heat forecast. Thus, we will also need to closely monitor the
evolution of upstream convection next week.
For now, expect warm and humid summertime conditions to persist and
even intensify over the next seven days in Eastern Kentucky.
Interests with outdoor plans next week are accordingly encouraged to
review heat safety information ahead of time at
weather.gov/safety/heat.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 720 AM EDT THU JUL 24 2025
Flight conditions at the regions TAF sites will be VFR through
the period. Few to scattered cumulus will again develop this
afternoon, with a low chance of a shower or storm north of
Interstate 64 in the afternoon or early evening, making KSYM the
only terminal which may see any convection, though confidence is
too low to mention at this time.
Winds will generally be variable under 8 kts thanks to high
pressure east of the region.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...GEERTSON
SHORT TERM...GEERTSON
LONG TERM...MARCUS
AVIATION...HATCH
Source: JKL issues Area Forecast Discussion (AFD) at Jul 24, 7:51 AM EDT (https://mesonet.agron.iastate.edu/p.php?pid=202507241151-KJKL-FXUS63-AFDJKL)
---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!