902
FXUS63 KJKL 090643 AAC
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
243 AM EDT Thu May 9 2024

.KEY MESSAGES...

- Our main thunderstorm potential lasts into early Thursday, with
  some showers then possible at times through early next week.

- Severe thunderstorms are possible until late tonight or early
  Thursday morning. Large hail and damaging winds are the primary
  threats, but there is also a risk of tornadoes. Locally heavy
  rainfall could also lead to flash flooding, especially in the
  Cumberland basin.

- Above normal temperatures are forecast through Thursday. A cold
  front passing on Thursday will bring cooler temperatures from
  Friday through early next week.

&&

.UPDATE...
Issued at 242 AM EDT THU MAY 9 2024

Hourly grids were updated to account for recent little convective
activity currently occurring over eastern KY although upstream
activity over southern IN and portions of western and central KY
should continue east southeast into eastern KY later tonight. The
instability gradient is generally southwest of eastern KY and the
stronger storm should generally remain south of the TN border.
However, some heavy rain could occur in the southernmost tier or
two tiers of counties.

UPDATE Issued at 1136 PM EDT WED MAY 8 2024

Updated temperatures and PoPs through the remainder of the
overnight. Current temperatures in the lower 60s will likely
remain steady overnight given persistent cloud cover and periods
of rain/showers/thunderstorms.

The Flood Watch was pared back by canceling along a line from
Montgomery County to Martin County and to the north, and continues
south of that line. Flood Advisories continue for parts of south-
central and southeast Kentucky into the overnight.

UPDATE Issued at 626 PM EDT WED MAY 8 2024

Main changes with this update were to lower temperatures where
there is ongoing convection in our southern counties. Otherwise,
the forecast looks good.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 345 PM EDT WED MAY 8 2024

Effective warm frontal boundary has lifted north across southern KY,
with new storms increasing in coverage now that earlier stratiform
rains have ended. Upstream storms have produced some hail and wind
reports, with a potential tornado farther into western KY. As the
afternoon rolls on, expect instability to increase in our southern
KY counties, bringing a threat for hail, damaging winds, and at
least a narrow window for tornado potential. The farther you get
from the KY/TN border, the smaller the window for severe potential
late this afternoon and evening. In fact, overall rainfall totals
from hi-res models have come down the farther north you go. Will let
the ongoing Flood Watch hang on for now, but wouldn`t be surprised
if it could let parts of it go later this evening.

As we get into Thursday, a broad area of low pressure will be
crossing northeast KY. We`ll keep in chances for thunderstorms, but
these will not be severe, and those chances will end by late
afternoon as the low heads to the mid-Atlantic coast. We`ll see some
sunshine by then as well, and expect temperatures to rise to the
upper 70s to around 80.

Thursday night, another shortwave rotates across the Midwest and
will bring in some light rain chances towards daybreak Friday. Lows
should generally be in the lower 50s.

.LONG TERM...(Friday through Wednesday)
Issued at 356 PM EDT WED MAY 8 2024

The 08/12z model suite analysis shows mean troughing extending
from Eastern Canada down in the the Northeast US/Great Lakes/Ohio
Valley through Friday and most of the upcoming weekend. Shortwave
upper level disturbances passing through the trough will bring an
opportunity for weak convection on both Friday and Saturday
afternoons. Instability is very meager on both days, but may be
sufficient for a few isolated rumbles on thunder on Saturday.
Heights finally begin to rise on Sunday, likely keeping the
afternoon cumulus field subdued. Temperatures will be cool on the
cool side with highs generally in 60s on Friday, mid 60s to near
70 on Saturday and upper 60s to mid 70s on Sunday. Skies are
expected to trend partly cloudy to clear each night, setting the
stage for chilly nights with lows ranging in the 40s and extensive
fog formation in the river valleys.

As the upper level trough departs northeastward, ridging briefly
returns later Sunday and into early Monday. Meanwhile, another
upper low/trough will eject from the Desert Southwest out onto the
Plains. This will foster a new low pressure system tracking
slowly from the Red River Valley of the South on Monday to across
the Ohio Valley by Wednesday. After one more chilly night with
lows in the 40s on Sunday night, southerly flow will push
temperatures noticeably warmer with forecast highs in the mid to
upper 70s and lows in the 50s to lower 60s through Wednesday. Weak
diurnally-modulated modulated convection is anticipated each
day from Monday through Wednesday. GFS soundings suggest that the
instability will remain to shallow for thunder on Monday, but
should become deep enough for at least a few thunderstorms on
Tuesday and Wednesday. Weak lapse rates and marginal shear should
preclude any notable severe weather threat.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 235 AM EDT THU MAY 9 2024

A lull in convection was occurring at issuance time across the
region with a few showers near the TN border and some storms to
the west and south of eastern KY. Convection to the west of the
area should arrive around 08Z or 09Z and track east, though the
strongest convection should remain west and south. In the lull,
varying amounts of clouds are leading to some fog or status in
some locations and MVFR or even IFR reductions while other areas
were experiencing VFR. As the convection moves into the area, at
least brief reductions to VFR ceilings and or visibilities are
anticipated a few hours either side of 12Z for most locations.
Improvements to VFR should then follow for most areas as coverage
of convection decreases. Some increase in coverage could occur
again during peak heating as a cold front approaches. Behind this
activity, reductions down to MVFR or perhaps lower are
anticipated in the north to end the period. Some fog would also
be possible with visibility reductions if clouds were to thin
enough falling recent rain. Winds will average between southeast
and southwest tonight at generally 10KT or less before becoming
southwest to west as the cold front moves through on Thursday into
Thursday evening.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 8 AM EDT this morning for KYZ058-059-068-069-
079-080-083>088-108>118-120.

&&

$$

UPDATE...JP
SHORT TERM...SHARP
LONG TERM...GEERTSON
AVIATION...JP