Severe Thunderstorm Warning 29, NWS Jackson, KY

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
845 PM EDT Wed Apr 13 2022

.UPDATE...
Issued at 813 PM EDT WED APR 13 2022

Temperatures in the valleys were cooling faster than originally
expected. The drying low levels and calming winds has allowed for
noticeable decoupling at those locations. Adjustments were made
to the temperature and wind through the front's arrival to account
for the split. The dew points were running slightly below the
obs, so those were brought up and blended using the short blend.
The POPs were not adjusted at this time, but another update may
occur depending on the track of the upstream QLCS activity and
potential overnight dissipation.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 500 PM EDT WED APR 13 2022

20Z sfc analysis shows a pressure ripple moving through in
association with the MCV currently moving some light rain showers
to the CWA. This wave also helped to bring down some higher wind
gusts of 40 mph or so in the clearing out ahead of it. This
clearing allowed sunshine to spike temperatures but then the
thicker MCV clouds and showers took them back down, but do expect
a couple more hours of sunshine and heating to rebuild
instability over our west before sunset. Temperatures currently
vary from the upper 70s to near 80 in the far east to the mid 60s
in the west and north where the MCV's rain cooled the air.
Dewpoints also varied across the wave with some drier values near
50 in the far east thanks to the better sunshine earlier and low
to mid 60s in the wake of this lead feature. Meanwhile, winds are
generally from the south southwest at 10 to 15 mph with gusts to
30 mph in general, but up to 40 mph just ahead of the sfc wave.

The models are just in okay agreement aloft with themselves and in
particular having trouble capturing and modeling the MCV. While
they all have it to a certain extent they uniformly dampened it
too quickly. Otherwise, the main feature is the very deep and well
wrapped up closed low spinning east from the Northern Plains to
the Upper Midwest tonight and Thursday. This dominant feature is
handled very well by the models with the main energy lifting
northeast of Kentucky. The 5h height falls associated with the
gyre to the north bottom out later Thursday night with some
rebounding by dawn Friday in the nearly zonal flow south of the
upper low. Given the narrow model spread post MCV, did stick with
the blended solution from the NBM without much wide-scale
adjustments. For the near term, current conditions and some of
the CAMs simulated radar guidance proved most useful.

Sensible weather will feature a likely rather warm but quiet
evening before the main batch of storms start to move into the
area - closer towards midnight. Expect a squall line or its
remnants to move into eastern Kentucky toward late evening and
through the first part of the overnight. The actual front follows
prolonging the threat of showers and possible thunderstorms. The
main severe threat remains damaging wind gusts from whatever line
holds together enough to move into the CWA. Should a discrete cell
or two manage to develop ahead of this expected line a tornado
cannot be ruled out given the ample low level helicity to go along
with rebuilding instability. Additionally, a QLCS spawned tornado
or two remain possible with the highest threat found generally
west of I-75. Otherwise, the squall line will likely fall apart
per usual over our CWA with an uptick in coverage possible,
following this initial dampening, owing to the arrival of the
actual cold front. Post frontal, the winds die off from the west
with drier air clearing out the PoPs west to east into early
Thursday morning along with cooler temperatures. This dry air
will make for a return of sunshine on Thursday as temperatures see
a limited rebound. Clear skies and lighter winds will set the
stage for a cool night with an anticipated ridge to valley
temperature split to develop and perhaps some limited fog in the
river valleys.

Did end up adding in a bit of an extra temperature drop off for
the valleys this evening before the approaching front and
convection mixes them back out. Also enhanced the terrain
distinctions in the temperatures Thursday night. As for PoPs, made
the most adjustments in the near term with some tweaking for the
dissolution of the mesoscale squall line followed shortly by the
arriving synoptic front.

.LONG TERM...(Friday through Wednesday)
Issued at 325 PM EDT WED APR 13 2022

Surface high pressure will start the period off, sitting across the
spine of the Appalachians and allow for warmer air to advect in
through the day. Mid level heights will rise modestly during the
day, with quasi-zonal flow in place aloft. A closed low sits
across Ontario, while shortwaves nose in from the Pacific
Northwest and across Southwestern Canada. A fairly moisture
starved cold front will take aim at the area into the weekend,
bringing isolated to low end scattered showers. Guidance has
continued to trend down in QPF, with the GFS and Canadian
suggesting nearly entirely dry solutions. A shortwave dropping
from Saskatchewan through the Northern Plains and into the Great
Lakes will support a low with a cold front running south and
curling west across the Mid and Lower Mississippi Valley. The GFS
is much quicker than the ECMWF, which also lines up within
ensemble runs. Nearly a third of ENS members (34%) suggest a much
deeper, more southerly positioned, and slower trough evolution,
while 54% of GEFS members are in favor of a flatter and more
progressive wave Sunday and into next week. Given the differences
in strength, timing, and location, have geared toward the blend
until better agreement emerges into early next week. High pressure
will then press in from the Mid Mississippi Valley post-front,
allowing for dry conditions to return Tuesday evening and through
the end of the period.

Sensible weather will feature periods of showers and near to
slightly below average temperatures through the period. Afternoon
highs will top out in the low to mid 70s Friday, before decreasing
through the weekend with added cloud coverage/showers and the
passing front. They will moderate some into next week, but generally
stay cooler than average through the end of the period. Similarly,
lows will be mild Friday night into Saturday, ranging from the upper
40s and low 50s, before dropping into the mid 30s to low 40s through
the remainder of the extended.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 845 PM EDT WED APR 13 2022

VFR conditions will hang on through late this evening, before an
approaching line of showers and scattered thunderstorms move in
from the west from 03 to 08z out ahead of an advancing cold
front. These storms will gradually weaken as they head deeper into
eastern Kentucky during the early overnight hours. KSME will
stand the best chance at seeing some stronger wind gusts and some
temporary MVFR or lower conditions. Eventually, as the cold front
makes it through the area, ceilings will lower down to MVFR at all
locations, before clouds scatter out from west to east Thursday
morning, as high pressure builds in across the region. Southeast
to southwest winds of 5 to 10 kts, will generally increase to
10 to 15 kts, with gusts of 20 to 25 kts as the line approaches
from the west. An increasing low level jet will also allow for a
smaller window of LLWS across the area, before the main line of
showers and storms approach, mixing out the inversion. Winds will
then shift to the west to west northwest behind the storms and
cold front.

&&

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

UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM...BB
AVIATION...GEOGERIAN

Hazardous Weather Outlook...UPDATED
National Weather Service Jackson KY
345 PM EDT Wed Apr 13 2022

KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120-142245-
Fleming-Montgomery-Bath-Rowan-Estill-Powell-Menifee-Rockcastle-
Jackson-Pulaski-Laurel-Wayne-McCreary-Whitley-Knox-Bell-Harlan-
Elliott-Morgan-Johnson-Wolfe-Magoffin-Floyd-Lee-Breathitt-Knott-
Owsley-Perry-Clay-Leslie-Letcher-Martin-Pike-
Including the cities of Flemingsburg, Camargo, Jeffersonville,
Mount Sterling, Owingsville, Morehead, Irvine, Ravenna,
Clay City, Stanton, Frenchburg, Brodhead, Mount Vernon, McKee,
Annville, Burnside, Somerset, London, Monticello, Stearns,
Whitley City, Corbin, Williamsburg, Barbourville, Middlesboro,
Pineville, Cumberland, Harlan, Sandy Hook, West Liberty,
Paintsville, Campton, Salyersville, Prestonsburg, Wheelwright,
Beattyville, Jackson, Hindman, Pippa Passes, Booneville, Hazard,
Manchester, Hyden, Jenkins, Whitesburg, Inez, Coal Run,
Elkhorn City, Pikeville, and South Williamson
345 PM EDT Wed Apr 13 2022

This hazardous weather outlook is for portions of eastern Kentucky.

.DAY ONE...Tonight.

Thunderstorms are possible tonight. A few of these storms may be
severe, with damaging wind gusts the primary threat, although an
isolated tornado cannot be ruled out, mainly west of I-75.

Outside of thunderstorms, gusty south to southwest winds are
expected this evening and into the overnight with gusts up to 35
mph. Some locally higher gusts are possible, especially at higher
elevations.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

No hazardous weather is expected.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report any storm damage and tonight.

GREIF/BB