Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/19/23

Area Forecast Discussion

National Weather Service Louisville KY

 737 PM EDT Sun Jun 18 2023

...Updated Aviation Discussion...

.Forecast Update...
Issued at 553 PM EDT Sun Jun 18 2023

Scattered convection is ongoing across southern KY this evening near
a warm front. The warm front continues to lift slowly northeastward,
with modest destabilization occurring across south-central KY thanks
to continued sfc heating and low-level moisture advection.

Additional scattered convection is expected across south-central KY
through the remainder of the evening, with storms weakening as they
attempt to lift further northeast into drier, more stable air.
Recent BNA ACARS soundings show a moist, modestly unstable airmass
with around 500-800 J/kg MUCAPE and 1.6 inch PW. SDF ACARS soundings
are considerably drier with a 0.7 inch PW.

Widely scattered storms across the southern half of KY will drift
NNE at around 15 mph this evening and could produce a brief
downpour, lightning, and perhaps a 30+ mph wind gust. Effective bulk
shear is currently weak and a limiting factor for updraft
maintenance. However, deep shear does increase to 25-30 kts toward
sunset and will provide slightly better organization for individual
cells.

&&

.Short Term...(This afternoon through tonight)
Issued at 255 PM EDT Sun Jun 17 2023

Currently... the region is dry and breezy with clouds beginning to
stream over the region. The low pressure center is positioned over
Missouri and will continue moving eastward. As the low center
approaches the region, winds will shift southwesterly and aid in
bringing moisture into the area. Showers and storms will track
through the area from southwest to northeast, however, as they
travel northeast they will likely dissipate due to drier air. Areas
south of I-64 and west of I-65 could see some scattered showers and
storms this afternoon and into this evening.

Tonight and Tomorrow... the first wave of showers/storms will
dissipate and the main wave of showers/storms will blanket the
region beginning around 04Z in the southwest and working to the
northeast by about 11Z. These showers and storms will remain in the
region throughout the day. Severe potential is low due to little
instability. Forecast soundings show a well saturated column and
PWATs around 1.8-2.0 inches. The main threat with these
showers/storms is localized regions of heavy downpours. QPF shows
about 1.0-1.5 inches of rain everywhere and locally 2.0-2.5 inches.
Ponding in areas that see multiple slow moving showers is possible,
however, with the area being in either a D0 or D1 drought, the soil
will likely respond quickly. Tomorrow will be breezy as the low
center is over the region and high temperatures will be in the mid
70s.

.Long Term...(Monday through Saturday)
Issued at 251 PM EDT Sun Jun 18 2023

Key message: scattered showers and storms this week and into the
weekend, with coverage maxima likely during the afternoon and
evening hours. The rain will be helpful, but given its convective
nature, some locations will benefit more, or less, than others.

An upper low overhead at the start of the Long Term will sink into
the Deep South through mid-week possibly bringing record rains to
the Carolinas, drift back to the north late in the week as ridging
builds over the Bahamas and Caribbean, and then open up into a
trough and push eastward this weekend. There will be enough moisture
and instability present to support scattered showers and
thunderstorms, especially in the afternoons and evenings. Shear and
mid-level lapse rates look weak with high freezing levels. Can`t
rule out a few storms generating some locally gusty winds and heavy
downpours around peak heating, but DCAPE progs are not particularly
impressive through at least Thursday and the overall threat for
organized severe weather looks small. Better chances for severe will
be well to our west in the Plains.

Total rainfall amounts during the Long Term generally range from
around half an inch in southern Indiana to one and a half inches in
the Lake Cumberland and southern Blue Grass regions. Of course, with
convective summertime rainfall, there can be large differences over
short distances, and some folks will benefit more than others.
Still, rain will be welcome and while eradication of the drought in
east central Kentucky isn`t particularly likely quite yet, we could
see a good dent put in it by this weekend.

&&

.Aviation...(00Z TAF Issuance)
Issued at 737 PM EDT Sun Jun 18 2023

Showers and SCT TSRA have been limited to southern KY this evening,
where a warm front is draped NW to SE. However, all terminals
including BWG are likely to start off this TAF period VFR.

However, a wave of low pressure currently over eastern MO will
rotate over western KY tonight and central KY tomorrow. Expect
increasing rain chances late tonight, with widespread SHRA and MVFR
ceilings on Monday. In particular, expect ceilings to deteriorate
from SW to NE Monday morning between roughly 08-16Z. TEMPO IFR
conditions are also expected, most likely in heavier SHRA or TSRA.

TSRA chances are roughly 30-60% on Monday, so at least PROB30 groups
are worth mentioning but VCTS or prevailing TSRA will also be
possible at times. Confidence in detailed TSRA timing is relatively
low, as showers and scattered convection will spend much of the day
spinning cyclonically over the region.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&

$$

Update...EBW
Short Term...SRM
Long Term...13
Aviation...EBW