Area Forecast Discussion
Issued by NWS Louisville, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KLMK 031923

Area Forecast Discussion
National Weather Service Louisville KY
323 PM EDT Sat Jun 3 2023

.Short Term...(This evening through Sunday)
Issued at 320 PM EDT Sat Jun 3 2023

Sfc high pressure to our north over Canada along with an upper low
over New England and a strong upper high across the Upper Midwest
continue to be the main influences of our weather keeping us mainly
dry with a north to northeasterly flow over the Ohio Valley. A mid-
level disturbance which can be seen on the current WV loop is
working to the southwest and sparking some isolated to scattered
convection across southern PA and WV this afternoon. This energy
will continue to approach northeastern and eastern KY later this
afternoon and evening. Additional showers and storms could form and
possibly work into our CWA out of eastern KY and southern Ohio this
evening. While current mesoanalysis shows 1500-2000 J/kg SBCAPE and
soundings show lots of dry air and some steep low-level lapse rates
confidence is not high that much if any activity will get going
across our area this afternoon or evening. If it did it would likely
be located across the Bluegrass and north of I-64. Given the DCAPE
values, any storm that forms could produce localized gusty damaging
winds. Another point of interest on visible satellite has been
smoke associated with wildfires out of Quebec working across the
eastern Great Lakes. Some of this smoke is on track to pass over our
southern IN/northern KY counties this evening into tomorrow. Could
add some additional haze to the atmosphere over the area. May have a
few more clouds but generally looking at mostly clear skies
overnight and light northeast winds with lows in the low to mid 60s.

Mid level disturbance will cross central KY overnight into tomorrow
morning. This along with an increase in PWAT values between 1.0-1.1"
mainly across south-central KY into TN and afternoon instability we
could see another slight chance of isolated showers/storms in the
afternoon from just around the Parkways southward into TN. A few
could form further north towards Louisville or Lexington but chc.
and confidence remains low. With a slight increase in cloud cover
and upper level high dropping further south temperatures will be a
bit cooler but still warm in the upper 80s to near 90.


.Long Term...(Sunday night through Saturday)
Issued at 320 PM EDT Sat June 3 2023

...Mostly Dry with Warm Temperatures...

Synopsis...Next-week pattern aloft will remain blocky as the
retrograding high will wander over the northern Plains through
midweek while sandwiched by a couple of upper lows over the
Northeast and California. Then, the combination of a persistent
shortwave energy influx reinforcing the Northeast low and a weakness
in the negative height anomalies over the West will allow the high
to resume its retrograding track and relocate over the Canadian
Prairie. Meanwhile, the axis of the Northeast negative height
anomalies will expand into the Ohio Valley which will potentially
condition the large-scale environment for higher rain chances
late next weekend or the coming week.

Model Evaluation/Confidence...There is above-average model agreement
in the synoptic evolution through next Wednesday with increasing
model differences by next weekend associated with the Northeast
upper-low ejection and the amplification of another trough closing
off over the Upper Midwest. Given the model-to-model and run-to-run
variability, there is low confidence in timing and intensity of
precipitation chances for next weekend.

Sun Night - Tuesday...There will be isolated, decaying diurnal
convection along the Tennessee boundary for a couple of hours after
sunset on Sunday, but overnight conditions will be quiet and mostly
clear as another shot of dry air filters in from north. Furthermore,
there is a low chance of patchy fog along the river valleys and
adjacent areas before sunrise especially some rain fell on Sunday.
Monday will be mostly dry for most of the forecast area except for
the southern extent where an isolated shower or storm might overcome
dry-air entrainment and capping inversion aided by surface lifting
ahead of an incoming back-door cold front. For Tuesday, the official
forecast remains dry; nonetheless, there are still a few CMC and GFS
members hinting at a rain chance for this time frame, which cannot
be ruled out amid PW recovery and vorticity advection.Temperatures
will remain above average but slowly trending down by a few degrees
each day.

Wednesday - Saturday...This period will be initially characterized
by dry air advection and light northerly breezes. Temperatures in
the afternoon will be more seasonal as highs stay in the low 80s.
Although there will be several vort max passing over the region, a
stable environment will inhibit rain processes through Friday. As
mentioned above, precipitation and storm chances will probably ramp
up next weekend; however, timing and intensity are still uncertain
at this point. A more dynamic environment could support organized


.Aviation...(18Z TAF Issuance)
Issued at 140 PM EDT Sat Jun 3 2023

Very little changes to the overall forecast through the TAF period
as conditions will remain VFR. With a large sfc high across eastern
Canada to our north and an upper-level high over the Upper Midwest
our winds will remain out of the north-northeast to northeast. This
afternoon as a weak mid-level system moves in from the NE we could
see some scattered Cu form and there is a slight chance around LEX
of an isolated storm late in the day towards evening. As we lose the
daytime heating the chance of any showers/storms becomes zero across
the area. On visible satellite, we can see smoke associated with the
wildfires out of Quebec coming towards the Ohio Valley. This might
add some additional haze as well as any clouds associated with any
convection that forms to our east and northeast this evening and
overnight. Tomorrow as the mid-level energy continues to work across
the area we may see additional isolated showers and storms form,
mainly south of LEX-SDF-HNB but they can`t be ruled out that far




Short Term...BTN
Long Term...ALL
Aviation...BTN is the U.S. government's official web portal to all federal, state and local government web resources and services.