Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 271049
Area Forecast Discussion
National Weather Service Louisville KY
649 AM EDT FRI MAY 27 2016
...Updated Aviation Discussion...
Issued at 540 AM EDT Fri May 27 2016
Solid rain shield still lifting from the Missouri Bootheel into
southern Illinois, and maybe just grazing the Wabash Valley. Seeing
a small signature of a warm advection wing and/or last night`s old
boundary lifting north across western Kentucky, but no sign of
precip breaking out this far east. Hi-res models are coming around
to the idea of staying dry through the morning, but given the juicy
atmosphere and the continued possibility of a stray shower across
the Hoosier National Forest, will leave the early morning 20 POP as-
Webcams and sfc obs are showing a few decent pockets of fog, mainly
across south-central KY where the heaviest rain fell Thursday. Don`t
think this will last very long as the boundary should lift through
shortly, but did tweak the grids to show this brief, patchy fog for
a couple hrs.
.SHORT TERM (Now through Saturday)...
Issued at 300 AM EDT Fri May 27 2016
Unsettled pattern remains in place with amplified flow aloft, and a
juicy air mass residing over the Ohio Valley. However, the best
moisture feed remains over the Mississippi Valley, so it`s been a
mainly dry night across central Kentucky, and only a couple of
showers have developed over southern Indiana, but still confined to
the Wabash Valley.
Boundary left over from Thursday afternoon convection is quite
difficult to identify in a sloppy surface pressure pattern, but
could still spark a shower or storm this morning before it lifts
north of the area. Otherwise expect a dry day across much of central
Kentucky as we`ll be in a squeeze play between the main moisture
plume to our west, and isolated-scattered storms that over the
Cumberland Plateau. The latter convection will likely bleed
northward into east-central Kentucky, including the Bluegrass
region, late in the day into this evening. Confidence is limited so
will only carry a 20 POP there. With a better shot at sunshine
today, temps will push well into the mid/upper 80s, and we could
even squeeze out a 90, with Louisville as the most likely location
given the heat island influences.
Upper low tries to lift out of the Plains on Saturday, and impulses
coming through the base of that trof will make for a more
convectively active day across the Ohio Valley. Still not expecting
anything organized, and certainly not a day-long washout, but enough
of the area will see rain to justify a low-end likely POP in the
afternoon. Plenty of clouds will hold temps in check, so most
locations will top out in the lower/mid 80s, but depending on timing
a few spots west of I-65 could stay in the 70s.
.LONG TERM (Saturday Night through Thursday)...
Issued at 255 AM EDT Fri May 27 2016
Upper pattern really flattens out Sat night, so the last of the
widespread/organized precip should exit the region during the
evening. However, there`s not much of a change in the low-level air
mass, so we`ll continue to see warm and humid conditions well into
next week. Will depict a warmer and drier pattern, especially
heading into Mon-Tue, but with such a juicy air mass it won`t take
much to spark diurnal convection, so will continue to advertise 20
POPs by day and dry nights. Temps will be solidly above normal, but
it will be difficult to get enough sunshine to crack the 90 degree
mark in this pattern.
Toward mid-week, another upper trof digs into the Plains and the
pattern amplifies again. The other unknown is whether this pattern
can tap into remnant moisture from the tropical system that`s
progged for the Southeast this weekend. Will see POPs ramp back up
to a solid chance Wed-Thu, and daytime temps will not be quite as
.AVIATION (12Z TAF Update)...
Issued at 640 AM EDT Fri May 27 2016
Convection has been active across southeastern MO into southern IL
early this morning, remaining to the west of the TAF sites with only
sct/bkn mid and high clouds across our area. So far early this
morning, SDF and LEX have remained with VFR vsbys and this should
continue from the start of the current forecast period. Meanwhile,
local fog at BWG has reduced vsbys to between 1/2 and 2 miles early
this morning. Will start BWG as MVFR in fog at 12z before going
P6SM by 14z.
For this morning, showers well to the west should remain there as
they move north-northeast. Otherwise, VFR conditions will prevail
for the day with only an isolated afternoon storm possible, but not
included in the TAF. Surface winds will be SSW at 10-15 kts. For
tonight, mid and high convective cloud debris should impact the
area, but not showers. At SDF, there could be a few showers nearby
Saturday morning but remaining VFR.