Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 241457
Area Forecast Discussion
National Weather Service Louisville KY
1057 AM EDT SUN APR 24 2016
Issued at 1045 AM EDT Sun Apr 24 2016
Well...Midnight Shift forecast humming along nicely with
temperatures responding nicely after morning lows in the 40s and
even some upper 30s (Cynthiana 38 on KY Mesonet). BNA and ILN 12z
soundings showing a layer of moisture at about 4K and some high
cirrus above with afternoon highs in 75-80 across North and 78 to
83 across the South.
Afternoon forecast will delve into the unsettled week ahead with a
series of Pacific lows moving into better moisture and instability
across the center of the country and eventually the Ohio Valley.
No updates required.
.SHORT TERM (Now through Sunday)...
Issued 300 AM EDT Sun Apr 24 2016
The synoptic pattern early this morning features a trough across the
west-central CONUS, which will help induce a downstream ridge across
the Ohio Valley through the short term period. This will bring warm
and dry conditions to the region through the period.
The latest observations show temperatures cooling into the upper 40s
and 50s early this morning, under clear skies and mainly light
winds. Latest observations are showing some patchy fog developing,
although have yet to see any area webcams showing the fog as being
overly dense. Will keep patchy fog in the forecast this morning and
continue to monitor webcams to see if it becomes more dense.
Otherwise, expect a very pleasant day with mostly sunny skies. High
pressure currently located over the Great Lakes region will push
east today, allowing for southerly return flow to commence. These
southerly winds coupled with strong solar insolation should allow
temperatures to climb into the upper 70s and 80s.
Lows tonight will be a bit warmer as winds stay up and upper-level
cloudiness begins to increase. Overnight lows will dip into the
Have continued to go above guidance for temperatures on Monday. Deep
mixing will lead to gusty SSW winds and a good deal of sunshine will
help temperatures climb into the low/mid 80s, with even some upper
80s possible in the typically warmer spots. Guidance is likely
underdoing how dry our soils have become, so feel fairly confident
in going several degrees above guidance on Monday.
.LONG TERM (Sunday night through Friday)...
Issued at 310 AM EDT Sun Apr 24 2016
...Turning more active towards midweek...
The synoptic pattern at the start of the long term period will
feature a strong trough digging into the western CONUS. A couple of
disturbances emanating from this mean trough will be the focus of
the long term period, as they will bring a couple chances for
thunderstorms this week.
Monday night will begin with a sharpening warm front located well to
the north across the lower Great Lakes region. The first
disturbance riding over the ridge aloft will slide southeast along
this boundary, helping to induce showers and thunderstorms late
Monday into Monday night. At this time, it appears the activity
associated with this will stay mainly to the north of the region
through Tuesday morning.
Things become a bit more complicated on Tuesday, as it appears there
could be two main foci for convection. One will be along a
potential outflow boundary that could dive south into the region
from convection to the north Monday night. The other, more likely
scenario will be along the approaching front sagging south into the
Ohio Valley. This would focus convection mainly to the north through
much of the day, but it will slide into the LMK CWA late Tuesday
afternoon/evening into the early overnight hours. This activity
along the boundary will be closer to the better mid-level flow
associated with the PV anomaly sliding southeast over the ridge, so
it will have access to better deep-layer shear (around 30 knots) and
thus there could be a few stronger storms mainly north of I-64.
Attention will then turn toward the west on Wednesday as the
negatively-tilted trough ejects out into the Central Plains and into
the Midwest. The front responsible for the convection late Tuesday
will lift back to the north in response to the ejecting wave on
Wednesday. Some convection will develop along/south of this
boundary on Wednesday (coverage possibly aided by outflow from
storms to the west overnight), but the main deep forcing for ascent
will move into the region Wednesday night. Once again, some strong
storms could be possible late Wednesday as deep-layer shear
increases, but as it stands now the timing looks to be rather
unfavorable for a more robust severe event here in the Ohio Valley
(nocturnal surface inhibition).
Things will begin to dry out through the day on Thursday into Friday
as the cold front slides southeast and high pressure attempts to
build into the region. However, yet another strong system ejecting
into the central CONUS will bring a renewed threat for
showers/storms to the region by next weekend.
.AVIATION (12Z TAF Update)...
Updated at 641 AM EDT Sun Apr 24 2016
High pressure at the surface and aloft will result in VFR conditions
at the terminals through the upcoming period. The only exception
will be at KBWG this morning where some patchy fog will lower
visibilities into the MVFR/IFR range through the first hour of the
forecast. Later this morning, winds will pick up out of the
southeast and then shift to the southwest. A diurnal Cu field may
develop with bases around FL030-040 along with high cirrus possible
late in the day. VFR conditions are expected this evening and into
the overnight hours.