Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 250145
Area Forecast Discussion
National Weather Service Louisville KY
945 PM EDT FRI JUN 24 2016
Issued at 942 PM EDT Fri Jun 24 2016
The forecast is generally on track tonight. The main issue in the
near term will be the potential for fog overnight. Most of the short
term guidance this evening suggests that far south and east central
Kentucky will stand the best chance for seeing some dense fog
towards morning. Just made some minor adjustments to the fog grids
to nudge the areas of dense fog wording a bit more to the southeast.
.SHORT TERM (Now through Saturday Night)...
Issued at 320 PM EDT Fri Jun 24 2016
...Dense Fog Possible Late Tonight and Early Saturday Morning...
Frontal boundary has not made much progress to the south today. This
morning`s low clouds have mixed out, but have been replaced by a
rather dense Cu field. Temperatures have warmed into the 80s, with
the cool spots in the NE/E sections and the warmer spots residing in
our southwestern areas. For the remainder of the afternoon, we
expect generally partly cloudy skies with afternoon temps maxing out
in the next 1-2 hours. This evening should be rather tranquil with
temperatures falling into the upper 70s.
For tonight, high pressure will nose into the region from the Great
Lakes states. Drier air aloft will continue to push in while a
shallow layer of dry air may push into southern Indiana. Model
proximity soundings show a temperature inversion developing
overnight which will likely trap moisture underneath. The
combination of clear skies, light winds, and the inversion with
moisture underneath will likely result in fog developing. At this
time, it appears that patchy dense fog may be more common across
southern Indiana and portions of northern KY. However, more
widespread dense fog may develop across mainly southern KY. For
now, plan on issuing a Special Weather Statement to heighten
awareness of the fog potential overnight. Should conditions
deteriorate more than forecast tonight, a Dense Fog Advisory may be
required later tonight. Lows will range from 65 to 70 in most
areas, a few of our typical cool spots may be slightly cooler.
Dry conditions are expected across the region for Saturday.
Afternoon temperatures will top out in the upper 80s to the lower
90s. We may see a risk of an isolated shower or storm in the late
afternoon across our southwest sections, though it appears
convection may be more focused out in the I-24 corridor of west KY.
Lows Saturday night will cool into the upper 60s to the lower 70s.
.LONG TERM (Sunday through Friday)...
Issued at 325 PM EDT Fri Jun 24 2016
...Round of Strong Storms Possible Sunday and into Monday...
...Much Cooler Weather Expected for Mid to Late Week...
Mid-level ridge axis will break down across the region late this
weekend as a strong short wave trough moves through the northern US
and southern Canada. This will drive a cold front through the
region Sunday and into Monday. This should result in a round of
showers and thunderstorms from late Sunday through the day on
Monday. Combination of moderate instability along with good
convergence along the boundary could result in some strong to
possibly severe storms during that period. Main threats look to be
damaging winds at this time. We plan on highlighting this threat in
the Hazardous Weather Outlook product. Highs Sunday and Monday look
to warm into the upper 80s to the lower 90s with overnight lows in
the lower 70s.
After the front goes through the region, we`ll see drier and cooler
weather return to the region for Tuesday and Wednesday. Highs
Tuesday will be cooler with readings topping out in the mid-upper
80s, but Wednesday will be the coolest day with highs only reaching
the upper 70s to around 80 in most areas. Dewpoints will drop into
the upper 50s to lower 60s which will be more refreshing than the
low-mid 70s dewpoints that we`ve seen of late.
The forecast becomes more challenging as we head into the later part
of the week. The overall flow pattern will be one with a ridge out
west and a baggy trough axis in the east. This will place the Ohio
Valley in a notorious northwest flow. During this time, we`ll have
to watch for perturbations moving along the periphery of the ridge
and then riding down into the Ohio Valley. While there has been a
constant signal from the Euro of one these arriving around Thursday,
the models really struggle with these type flow regimes.
Nonetheless, we will keep chance PoPs in the forecast at this time.
Temperatures will remain below normal for late June and early July
with highs mainly in the lower 80s with overnight lows in the 60s.
.AVIATION (00Z TAF Update)...
Issued at 656 PM EDT Fri Jun 24 2016
Low level moisture remains across the region this evening despite
the dry air aloft moving in. Skies are expected to become mostly
clear overnight with winds becoming light and variable to calm. The
main concern for the overnight hours will be the potential for fog.
Visibilities are expected to drop to MVFR at SDF and LEX and into
the IFR range at BWG. Any fog that develops will dissipate shortly
after sunrise tomorrow. The remainder of tomorrow will feature light
winds and mostly clear skies.