Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 261053

Area Forecast Discussion
National Weather Service Louisville KY
653 AM EDT Tue Sep 26 2017

...Updated Aviation Discussion...

.Short Term (Now through Wednesday)...
Issued at 310 AM EDT Tue Sep 26 2017

Today will be another dry, warm day with highs in the upper 80s to
around 90. Ridging remains in place at the surface and aloft,
resulting in plentiful sunshine and light winds. Tonight will
feature mostly clear skies, with lows in the low to mid 60s.

Cloud cover will increase on Wednesday with the arrival of a cold
front. This boundary is currently draped from Wisconsin down through
Iowa, Missouri, and Oklahoma. The parent upper level wave is very
evident on water vapor imagery over the northern High Plains early
this morning. Over the next couple of days, the upper ridge is
forecast to persist over the lower Ohio and Mississippi River
valleys. This will force the low pressure system well to our north
into Canada, with the surface cold front gradually washing out
underneath upper ridging as it moves through Wednesday. Surface
convergence will be weak, and moisture depth will be limited. Recent
model runs still suggest at least some potential for isolated
showers, mainly north of the WK/BG Parkways Wednesday afternoon. The
GFS/GEFS are the highest in terms of QPF, with the ensemble mean
still only up to around a tenth of an inch along and north of the
Ohio River.

Bottom line: Wednesday will be largely dry for most. NNW winds will
increase Wednesday afternoon and evening. Highs should still reach
the mid/upper 80s prior to the arrival of cooler air.

.Long Term (Wednesday Night through Monday)...
Issued at 320 AM EDT Tue Sep 26 2017

The long term portion of the forecast is expected to remain dry,
with temperatures cooling off behind Wednesday`s cold front. An
upper level trough is forecast to swing southeast through the Great
Lakes late this week, with Canadian high pressure at the surface
gradually building southeast throughout the weekend. Expect fair
weather and low humidity, with highs generally in the 70s. Although,
temperatures in some locations may not make it out of the upper 60s
on Saturday. In short, more like Fall. Overnight lows will be in the
40s and 50s. The two weekend mornings look the coolest, with many
areas down into the 40s.


.Aviation (12Z TAF Update)...
Issued at 645 AM EDT Tue Sep 26 2017

Main challenge will be fog this morning, as BWG and HNB bounce in
and out of IFR visibilities, and BWG even tried to drop below field
mins briefly. Trapped low-level moisture is quite shallow this
morning, so any residual fog should quickly burn off by about 13Z,
with vis and ceiling unlimited by 14Z.

Rest of the valid TAF period will feature few-sct diurnal cu, and
light/variable winds until the late-night restrictions to vis come
into play again before daybreak Wednesday.




Short Term........EBW
Long Term.........EBW
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