Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 171650

1250 PM EDT Wed Sep 17 2014

...Updated Aviation Discussion...

...Forecast Update...
Issued 955 AM EDT Wed Sep 17 2014

Broad but weak high pressure continues to sprawl from southern
Indiana eastward across Ohio and most of the Keystone State. Fog
continues to hang in over parts of southern Indiana, and we actually
saw visibilities deteriorate a solid 30-60 minutes after sunrise
over south-central Kentucky. Still looking at visibilities of 1 mile
or less over much of that area, but not quite low enough to
constitute a Dense Fog Advisory. Special Weather Statement is valid
until 1430Z to address the low visibilities.

Only real forecast challenge will be timing of when the fog
dissipates, most likely in the next hour although a few valleys may
take a bit longer. Will update products once we clear out.

.SHORT TERM (Now through Thursday)...
Issued at 325 AM EDT Wed Sep 17 2014

In the near term, IR and 11-3.9 micron satellite imagery reveal
mostly clear skies across southern Indiana and central Kentucky.
Some patchy low clouds and fog were noted across the eastern third
of the forecast area.  The main forecast concern this morning will
be fog development.  Current indications are that we should continue
to see fog develop over the region.  We feel that the most extensive
fog will be across southern Kentucky later this morning.  We will
continue to monitor conditions over the next few hours.  Will be
issuing a Special Weather Statement shortly to highlight the fog
potential this morning.  If fog grows more extensive, a Dense Fog
Advisory may be required in the next few hours.  Low temperatures
will cool into the mid-upper 40s in the north with upper 40s to the
lower 50s in the south.

For today, a quick moving mid-level trough axis is forecast to slide
through the region.  Model soundings are still quite dry with this
feature, but enough moisture will be present to produce slightly
more cloud cover than we saw on Tuesday.  Some very light sprinkles
may be possible, but overall, the day looks to be dry.  Stuck close
to the weighted model (WModel) blend here with afternoon highs
warming into the upper 60s north of the I-64 corridor with upper 60s
to the lower 70s across much of Kentucky.

For Tonight and Thursday, mostly clear skies are expected to return
to the region tonight.  Again have stuck close to the weighted model
guidance here with lows cooling into the lower 50s in most areas.  A
few rural locations may drop back into the upper 40s.  Dry and mild
conditions are expected for Thursday with highs warming into the
lower 70s.

.LONG TERM (Thursday night through Tuesday)...
Issued at 302 AM EDT Wed Sep 17 2014

Dry weather will continue Thursday night through Saturday with high
pressure ridging in from the northeast. Aloft heights will build
into the weekend. This will bring warming temperatures for the first
portion of the long term. Highs Friday will be in the mid to upper
70s with highs Saturday in the lower 80s.

Rain chances will be on the increase Saturday night into Sunday as a
low pressure system drops into the Great Lakes region and then pulls
off to the northeast. This will eventually drag a cold front through
the forecast area. However, there are some differences in the long
term models on how fast the front moves through. For now will keep
Monday dry, but if the front slows down there will be a chance for
some lingering showers across east central KY.

High pressure will build in behind the front bringing clearing
skies. Aloft the area will remain in northwest flow. Cooler air will
once again settle back into the region next week. Highs will drop
back into the lower 70s, with highs in the 60s possible by
Wednesday. Lows will drop back into the 50s and 40s.


.AVIATION (18Z TAF Update)...
Issued at 1245 PM EDT Wed Sep 17 2014

Morning fog/stratus finally lifting at BWG, leaving us with a VFR
afternoon. Just enough low-level moisture that we will see a
strato-cu ceiling at times, but no restrictions to flight category.

The challenge will be fog potential around daybreak Thursday.
Similar setup to this morning, but we will be a bit more on the
periphery of the surface high. Still, winds will be nearly calm and
temps are expected to cross over the dewpoints, so IFR fog seems a
pretty good bet in BWG. Will carry borderline IFR/LIFR conditions
for a couple of hours. SDF and LEX should remain unrestricted, with
light winds generally out of the NE.




Short Term.....MJ
Long Term......EER
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