Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 290502

102 AM EDT Tue Jul 29 2014

...Updated Aviation Discussion...

...Forecast Update...
Issued at 932 PM EDT Mon Jul 28 2014

Clouds have pretty much cleared out so have updated the sky cover
forecast to reflect that.

Given current and upstream dew points, have decided to drop
Louisville`s MinT a couple of degrees tonight, thus putting the
forecast low into record territory.  It`s not a slam dunk, though,
as a weak disturbance diving southward into the mean upper trof may
bring a slight uptick in clouds along and west of I-65 around dawn.
Clouds would prevent the temperature from dropping as much as it
would with clear skies.

Earlier this evening we introduced some patchy fog to the eastern
valleys for tomorrow morning, and that still looks good.

.SHORT TERM (Now through Tuesday Night)...
Issued at 250 PM EDT Mon Jul 28 2014

The synoptic pattern this afternoon features an unusually amplified
pattern for late July, with a large ridge over the western CONUS and
a downstream trough over the Ohio Valley.  This trough will remain
in place through the short term period, providing unseasonably cool
July temperatures.

A good amount of strato-cu continues to affect much of the region
this afternoon.  A PV anomaly diving through portions of central
Ohio may help provide just enough ascent to squeeze out a few
sprinkles or showers across north-central KY or southern IN this
afternoon, but think most will end up staying dry given rather
shallow moisture.  Highs have been slow to climb given the heavy
cloud cover as temperatures have remained mostly in the low to mid

The strato-cu should largely dissipate tonight, leaving mostly clear
to partly cloudy skies.  As high pressure noses in from the
northwest, winds should go rather light, setting the stage for a
good radiational cooling night.  A few record lows will be in
jeopardy tonight as temperatures fall into the low and mid 50s,
perhaps even some upper 40s possible in the typical cool spots.
Here are some of the record lows for July 29th:

Bowling Green: 52, 1925
Frankfort: 52, 2013
Louisville (SDF): 58, 1928
Lexington: 54, 2013

Tuesday will be similar to today as the upper trough remains in
place.  Cloud cover looks to be a bit less widespread than today,
thus think highs may be a few degrees warmer.  Highs will range from
the mid 70s to the lower 80s.

Tuesday night will once again be cool as a surface ridge remains
nearby and skies will once again be mainly clear to partly cloudy.
Therefore, lows will once again drop into the mid to upper 50s.
Here is a look at some of the record lows for July 30th that may
also be threatened:

Bowling Green: 53, 1965
Frankfort: 52, 2013
Louisville (SDF): 55, 1965
Lexington: 51, 1965

.LONG TERM (Wednesday through Monday)...
Issued at 245 PM EDT Mon Jul 28 2014

Broad upper trof will cover the eastern CONUS for most of the coming
week, with a fairly weak surface pressure pattern in place under it.
Models try to spit out QPF just about every afternoon, but this has
been overdone for much of the summer and extended GFS MOS never
shows more than slight chance. With most of the forcing remaining to
our north as vort lobes pinwheel around the James Bay low, will keep
the forecast dry through Thursday. It appears our luck may run out
Friday into the weekend as the upper trof sharpens a bit, but even
that warrants no more than a 20-30 POP in the absence of any real
surface boundary, and with the Gulf never really opening up.

Temps will run below normal through the period. Wednesday max temps
are close to MOS consensus, while we will lean on the low end of
guidance for Wednesday night as strong radiational cooling will let
some of the typical cool spots drop into the mid 50s. Look for a
gradual recovery in the latter part of the week, but still below
climo and slightly below guidance, with dewpoints staying in the
comfortable range without any significant return flow to tap the


.AVIATION (00Z TAF Update)...
Issued at 100 AM EDT Tue Jul 29 2014

High pressure building in from the Plains to the Ohio Valley will
give us light northwest breezes and VFR conditions through the TAF
period. Dry air advection should be the limiting factor for any fog
chances at the terminals.  LEX would be the only terminal to see a
small chance for light br this morning but think that those chances
are too slim to mention in the TAF.




Short Term.....KJD
Long Term......RAS
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