Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 062254

Area Forecast Discussion
National Weather Service Louisville KY
654 PM EDT TUE OCT 6 2015

...Updated Aviation Discussion...

.SHORT TERM (Now through Wednesday Night)...
Issued at 300 PM EDT Tue Oct 6 2015

Sfc high pressure will continue to build south into our region
through tomorrow with weak upper level ridging aloft.  This will
result in a dry forecast and perhaps a slightly cooler airmass than
we`ve seen the past few days.  We should see few-sct upper level
clouds continue over the region tonight with few-sct low to mid
level clouds more likely tomorrow/tomorrow night.

For temperatures, went with lows in the 50s both tonight and Wed
night.  High temps tomorrow should be slightly cooler than today
with temps ranging through the upper 70s/lower 80s.  With fewer
clouds expected tonight especially in central KY, light patchy fog
will be possible.

.LONG TERM (Thursday through Tuesday)...
Issued at 310 PM EDT Tue Oct 6 2015

The synoptic pattern at the start of the long term period will
feature generally split flow across the CONUS, with the northern
stream affecting the Ohio Valley through the period.  Of note will
be a PV anomaly diving through the flow aloft on Friday, helping to
amplify a trough over the region this weekend.

Thursday will likely be the warmest day of the period, as
southwesterly surface flow will help foster relatively deep mixing
Thursday afternoon.  The only limiting factor will be increasing
mid/upper-level clouds from the northwest ahead of the approaching
system.  These clouds may hinder temperatures a bit, but current
indications are that we should see some sunshine through the day
which will help push temperatures into the low to possibly even mid

The PV anomaly and associated cold front will push through the
region late Thursday night through Friday.  The GFS trended slightly
more amplified with the trough with this run, bringing better upper-
level support into at least the northern CWA.  This solution had
decent agreement with the 06/00Z ECMWF solution.  However, the
06/12Z ECMWF solution has come in even more amplified, which
actually allows a secondary surface low to develop across the
Appalachians, which would help keep showers in the southeastern CWA
through the first part of Saturday.  Would like to see another run
or two showing this solution before jumping on it.  Therefore, will
favor the 06/00Z ECMWF and 06/12Z GFS/GEFS solutions.  Given the
general agreement in at least the entrance of the front/precip into
the region and better forcing, will up pops a bit from the previous
forecast.  There is enough instability along the front to continue
with slight chance of thunder mention, but think the timing of the
front (late Thursday into the first part of Friday) will help limit
the amount of instability that is able to build.  A slightly slower
solution would tend to favor better chances for thunder, especially
in the east/southeast parts of the CWA.

A trough and cooler temperatures will move in behind the front
Friday into the upcoming weekend, but a warmup looks in store once
again early next week as the upper-level flow become more zonal.
After temperatures dipping into the upper 60s on Saturday, readings
will return to the 70s and lower 80s Sunday into early next week
with dry conditions expected.


.AVIATION (00Z TAF Update)...
Issued at 650 PM EDT Tue Oct 6 2015

Plan on VFR conditions through the period as the region remains
under the influence of surface high pressure and ridging aloft.
Light/variable winds tonight will be ENE Wednesday with scattered cu
developing during the day. There is a chance of light fog at BWG
during the pre-dawn hours but will hold off mentioning in the TAF
for now.


.LMK Watches/Warnings/Advisories...


Short Term........AMS
Long Term.........KJD
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