Area Forecast Discussion
Issued by NWS Louisville, KY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KLMK 180112

Area Forecast Discussion
National Weather Service Louisville KY
912 PM EDT Tue Oct 17 2017

.Forecast Update...
Issued at 910 PM EDT Tue Oct 17 2017

Well...current forecast is humming along nicely with a few
striations of cirrus under high pressure in WV/VA.  Current
temperatures are in the 50s with light SE wind component.  With
water temps around 70 F, and low temps dropping to around 40 should
allow steam fog to develop. Will continue to mention some patchy
frost for sheltered locations, mainly in the Bluegrass. Forecast on
track, gorgeous autumn weather on Wednesday!


.Short Term...(This evening through Wednesday night)
Issued at 244 PM EDT Tue Oct 17 2017

GOES-16 shows mostly clear skies across the region this afternoon
with only some high cirrus drifting in from Western Kentucky.
Temperatures are generally ranging from the low to mid 60s with
dewpoints in the upper 30s to low 40s. High pressure over eastern
Kentucky and West Virginia has kept surface flow relatively light.
Overall a fantastic fall day for southern Indiana and central

Decided to lean on the cool side of model guidance for tonight`s
setup. While the surface high will be drifting east of the CWA
overnight setting up a southerly return flow, several model
soundings develop a strong inversion with light to calm winds across
the region. Should see temperatures falling into the low 40s to
upper 30s by sunrise tomorrow, with cooler temperatures in sheltered
areas and valleys where patchy frost could develop again. The threat
of widespread frost is low, so have highlighted the frost potential
in an SPS. River valley fog should form again tonight as most bodies
of water are still quite warm, and some of that fog could be dense
at times. This has also been highlighted in the SPS.

850mb flow begins to veer around to the southwest tomorrow afternoon
and advect in some slightly warmer air. As a result, afternoon high
temperatures should be about 3-5 degrees warmer compared to today.
The warmer temperatures will also create a strong cap around 850mb,
and keep any cloud cover limited to just some passing cirrus.
Temperatures tomorrow night will be cool once again, but with
slightly higher winds expected through the lower atmosphere, lows
should fall into the low to mid 40s.

.Long Term...(Thursday through Tuesday)
Issued at 258 PM EDT Tue Oct 17 2017

Not many changes to the long term discussion. High pressure will
keep the region dry Sunday/Monday when a large upper level trough
and associated cold front approach from the west. Long range
guidance still has some differences in timing and amplitude of the
trough, but there is general agreement that it will be potentially
wet and cloudy Sunday into Monday, with much cooler temperatures to
follow behind the cold front.


.Aviation...(00Z TAF Issuance)
Issued at 650 PM EDT Tue Oct 17 2017

Well...go outside on this pleasant fall evening and observed 2/8 CI
with plenty of cerulean sky surrounding. A weak upper level
disturbance over S IL will keep some sct CI over the area, however
the main weather feature is sfc high pressure over CRW.  Winds are
now light SELY across the area and will slacken overnight.

UPS crossover temperature not in play for significant fog. However,
despite the arid atmosphere, fog development is still possible late
tonight at fog-prone locations such as BWG. Creek at BWG airport may
be the catalyst for mvfr fog at BWG.

South winds and few CI will be the story for Wednesdays flying
weather. VFR!




Short Term...DM
Long Term...DM
Aviation...JDG is the U.S. government's official web portal to all federal, state and local government web resources and services.