Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 231702

Area Forecast Discussion
National Weather Service Louisville KY
1202 PM EST MON NOV 23 2015

...Updated Aviation Discussion...

.SHORT TERM (Now through Tuesday)...
Issued at 316 AM EST Mon Nov 23 2015

We`re set for a dry forecast in the short term as surface high
pressure and dry NW flow aloft dominate the pattern. Skies will be
mostly sunny today, with a steady SW wind. High temps look to be
around 10 degrees higher than yesterday, however will still be
around 5-7 degrees below normal for this time of year. Mid and upper
40s NE, to around 50 SW.

Skies will be mostly clear tonight, although a few upper clouds are
expected to stream overhead. Overall, low temps will be milder,
however the decoupled cool spots will still drop into the mid and
upper 20s. Elsewhere, expect mostly low 30s.

Temps continue to trend milder Tuesday under mostly sunny to partly
cloudy skies. Most highs should range in the 52-57 range.

.LONG TERM (Tuesday Night through Sunday)...
Issued at 316 AM EST Mon Nov 23 2015

Tuesday Night - Thanksgiving Day...

Our dry and continually milder pattern continues through mid week
and Thanksgiving Day. This will result from an upper pattern
transition to SW flow aloft, with steady southerly surface winds on
the western edge of a surface high pressure. We will see an increase
in upper clouds on Thursday ahead of the next storm system, but rain
is expected to arrive Thursday night and Friday.

Wednesday highs are expected to be in the upper 50s and low 60s,
with Thanksgiving Day highs in the low and mid 60s. Overnight lows
by Wednesday night will also be noticeably milder. Look for low and
mid 40s.

Thursday Night - Friday Night...

A highly amplified and unusually oriented upper pattern will set the
stage for a wet period of weather as we head into the weekend. By
Thursday night, the Ohio River Valley will be placed under
increasingly strong and deep SW flow. This will be between a trough
stretching from NE Canada back over the northern Plains and into the
western CONUS, and an elongated upper ridge from the Gulf of Mexico
extending out in the central Atlantic. This will set up a steady
plume of deep moisture mostly from the eastern Pacific that will
slowly slide SW to NE over our region Thursday night through Friday
night. Will mention rain chances solidly in the likely range, with a
fairly sharp gradient in rainfall from west to east expected. Totals
by Saturday morning could be as high as around an inch in our far
west. Locations along the I-75 corridor in our east should exepct
between a third and a half an inch.

Temps will stay mild on Thursday night and Friday as we stay on the
warm side of the front and under southerly flow. Highs Friday are
expected to be in the 59-64 range.

Models begin to diverge in the handling of upper features by Friday
night, mostly with the western CONUS energy hanging back and the
expected strength of a northern stream trough to our NE. This leads
to uncertainly in how much progress the front and deep moisture
plume make it through our CWA. The GFS is more progressive and dries
things out/cools us off by Saturday morning. The ECMWF hangs the
front and moisture plume up, with continued rainfall over our region.

So, will keep mention of chances of rain until models work their
differences out.

Saturday - Sunday...

Confidence is even lower during the heart of the weekend as
solutions remain divergent. The GFS offers a colder but overall
drier solution for Saturday, with overunning rainfall returning on
Sunday. The ECMWF is supporing the less amplified solution which
keeps the front and moisture plume hung up mainly across our south,
where light-moderate rain would continue to fall.

Will note that cold air looks to lag just far enough behind the
precipitation late Friday night through Sunday to keep any wintery
precip mention out of the forecast. Thermal profiles do get pretty
close however with current data, so will have to continue to monitor
over the coming days.


.AVIATION (18Z TAF Update)...
Updated at 1200 PM EST Mon Nov 23 2015

Sfc high pressure and weak upper level ridging will dominate the TAF
period.  VFR conditions are expected.  SSW winds may gust to 15-17
kts this afternoon in a little bit of a pressure gradient.  Winds
should relax by 23-0Z this evening and shift more to the south.  We
won`t see any clouds until tomorrow morning when upper level clouds
make their way into the region.


.LMK Watches/Warnings/Advisories...


Short Term........BJS
Long Term.........BJS
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