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Area forecast discussion 
National Weather Service Louisville Kentucky
1208 PM EDT Fri Sep 19 2014

..forecast update...
Issued 1200 PM EDT Fri Sep 19 2014

Made little change to the forecast for the late morning update.
Forecast soundings show very little or no fair weather cumulus
developing this afternoon, ensuring that today will stay practically
cloud free. East winds will continue through the afternoon, at
around 6 to 9 mph. Expect a clear night with winds backing to light
southerly by morning, temperatures early Saturday will run several
degrees warmer that those of earlier today.



Short term (now through sunday)...
issued at 319 am EDT Fri Sep 19 2014

Morning infrared and surface observations show clear skies across southern
Indiana and central Kentucky this morning. Temperatures ranged from
the upper 40s to the lower 50s in the north with middle to upper 50s
across the south. We expect clear skies to continue with a light
northeasterly wind. The surface winds are expected to remain
elevated enough to keep fog production minimized. Some valley fog
will still be possible, but it looks to remain limited.

Sprawling high pressure will move into southern New England today
and result in another mostly sunny and mild day across the Ohio
Valley. A look at the last 5 days of model verification statistic
shows that the model output is still exhibiting a warm bias of 2-3
degrees on daily maximum temperatures. With that said, have gone
below guidance again with afternoon temperatures warming into the
upper 70s across southern Indiana and northern Kentucky. Upper 70s
to around 80 will be possible down across southern Kentucky.

For tonight, winds are expected to shift more to the south and
southwest which will set the stage for return flow. This should
keep temperatures mild again with dewpoints slowly rising throughout
the night and into Saturday morning. Overnight lows will not be as
cool with middle-upper 50s across southern Indiana and northern
Kentucky and mainly lower 60s across southern Kentucky.

Saturday will feature a continued southwesterly wind flow on the
back side of a departing high pressure system. However, a moist
mid-level flow and warm air advection scheme will likely result in
mid-high level cloudiness streaming into the region from the
southwest. While model data suggests highs warming into the middle
80s, we continue to take into account the warm biases of late.
Therefore, will be undercutting the guidance by a few degrees.
Afternoon highs will likely run into the upper 70s to the lower 80s
across southern Indiana and into the lower 80s across southern Kentucky.
We could potentially see a stronger gradient of
temperature...especially to our southwest where mid-upper 80s are
not out of the question...especially if less clouds develop than
forecast.

Long term (sunday night through friday)...
issued at 258 am EDT Fri Sep 19 2014

The long term will begin with an upper level trough dropping into
the Great Lakes region. An associated surface low will remain just
north of the US/Canada border as it pulls off to the northeast
through the weekend. This will swing a cold front through during the
day on Sunday.

The latest model runs have sped this system up quite a bit. The
latest guidance suggests rain will begin to enter the forecast area
late Saturday night and may spread into central Kentucky by daybreak
on Sunday. The front looks to clear the forecast area by Sunday
evening with most of the rain exiting by 00z Monday. Will keep a few
showers in the far east Sunday evening, but this period may actually
be dry. Temperatures will be a bit tricky with the rain chances and
front moving through. For now will go with highs in the upper 70s to
around 80.

Surface high pressure will build in behind the front and will drift
across the region and move off to the east through the remainder of
the long term. Aloft a ridge will build across the area from Tuesday
on. This will result in a dry forecast. After a big cool down on
Monday, temperatures will gradually warm through the week. Monday's
highs will be in the lower 70s while upper 70s to lower 80s can be
expected by Thursday. Lows Tuesday morning will be in the upper 40s
to lower 50s. These will warm to the middle 50s by Friday morning.

&&

Aviation (12z taf update)...
issued at 645 am EDT Fri Sep 19 2014

High pressure moving from the Great Lakes into southern New England
will provide VFR conditions across the region. Mostly sunny skies
and a light northeasterly to easterly surface wind will be seen at
the terminals this morning through the afternoon hours. VFR
conditions will continue into the evening and overnight hours with
winds shifting more to the south as the night wears on.

&&

Lmk watches/warnings/advisories...
Kentucky...none.
In...none.
&&

$$

Update.........Jsd
short term.....Mj
long term......eer
aviation.......

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