Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 221705

Area Forecast Discussion
National Weather Service Louisville KY
1205 PM EST Wed Feb 22 2017

...Updated Aviation Discussion...

.Short Term (Now through Thursday)...
Issued at 310 AM EST Wed Feb 22 2017

In the near term, upper level low across the southeastern US will
continue to push off to the southeast and into the northern Gulf
today.  Plenty of cloud cover will remain over the area early this
morning and into the early afternoon.  Ongoing shower activity
across southern KY will continue to shift south and east this
morning with most locations going dry by noon or so local time.  In
the wake of the rain moving out of the region, some patchy fog will
be possible this morning across southern Indiana and the western
part of our Kentucky counties.  Overall coverage and density of the
fog does not look all that great, but some locally dense fog will be
possible in the typical fog prone areas.  Lows this morning will
cool into the 50s.

Deeper moisture associated with the upper level low will shift
eastward and away from the region this afternoon.  So we expect to
see clearing skies with a mild afternoon on tap.  Latest guidance
suggest highs will warm into the upper 60s in the east with upper
60s to lower 70s out across the west and southwest.  Louisville and
Bowling Green could max out near record highs for this date.

Quiet weather weather is expected tonight with lows in the mid to
upper 50s.  A warm front will lift northward across the region on
Thursday and we could see some scattered showers with that feature
as it races to the north/northeast.  Once this feature moves
through, temperatures look to warm significantly in the afternoon
with highs topping out in the 70-75 degree range across southern
Indiana and northern Kentucky with 72-76 degree readings across far
southern Kentucky.

.Long Term (Thursday night through Tuesday)...
Issued at 334 AM EST Wed Feb 22 2017


Unseasonably warm weather is expected at the beginning of the
extended forecast period as a deep southwesterly flow will pump mild
air and moisture into the region.  Lows Thursday night will likely
cool into the mid-upper 50s.

As we move into Friday, a strong cold front will approach the region
from the west.  We`ll be deep in the warm sector on Friday with a
stiff southwesterly wind.  Winds will be in the 15-20 MPH range with
gusts into the 30-35 MPH at times Friday afternoon.  Depending on
cloud coverage, Friday will be downright warm and may end up
breaking all time February high temperature records.  Current
guidance suggests highs in the upper 70s, but the models usually are
too conservative on temps within a southwesterly flow pattern.
Current thinking is that we`ll see readings warm into the 75-80
degree range, perhaps a little warmer if we get more sun that

The models continue are still a tad slower with the front
approaching the region late Friday.  In general, we believe that
much of the day will be dry with showers and thunderstorms
developing out to our west in the afternoon and then heading
eastward into our region Friday night.  Good moisture quality,
decent wind shear and instability still remain good enough for
strong to severe thunderstorms developing to our west and northwest.
The best combination of kinematic and thermodynamic forcing looks to
remain to our northwest across east-central IL into central and
northern IN/OH...along and just southeast of the surface low.  The
most likely scenario at this time is that we`ll see a strong squall
line develop to our west and northwest Friday afternoon/eve and then
it will move eastward into southern IN and KY Friday night.  The
storms may get into region as nocturnal stability increases. However,
strong forcing along the frontal interface, combined with the strong
wind fields will likely keep the storms strong to severe as they
come into our western forecast area overnight Friday.  We believe
the highest risk of severe weather Friday afternoon/eve will be in
areas along and west of I-65.  Damaging winds will likely be the
main severe weather threat.

Strong cold advection on Saturday will keep temperatures down over
what we see on Friday.  Highs Saturday will likely top out in the
lower 40s across southern Indiana and northern KY with mid-upper 40s
elsewhere.  Winds will remain gusty out of the northwest, so
Saturday looks to be a rather raw day across the region.

High pressure will build into the region on Sunday but temperature
recovery will not be all that quick.  Highs will range from the
lower-mid 40s across southern IN and northern KY with upper 40s to
around 50 across southern KY.  A weak system will move across the
region Sunday night and may bring rain possibly mixed with some snow
to the southern Indiana and northern KY.

The outlook for Monday through Wednesday continues to look active
and very wet across the region.  A broad southwesterly flow pattern
will remain in place with multiple perturbations aloft moving
through the region.  Periods of moderate to heavy rainfall are
likely from Monday through Wednesday with mainly above normal
temperatures.  Highs during the period will likely top out in the
60s with overnight lows in the upper 40s to the lower 50s.

Total rainfall amounts through the next 7 days will likely average
in the 2-3 inch range across the state...with some isolated spots
possibly seeing up to 4 inches of rainfall.


.Aviation (18Z TAF Update)...
Issued at 1215 PM EST Wed Feb 22 2017

Weak and sloppy gradient in place between the cutoff low over the
Gulf of Mexico and weak northern stream system moving into the Great
Lakes, with light SW winds. Plenty of stratus this morning has
lifted, and is now just barely VFR. Expect to maintain status quo
until after midnight tonight.

Look for stratus to build down into MVFR, with ceilings likely going
fuel-alternate well before daybreak. Could see IFR at times,
especially if hi-res guidance like the GFS LAMP is to be believed,
but with only moderate confidence in fuel-alternate, will not take
it down that far. Both MVFR ceilings and visibilities will persist
most of the morning as another weak front starts to impinge on the
Ohio Valley from the north. Any precip chances associated with that
front are beyond the scope of the LEX TAF, and probabilities are too
low for inclusion in the planning period at SDF.




Short Term........MJ
Long Term.........MJ
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