Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 062310

Area Forecast Discussion
National Weather Service Louisville KY
710 PM EDT FRI MAY 6 2016

...Updated Aviation Discussion...

.SHORT TERM (Now through Saturday Night)...
Issued at 300 PM EDT Fri May 6 2016

In the near term, mostly sunny skies were noted across the region. A
diurnal Cu cloud had developed across the region.  Some enhanced Cu
with possibly a few sprinkles had developed as far west as the US
27/127 corridor.  Temperatures ranged from the mid 60s in the east to
around 70 in the west.  We are not anticipating any major changes
over the next several hours.  We expect the Cu field to diminish
later this evening while temperatures will likely top out at their
daily maximums in the next 1-2 hours.  Overall highs in upper 60s to
the very low 70s are expected.  Breezy northwesterly winds of 8-10
MPH with gusts up to 15-20 MPH will be possible until around 6-7 PM.

For the evening hours, the weather looks rather pleasant with
clearing skies and temperatures falling into the mid-upper 60s.  For
the overnight hours, clouds will be on the increase and a small mid-
level disturbance will rotate through possibly setting off a few
sprinkles or showers across our NE sections.  Lows will drop to
around 50 in most locales.

For Saturday, the day will start off dry with partly cloudy
conditions. An increasing pressure gradient will be noted with gusty
west-southwesterly winds.  Wind speeds in the afternoon will be in
the 10-20 MPH with gusts of 25-35 MPH possible at times. Afternoon
temperatures will warm into the upper 70s with a few lower 80s
possible...especially south of the I-64 corridor.

During the afternoon, a cold front will drop into the region from
the north.  Associated with the cold front, an approaching mid-
level wave will dive in from the northwest.  Synoptic scale lift
associated with the wave and a fast moving jet streak through the
base of the trough will result in scattered convection developing.
Model proximity soundings in our northern areas suggest that
temperatures will be in the upper 70s with depends in the upper
50s to the lower 60s.  This yields about 1000-1200 J/Kg of CAPE with
a largely unidirectional profile suggestive of pure speed shear.

Local convection allowing models suggest that multiple
lines/clusters of convection will develop upstream in central IL by
mid-late afternoon.  This activity should then propagate east-
southeast into southern IN and northern KY by the evening hours. The
best chances for precipitation Saturday afternoon look to be across
southern IN north of I-64.  This activity may develop southward and
move south of the Ohio River after 800 PM Saturday evening and then
diminish somewhat overnight Saturday and early Sunday morning.

Given the speed shear and instability expected, some strong to
severe storms will be possible.  The main threat would be damaging
winds, but some marginally severe hail would be possible in stronger
cores.  Lows Saturday night look to cool into the lower-middle 50s
in the north with upper 50s to around 60 in the south.

.LONG TERM (Sunday through Friday)...
Issued at 315 PM EDT Fri May 6 2016

Diffuse frontal boundary will settle across the region on Sunday
yielding partly to mostly cloudy conditions with scattered showers
and thunderstorms across the region. For now, guidance continues to
hint at scattered coverage across much of the region with the
exception of the far southwest.  Temperatures will likely exhibit a
gradient with lower 70s across the northeast to the upper 70s to
around 80 across the southwest.

By Sunday night, the diffuse boundary is forecast to lift northward
as a warm front.  We`re likely to see some elevated convection with
this and the best chances would be across our northern
sections...likely north of I-64.  As a result, much of region should
be in the warm sector so lows will likely cool into the lower 60s in
the south with some mid-upper 50s across the north.  Monday should
feature a day of typical warm sector weather. A southwesterly breeze
and some isolated-scattered convection will be possible with highs
in the upper 70s to the lower 80s.  Overnight lows Monday night will
drop to around 60.

For the Tuesday through Friday period, a rather stormy and wet
pattern is likely.  A persistent southwesterly flow aloft will
result in good moisture transport into the Ohio Valley.  Several
perturbations will move through within the flow with the main storm
track just to our north and west.  The best chances of convection
look to be on Tuesday and again on Thursday as the strongest
perturbations pass through the region.  Instability and mesoscale
features are still hard to time and identify, but the overall
pattern looks very supportive of episodic strong/severe convection.
Rainfall amounts of 1-2 inches will be possible, but given the
convective nature, some isolated areas of 3+ inches can not be ruled
out.  Temperatures through the period will be seasonal with highs in
the upper 70s to around 80 and overnight lows in the upper 50s to
around 60.


.AVIATION (00Z TAF Update)...
Updated at 705 PM EDT Fri May 6 2016

Afternoon cu are dissipating across the region this evening.  BWG
should stay mostly clear through the overnight hours.  SDF/LEX,
however, may see some mid to upper level clouds from a weak
disturbance diving SE from IL.  Some of the high-res models indicate
that a few sprinkles or showers may also be possible overnight from
this disturbance but feel those chances are too slim to include in
the TAFs.  WNW winds this evening may back slightly to the WSW

For Sat, expect westerly winds to pick up to 10-14 kts with gusts
around 20-25 kts.  VFR conditions are expected to continue with
afternoon cu developing around 5 kft agl.

A frontal boundary will approach our region near the end of the TAF
period bringing showers/storms to the area just beyond 0Z.  Will go
ahead and include a VCTS group at SDF at 1z for this convection.


.LMK Watches/Warnings/Advisories...


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