Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 251737
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
137 PM EDT Sat Mar 25 2017

...Updated Aviation Discussion...

.Forecast Update...
Issued at 1224 PM EDT Sat Mar 25 2017

Updated the Hazardous Weather Outlook to include mention of a few
wind gusts up to 40 mph today. Most gusts should stay in the 25 to
35 mph range, but the Kentucky Mesonet has already picked up some
values up to 40. Good mixing up into the stronger winds aloft should
be short-lived however as upper sky cover is already beginning to
take over our western CWA. Think this will limit the potential
beyond a short window and do not plan on any additional action
unless stronger gusts become more widespread.

&&

.Short Term...(This evening through Sunday night)
Issued at 255 AM EDT Sat Mar 25 2017

Deep southerly flow continues to draw unseasonably warm and
increasingly moist air into the Ohio Valley, ahead of a closed and
stacked low pressure system over Oklahoma. The low will lift NE
across Missouri today and tonight, with the warm conveyor belt
slowly translating eastward across Kentucky. As is often the case,
hi-res models continue to show a slower trend, so will further delay
POPs for today as this system takes its sweet time. Likely POPs
today now appear to be limited to the late afternoon hours and areas
west of I-65. Strong warm advection and slower arrival of precip
should allow max temps to climb into the mid/upper 70s, with some
bust potential coming into play if rain arrives a couple hrs earlier
than advertised.

Still looking at categorical POPs tonight as the negatively-tilting
upper trof axis pushes in. Timing with the diurnal minimum in
instability will limit severe potential, but could see a few strong
storms as the initial convection pushes into south-central Kentucky
early this evening.

Upper low slowly makes its way into the Great Lakes on Sunday, so
will hang on to lingering high POPs through the day as we remain
under the cold pool with ample low-level moisture. Not expecting
much organization, so coverage at any given time will be scattered
but most locations should get measurable precip at some point.

.Long Term...(Monday through Saturday)
Issued at 255 AM EDT Sat Mar 25 2017

Pattern remains fairly progressive through the week, with a series
of bowling-ball lows ejecting out of the Southwest and being guided
ENE across the Ohio Valley, over the top of flat ridging in the
southeast CONUS.

Shortwave ridging will provide a break in the action Sunday night
into Monday morning, but the next system quickly arrives late
Monday. Steepening mid-level lapse rates will provide decent
instability, so we could see a few strong storms if they arrive
closer to the heat of the afternoon. Likely POPs into Monday
evening, with precip chances lingering into Tue as the sfc trof
hangs back behind the departing low center.

Will see shortwave ridging aloft on Wednesday, but models disagree
on whether a sfc boundary will hang up over the Ohio Valley.
Therefore we`ll hang on to a slight chance for precip on Wednesday.

Next system comes out of the Plains Thursday night, give or take 12
hrs or so. Bottom line is that it will rain at some point late in
the week, but confidence in the timing is limited by model
discrepancies, including potential phasing between the northern and
southern streams. Overall pattern will keep temps solidly above
climo through the period, with very mild nights due to the moist air
mass.

&&

.Aviation...(18Z TAF Issuance)
Issued at 135 PM EDT Sat Mar 25 2017

Gusty south winds will continue this afternoon under VFR conditions
ahead of an approaching low pressure system.  Expect south winds of
15-20kts with gusts in the 25-30 kt range through this evening.  As
the low pressure system slowly wobbles into the Ohio Valley, showers
and some t-storms will be possible tonight.  After an initial round
of convection, light rain showers look to prevail for the early
morning hours with MVFR conditions.  A few models indicate IFR but
will remain MVFR with the consensus of short range guidance.  Rounds
of showers and MVFR cigs look to continue through early Sunday.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&

$$

Update...BJS
Short Term...RAS
Long Term...RAS
Aviation...AMS



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