Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 150711

Area Forecast Discussion
National Weather Service Louisville KY
311 AM EDT Sun Apr 15 2018

.Short Term...(Today through Monday)
Issued at 249 AM EDT Sun Apr 15 2018

Rain is beginning to taper off near the KY/MO border as the dry slot
of a mature mid-latitude cyclone advances eastward. Thankfully, the
rain we`ve endured for the past 24-30 hours hasn`t caused any
flooding issues in our area yet as its remained light and steady and
been able to soak into the ground. Regional radars show the
strongest echoes generally south and east of the Tennessee border,
and current storm motions will keep the heaviest rains east of the

Short range guidance indicates a gradual west-to-east end to the
rain this morning and early afternoon as the drier air works in
aloft. It`s possible we may see the sunshine briefly this morning
and/or afternoon, as GOES-16 reveals a narrow area of clearing
between the mid-latitude cyclone comma head and its warm conveyer
belt. However, model soundings indicate steep low level lapse rates
and a narrow layer of moisture trapped near the top of the boundary
layer within the dry slot, indicating that we`ll probably be
blanketed under strato-cu for most of the day. Temperatures will
remain steady or slightly fall through the morning and afternoon
thanks to strong CAA behind a cold front.

Moisture depth in the lower atmosphere will begin to increase as the
comma head approaches from the west in the late afternoon. Several
high-res models indicate scattered rain showers developing and
continuing into Monday morning. Drier air in the lowest 1000ft may
hamper some precipitation from reaching the ground, or at the very
least limit the rain to light showers or sprinkles. As temperatures
cool late tonight into tomorrow morning, the rain showers should
transition to snow showers. The 00z 3km/12km NAM, GFS/GEFS, ECMWF
and SREF all show potential for light snow across southern Indiana
and central Kentucky. With warm ground temperatures, don`t expect
the snow to stick to roads or cause much in the way of impacts, but
would not be surprised to see very light snow accumulations across
grassy and elevated surfaces Monday in southern Indiana and northern
Kentucky. Hard to believe it`s mid-April, right?

The other story Monday will be the cold temperatures and wind.
BUFKIT NAM/GFS soundings show 20-25kt wind gusts mixing down to the
surface throughout the day Monday, and temperatures may struggle to
reach 40 degrees across northern parts of the CWA during the day.
Resulting wind chills will generally be in the 20s and 30s, making
for a rather raw April day.


.Long Term...(Monday night through Saturday)
Issued at 308 AM EDT Sun Apr 15 2018

Clouds will begin to clear out Monday evening as the storm system
departs to the east. Temperatures Monday night will probably get
close to freezing for much of the region, however, winds may stay up
enough Monday night into Tuesday morning to keep frost at bay. Best
chance for frost to develop will be across south-central Kentucky
where winds are forecast to be lightest.

A brief warm up will begin Tuesday and continue through Wednesday as
weak ridging moves in aloft and winds shift to the south again. The
cooler air will return late Wednesday as a cold front passes through
the region. We may see some precipitation develop ahead of the
front, but overall amounts should remain pretty light. Cool and dry
weather will prevail Thursday into the first part of the weekend.


.Aviation...(06Z TAF Issuance)
Issued at 112 AM EDT Sun Apr 15 2018

Band of light to moderate rain showers will stream northeastward
across central and eastern KY during the rest of the overnight
hours.  The back edge of this rainfall looks to push east of the I-
65 corridor after sunrise.  In general, MVFR conditions are expected
at the terminals overnight with visibilities generally remaining
VFR.  We could see some dips into the high end of the IFR range
toward sunrise and we`ll continue to monitor that overnight.  Winds
early in the period will be out of the SSE and then gradually veer
to the southwest toward morning. Mix of high end IFR to low end MVFR
ceilings look to lift during the morning hours and we should see a
return to VFR ceilings by midday or so.  Winds later today and this
afternoon will be out of the southwest at 8-12kts with some gusts
in the 15-20kt range being possible.




Short Term...DM
Long Term...DM
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