Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 202047

National Weather Service Jackson KY
347 PM EST Fri Jan 20 2017

Issued at 1259 PM EST FRI JAN 20 2017

Temps were running slightly warmer than the forecast temperature
curve, and with clouds breaking, have raised max temps a couple
degrees for this afternoon.

UPDATE Issued at 949 AM EST FRI JAN 20 2017

Aside from a few sprinkles in some places, it appears the precip
is finished, and the POP has been reduced to below 20% for the
remainder of today. There are also some breaks in the clouds, and
the sky cover for today into tonight has been updated based on
latest obs and model forecasts. Otherwise, have only blended
mid-morning obs into the afternoon forecast.

UPDATE Issued at 745 AM EST FRI JAN 20 2017

Freshened up the grids to reflect the back edge of the rain
showers and lower PoPs through the rest of the day. Also touched
up the T and Td grids per the latest obs and trends. These have
been sent to the NDFD and web servers. A new set of zones were
issued, as well.


.SHORT TERM...(Today through Saturday)
Issued at 350 AM EST FRI JAN 20 2017

08z sfc analysis shows a healthy area of low pressure moving
through the Mid Mississippi Valley. From this, a warm front is
lifting into eastern Kentucky with a band of moderate rain showers
pushing across the CWA ATTM. Most locations will measure from
this early this morning with an average of a quarter to half an
inch of rain common through dawn. Another very mild night is
underway for this time of year with readings not far from 50
degrees and dewpoints similar. Aside from in the band of heavier
showers, winds are generally light and from the south to southeast
across the area early this morning.

The models are in good agreement aloft through the bulk of the
short term portion of the forecast. They all depict a lead trough
pivoting through the Great Plains/Midwest and sending the core of
its energy through Kentucky early this morning. Heights will then
rebound over the CWA today as the next mid level low grinds into
the Central Plains. This will resume our bout of deep level
southwesterly flow along with ample bits of energy riding through
the region. The model spread with these key features does expand
late in the period, but the general pattern is pretty well set
continuing the southwest flow to 00z Sunday and beyond.
Accordingly, have favored a general model blend with a hedge
toward the latest HRRR in the near term.

Sensible weather will feature the bulk of the pcpn with this
latest wave passing through by dawn for most places - running out
ahead of the lifting warm front. In the wake of this, some
lingering showers will remain behind this morning and fade out by
afternoon as the trend favors drying through the rest of the day
but also continued warm conditions. For tonight, do anticipate a
ridge to valley temperature split opening up along with patchy
valley fog developing. The next wave of pcpn then moves into the
area from the southwest on Saturday afternoon with another
quarter to half inch of rainfall possible through evening - while
this unusual winter warmth continues unabated.

Again used the CONSShort and ShortBlend as the starting point for
most elements through the short term portion of the forecast. Did
make some terrain based adjustments for lows tonight given the
pattern favorable for an inversion and temp splits. Also,
adjusted PoPs to better time the passage of the bulk of the
showers this morning.

.LONG TERM...(Sunday through Friday)
Issued at 347 PM EST FRI JAN 20 2017

The extended forecast period begins on Sunday with a continued
active pattern in place across the CONUS. On Sunday, a strong upper
low crosses into the lower MS valley as it travels along the Gulf
Coast before lifting NE into the Appalachians. Current track takes
the heaviest precip along the spine of the Appalachians and into
the headwaters of eastern Kentucky. Models have been pretty
consistent on this track for the past few runs. In fact, as this
feature develops and lifts north, instability will still be
present continuing to support convection, mainly slight chance,
through the day on Sunday. As this feature exits Tuesday morning
and colder air filters in behind it, some of the exiting showers
will change to a rain and snow mix Tuesday morning on top of the
higher elevations but with very little accumulation expected.

Heading into midweek next week, the next wave tracks across the
central Plains and into the Midwest bringing a round of light
showers into eastern Kentucky. Both the GFS and Euro agree with a
drying trend to this feature as QPF amounts will likely be less than
a tenth of rainfall for Wednesday and Wednesday night. However,
following this feature will be a more seasonal airmass filtering
into the area by Thursday and Friday. This will lead to a return of
northwest flow and a period of snow showers possible Thursday
afternoon and Thursday night. Overall, a trend to more normal
temperatures is expected towards the end of next week if not
cooler than normal.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)

A mix of VFR and MVFR conditions existed at TAF issuance, but
conditions were showing an overall improvement. Restrictions were
due to ceilings. From late afternoon on, VFR is expected to last
well into the night. Some locations are expecting ceilings to
again drop to MVFR for a time Saturday morning, but confidence is
not high in this scenario.




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