Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 192240

National Weather Service Jackson KY
540 PM EST Thu Jan 19 2017

Issued at 540 PM EST THU JAN 19 2017

WSR-88D radar showing initial band of precip moving toward the
Bluegrass and this is lining up close where the warm front is
most likely located. The overall better upper level dynamics and
rainfall will progress north and east through the night. The
challenge this shift will be how much do we speed this up based on
the latest surface/remote sensing trends versus the latest
guidance trends. That said much of the guidance remains on the
slow side at this point including the HRRR. Did opt to speed
things up some this update based on the radar trends and will
continue to assess this for the next update. Otherwise this update
included freshening up the latest obs and overall trends for


.SHORT TERM...(This evening through Friday night)
Issued at 415 PM EST THU JAN 19 2017

A small area of showers has moved into the southern part of the
JKL forecast area this afternoon. This is teaser in front of a
large area of rain/showers over central and western KY at mid
afternoon. The precip was the result of an upper level wave
coupled with warm air advection. Models agree on this precip
moving through the region tonight. Downslope flow will cut into
the precip in our eastern counties, but even there it should
eventually rain. However, precip totals will be lighter in the
east. Most of the precip will be exiting to the northeast with the
warm front around dawn on Friday, with just some spotty very
light showers possibly lingering into the day due to persistent
low level moisture. A few peaks at the sun in the warm air mass
will push readings into the 60s during the day. Mild, benign
weather is in store Friday night. Cloud cover on Friday night is
somewhat uncertain. MOS data and blended model data suggest quite
a bit of cloud cover. However, forecast soundings look like the
clouds could break. Have played it toward the MOS and blended data
for the time being.

.LONG TERM...(Saturday through Thursday)
Issued at 355 PM EST THU JAN 19 2017

The extended forecast period begins on Saturday with a continued
active and somewhat progressive pattern through the weekend and
into next week. The first feature of the extended will eject northeast
from the lower MS valley and into the southern Appalachians
bringing light rainfall into eastern Kentucky. As the next feature
continues to lift north through the area, some decent instability
will advect into the area Saturday afternoon through Sunday
afternoon. In fact, models and SPC show at least a slight chance
for general thunder in the area. Will stay with collaboration with
neighboring forecasters and SPC and keep thunder in the forecast
through the weekend. In addition, the unseasonal airmass advecting
into the area will allow for temperatures soaring into the upper
60s for highs across eastern Kentucky, possibly breaking a few
records on Saturday and while not as quite as warm on Sunday,
still a good 20 to 23 degrees above normal.

Heading into Monday, another upper low dives into the lower MS valley
before ejecting east and up along the lee side of the Appalachian
Mountains bringing additional rain into eastern Kentucky.
Expecting an additional half an inch with this rainfall to impact
the far eastern Kentucky areas. As this feature exits, colder air
filtering in behind may allow for rain to change to a mix of rain
and snow on top of Black mountain on Monday night. After a break
in the weather on Tuesday, another bout of southerly flow will
allow high temps on Tuesday and Wednesday will climb near 60
degrees again before another bout of rainfall moves into the area
late Wednesday afternoon through Wednesday night.

As the front passes through late Wednesday night, this will begin an
overall cooling trend through Wednesday night and beyond Day 7.

In summary, much of the extended remains warm and wet with the
consensus being around a couple inches of rain through eastern
Kentucky but the GFS is quite a bit wetter than the Euro on the
Sunday night into Monday system. The consensus is a bit less but
something to keep in mind heading into next week.


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

Showers have started to move into the region from the southwest,
and have resulted in localized mvfr visibility near the TN border
at the start of the period. Elsewhere, conditions were VFR, but
ceilings were showing an overall lowering trend. The increasing
clouds and showers were due to a warm front approaching.

Showers will overspread the rest of the region this afternoon and
tonight. MVFR conditions (and perhaps some IFR in the west) will
also spread northeast over more of the JKL forecast area, but the
advance will be slowed over the far eastern part of Kentucky due
to low level downslope wind flow. Showers will taper off with
passage of the warm front from southwest to northeast overnight
and early Friday morning. However, downslope flow in the east will
also be lost with passage of the front, and all areas can expect
MVFR conditions on Friday morning.




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