Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
609
FXUS63 KJKL 230922
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
422 AM EST Fri Feb 23 2018

.SHORT TERM...(Today through Saturday)
Issued at 422 AM EST FRI FEB 23 2018

A surface warm front is currently aligned from the Kentucky/Tennessee
border down to the Arklatex region. An ongoing low level jet has
been escorting plenty of anomalously high PWAT air along the
Mississippi and portions of the Ohio River. Heavy rainfall has
stayed just to our northwest overnight. In eastern Kentucky, dense
fog from earlier has diminished, as visibilities have been
improving. Temperatures currently range from the mid 40s in the
cooler locations, to the lower 60s, where southerly winds have
already engaged. Aloft, deep southwesterly flow remains in place
across the Mississippi Valley, in between a deep trough parked
across the Rockies, and the stout ridge still residing across the
western Atlantic.

The warm front will lift north today, with some shower activity
likely bleeding over into the Bluegrass counties through this
morning. Some isolated to scattered shower activity will be possible
across the rest of eastern Kentucky, as highs return to the mid
to upper 70s for most locations, and we remain in the warm sector.

Tonight, another low level jet will nose in from the southwest,
with the surface boundary laying out mainly along the I-64
corridor. Showers will ramp up after midnight, with better
rainfall across the Bluegrass. Higher POPs will continue into the
day on Saturday, as the surface boundary lifts back north towards
the Ohio River. Will continue to mention thunder as a possibility
Saturday afternoon, as some modest instability remains in place.

Given the repeated rounds of moderate to at times heavy rainfall
moving through into this weekend, have hoisted a flood watch for
locations along and north of I-64, where in general, the higher
rainfall has occurred in recent days.

.LONG TERM...(Saturday night through Thursday)
Issued at 349 AM EST FRI FEB 23 2018

The period will begin with the region in the warm sector ahead of
an approaching cold front from the northwest. A shortwave trough
will help to deepen a low pressure across the Plains and eject
this into the Great Lakes Saturday into Sunday and the attendant
Cold front will push slowly eastward. There could be a lull in the
rain shower activity in the early evening hours on Saturday
especially in the far southeast portions of Kentucky. The cold
front will increase rain showers and possibly a thunderstorm
through the overnight and early Sunday morning. In the wake of the
front, an area of surface high pressure does begin to build
eastward toward the Ohio Valley. There is however support for a
weaker upper level wave and upper level jet streak helping to keep
some chance of showers in the far southeast Sunday night into
early Monday, with perhaps a weak surface low pressure developing
in response to this. Most of the models have a decent handle on
this, but the GFS remains the outlier allowing for a slightly
stronger surface high. Did opt to keep this chance POPs at this
point given the better POPs will be south of Kentucky.

We do see another break as high pressure builds solidly eastward
across the Ohio and Tennessee Valley, with some slight ridging
aloft. This will keep the region dry Monday night into Tuesday
evening. Then we will see the upper levels flatten some and small
perturbations will ride through the flow. The previously mentioned
items along with an increasing low level jet at times will lead to
more rain showers starting Wednesday and going into Thursday. The
models do remain out of alignment on when and where the greatest
amounts of precipitation will occur. Therefore, opted to cap the
POPs at high likely given some of the uncertainties that remain.
The model blend does give us two higher periods of POPs, with one
Wednesday afternoon and the second one overnight Wednesday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 143 AM EST FRI FEB 23 2018

IFR/LIFR ceilings/fog will be prevalent in the valleys through
around 09z, including LOZ and SME. A warm front will develop and
eventually lift north across the area towards dawn, helping to mix
out the dense fog. An accompanying low level jet will also provide
a limited window of low level wind shear between 10 and 13z.
More sustained showers will threaten the Bluegrass towards dawn,
before diminishing through the rest of the morning. Light east to
southeast winds will veer around to the south southwest during
the day, increasing to around 10 kts, with some gusts of 15 to 20
kts at times. Ceilings will generally remain VFR during the day,
with a threat of some showers developing in the afternoon. Winds
will diminish into the evening hours.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Flood Watch from late tonight through Sunday morning for KYZ044-
050>052.

&&

$$

SHORT TERM...GEOGERIAN
LONG TERM...DJ
AVIATION...GEOGERIAN



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.