Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 141257
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
857 AM EDT Mon Apr 14 2014
Issued at 850 AM EDT Sat Apr 12 2014
Rain shield associated with the pre-frontal low-level jet is making
its way across central KY and southern IN at this time. Behind it
there appears to be a decent dry slot, which will provide a break in
the action around the middle of the day. Radar finelines show the
actual cold front quite nicely from west-central Indiana, across
southern Illinois and into southeast Missouri. Still looking for
POPs to ramp up again later in the day as this front moves in, and a
secondary wave rides up out of the Deep South. Have refined the POP
grids to better show this break in the point-and-click and other
high-res forecast products.
It looks like we are going to have a difficult time getting back to
Wind Advisory thresholds as the day progresses. Not about to cancel
it just yet, as we have recently had a decent surge with gusts close
to 40 mph at SDF, but it appears that headline will be cancelled
well before its 19Z expiration. Will continue to monitor trends.
.SHORT TERM (Now through Tuesday)...
Issued at 258 AM EDT Mon Apr 14 2014
At 07Z low pressure was centered near Chicago with a cold front
dropping down to Dallas. Widespread showers and a few thunderstorms
will be found ahead of the front today across southern Indiana and
central Kentucky. In addition, it will also be windy as the front
approaches and the pressure gradient tightens. Some data suggest
strong wind gusts today, and we`ve had non-convective gusts over 30
mph already overnight, so after talking with neighboring offices
have decided to go with a Wind Advisory for this morning and early
afternoon. Temperatures today won`t vary much...rising a few
degrees when it`s dry and falling a few degrees in rain.
The front will cross the region from west to east this evening.
Light rain will persist behind the front. Winds will switch rather
abruptly to the northwest, and cold air will pour into the region.
After midnight tonight a light wintry mix will be possible, but
should have little if any impact due to the light nature of the
precipitation, air temperatures above freezing, and a warm ground.
Lows by dawn should be in the middle 30s.
On Tuesday the upper trof associated with this messy system will
finally cross overhead, bringing an end to any light precipitation
in the morning. We may see some partial clearing by afternoon.
North winds of 10 to 15 mph, with some higher gusts, will continue
to pull unseasonably cold air into the region, with highs only in
the lower and middle 40s. Some records for low daily maximum
temperature may be threatened.
.LONG TERM (Tuesday Night through Sunday)...
Issued at 315 AM EDT Mon Apr 14 2014
...Freeze Watch for Tuesday Night/Wednesday Morning...
Surface high pressure will settle over the Ohio Valley Tuesday night
with mostly clear skies and light and variable winds looking likely.
Dew points are expected to drop into the low 20s, and with the good
radiational cooling temperatures are expected to drop below freezing
and into the mid and upper 20s in most spots. Expect that some
eastern valleys could drop into the lower 20s, while a few urban
areas may stay around 30. Confidence is high enough that a Freeze
Watch has been issued for the entire CWA. The only limiting factor
at this point would be if winds overnight stay up just enough
to limit a hard freeze. Along with the threat of the hard freeze,
areas to widespread coverage of frost is expected. A few record lows
could also be in jeopardy.
City Forecast Low Record Year
Louisville 29 27 1875
Lexington 24 20 1875
Frankfort 26 25 1962
Bowling Green 27 27 1928
Wednesday - Thursday Night...
Surface high quickly lifts off to the northeast on Wednesday with
benign and broad southwest flow aloft developing as another trough
digs in the western CONUS. This will be a dry period of weather with
moderating temperatures. Highs Wednesday should find their way to
the low and mid 50s despite the cool start, with highs Thursday back
in the low to mid 60s. Wednesday night will be milder than Tuesday
night, but temperatures will still be well below normal in the mid
and upper 30s. A few eastern valleys could drop around freezing and
will mention a few patches of frost in that area for a second night
in a row. Lows are back in the mid 40s for Thursday night.
Friday - Saturday...
An upper level disturbance in the northern stream will move east
across the Great Lakes Friday/Saturday, and into New England Sunday.
The associated cold front will cross the Ohio Valley late Friday,
warranting chance POPs Friday and Friday night. A few rumbles of
thunder appear possible along with the solid chance for rain. Highs
will continue to be in the 60s with lows in the 40s.
Saturday Night - Sunday...
Will keep the end of the weekend dry for now as confidence is low in
the evolution of the upper pattern by this time. Dry northwest flow
looks like the best bet at this time, with temperatures still in the
60s for Easter Sunday. This forecast could change as models get a
better handle on the upper air features by this time.
.AVIATION (12Z TAF Update)...
Issued at 651 AM EDT Mon Apr 14 2014
A band of showers ahead of an approaching cold front will affect the
terminals in the first few hours of the TAF period. Then from mid
morning to mid afternoon showers should be more widely scattered,
though ceilings have been consistently progged by model data to
lower into MVFR. Then this evening shower chances will start to
increase as the cold front enters central Kentucky.
Winds ahead of the front today will be strong and gusty out of the
SSW, with the gustiest winds expected to occur during the morning
hours. With frontal passage early this evening winds will shift to
Light rain will fall behind the front, and may end as a very brief
period of very light wintry mix in the pre-dawn hours Tuesday. Low
ceilings are expected to continue through the night tonight, and
will probably take until the tail end of this TAF period, or
possibly later, to lift and/or scatter.
KY...FREEZE WATCH from Tuesday evening through Wednesday morning FOR
WIND ADVISORY until 3 PM EDT /2 PM CDT/ this afternoon FOR
IN...FREEZE WATCH from Tuesday evening through Wednesday morning FOR
WIND ADVISORY until 3 PM EDT /2 PM CDT/ this afternoon FOR