Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 211912

Area Forecast Discussion
National Weather Service Louisville KY
312 PM EDT Sun May 21 2017

.Short Term...(This evening through Monday night)
Issued at 245 PM EDT Sun May 21 2017

A narrow cold frontal rain band continues to push east this
afternoon, with scattered showers slowly becoming more common east
of I-65. Instability is quite meager this afternoon due to extensive
cloud cover and mid-level lapse rates close to moist adiabatic. The
latest SPC meso page suggests a plume of greater than 500 J/kg
MLCAPE along and ahead of the front. Any lightning will remain
isolated east of I-65 this afternoon and evening.

The cold front will usher in cooler, less humid air for the rest of
the short term. Skies will gradually clear out from west to east
this afternoon into tonight, with lows tonight in the low to mid
50s. Monday will start sunny and become partly sunny later in the
day, with highs in the low to mid 70s. Brief surface high pressure
building through the region will keep things dry tomorrow, with an
upper trough confined to the Upper Midwest.

Most areas will stay dry Monday night, with lows again in the low to
mid 50s. There is just a slight chance for some showers across far
southern KY as a southern stream system moves northeast.


.Long Term...(Tuesday through Sunday)
Issued at 305 PM EDT Sun May 21 2017

Dry weather will be short-lived this week, with a deep upper trough
digging southeast into the Midwest Tuesday-Tuesday night. Isolated
to scattered showers will be possible Tuesday afternoon, along with
a slight chance for thunder. Highs in the mid 70s are likely for

The highest rain chances will be Tuesday night and Wednesday as
upper troughing moves over the Ohio Valley and surface low pressure
moves northeast through the region. There is a chance for
thunderstorms Wednesday afternoon and evening. With some cold
advection and widespread cloudiness, highs on Wednesday will only be
in the mid to upper 60s.

We`ll stay under the influence of the upper low into Thursday, with
isolated to scattered showers possible. Highs will be in the upper
60s to around 70 degrees. Thursday evening through Friday looks dry
as weak upper ridging and surface high pressure build in. Highs on
Friday will warm back into the mid 70s to low 80s. Next weekend
looks warm with highs back into the 80s, but with plenty of rain and
storm chances as a couple of shortwaves eject east in the WSW flow


.Aviation...(18Z TAF Issuance)
Issued at 125 PM EDT Sat May 20 2017

Have a line of broken showers nearing SDF this hour, and some
lighter development in the BWG/LEX area. The first line may yet get
to the point of bringing some thunder to the LEX vicinity late this
afternoon. Otherwise, expect a wind shift behind this line, with
ceilings improving within an hour or two behind it. Model time
height sections indicate some low level moisture around daybreak
Monday, but think the dry air building in will prevent fog




Short Term...EBW
Long Term...EBW
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