Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 011055

Area Forecast Discussion
National Weather Service Louisville KY
655 AM EDT THU OCT 1 2015

...Updated Aviation Discussion and Forecast Update...

...Forecast Update...
Issued at 655 AM EDT Thu Oct 01 2015

Band of moderate to heavy rain has developed this morning across
east-central KY, including Lexington, within isentropic lift and
divergence aloft zone to the east of the mid-level closed low. This
band will temporarily reduce visibilities and cause some ponding of
water on roads and low spots. The axis should continue to progress
slowly north and west through mid morning, with a tendency toward
gradual weakening as it moves into north-central KY by mid and late
morning. Elsewhere, isolated to scattered showers are possible the
rest of the day over southern and eastern parts of the forecast
area. Made some modification to precip probabilities in the axis of
rain. Otherwise, only minor changes needed to ongoing forecast at
this time.

.SHORT TERM (Now through Friday)...
Issued at 305 AM EDT Thu Oct 01 2015

Mid-level low is closing off over southern IL at this time as
advertised by short term models. IR and water vapor imagery show
good mid-level moisture ahead of this feature, while surface
observations indicate low clouds reside over east-central and
eastern KY. Currently, radar indicates isolated to scattered showers
over east-central KY. The trend over the next few hours will be for
the low clouds and scattered showers to expand/move westward into
central KY. There may be a slight increase in shower coverage given
weak isentropic lift ahead of the low aloft, consistent with the
HRRR although its reflectivity forecast is a bit overdone currently.

During the day today, models suggest that scattered showers will
continue to develop over the east half of KY in a favored ascent
zone, with a continued push to the west and north. However, showers
should have a tendency to weaken later today as they encounter
stretching deformation zone to the north and east of the mid-level
low roughly along/north of I-64 and along/west of I-65. Clouds could
even thin a bit over southern IN for a time late today/this evening.
Temperatures over east-central KY will not rise much today, with
highs around 60/lower 60s, with mid 60s over west-central KY.

For tonight and Friday, the deformation axis should rotate westward
to the north of the mid-level low as it sinks southward into the
Gulf Coast states. This will allow moisture and showers to increase
and push north and west over much of our forecast area, especially
central KY. As a result, will increase precip probabilities on
Friday as numerous showers are expected. Low clouds, showers, and a
brisk north to northeast surface wind will keep temperatures in
check with most areas remaining in the 50s for highs Friday
afternoon (it will be a chilly damp day), except around 60 or lower
60s in parts of west-central KY.

.LONG TERM (Friday Night through Wednesday)...
Issued at 258 AM EDT Thu Oct 01 2015

The long term forecast will start off quite chilly and rainy, but
should improve towards the middle of next week. The cutoff upper low
will continue to sink south Friday night and stall out across the
southeastern states Saturday. Thereafter, the models are still
having a hard time latching on to a solution regarding the path of
Joaquin. This will have an effect on how fast the trough moves out
early next week.

Rain showers will continue Friday night into Saturday night as a
fetch of moisture streams in around the northern periphery of the
upper low. Clouds, gusty winds out of the northeast, and
temperatures topping out in the 50s will make for a raw day
Saturday. There will be little spread in the highs and the lows
Saturday given all the rain and cloud cover. Sunday poses a bit more
of a challenge and could very well depend on the track of Joaquin.
For now will carry only slight chances for rain with temperatures
warming into the upper 60s to around 70.

For the next work week, ridging should build in aloft and at the
surface. Drier conditions are expected to prevail with temperatures
warming through mid week . Highs look to rise back into the mid to
upper 70s by Wednesday with lows in the mid 50s. The next chance for
rain looks to come Wednesday night into Thursday as a front
approaches from the northwest.


.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Thu Oct 01 2015

A band of moderate to heavy showers over LEX at this time is causing
MVFR conditions. The band should shift slowly westward this morning,
and visibility will improve at LEX after rain diminishes in the next
hour or so.

However, low clouds should prevail at LEX with continued overall
MVFR conditions this morning. The band of rain should slowly weaken
as it progresses slowly west, so it should not affect SDF in the
same way as LEX. Nevertheless, isolated to scattered showers are
possible at SDF and LEX for the rest of the morning into early

Conditions remain VFR at SDF and BWG at this time, but ceilings
still could lower into MVFR category this morning. Ceilings should
then lift again later today with VFR returning at SDF and BWG. Lower
clouds and showers should move back into the whole area late tonight
and especially on Friday.


.LMK Watches/Warnings/Advisories...


Short Term.....TWF
Long Term......EER
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