Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 081650
Area Forecast Discussion
National Weather Service Louisville KY
1250 PM EDT THU OCT 8 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Friday)...
Issued at 312 AM EDT Thu Oct 8 2015
Other than some patchy fog being possible early this morning, expect
a pretty quiet day with SW winds increaing to around 5-10 mph. The
warm air advection combined with some heating should allow for highs
to range between 80-85. Higher res models are now hinting at some
very light QPF this afternoon ahead of a weak disturbance in the mid
level flow. Given the mid level moisture and relatively dry air in
place, have elected to only mention a slight chance of sprinkles for
a few hours this afternoon.
After the late afternoon/early evening sprinkle chances pass to the
east, do expect to have a dry lull through the first part of the
overnight. However, as we near dawn deeper moisture along with
larger scale ascent ahead of positively tilted shortwave trough will
allow for increasing shower chances across southern Indiana and
north central KY. Will only go with iso-sct coverage in these areas
before sunrise. Expect lows in the 60-65 range.
As we move into the daylight hours of Friday, expect coverage of
showers (and a few rumbles of thunder) to increase across southern
IN/north central KY as the deeper moisture and ascent take hold
ahead of the upper disturbance. Numerous to widespread showers and a
few storms will then translate east across the CWA through the
afternoon and evening hours as the upper system and associated cold
front slide through.
Model data continues to suggest that some meager instability (500-
900 J/Kg ML CAPE) will develop through the afternoon hours, moreso
across our eastern CWA. The instability and deep ascent ahead of the
upper disturbance and surface front combined with marginal deep
layer shear values around 30 knots could produce a few storms. A few
could produce brief heavy rainfall and perhaps gusty winds. Look for
highs to top out in the 70-75 range ahead of the front on Friday.
Overall for Friday, expecting around a tenth to a quarter of an inch
of rain in many spots across southern IN/north central KY. East
central KY could see as much as a quarter to a half an inch of rain
in many spots.
.LONG TERM (Friday Night through Wednesday)...
Issued at 311 AM EDT Thu Oct 8 2015
Showers will gradually taper off from northwest to southeast Friday
night as the upper trof axis crosses overhead. Low level moisture
may be slow to leave Saturday morning, so will hang on to clouds for
several hours into Saturday, along with the chance of a few
sprinkles in the east. High temperatures Saturday will depend a lot
on just how much sun we end up with. Will go for middle and upper
60s for now.
The rest of the weekend looks nice as a long ridge of high pressure
traverses the Ohio Valley. Sunday should be especially enjoyable
with plenty of sunshine and high temperatures around 70.
Monday and Monday night a surface cold front and attendant upper
trof will sweep across the region. Moisture will be limited with
this system, though precipitable water values do rise slightly above
normal. Most GEFS plume members show a little bit of QPF and the
GEFS ensemble mean shows a hundredth or two as the system interacts
with a pool of 850-700hPa moisture. After coordinating with
surrounding offices, will restrict most PoPs to Monday evening in
conjunction with the upper trof, and will keep rain chances low.
The long term will then finish out with another dome of pleasant
high pressure moving through and highs in the lower 70s.
.AVIATION (18Z TAF Update)...
Issued at 1249 PM EDT Thu Oct 8 2015
VFR conditions are expected through the TAF period. Some SCT/BKN
clouds from FL050-FL080 will affect sites through the afternoon
hours. There may be a few sprinkles or light showers out of these
clouds later this afternoon, but chances are too low to warrant any
mention. After a generally calm and quiet night, a cold front will
approach from the northwest Friday morning. This front will bring
rain showers with it, but coverage before 09/18Z appears rather
sparse so will not include anything more than VCSH at this time.