Area Forecast Discussion
Issued by NWS Louisville, 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
FXUS63 KLMK 151101

Area Forecast Discussion
National Weather Service Louisville KY
701 AM EDT Tue Oct 15 2019

...Updated Aviation Discussion...

.Short Term...(Today and tonight)
Issued at 245 AM EDT Tue Oct 15 2019

Deepening upper low over the Upper Midwest will push into the Great
Lakes tonight, and push a cold front into the Ohio Valley.  Ahead of
the front today we`ll see low-level return flow develop, with
increasing SW breezes. Even with at least partial cloud cover, the
warm advection regime should allow temps to warm a few degrees
beyond Monday, with most locations hitting mid/upper 70s.

Precipitable water values will also ramp up dramatically late in the
day, and we expect widespread showers once the forcing arrives in
the evening. Only modest elevated instability is in play, which will
be enough to support a few embedded thunderstorms but nothing sfc-
based to produce a severe threat. Expect a quick-hitting quarter
inch of QPF across most of the area, with some southern Indiana
locations possibly picking up closer to a half inch where there is
more of a convective character to the precip.

Front pushes through the area fairly quickly, getting over into the
Bluegrass and Lake Cumberland areas toward Wed morning. Temps will
quickly drop to near or below normal as gusty NW winds bring in a
much cooler air mass.

.Long Term...(Wednesday through Monday)
Issued at 245 AM EDT Tue Oct 15 2019

Wednesday through Saturday...

As the cold front continues to push eastward out of the region,
showers will gradually diminish from W to E by Wednesday afternoon.
Given the cloud cover associated with this system, and gusty NW
winds, afternoon highs will likely struggle in the mid to upper 50s.

As we move into Thursday, a strong sfc high coupled with strong
ridging aloft will build in from the west and maintain influence
over the region through Saturday. During this stretch, conditions
look to remain dry with mostly clear skies. Temperatures will start
off a bit cool Thursday, with afternoon highs in the lower 60s
before gradually moderating into the low 70s by Saturday. At this
time, there seems to be a decent signal for frost Thursday and
Friday morning, as temperatures will be in the mid to upper 30s,
with calm winds, and minimal dewpoint spreads.

Saturday Night - Monday...

By Saturday night, deep SW flow will gradually begin to replace the
strong upper level ridging that held throughout the week. However,
the greater concern will come at the start of the new week, as a
deep upper level trough over the Plains migrates towards the Ohio
Valley, bringing with it the chances for showers and storms. Will
not get too specific with heavy rain/severe potential at this time,
given the various model timing discrepancies, however, most do seem
to agree that this system will bring quite a surge of moisture to
the region.


.Aviation...(12Z TAF Issuance)
Issued at 655 AM EDT Tue Oct 15 2019

VFR conditions will continue through late afternoon with SSW gusts
increasing to 16-18kt as return flow sets up. Strato-cu ceiling will
develop first in BWG but remain VFR.

Cold front moves in this evening, with precip getting into HNB
around 00Z, with impacts to SDF and BWG later in the evening and LEX
around midnight. Just enough elevated instability to support mention
of VCTS/CB, but regardless ceilings should drop into fuel-alternate
MVFR. Wind shift to WNW with gusts around 20 kt in the cold
advection in the pre-dawn hours, with BWG dropping into IFR closer
behind the front. Planning period at SDF will improve to VFR, with
NW winds staying up at 12-15 kt.




Short Term...RAS
Long Term...SSC
Aviation...RAS is the U.S. government's official web portal to all federal, state and local government web resources and services.