Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 282326

Area Forecast Discussion
National Weather Service Louisville KY
726 PM EDT Wed Jun 28 2017

...Updated Aviation Discussion...

.Short Term...(This evening through Thursday night)
Issued at 200 PM EDT Wed Jun 28 2017

Seeing a stronger south wind today, ushering in a transition from
the drier pleasant days earlier in the week to a more typical summer
humidity by the end of the week. This change is occurring as high
pressure to our east gets pushed from the west by a slow-moving cold
front. This front will not impact our rain chances in the short
term, though it does still look like some diurnally driven airmass
showers/storms will be possible over at least southern Kentucky
Thursday afternoon/early evening. Precipitable water boundary will
advect north into the region, and that area should be a favorable
place for at least some development.

Temperatures Thursday should be a little warmer than today, but
again more noticeable will be the increased humidity. Lows each
night will be warmer, closer to normal for the end of June tonight
and then a little above Thursday night.

.Long Term...(Friday through Wednesday)
Issued at 200 PM EDT Wed Jun 28 2017

The trend continues a little slower for that front impacting our
weather Friday afternoon, but we should have another round of
airmass showers/storms form again over at least southern KY. Would
not be surprised to see storms forming off to our northwest push
into the region late in the afternoon into the evening hours. But
chances will continue into the night period, as a series of
vortmaxes cross us in the southwest flow aloft. Went a little warmer
than guidance for temperatures from blended guidance, given
potential for later in the day storms and good insolation ahead of

Models continue to question whether the front will push far enough
south to clear us out for the afternoon period Saturday. Another
vortmax crossing the region in several of these models would lean
toward at least some need for at chances in our east. In response,
blended model guidance came up quite a bit from previous forecast.
Same question mark comes in for Sunday with GFS splashing all of KY
with light QPF. The GEM/Euro combination as well as the 00Z/12Z GEFS
all keep us dry, so will lean in that direction given high pressure
at the surface over us and no real signal for a vortmax crossing us
aloft...though we do have a broader trough over the region.

Models have trended toward a drier Monday, now holding off our next
system to Tuesday. Given run to run variability in the far extended,
would prefer not to go with any one period far away from our climo
pop for this time of year, isolated. So will cap pops rest of the
period at 40 percent.


.Aviation...(00Z TAF Issuance)
Issued at 720 PM EDT Wed June 28 2017

VFR conditions will prevail through the forecast period.  A moderate
LL jet late tonight will result in marginal LLWS at all TAF sites
with winds increasing to 35-38 kts from the SW at 2 kft between
roughly 8-12Z. The LLJ will decline after sunrise with LLWS
diminishing as well.  SSW winds will be gusty from late morning
onward with gusts up to around 20kts during the afternoon hours
tomorrow. Gusts will decline after sunset.




Short Term...RJS
Long Term...RJS
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