Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 262335

Area Forecast Discussion
National Weather Service Louisville KY
735 PM EDT Sat May 26 2018

.Short Term...(This evening through Sunday)
Issued at 322 PM EDT Sat May 26 2018

Skies across the region were partly to mostly sunny.  NWS surface
obs and KY Mesonet obs show temperatures in the lower 80s across
much of the region.  The warmest temps were across NW KY where
lesser amounts of clouds were seen.  Area radars do show some
isolated to scattered convection mainly east of the I-65 corridor.
Much of the short term CAMs guidance keeps the highest probability
of storms east of the I-65 corridor through mid evening with storms
waning pretty quickly after sunset.  Temperatures should be near
their diurnal highs for the day and settle into the upper 70s and
lower 80s this evening.  Locally cooler conditions will be seen in
areas that see a shower or storms.

Overnight, convection looks to be very isolated with partly cloudy
skies remaining.  Some patchy fog will be possible, especially in
areas that get in on some afternoon rainfall.  Lows will cool into
the mid-upper 60s with lower 70s in the urban areas.

For Sunday, overall guidance has trended a bit drier with the
forecast.  Still believe that we`ll see a wave of diurnally driven
convection with the highest chances SE of a line from Bowling Green
to Richmond.  High temperatures look to warm into the 83-88 degree

.Long Term...(Sunday night through Saturday)
Issued at 246 PM EDT Sat May 26 2018

The focus in the long term period will be on the remnants of
Subtropical Storm Alberto and potential for heavy rainfall across
the lower Ohio Valley mid-week.

For Memorial Day, high pressure is expected to be centered over the
lower Great Lakes while Alberto makes landfall along the Gulf Coast.
Scattered showers and storms will be possible mainly across south
central Kentucky during the afternoon/evening hours along an
enhanced convergence zone or residual surface boundary. Precip
chances will vary from 10 percent across southern Indiana to 40-50
percent along the Tennessee border.

Alberto is then forecast to track northward through the Tennessee
Valley and Kentucky late Tuesday and Wednesday per the latest
official NHC forecast track. This will pull anomalously high
moisture northward into our region, where the latest guidance shows
PWATS climbing above 2 to 2.2 inches. An axis of heavy rain is
forecast to fall along/east of the track. In addition, the warm and
moderately unstable environment will likely lead to scattered to
numerous showers and some thunderstorms outside of the center.
Finally, soundings show the potential for stronger winds to mix down
and neighboring offices collaborated to increase wind and wind gusts
over the model consensus to around 25 mph as a start but there is
potential for higher gusts. For this forecast, stayed with the model
consensus precipitation chances which will show 60-80 percent
peaking Tuesday night through Wednesday night.

Overall, the key messages heading into the middle of next week is
the potential for widespread 2-4 inches of rain with locally higher
amounts possible depending on the eventual track of the system.

In its wake, a mid-level wave out of the central Plains quickly
moves in and will likely bring another round of showers/storms
mid/late week. Might need to watch the potential for a few stronger
storms with a better shear environment in place.

Temperatures through the week will remain above normal for this time
of year with highs in the mid to upper 80s and lows in the mid 60s
to around 70. With dewpoints in the upper 60s to lower 70s, it will
be quite humid for the lower Ohio Valley.


.Aviation...(00Z TAF Issuance)
Issued at 725 PM EDT Sat May 26 2018

Prevailing VFR expected through the valid TAF period. Mid-level
disturbance has kicked off widely scattered showers and
thunderstorms that are currently affecting LEX. Will initialize with
a couple hrs of VCTS but expect that to dissipate within an hour or
so after sunset. Will keep the other sites dry, including HNB as
isolated convection over Indiana should stay to the north.

Winds go light and variable overnight, with some hint of an easterly
wind developing Sunday afternoon as we get on the very outer
periphery of Alberto`s circulation. Will bring in a mid-level
ceiling, and while isolated storms are not out the question after
about 18Z, only BWG will be worthy of a PROB30 mention.




Short Term...MJ
Long Term....ZT
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