Area Forecast Discussion
Issued by NWS Louisville, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 271716

Area Forecast Discussion
National Weather Service Louisville KY
116 PM EDT Sun May 27 2018

.Forecast Update...
Issued at 1025 AM EDT Sun May 27 2018

Current observations and analysis shows light winds and mostly clear
skies across southern Indiana and central Kentucky and already
warming into the upper 70s to around 80 degrees. It`s quite humid
with dewpoints around 70. A few very isolated showers remain but
overall coverage of showers and storms has decreased since earlier
this morning.

Forecast soundings for this afternoon show the very weak cap eroding
as we reach convective temperatures in the 80s. The moderately
unstable airmass combined with residual surface boundaries from
earlier showers/storms will promote the development of isolated to
widely scattered storms. With very weak flow, storms will be slow
moving and pulse in nature and also efficient rain producers given
the higher moisture around.

Minor adjustments made to the hourly grids through this afternoon
but overall no major changes needed.

Issued at 640 AM EDT Sun May 27 2018

Some showers and storms continue to pop up along the outflow
boundary from the storms that moved in overnight. Overall coverage
remains low with this precipitation. We should see a lull in
activity for a few hours this morning before isolated to scattered
storms pop up again this afternoon. The forecast was updated based
on recent radar trends.


.Short Term...(Today and tonight)
Issued at 250 AM EDT Sun May 27 2018

An area of storms with heavy rain and quite a bit of lightning has
moved into southeastern IN this morning. The latest high resolution
model guidance suggests this activity will sink south and east over
the next few hours. The gust front is well out ahead of the storms
and with this we have seen a weakening trend in most of the area of
storms over the last half an hour or so. They should continue to
weaken as the work their way south.

After the early morning storms move out, there looks to be a
relatively dry period through the rest of the morning. This
afternoon sounding show quite a bit of instability developing.
However, winds will be relatively light and the question mark for
storm development will be a trigger. Boundaries left over from this
morning`s convection could serve as one source. At any rate, storms
this afternoon should be isolated to scattered in nature. The main
concern will be heavy rain and lightning.

The storms should start to dissipate as we near sunset. Tonight
looks to be mostly dry. Winds will become light to calm.,
particularly across north central KY. With plenty of low level
moisture, some fog looks likely to develop.

Temperatures today will top out in the mid to upper 80s. Lows
tonight will be in the upper 60s to low 70s.

.Long Term...(Monday through Saturday)
Issued at 300 AM EDT Sun May 27 2018

Monday - Wednesday...

The remnants of Subtropical Storm Alberto will impact the region the
first portion of the week bringing multiple rounds of rainfall to
the region. Rains along the northern edge of the subtropical system
will enter the region Monday with mainly central KY seeing isld-sct
showers/storms.  Tropical moisture and stronger wind fields will
arrive later in the day Tues continuing through Wed as the low
pressure center passes northward through west central KY according
to the latest forecast from the National Hurricane Center. With
precipitable water values in the 2-2.2 inch range, expect to see
rounds of very heavy rainfall late Tue into Wed.  In addition, winds
will be gusty although nothing above 25-30 mph is forecast at this
point. The biggest forecast concern with the remnants of this
subtropical system is flash flooding in areas that receive the
heaviest rainfall late Tue through Wed.

Thursday - Saturday...

The pattern will remain unsettled in the wake of the remnants of
Alberto for the latter half of the week.  Continued chances for
showers/storms are possible for Thu/Fri as multiple mid level
impulses push through the Ohio Valley.  By Saturday, most should see
a break in precipitation as upper level ridging builds into the


.Aviation...(18Z TAF Issuance)
Issued at 115 PM EDT Sun May 27 2018

Latest satellite imagery shows building cumulus across forecast area
as convective temperatures are being reached in the unstable
environment. Earlier convection laid out multiple boundaries and
with additional pop-up showers already forming, expecting scattered
pulse showers and storms to peak by 21z. Greatest coverage likely to
be at SDF, BWG, and HNB. At LEX, cu field is not as impressive and
there is a slight dewpoint minimum that may result in less coverage.
After shower/storm activity wanes early evening, the light winds,
mostly clear skies, and plentiful low level moisture will likely
lead to patchy fog. Statistical guidance and hi-res models show
hints of locally dense fog developing, but for now have trended
forecast with 2-4 miles beginning after 09z.




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