Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 310133
Area Forecast Discussion
National Weather Service Louisville KY
933 PM EDT SAT JUL 30 2016
Issued at 932 PM EDT Sat Jul 30 2016
Coverage and intensity of showers will continue to diminish as the
push east across central KY this evening. Have reduced Pops to 20
percent, then trending toward a dry overnight as weakly defined
boundary is washing out over the region and instability is lost.
Patchy fog is also a concern for tonight as moist low levels and
recent rainfall may combine with light winds and partially clear
skies. Still have to contend with some upper level clouds like last
night, although they don`t appear to be as prominent. Overall most
concerned about eastern and southern KY, south of where that
boundary washed out, but can`t rule out patches of fog everywhere.
.SHORT TERM (Now through Monday Night)...
Issued at 302 PM EDT Sat Jul 30 2016
Scattered thunderstorms have popped up in the warm, moist, unstable
atmosphere this afternoon. Though a nearby surface trof is helping
to spur the activity, it is still expected to be largely diurnal in
nature and diminish this evening. Clouds will scatter overnight,
leading once again to patchy fog formation towards morning.
On Sunday the surface trof will still be hanging around the region
and a shortwave trof will move overhead during the afternoon,
helping to spark widely scattered afternoon thunderstorms once
again...with storms diminishing in the evening.
Moving into Monday, capping will be a little stronger with warmer 7H
temperatures and 5H ridging starting to build in. Nevertheless,
widely scattered thunderstorms may still pop up in the heat of the
day as a possible 5H speed max moves in in the afternoon.
Monday night MCS activity should stay mostly just off to our west,
but will allow for some scattered activity in our western counties
Precipitable water values hover around normal for this time of year,
so while locally heavy rain will be possible with any thunderstorm,
torrential downpours and flooding should be fairly rare. Training
thunderstorms will provide the best opportunity for local flooding.
.LONG TERM (Tuesday through Sunday)...
Issued at 311 PM EDT Sat Jul 30 2016
...Pattern Change with Amplifying Ridge brings MCSs into the
Overall pattern will feature an upper ridge centered over the
southern Plains and western Gulf Coast. Ohio River Valley remains on
the NE periphery of this upper ridge through the long term, much
like we saw a couple weeks ago. At the surface a weak warm front
will begin lifting back north over the area Tuesday through
Wednesday. We`ll remain in a favorable position for the "ring of
fire" conceptual model Thursday through Friday, before a cold front
trailing from an eastern Canada system slides into the area Friday
night into Saturday.
Overall, this puts us in a hotter/muggier and continued active
pattern. Activity early to middle next week focuses more on
potential for MCS`s to dive into our region as overlap between
slightly stronger NW flow aloft combines with moderate to strong
instability. Best timing for an MCS still appears to be in the
Tuesday night to Wednesday time frame, but will not get too
confident in timing just yet.
Other than the MCS activity, expect scattered showers and storms
with the warm front on Tuesday, and mainly diurnally driven storms
on Thursday and Friday. Coverage of storms should then increase as
we approach next weekend and a frontal boundary drops into the
This pattern will feature warmer/muggier temperatures as H85 temps
and thicknesses increase. As mentioned in previous discussion, don`t
want to get too aggressive just yet as clouds/MCS activity can bust
an otherwise slam dunk on above normal temps. Targets in the low 90s
each day seem reasonable, with potential to go warmer if T-storms
don`t impact ability to heat up. On the flip side, an MCS at the
wrong time can leave temps struggling in the 80s all day. Best
chance for hotter/muggier temps should be Thursday and Friday when
more diurnally driven storms are anticipated.
.AVIATION (00Z TAF Update)...
Issued at 712 PM EDT Sat Jul 30 2016
Scattered convection will continue across the region for the next
few hours before dying off after sunset. For the overnight period,
skies will likely partially clear out and areas of fog will form
once again. MVFR vsbys still look likely, though a few drops to IFR
at KBWG are possible. By sunrise, the fog will start to lift into a
broken stratocu deck with MVFR ceilings. These ceilings should lift
through the morning. More diurnal convection is likely Sunday