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fxus63 kpah 291542 
afdpah

Area forecast discussion
National Weather Service Paducah Kentucky
1042 am CDT Thu Jun 29 2017

Update...
issued at 1042 am CDT Thu Jun 29 2017

Made modest tweaks to the near term pop/wx grids to introduce
slight chance pops a little further north, to about a Cape
Girardeau to Evansville line and points south, and increased
existing rain chances a bit peaking across the southern pennyrile
and Kentucky/Tennessee border region.

12z bna radiosonde observation and satellite/radar trends suggest a little more
moisture in the lower layers than was apparent earlier this
morning. Cu fields are popping up across northwest Tennessee and semo with
showers developing in middle Tennessee. 3-6 km lapse rates are
quite weak however, around 5.5 c/km, with a weak inversion also
apparent around 700mb, which will limit available cape and make it
tough initially for any parcels that get going, but an
approaching 500mb trough should increase large scale ascent
through peak heating allowing for a slightly more favorable
shower/thunderstorm environment across the area this afternoon.
With weak/non- existent low level forcing and weak ml lapse rates
coverage should still be isolated to widely scattered.

&&

Short term...(today through Saturday night)
issued at 212 am CDT Thu Jun 29 2017

A gradual moistening trend will continue today through Friday
night ahead of a cold front. Precip chances will generally be very
low until Friday afternoon, when thunderstorms will start to
increase from west to east. The highest rain chances will be
Friday night as the cold front reaches southeast MO and southern
Illinois. A slow drying trend will occur Saturday night as the front
exits our region.

In more detail, today looks mainly dry and a little warmer/more
humid than Wed. Both the hrrr and GFS qpf indicated some light
amounts this afternoon working northward from the Tennessee Valley
into southern Kentucky and extreme se MO. The air mass will be uncapped
and quite unstable, with CAPES around 1500 j/kg. A broken layer of
cumulus clouds should develop by midday. A few isolated showers or
weak thunderstorms could form in the warmth of the afternoon,
possibly aided by a weak 500 mb shortwave over the lower
Mississippi Valley. This activity should be confined to southern
parts of west Kentucky/se MO.

Tonight should become mostly cloudy as mid and high level moisture
increases. Some of this moisture could be blowoff cloudiness from
a predicted thunderstorm complex to our northwest over the mid
Mississippi Valley. There is a small chance the remnants of this
complex could reach srn Illinois and se Missouri around sunrise.

The forecast for Friday through Saturday hinges on the timing and
location of convective complexes along and ahead of the cold
front. There is quite a bit of model variability. However, it
appears likely that an organized area of thunderstorms will cross
our region sometime Friday afternoon or evening. Depending on the
amount of cloud cover/solar heating, the atmosphere is forecast
to become moderately to strongly unstable Friday. The 00z NAM/GFS
both indicate a weak 500 mb shortwave will move east across se
Missouri/west Kentucky early in the evening. This shortwave is
associated with slightly stronger wind fields than what the
models indicated Wednesday. If this all pans out, then some risk
of strong to severe storms would exist during the aftn and
evening.

Some redevelopment of convection may occur along the front across
our region Saturday, but the models are quite far apart on the
location and timing. The 00z GFS is slower with the front,
allowing stronger instability to develop and a higher chance of
storms. The NAM is relatively stable, possibly due to the combined
effects of earlier convection and faster frontal movement. The
forecast will contain chance pops, highest in western Kentucky.
Any lingering storms will end early Saturday night as the parent
500 mb shortwave passes to our east and low-level winds die off.

Long term...(sunday through wednesday)
issued at 212 am CDT Thu Jun 29 2017

The long range models and their ensemble mean solutions are in
decent agreement. It will be seasonably warm and humid through the
period. We will be predominantly warm sector with high pressure to
our east and a frontal boundary to our north. The upper pattern will
be unsettled from the west-northwest. With time, the models push a trof toward
the region, affecting our area especially from Tuesday through late
Wednesday. As a result of the unsettled pattern we have a daily
chance of showers and storms. Temperatures were split between
existing numbers and ec/ecens/GFS MOS.

&&

Aviation...
issued at 212 am CDT Thu Jun 29 2017

Some high clouds from storms across northern Missouri and Illinois
will continue through the early morning hours. A broken deck of
cumulus clouds will develop by midday and continue through the
afternoon. Bases will be in the VFR category. Winds will become
gusty from the south/southwest, gusting to around 15 knots this
afternoon. Cumulus clouds will scatter out this evening.



&&

Pah watches/warnings/advisories...
Illinois...none.
MO...none.
In...none.
Kentucky...none.
&&

$$

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