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fxus63 kpah 221149 
afdpah

Area forecast discussion
National Weather Service Paducah Kentucky
649 am CDT Fri Jun 22 2018

Update...
issued at 645 am CDT Fri Jun 22 2018

For aviation discussion only.

&&

Short term...(today through Sunday night)
issued at 330 am CDT Fri Jun 22 2018

A rather strong upper level low pressure system for this time of
year will move east across southern Illinois today, then lift
northeast across in tonight. At the surface, cyclonic flow will
continue across the forecast area. Scattered showers and isolated
thunderstorms will continue to pinwheel around the south and
southeast sides of the upper low today. The highest rain chances
appear to be to the southeast of the low, over southeast IL, SW in
and into the pennyrile region of wrn Kentucky. Extensive cloudiness
wrapping around the upper low should also serve to hold afternoon
temps in the upper 70s to lower 80s. Precip chances should
diminish tonight as the upper low exits off to the northeast, and
a weak area of high pressure slips into the region.

We will stay in a h50 zonal flow pattern for the remainder of the
weekend. This pattern will likely bring weak short waves eastward
in from the Southern Plains, which will support one or more
convective complexes. One such complex is expected to initiate
over the Southern Plains Saturday and may affect portions of the
mid MS valley region Saturday night, especially if the area can
maintain favorable mid level lapse rates/instabilities.

Therefore, will increase shower/thunderstorm chances again
Saturday night, especially over about the southern half of the
forecast area. Once this system moves east on Sunday, we should be
left in a fairly uncomfortable air mass with increasing levels of
heat and humidity. Thinking is that any convection Sunday will be
quite scattered in nature and diurnally driven given the lack of
overall low/mid level forcing present in the wake of the Sat night
system.

Long term...(monday through thursday)
issued at 330 am CDT Fri Jun 22 2018

As we start out the new week, an upper level ridge will be situated
over the region. At the surface, the features are much more muddled
by the models, which makes things difficult when it comes to
forecasting precipitation chances. A surface high will be trying to
build into the area late in the weekend and into Monday at least for
eastern parts of the area. However, models are not in agreement on
how strong this high is and how deeply it builds into the region.
The models that do not indicate a strong surface high in place, do
indicate a boundary in place over the area that might be the focus
for some storm development on Monday. This is also in line with the
latest GFS ensemble means.

The upper level ridge starts to shift east on Tuesday, as our next
upper level disturbance arrives from the west. There are timing
differences of course this far out but this feature at least
warrants some small pops for now. Another potential upper level wave
will impact the area on Wednesday, but again, timing issues are
prevalent. Upper level ridging is progged to build into the area
toward the end of the week but as was the case last week, isolated
to widely scattered convection could still be possible.

Temperatures will start out on Monday in the upper 80s to around 90
degrees but the rest of the week looks fairly toasty with highs in
the lower 90s as low level winds become southwesterly. Heat
indices could climb above 100 degrees mid to late week. However,
any prolonged widespread rain event will tamper those highs, but
for now we will run with numbers closer to the available model
consensus until a better agreement in any precipitation chances
comes into view.&&

Aviation...
issued at 330 am CDT Fri Jun 22 2018

A rather strong low will pass east across Illinois and Indiana over
the next 24 hours. The trailing cold front will be poorly defined,
making the timing of showers and thunderstorms a challenge. Although
a shower or thunderstorm is possible almost any time, the best
chance appears to be in the morning hours in se Missouri and far
west Kentucky. Southwest Indiana and northwest Kentucky will have a
better chance later in the morning into the afternoon.

Outside of showers and storms, mainly VFR conditions are expected.
The exception is during the morning hours on Friday, when areas of
MVFR cigs are likely. These MVFR cigs may linger into the early
afternoon, especially at kevv/kowb.

The chance of showers and storms will drop off late in the day as
the low and cold front move off to the east. No precip will be
mentioned for Friday evening in the tafs.

&&

Aviation...
issued at 645 am CDT Fri Jun 22 2018

A rather strong low will pass east across Illinois and Indiana over
the next 24 hours. The trailing cold front will be poorly defined,
making the timing of showers and thunderstorms a challenge. Although
a shower or thunderstorm is possible almost any time, the best
chance appears to be over southeat Illinois/SW in/wrn Kentucky during the day.
IFR/MVFR conditions will be possible at times near the shower
activity.

The chance of showers and storms will drop off late in the day as
the low and cold front move off to the east. No precip will be
mentioned after 00-02z this evening.



&&

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

$$

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