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fxus63 kpah 190531 
afdpah

Area forecast discussion
National Weather Service Paducah Kentucky
1131 PM CST Mon Nov 18 2019

Update...
issued at 818 PM CST Mon Nov 18 2019

Updated pops to reflect surface and radar observations from the
shortwave energy. This expanded the region of a slight chance of
drizzle/light rain showers into additional parts of western
Kentucky through tomorrow morning. Given dry air near the
surface, wouldn't be surprised to see a report of sleet tonight as
well, but have left this out of the forecast due to low
confidence. Otherwise, forecast remains in good shape.

&&

Short term...(tonight through wednesday)
issued at 215 PM CST Mon Nov 18 2019

More energy will be spilling down the Mississippi River valley as
deep northwesterlies keep a seasonally Cool Run of air into the
forecast area. Satellite shows plenty of cloud cover incoming with that
energy, but little in the way of actual pcpn. The models overdid
that aspect with similar energy last night, and we believe they
are doing so again tonight. We'll therefore follow our persistence
strategy forecast of drier vs wetter, but smooth into it with our
collaborative seams, as best as possible.

Wednesday is a nice transition to more seasonal temps day with
high pressure shifting east, and increasing heights helping US
break out of the deeper northwesterlies, which shift east with the
parent low. 60s reappear in the forecast for the first time in
awhile.

Long term...(wednesday night through monday)
issued at 215 PM CST Mon Nov 18 2019

The mid week warmup precedes a coming rain event that largely
occurs in the late Wednesday night through Friday time frame.
While model differences exist in the phasing of the upper
parent/energy, consensus agreement is there for a wet period
signal esp Thursday-Thursday night, with qpf ranging from about
a half inch in our north, to near one and one quarter inches in
our south. Nbm members show hints at thunder chances nosing into
the semo Ozarks in the dynamically strong system perhaps for a
brief window of time Thursday PM, but at this writing, we leave
any such chances to our west/outside of the forecast area.

Model member variance increases on system passage/departure early
next weekend. Cooler air spilling in on its backside, esp at
night when surface-boundary layer temps near critical freezing
mark, may make for some change-over pcpn and perhaps some light
accums. With such differing member solutions, blended/average is
pretty much wholly accepted by seemingly all offices, so grids
reflect light accums (half inch or less) mainly north/west most
counties late Friday night-early Saturday, before lingering pcpn
chances finally draw off and move out Saturday night.

&&

Aviation...
issued at 1130 PM CST Mon Nov 18 2019

The southeast movement of a minor shortwave/vorticity lobe over
east central Missouri in the vicinity of an elevated northwest to
southeast oriented warm front is making for a challenging
ceiling/cloud base forecast for the 06z weather forecast office pah taf issuance.

Interchangeably inserted categorical rain in tempo groups with
vicinity rain shower mention in primary forecast groups overnight
for all taf sites and primarily for kowb in the early daylight
hours on Tuesday. Until this system completely moves east of the
taf sites cannot rule out rain chances. For now, the visibility
due to the rain will remain in the VFR category.

Ceilings and cloud bases on the western end of the previously
mentioned shortwave will be tricky. Attempted to reflect the
multiple (or secondary) cloud decks in the tafs, especially
during the first 12 hours of the forecast period. May be too
low with the cloud decks, but kept the majority of the cloud
forecast in VFR category.

The main changes in the forecast groups was also driven by the
change in the mean wind forecast with time.

&&

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

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