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Area forecast discussion 
National Weather Service Paducah Kentucky
1221 PM CDT Thursday Sep 3 2015

Update...
issued at 1220 PM CDT Thursday Sep 3 2015

The aviation section has been updated for the 18z taf issuance.

&&

Short term...(today through saturday)
issued at 327 am CDT Thursday Sep 3 2015

The 00z models try to pinch the upper ridge from the east Friday
into Saturday, which leads to a little bit more pronounced surface
ridging by Saturday. The models are spitting out quantitative precipitation forecast just
northeast of our region, especially Friday night, but MOS pops are
mostly single digits. Won't be surprised if we end up with some
pops Friday night or Saturday, but for now will just mention it
here and keep the forecast dry, and in line with neighboring
offices.

A literal handful of showers and one brief thunderstorm developed
across the forecast area yesterday afternoon. They were short-
lived, and with one exception, did not produce lightning. The 00z
arw and nmm WRF runs both generate some isolated convection across
the region this afternoon, and the latest hrrr shows some isolated
weak showers. With that support, will play the persistence card and
add isolated showers and storms to all but the far northwest and
western fringes of the area this afternoon. Will wait and see
what happens this afternoon before considering it for Friday
afternoon.

Temperatures climbed toward the warmer mav/ec guidance yesterday
afternoon, so will continue to go that way with high temperatures
today and Friday. The 00z mav has 97 for Paducah Friday, but that
seems a bit spurious compared to surrounding MOS sites. Saturday
is a bit less clear cut, with the upper ridge weakening and
indications of a minor surge of surface high pressure over the
Evansville tri state.

Stayed on the warm side of guidance Saturday over the tri state,
but that does result in a couple of degrees of cooling from
friday's levels. Outside of the tri state, Saturday could be just
as warm as Friday. The humidity is nothing like we had mid-Summer,
but it could be just enough to allow heat indices to approach 100
in a few locations each afternoon.

Low temperatures tonight will be similar to this morning's lows,
which are a bit lower than the consensus of guidance in most
locations. Lows Friday night may be closer to the consensus with
more wind expected.

Long term...(saturday night through wednesday)
issued at 327 am CDT Thursday Sep 3 2015

The deterministic runs of the Med range models have been somewhat
unstable of late, and the latest GFS 500 mb height spaghetti pattern
shows significantly increased chaos by Tue (day 6), though the
latest GFS/European model (ecmwf) ensemble means appear quite similar overall. This
will affect confidence in the latter period forecast, regarding
impulses of energy in the nrn stream which may or may not produce a
secondary sfc front in our region.

Early in the extended period, the pah forecast area will be affected
by an amplified srn stream pattern, with ridging aloft west of the
MS river and troffing over the Atlantic Seaboard. Meanwhile, by Mon,
a cold front is progged to impinge on the ridge over our region.
There might be enough lift to produce a few showers and tstms in the
nwrn half of our region Mon afternoon, perhaps progressing a bit
farther sewd Mon night. The latest European model (ecmwf) appears to break down the
ridge more than the GFS by Tue, and is therefore more generous with
its quantitative precipitation forecast into Wed. For now, we downplayed pops a bit for Mon/Mon
night because of the lingering mid/upper ridge, then went generally
with the model initialization blend after that, which provided no
more than 40% pops for any 12 hour period. At this time, it appears
that model consensus and HPC point toward a Bona fide sfc fropa at
the very end of the present day 7 (wed).

Expect above average temps through the extended period, slowly
decreasing by day 7 to near seasonable levels.

&&

Aviation...
issued at 1221 PM CDT Thursday Sep 3 2015

A few isolated showers or thunderstorms will be possible again across
the region this afternoon, but the coverage is expected to be too
sparse to mention in any of the tafs. Otherwise, the only concern
to aviaton is MVFR fog potential at all terminals late tonight.
Like the last few nights, the fog, if it develops, will burn off
by around 14z. Cu should then start developing soon after with
only isolated chances for convection.

&&

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

$$

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