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Area forecast discussion 
National Weather Service Paducah Kentucky
545 am CDT sun Aug 2 2015

Update...
issued at 545 am CDT sun Aug 2 2015

Aviation update.

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Short term...(today through tuesday)
issued at 240 am CDT sun Aug 2 2015

Challenge today is whether or not the high res models are on to
something developing isolated convection over the west 1/2 of the
area this afternoon and evening in a corridor of higher moisture,
instability and no cap. There is very little surface/blyr convergence
and only weak support aloft. So do not expect much. But even the
rap shows the moisture source yesterday that resulted in isolated
convection parts of Missouri pivoting east into semo/SW Illinois for
today. Will carry 10-14 probability of precipitation and mention a slight chance of thunderstorms and rain
in this corridor. Mainly dry overnight tonight.

For Monday, a front drops south into the area. Will carry slight
chance probability of precipitation for convection northern 1/3 of the area. The front will
likely stall, with small chances continuing northern 1/3 of the area
Monday night, then across a bit more of the area with the approach
of a middle level disturbance heading east-southeast from the plains Tuesday.
Generally followed the European model (ecmwf) for probability of precipitation/weather Mon-Tue. Temperatures will
continue to be a blend of persistence and MOS.

Long term...(tuesday night through saturday)
issued at 240 am CDT sun Aug 2 2015

The upper level pattern to start off the week will feature a large
closed low system over eastern Canada and an upper high over
southern Arizona/New Mexico. Our area will be in northwest flow
aloft and we have been watching the potential for some energy
spilling over the ridge and impacting US by middle week. The signal
continues to be rather strong that there will be a decent chance for
precipitation Tuesday night through Wednesday night. The problems
lie in the details...as models still do not have a great handle on
the actual strength...speed and path of the upper level wave.

The European model (ecmwf) seems to be fastest with the speed of the incoming wave
and has precipitation overspreading the area Tuesday night starting
in the west. Then as the wave moves east...we will see chances
continue on Wednesday. Again...because of the model differences in
the placement of the quantitative precipitation forecast...not ready to raise probability of precipitation into the likely
category just yet. Too much uncertainty...and we can provide
better detail over the next few days as models stabilize on a
more consistent solution.

As has been advertised for the past couple of runs now...we should
see this upper wave depart Wednesday night. After that...models
become very murky with the details on what will happen toward the
end of the week. The GFS looks completely overdone with probability of precipitation while
the European model (ecmwf) has been back and forth so much with regards to probability of precipitation.
Being that we are still in northwest flow aloft even after the
midweek wave...suffice it to say...we will likely have periodic
chances for showers and storms through the end of the week as weak
perturbations move through aloft. Timing and location of probability of precipitation
will be the main challenge so will not get fancy with that at this time.
However...it does look like a frontal boundary will be dropping
south Thursday through Friday and that will help to focus some
convection. So once models gain a better handle on the timing of
that front...we should be able to pinpoint probability of precipitation with a bit more
confidence.

It does appear as though the weekend might be dry as an upper level
ridge finally tries to build east across the region and high
pressure builds in at the surface. Temperatures will actually cool down
a bit as this occurs.

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Aviation...
issued at 545 am CDT sun Aug 2 2015

VFR conditions with variable high cloud cover and light south-southwest winds
today through tonight. Maybe a few diurnal cumulus primarily west of a
kpah to kevv line.

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

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