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Area forecast discussion 
National Weather Service Paducah Kentucky
108 am CDT Wednesday Jul 1 2015

Short term...(today through Friday night)
issued at 1248 am CDT Wednesday Jul 1 2015

Precipitable waters show a steady climb to almost 2.25" by 12z Thursday...which
exceeds the 99th percentile. 1000-500 mb mrh saturates over the
course of the next 24-36 hours...as incoming system fed by northwest flow
aloft energy develops front/sags it into/across lower Ohio River
valley by Thursday morning. As all of this transitioning
occurs...we'll see the lower tropospheric flow along/just atop the
boundary become oriented parallel to the mean flow aloft...and as
thunderstorms activate along 850 mb Theta-E ridge lines bisecting
pah forecast area...we anticipate highly efficent/soaking rains on the
magnitude of 3" or more on average. Where mesoscale convective storm
repeats/training occurs...locally higher amounts to 4 or 5 inches
look possible. As a result...we have gone ahead and
collaboratively blended the lsx flash Flood Advisory into one of our
own...basically covering the southwest half of the forecast area...where
certainty probability of precipitation/maximum quantitative precipitation forecast amounts (3" or more) are expected...for the
Wednesday night-Thursday time frame of greatest concern.

Long term...(saturday through tuesday)
issued at 1248 am CDT Wednesday Jul 1 2015

Medium confidence in the extended...with low confidence in exact
timing of precipitation outside of maximum heating.

We will start off Independence day with a stationary front stalled
over the area. This will provide a focus for thunderstorm
development especially during the day. The front lifts to the
northern fringe overnight decreasing chances of rain and coverage.
As we head through Sunday into Tuesday there is not much of a
surface reflection but we remain overshadowed by a trough over the
eastern half the nation while high pressure resides over the
southwest. This pattern will spokes of energy to rotate through the
area day or night allowing for a thunderstorm any time in the
extended. The trend of the superblend was to lower the probability of precipitation with
relatively low quantitative precipitation forecast.

As for temperatures lowered a little from the extended intit due to the
expected cloud cover and smoke from the Canadian fires. For the same
reason allowed the lows to remain up as the clouds and smoke will
work like a blanket holding temperatures up a bit overnight.

&&

Aviation...
issued at 1248 am CDT Wednesday Jul 1 2015

Smoke in a layer between 5k and 20k feet will continue to restrict
slant visibilities during the pre dawn hours today. Meanwhile...mean
winds will be light...with VFR visibilities expected. An approaching low
pressure system will start to generate more showers and a few
thunderstorms across parts of the region as the day wears on. Probability of precipitation spike
most markedly after 00z Thursday with plummeting flight rules
anticipated by Thursday morning.

&&

Pah watches/warnings/advisories...
Illinois...Flash Flood Watch from this evening through Thursday evening for
ilz084-085-088>094.

MO...Flash Flood Watch from this evening through Thursday evening for
moz076-086-087-100-107>112-114.

In...none.
Kentucky...Flash Flood Watch from this evening through Thursday evening for
kyz001>013-016-017-021-022.

&&

$$

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