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Area forecast discussion 
National Weather Service Paducah Kentucky
909 PM CDT Friday Jul 3 2015

Mesoscale discussion...
issued at 909 PM CDT Friday Jul 3 2015

On the sub-synoptic scale, the lingering shower and thunderstorm
activity is remaining along and southeast of the middle-upper level
trough axis that spaned across southwest Indiana and arched
southwest through parts of southeast Missouri at 00z Saturday (7
PM cdt).

The persistent cell activity stretching from Evansville Indiana to
Owensboro Kentucky...and Bernie and Harviell...south of Poplar
Bluff Missouri...are occurring along sharp thermal gradients
aloft. This is maintain good updrafts and some back building over
these areas. Trends from the 3km hrrr guidance suggest that the
updrafts should weaken and move out of the weather forecast office pah forecast area
sometime after 04z.

Warm cloud depths of 12-13kft above the average freezing level of
12.5kft above ground level...high precipitable water and moderate lift with slow
propagation speeds have made for very efficient rainfall producers
this evening. Given the antecedent rainfall during the past
several days...some areas saw minor Urban and Small Stream
flooding.

With the exception of the southeast corner of the pennyrile region
of west Kentucky...the upper trough currently moving through the
area should gradually cutoff further significant rainfall
production as the boundary layer continues to stablize overnight.

&&

Update...
issued at 642 PM CDT Friday Jul 3 2015

The aviation section has been updated for the 00z taf issuance.

&&

Short term...(this evening through sunday)
issued at 227 PM CDT Friday Jul 3 2015

576dm low over Northwest Indiana was seen on wvapor/model overlay with
a lobe extending SW across MO/IL...helping to trigger heat of the
day convection once again across the region. Weak shear and
marginal lapse rates means locally heavy rain should be the
primary hazards. Activity expected to diminish from northwest to southeast
tonight.

Weak high pressure builds in for Saturday. There may be enough
lingering low level moisture for isolated convection southern sections
mainly in the afternoon. The NAM was thrown out for Sat night as
it seems too slow with a weak southern 500 mb low...and holding moisture
back into our southeast counties. Should be a mainly dry Saturday night
following the ec/GFS solutions. Again just a slim chance of
convection S/southeast counties Sunday where marginal moisture will
linger.

Temperatures once again a blend of MOS and existing numbers.

Long term...(sunday night through friday)
issued at 227 PM CDT Friday Jul 3 2015

Used a blend of the ec/GFS through Wednesday night...then a
gefs/ecens/naefs blend for Thursday through Friday. Sunday night
should be dry...Monday morning perhaps as well...with probability of precipitation
increasing from SW to NE with time. Signal for decent convective
chances and quantitative precipitation forecast seems to be Tuesday through Wednesday as a frontal
boundary sags south into the area and either slows down or stalls.
Would not rule out having to deal with heavy rain once again.
Timing may eventually be adjusted along with the window of best
opportunity. After that...the ecens looked more like the gefs and
even operational GFS...keeping more of a southerly flow regime
across the area...and not as aggressive with the persistent northwest
flow aloft. Probability of precipitation much lower Thursday through Friday given lower
confidence and forecast lack of frontal focus.

&&

Aviation...
issued at 642 PM CDT Friday Jul 3 2015

An upper-level trough and surface cold front will continue to
force scattered showers and a few thunderstorms into the evening.
Most of the activity should be done by 03z. Kcgi and kowb have the
best chance of experiencing ts at the terminal. Weak northerly
flow and clearing skies will lead to the potential for low cloud or
fog development late tonight and early Saturday. Conditions should
improve to VFR by 15z. No convection is forecast for Saturday.
Winds will be light and variable.



&&

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

$$

Mesoscale...Smith
update...drs
aviation...drs

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