Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 241945

245 PM CDT Thu Jul 24 2014

.SHORT TERM...(Tonight through Saturday night)
Issued at 245 PM CDT THU JUL 24 2014

This short term period will be influenced by discrete and sharp
sensible weather gradient changes in temperature, dewpoint, and
wind fields across the WFO PAH forecast area. Even changes
associated with the high pressure ridge currently over the area
are changing from hour to hour, with the "donut hole" of
relatively dry air shrinking over Southeast MO, Southwest IL, and
the Purchase area of West Kentucky.

There is some concern whether the coverage of low temperatures in
the 50s may shrink a little faster than expected, given the
increase in thermal thicknesses aloft. Depending on the accuracy
of the model wind fields, there may be a slight upswing in winds
from the south before daybreak Friday.

The SREF and GFS deterministic guidance appear to have a good
handle on the sharp baroclinic gradient between the
Central/Southern Plains ridge aloft and the shortwave moving
southeast from the northern Plains toward Southern Indiana by
Friday afternoon. The leading edge of the developing warm front
and wind gradient will move into western sections of Southeast
Missouri late afternoon Friday.

At this time, given the return of moisture and isentropic lift
into the warm sector, do not anticipate any shower and
thunderstorm activity developing along the strengthening warm
frontal boundary along the Interstate 64 corridor in Southern

Bh the late afternoon/early evening on Saturday, multiple meso and
miso scale shortwave will work east-southeast across the northeast
half of the WFO PAH forecast area. This will lead to some
perturbation in the warm frontal boundary, as well as allow for
multicell thunderstorm boundary interactions. This will widen the
coverage area for PoPs and Weather across the area, with the
highest PoPs along I-64, decreasing further south and east.

Utilized a blend of high resolution guidance for the sensible
forecast weather elements, with most guidance verifying very well
considering the dramatic temperature/dewpoint gradients across the area.

.LONG TERM...(Sunday through Thursday)
Issued at 245 PM CDT THU JUL 24 2014

There continues to be very good agreement between the latest GFS and
ECMWF in the synoptic evolution through the period.

A cold front will be moving through the region Sunday afternoon and
evening, and it should mark the back edge of any thunderstorm
potential. At this time it appears that one or more MCSs may move
southeast through the region Saturday night and early Sunday, so
there may not be much of an airmass left to support thunderstorms
right along the front later Sunday.

Temperatures on Sunday will be highly dependent on convective
activity and the associated cold pools and cloud debris. However,
the potential exists for temperatures well into the 90s and heat
indices in the 100 to 105 degree range. Given the convective
potential through the day, these hot conditions are most likely over
southeast Missouri.

With an amplified ridge west/trough east upper pattern expected from
Monday through Thursday, dry and cool surface high pressure should
dominate our region. Temperatures should be well below normal at
least through Wednesday.


Issued at 1157 AM CDT THU JUL 24 2014

VFR conditions to predominate for majority of WFO PAH TAF sites
through forecast period. Main adjustments made to account for mean
wind directional changes through forecast period and for the
development of diurnal cumulus cloud bases and ceilings.

For KCGI, specifically, two items. To accommodate for fog
climatology near observation site, adjusted early morning
visibility to MVFR and isolated IFR development (MIFG). The second
issue was to pass along that the haze reports associated with the
KCGI observation this morning were due to construction work being
done near the ASOS sensor. This should be a temporary condition
and was not reflected in the forecast for this TAF site.




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