Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 172339

639 PM CDT Thu Apr 17 2014

Issued at 639 PM CDT THU APR 17 2014

The AVIATION section has been updated for the 00Z TAF issuance.


.SHORT TERM...(Tonight through Saturday night)
Issued at 256 PM CDT THU APR 17 2014

The trend toward minimal PoP/Weather impact for tonight through
Friday continues with this package. Ironically, the NAM-WRF model
family, including the Short Range Ensemble (SREF) remains the most
aggressive in saturating parcels enough to support at least small
precipitation chances.

The surface to mid-level trough continues to sharpen this afternoon
across Kansas and Missouri, and is evident in the persistent lift and
saturation implied through the Infrared, water vapor difference
channels, visible satellite and surface observations under cloud
cover. The NAM-WRF moisture/lift fields appear to match well with
observations, so weighted the short term forecast closer to a
scenario where a narrow Southwest to Northeast zone of lift develops
late tonight and early Friday across the WFO PAH forecast area.
Although the SREF PoPs were the most robust with this feature with
respect to PoPs, a more "watered-down" approach was considered, as
the lift weakens rapidly during the late morning and afternoon on
Friday. The proposed PoPS/Weather expected (mainly over KY/Southeast
IL late tonight and early Friday may still be too robust and we
could end up with a totally dry forecast for Friday.  This
definitely shows the impact of a dramatic shift in the Northern
Hemispheric upper level low on local weather.  Other forecasters had
noted that the ECMWF was at least hinting at a weaker solution
(lower PoPs) on Friday versus the GFS family.

With the loss of significant PoP chances on Friday and decent
ridging behind the weakening frontal boundary moving and decaying
across the area, decided to raise max/min temperature forecast by
roughly two degrees above forecast values.  This may be too
conservative and could be adjusted higher depending on the amount of
evaporation today and Friday.

.LONG TERM...(Sunday through Thursday)
Issued at 256 PM CDT THU APR 17 2014

Should be a nice Easter Sunday as we remain between high pressure
off the Northeast Coast and weak low pressure out over the western
Plains. Weak southerly flow and sunshine should help boost
temperatures well into the 70s to near 80.

The system out to our west will slowly make it`s way into our area
early next week. Again, the sfc low looks to be quite weak, and
the mid lvl trof should remain slightly positively tilted. Thus,
will not go too high with POPs or actual rain amounts at this
time. The 12z GFS QPF output just seems overdone over our west and
north given the expected pattern. Leaned toward the lighter ECMWF
for this package. High pressure should finally move back in for
the mid/late week time frame with above normal temperatures
continuing. In fact, high temperatures in the 70s appear likely
this entire long term period.


Issued at 639 PM CDT THU APR 17 2014

Skies are clear over the area this evening, as a storm system
over the Gulf Coast is bottling up the low-level moisture that
would otherwise be feeding into a weak surface boundary that has
stalled out just to our north and west. South winds will become
light and variable overnight, and then the area will be caught up
in the circulation about the Gulf Coast system, resulting in light
north or northeast winds by midday Friday. Clouds will increase
overnight, but most ceilings will be 12-15kft, with an
intermittent ceiling possible around 4-6kft. Precipitation is not
anticipated. Skies will clear in the mid to late morning hours.




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