Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 272335 AAA

635 PM CDT Mon Oct 27 2014

Issued at 635 PM CDT MON OCT 27 2014

Updated the aviation discussion for the 00Z TAF issuance.


.SHORT TERM...(Tonight through Wednesday night)
Issued at 309 PM CDT MON OCT 27 2014

Lots of high clouds this afternoon have held temperatures down a
few degrees, so the middle 80s may not quite happen in many
locations. The gusty winds have been impressive through the region
with frequent gusts 25-30kts and KMDH just gusting up to 38kts in
the last hour. That is one knot shy of Wind Advisory criteria.
Will continue to monitor, but most guidance indicates a slight
downward trend for the late afternoon.

A look at the reflectivity in the 12Z ARW and NMM WRF casts some
doubt on the overall coverage and intensity of the convection late
tonight and Tuesday. The 06Z NAM was also quite meager with its
QPF, but the 12Z run has intensified some. The 12Z models still
generate very marginal elevated instability, but any surface-based
instability is generally confined to west Kentucky in the late
morning and afternoon hours. Per the SPC Day 2 outlook, would
expect scattered to numerous thunderstorms to develop along the
Tennessee border and through the Pennyrile from late morning into
the early afternoon. Decided to knock a bit off of the PoPs with
the event, given the potential for less than solid precipitation.
Still have likely levels.

Even the 12Z GFS has trended slower to push the precipitation out
of the area Tuesday night. The 12Z NAM and ECMWF continue to
stream showers northeast from the Boot Heel through much of west
Kentucky at least through Tuesday evening. The models all hold the
larger-scale mid/upper-level trough back over our area until late
Tuesday night, so cannot discount the PoP potential for Tuesday

As for temperatures, tonight should be quite mild outside of the
precipitation arriving late in the west and northwest. Generally
went above guidance. There should be some sunshine behind the
precipitation over at least northern/northwestern portions of the
area Tuesday, so trended on the warm side of guidance. Trended a
bit cooler in the northwest Tuesday night, where good radiational
cooling is likely and dewpoints are into the upper 30s. Consensus
of statistical guidance seemed reasonable for highs Wednesday.

Surface high pressure will settle over the region, resulting in
very calm and clear conditions Wednesday night. Dewpoints well
into the 30s throughout the area should allow temperatures to drop
into the middle and upper 30s areawide. Frost is a strong
possibility late Wednesday night and early Thursday. Consensus of
guidance has this well in hand.

.LONG TERM...(Thursday through Monday)
Issued at 309 PM CDT MON OCT 27 2014

The primary weather concern in the long term will be the potential
for frost and/or freezing temperatures next weekend.

The extended portion of this forecast package begins with the the
last minor shortwave wrapping around the main closed low northeast
of Hudson Bay. This feature has enough energy to support cloud cover
and possibly trace precipitation, but for the purposes of this
forecast will keep the time period Thursday and Thursday night dry.
The trajectory of low level moisture remains well cut-off from the
Lower Mississippi River valley.

The dominant high amplitude Rocky Mountain high pressure ridge axis
will keep the WFO PAH forecast area in northwest flow through the
weekend. The main frontal passage will push through late Thursday

The big concern for temperature and moisture profiles for
frost/freeze development will be the timing and progression of the
approaching center of the Canadian high pressure ridge. At this
point in time, the operational GFS suggests that the closest point
the center of the high pressure ridge will move into the area will
be late Friday night into Saturday morning. It will not be in an
ideal position and there may be a residual gradient wind that would
prevent substantial frost development and limit the time period for
freezing temperatures. Southeasterly flow appears to develop in
earnest by Sunday morning and may limit any frost or freeze potential
to the eastern/northeastern corner of the WFO PAH CWA (Southwest
Indiana/West Kentucky Pennyrile).

For now will hint at the potential for frost/freeze in the Hazardous
Weather Outlook.


Issued at 635 PM CDT MON OCT 27 2014

With the approach and passage of a cold front, cloudiness will
increase and lower through approximately the first half of the
period. For the most part, VFR conditions will prevail...however
there could be MVFR cigs/vsbys in SHRA in the 12-18Z time frame.
Southerly winds AOB 10 knots will eventually veer around to the
west, and then northwest behind the front and remain AOB 10 knots.




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