000
FXUS63 KPAH 081004
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
404 AM CST Sun Dec 8 2013

.SHORT TERM...(Today through Monday night)
ISSUED AT 341 AM CST SUN DEC 8 2013

Main forecast issue in the near term is with the icing potential
early today...mainly southeast of a Murray KY to Greenville KY
line. Latest radar and satellite trends suggest most of the model
QPF may be underdone in that region. 40 DBZ echoes continue to
stream ne our of nw TN into that region, and recent IR images show
cloud top cooling underway upstream over wrn TN. Therefore, will
lean toward the upper end of the model QPF envelope, which
suggests one quarter to a third inch of precip. warming aloft
should ensure most of the precip that far se should stay in the
form of freezing rain. Gradual warming at the surface will also
take place...but it is still sub-freezing all the way down into
nrn MS...so it will take quite awhile to warm above freezing,
probably til late morning or noon. With all that said, will need
to upgrade the advisory to an ice storm warning, which we will run
until noon.

Will leave the ongoing advisory going for the remainder of wrn KY
today, as light sleet and freezing rain still looks like a good
bet. Amounts here tho will be much less, but with temperatures
still in the mid 20s this morning, it will not take much ice to
cause travel issues. All precip should taper by late morning, but
patch freezing drizzle may still be an issue into the night. Temps
across our se counties will likely fall back below freezing later
tonight. Will need to monitor.



.LONG TERM...(Monday through Saturday)
ISSUED AT 341 AM CST SUN DEC 8 2013

Only two precipitation events noted in the long term forecast. The
first is a quick/transient passage of wintry precipitation (light
snow) over Southwest Indiana Tuesday morning.  The fast west-east
flow aloft should limit any residence time for measurable
precipitation production, so slight chance PoPs are about the most
warranted at this time.

The center of the Arctic/Canadian high pressure moves into the WFO
PAH forecast area by Thursday, with the stronger flow aloft
remaining in the northwest flow over the Great Lakes region. Any
precipitation chances will remain shunted to the northeast in the
faster flow.

The second chance for precipitation occurs Friday night into
Saturday. The GFS/ECMWF differ in the evolution and redevelopment of
the colder air into the Great Lakes/Ohio Valley/Mississippi area.
This has lead to some uncertainty as to the precipitation types for
the second event.

The GFS thermal profile is warmer than the ECMWF and is much weaker
and further north with the high pressure center. In addition, the GFS
shifts toward a southwesterly flow aloft/while the ECMWF maintains a
northwest flow aloft. Given the extremes of the thermal profiles,
rain versus snow, had to consider a blended sounding that places
part of the WFO PAH forecast area (mainly north of the Ohio River)
in a freezing/frozen category with respect to precipitation type.
Given how shallow the layer will be and how much precipitation
loading through the layer is expected, the transition phase should
be fairly quick from wintry precipitation to liquid rain by late
Saturday morning. Precipitation amounts should be light, so do not
anticipate this to be a widespread issue for travel, etc.


&&

.AVIATION...
ISSUED AT 1120 PM CST SAT DEC 7 2013

Other than KPAH which has been in and out of MVFR cigs this
evening, all other sites remain VFR. Precip on the scope is having
a hard time reaching the ground due to dry lower levels. As the
moisture starts to saturate down over the next several hours, we
should see cigs lower to mvfr and eventually IFR. Forecast
precipitation type will likely start out as -snpl or simply some
flurries/lt snow during the early morning hours (maybe some -fzra
at KOWB).

The mid/high level moisture will exit the area during the
day on Sunday and warmer air will start moving into the region,
providing the possibility of freezing drizzle/rain through the
rest of the morning and into the early afternoon as sfc temps
remain around freezing or below. As more and more dry air
penetrates the area, any chances for precipitation should
gradually come to an end by afternoon sometime. Winds will be aob
10kts and begin as northeasterly but then shift to become
southwest by the end of the period.


&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...WINTER WEATHER ADVISORY until 5 PM CST this afternoon FOR
     KYZ001>008-010-011-013>016-018>020.

     ICE STORM WARNING until Noon CST today FOR KYZ009-012-017-021-
     022.

&&

$$

SHORT TERM...Meffert
LONG TERM...Smith