Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 252006
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
206 PM CST Thu Dec 25 2014
.SHORT TERM...(Tonight through Saturday night)
Issued at 206 PM CST THU DEC 25 2014
High pressure over the southeast U.S. will keep the PAH forecast
area dry and very mild into Friday evening. Lows tonight will only
drop into the middle 30s, with highs on Friday well above normal
in the lower to middle 50s.
Models are in good agreement bringing a surface low into northern
Illinois by 12z Saturday. GFS, ECMWF and GEM are in very close
agreement on the timing of the the associated cold front, moving
it across our region Saturday into Saturday evening. Models spread
precip across our area late Friday night into Saturday morning,
with likely pops for showers across the entire PAH fa on Saturday.
Rain will continue behind the front Saturday night, tapering off
in our northwest and western counties after midnight. Soundings
indicate moisture lacking by the time colder air begins to really
infiltrate into our west/northwest counties, so precip should
remain all rain through Saturday night.
.LONG TERM...(Sunday through Thursday)
Issued at 206 PM CST THU DEC 25 2014
The 12z ECMWF and GFS and in good agreement through mid week, and
have been followed closely. They resemble the consensus derived on
yesterday`s shift. The prior consensus was, and current depiction
is, staring 12z Sunday, a shortwave forecast to be over TX, with SW
flow aloft over our area, and a strong jet punching SSE out of west
Canada into the Pacific NW. The TX shortwave is still forecast to
dampen out as it heads NE toward and eventually into the TN valley
region by Sunday night.
Meanwhile, out west, as the jet energy continues to dig SSE, a
closed low is forecast to form somewhere around California or
slightly east into the intermountain west. The pattern will evolve
into a split flow regime by mid week, as the low closes off and
heads for AZ, while shortwave energy moves through a broad trof
about an upper low near Hudson Bay, across the Great Lakes region
and Northeast. This will turn our upper flow more WNW with time as
the system out west triggers shortwave ridging over the south
The resultant weather. The models push precip out more quickly on
Sunday. Will only carry a morning chance, with the afternoon dry
(rain). PoPs were removed for Sunday night, and taken back out for
Monday as well, with no features to key in on, and deeper layer
drying working in from the WSW.
Dry Tuesday through Wednesday night as well. Will keep an eye on the
models depiction of some moisture trying to work south toward the
area. But it seems to fizzle encountering mid level confluence
between the two systems described above. Otherwise arctic high
pressure will continue to settle southeast, centered over the
Plains by mid week.
Many question marks exist for Thursday and Thursday night.
Significantly cut back the moderate chance Pops to just slights for
now given such low confidence, despite what model blending does.
The 12z runs, show nothing at all for Thursday. In fact the ECMWF
never brings precip into the area at all through Thursday night,
whereas the GFS breaks down the shortwave ridge and allows a moist
SW flow to develop, with precip possible Thursday night. Prior runs
of the ECMWF were more aggressive bringing moisture and possible
precip north into the area. Too many question marks to go with
anything more than slights (20 percent) for now. Will also use
simplistic R-/S- wording.
Temperatures throughout were a blend of MOS/Ensemble MOS and
Issued at 1005 AM CST THU DEC 25 2014
Axis of strato-cu east of a KHNB-KHOP line moving east. CU rules
off the models suggest additional development possible, but very
limited coverage mainly east of the Mississippi through the
afternoon. Otherwise just some high clouds with a steady south
wind 5-10 kts, maybe a few gusts 10-20kts until sunset.