Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 261928
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
128 PM CST Fri Dec 26 2014
.SHORT TERM...(Tonight through Sunday night)
Issued at 128 PM CST FRI DEC 26 2014
Moist SW flow will bring changes. Mild afternoon, resulted in an
upward adjustment in temps. With south winds staying up tonight
with increasing clouds, will keep temps at or just above guidance.
Rain shower chances will be on the increase from the SW mainly
after midnight, and especially SEMO, far west KY into southern IL
late, lowest chances across the west KY Pennyrile area. Went with
categorical PoPs Saturday morning up through the middle of the
CWFA where the best surge of moisture and lift is progged. Kept
thunder out. However, there is marginal elevated instability in
some of the progs, some a few rumbles not out of the question,
mainly just north of the TN/AR state lines. The chance of showers
will translate east during the afternoon, with mainly scattered
coverage west. At the surface, cold front will slowly make passage
through the afternoon and early evening.
Best chance of rain/showers Saturday night into Sunday will be
across the SE 1/3 of the area tapering off to the north and west.
Models a bit slower moving the activity out Sunday than 24 hours
ago. Their inability to lock onto a reliable departure time
means will keep a buffer region of chance PoPs, while attempting
to depict a decent gradient where chances drop off central sections.
Sunday night should be essentially dry with high pressure in
control and moisture and forcing off to our east. As far as temps,
we gave weight to the HiRes NAM 2m temps blended with a lower
percentage of MOS for tonight through Saturday. After that, it was
an even blend.
.LONG TERM...(Monday through Thursday)
Issued at 315 AM CST FRI DEC 26 2014
The GFS/ECMWF ensemble means were in decent agreement in their
solutions at this time with the developing split flow across the
As sfc pressures continue to rise through mid week, the mid/upper
flow over the PAH forecast area will transition from wswrly to
wnwrly. Meanwhile, the GFS/ECMWF/GEM models have a strong signal for
a surge of arctic air to sweep out of the nrn stream and into our
area early Wed, dropping the dewpoints into at least the single
digits, possibly lower, for about 24 hrs. After a dry and frigid
Wed, the primarily nrly sfc winds should return to a swrly direction
by Thu, helping to boost temps and especially dewpoints somewhat. At
this time, the 00Z model runs suggest that the extended forecast
will be dry for the PAH forecast area (through 00Z Fri), after which
a large scale moist warm advection pattern will develop ahead of an
ejecting swrn CONUS mid level low. Added some GFS MOS into the
initialization blend temp numbers, and modified the dewpoints mid
week to reflect the arctic signal better.
Issued at 1135 AM CST FRI DEC 26 2014
Low level moisture more prominent over SEMO, where some sct-bkn MVFR
bases are located, while east of the Mississippi, drier low level
air yielding higher bases or just occasional high clouds streaming
NE across the area. SSW winds 8-12 kts will continue through the
afternoon with a few gusts 20 kts or so, give or take.
Winds subside this evening, with mainly sct-bkn VFR cu-stratocu.
After 06z, will introduce chance of -SHRA, then ramp up the chance
by 12-14z Saturday, as a lobe of energy and more significant
moisture moves NE into and across the area. Introductory MVFR cigs
and vsbys with the precip, but there could be intermittent IFR
conditions through the morning Saturday.