Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 240030
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
630 PM CST Sun Nov 23 2014
Issued at 630 PM CST Sun Nov 23 2014
Updated aviation discussion only.
.SHORT TERM...(Tonight through Tuesday night)
Issued at 100 PM CST SUN NOV 23 2014
Certainty Pops are playing out as advertised, with large mass of
overrunning rain anticipated to continue into the evening.
Overnight, the parent Low will be lifting northeastward, and
tightening the gradient substantially. Sustained Winds and Gusts will
reach toward advisory criteria by 09Z and hold thru much of the
day, as they shift from southerly to westerly upon system passage.
Rain winds down accordingly as well.
SWODY1 continues inclusion of thunder, and collab suggests we
should too, at least thru mid evening. While we think it is
unlikely, the elevated parameters do suggest its potential, so an
isolated mention will hold til dropping off shortly after 03Z per
the collab pic.
Improving but cool conditions will mark the remainder of the short
term forecast period as the system departs and lower heights hold
with a surface high building in Tuesday.
.LONG TERM...(Wednesday through Sunday)
Issued at 100 PM CST SUN NOV 23 2014
A parting shot from the broad cyclonic flow will move through the
WFO PAH forecast area at the beginning of the extended forecast
period. Although the mean trough axis will be along the east end of
the WFO PAH forecast area, one minor shortwave will dive down from
the upper Midwest, phasing in to the trough axis during the day on
The deterministic runs of the 00z Sunday ECMWF, Canadian (GEM), and
the GFS Ensemble numerical guidance focus the shortwave a little
further north over MN vs. the 12z Sunday deterministic GFS which
places the shortwave over Central Illinois. The main impact of this
spatial difference is the trajectory of the moisture/lift associated
with the shortwave, with the GFS having the greatest potential for
light precipitation on Wednesday. Will still acknowledge some minor
precipitation chance for Wednesday, but anticipate it will have very
minor impact for pre-Thanksgiving Day travelers.
Beyond the Wednesday system, the persistent East Pacific closed low
off the Western U.S. coastline will force a broad zonal flow
eastward across the conterminous U.S. This will temper the cold air
intrusions, but will place the WFO PAH forecast area within a
tighter gradient flow from north to south. The southward extent of
this gradient flow will impact the development of any shower
activity in the sheared flow aloft for next weekend. Forecast
confidence is low (less than 50%) as to the degree of precipitation
coverage next weekend. Plan a compromise, keeping any rain chances
focused toward the southern 1/3 of the WFO PAH forecast period
during the Day 6 through 8 time period.
Issued at 630 PM CST SUN NOV 23 2014
We are expecting improving vsbys as a low pressure system pulls away
toward the Great Lakes this evening. Some showers may develop
overnight ahead of a sfc cold front which is forecast to sweep
west-to-east through the region. These showers are not expected to
affect vsbys for significant lengths of time. Though there may be
breaks here and there, the predominant cigs are expected to be IFR
through the night with some potential LIFR, lifting some shortly
after sunrise, especially in the wrn half of the region. Late in the
night, winds are expected to howl in front of and behind the front,
gusting to 25 to 30 kts. The wind should sustain most of its
velocity throughout Mon afternoon.
IL...WIND ADVISORY from 3 AM to 6 PM CST Monday FOR ILZ075>078-
MO...WIND ADVISORY from 3 AM to 6 PM CST Monday FOR MOZ076-086-087-
IN...WIND ADVISORY from 3 AM to 6 PM CST Monday FOR INZ081-082-
KY...WIND ADVISORY from 3 AM to 6 PM CST Monday FOR KYZ001>022.