Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 140758
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
258 AM CDT Sun Sep 14 2014
.SHORT TERM...(Today through Tuesday night)
Issued at 250 AM CDT SUN SEP 14 2014
Models continue in good agreement in the overall short term
pattern. High pressure over the Ohio Valley region and lower
Great Lakes will shift only slightly eastward today. Should see
the beginning of a modest warming trend as this occurs. After
sunrise temps in the 40s...should see a good 30 degree warm up
from AM lows Sunday into the 70s with very comfortable humidity
levels. The gradual warm up will continue on Monday as winds
finally shift more southwesterly ahead of an advancing cold front.
Warming trend will continue ahead of this front Monday afternoon,
with highs in the upper half of the 70s to near 80. Aforementioned
weak front will move se into region later Monday and Monday
evening. Still looks to be very little low lvl convergence and mid
lvl support associated with the front, and even return moisture
looks modest at best. Thus, will go no higher that slight chc of
showers at this time along and just behind the frontal boundary.
Lingering clouds and northerly winds behind the front on Wednesday
could have a big effect of max temps that day, especially over the
southern portions of the forecast area where clouds will be last
to clear. Will lean toward the cooler end of the MOS envelope
right now and keep most locations in the 70 to 75 degree range. It
is possible temps will not make in out of the 60s where clouds do
not clear Wednesday afternoon.
.LONG TERM...(Wednesday through Saturday)
Issued at 250 AM CDT SUN SEP 14 2014
Most of the long term period will be dominated by a continuation of
the eastern trough/western ridge pattern. This ensures that cool and
dry weather will persist into Thursday. Toward the end of the
period...the models indicate the flow pattern will become quasi
zonal. This will allow temperatures to moderate to seasonal levels
by late in the week.
As far as the daily details...
Wednesday into Thursday...surface high pressure will drift slowly
east across the Great Lakes region. This high will produce a cool
and dry northeast flow in the low levels. There is some model
disagreement concerning the timing of moisture return at 850 mb. The
00z gfs and its ensemble mean bring a very tight dew point gradient
eastward into the Lower Ohio Valley on Wednesday. The gfs even
generates qpf across southeast Missouri on the west side of the
gradient. The 00z ecmwf keeps this moisture over western Missouri.
Given the lack of model continuity...the forecast will basically
follow the previous one. However...the potential exists for a band
of cloudiness and even some showers to affect over our region Wed
On Friday...there is strong model agreement that the low level flow
will become southerly as the surface high crosses the Appalachians.
A 500 mb shortwave ridge over the lower and mid Mississippi Valley
will be accompanied by dry conditions.
On Saturday...warm and humid southwest low level flow will continue
in advance of a cold front over the Missouri Valley. There are model
timing differences concerning the cold front...but there is enough
of a consensus to keep the forecast dry on Saturday.
Issued at 1128 PM CDT SAT SEP 13 2014
Little change from 00z to 06z Sunday TAF forecast. Although Cirrus
will be moving across the TAF sites through 12z Sunday, did not
include it in this package since it will have essentially no
impact to the lower ceiling limits of general aviation across the
local forecast area.
Although there will be decent boundary layer moisture near 12z at
each TAF sites, mixing under the ridge should not precipitate any
measurable cumuliform cloud development, so kept sky cover
essentially clear. The next forecast issuance may require the
introduction of some cloud cover into the end of the 12z-18z
Sunday time frame.