Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 190448 AAB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PADUCAH KY
1148 PM CDT Fri Jul 18 2014
Issued at 1130 PM CDT FRI JUL 18 2014
Updated for 6z aviation only.
UPDATE Issued at 848 PM CDT FRI JUL 18 2014
The public forecast has been updated to catch up to alot of moving
parts this evening. Skies have nearly cleared over the entire
area. The lone exception being in the Murray and Hopkinsville
Kentucky areas, where some very light radar echoes remain.
Southeasterly flow in the low-levels is likely to continue
through much of the night, as most guidance shows a weak surface
low riding northeast toward or into west Tennessee by morning. As
it gets closer light northeast winds are likely to develop
southward through southeast Missouri overnight and potentially
over the entire area by daybreak. Also would expect the light
drizzly echoes to spread north and a bit westward over the Lakes
and Pennyrile regions as forecast.
With the low approaching, would not expect much cooling tonight
over at least west Kentucky. Ended up raising low temperatures up
to the middle 60s throughout west Kentucky, but northwest portions
of the area should still radiate down into the upper 50s as forecast.
More adjustments may be necessary later this evening.
UPDATE Issued at 615 PM CDT FRI JUL 18 2014
UPDATED FOR 00Z AVIATION ONLY.
.SHORT TERM...(Tonight through Sunday night)
Issued at 135 PM CDT FRI JUL 18 2014
Rains stayed basically to our south, so in hindsight, the NAM was
essentially useless, as the other models resolved much better the
farther south track of better moisture and precip over the past
few days. Will continue to side with a ECMWF/GFS approach through
Sunday. They continue to paint scant QPF over the Pennyrile region
and east tonight through the weekend, probably more diurnal in
nature Sat/Sun. Kept a token slight chance PoP over there. Most
areas will remain dry. And, we have it dry west of there. Some
cloud cover will hang around given the slow movement of the trof,
and model time sections revealing abundant low level moisture.
Thought about a fog inclusion in at least the grid forecast. But
confidence not high enough yet, given potential cloud cover. Could
be some, thus we will update if need be. Temps will continue to be
a blend of weighted model guidance and persistence.
.LONG TERM...(Monday through Thursday)
Issued at 244 PM CDT FRI JUL 18 2014
The ECMWF and GFS ensemble means appeared to be pretty close in
their solutions this time around. However, toward the end of next
week, the upper ridge over much of the wrn CONUS was shown to be a
little stronger in the GFS ensemble means vs. the ECMWF ensemble
means. Also, the 12Z deterministic models agreed pretty well
initially in the details of the movement/evolution of a mid/upper
shrtwv moving through the nrn Plains on the nrn periphery of the
large, dominant ridge.
However, the deterministic models also began to differ late in the
week with the feature, i.e., the ECMWF continued to want to semi-cut
off a piece of energy from the amplifying shrtwv that is progged to
be over the OH River valley Wed night. If the 12Z ECMWF verifies,
the tight little low will traverse WI and nrn parts of IL and IN and
never really bring a cold front through the PAH forecast area...more
of a sfc trof. If the GFS verifies, a sharper wind shift and drier
air should move into parts of the region by Thu afternoon. The 12Z
GEM seemed to support a more progressive shrtwv movement like the
The initialization blend appeared to support a drier warmer trend
for the PAH forecast area early next week, with the more dominant
mid/upper ridge providing more subsidence. The Pennyrile region may
receive isolated tstms then. Wed night/Thu will be the time frame
with the highest PoPs (35-40%) across most of the area, as the lower
trop moistens up ahead of the shrtwv. Most of the shower and tstm
activity through the extended period will be diurnally-driven,
except perhaps Wed night when better dynamics come into play.
As the shrtwv is eventually replaced by nwrly mid level flow Thu
night/Fri, drier conditions should prevail. Expect temps near
climatological average, with summer-style dewpoints, especially
Issued at 1148 PM CDT FRI JUL 18 2014
Tempo mvfr deck for KOWB earlier with satellite and now obs
showing low deck already in there. Left winds up a little longer
in KOWB as well. Also kept mvfr deck for KEVV a little later after
midnight. With clear skies over KCGI and KPAH slowed the mvfr deck
slightly but still kept at least a tempo mvfr overnight. Should go
scattered after sunrise but may see some fog before then
especially at KCGI.