Area Forecast Discussion
Issued by NWS Paducah, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KPAH 230654
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
154 AM CDT TUE AUG 23 2016

.SHORT TERM...(Today through Thursday)
Issued at 154 AM CDT Tue Aug 23 2016

The current satellite imagery and surface plot shows more
plentiful moisture/clouds perched just to our southwest, poised to
make entry. Within/under them, are surface dew points in the lower
70s. The models have consistently lifted this broad area of
moisture from its Red River valley centered/source region,
northeastward with time Today, as a short wave of energy aloft
advects its positive vorticity toward the Tennessee valley.

As a result, today, we`ll see our pleasant lower 60s dew points
yield to increasing dew points, with lower 70s working their way
into/across SEMO to about the Mississippi river. That`s where the
main focus has been, and continues to be, for our 1st period
chance of pcpn. As one goes east of there, columnar moisture
drops off, the perturbation in the upper flow helping generate
lift flattens out/diminishes, and instability fields in relative
comparison are minimal.

Tonight-Thursday...the remainder of the FA warm sectors early in
the period...with surface TD`s now in the 70s CWA-wide and riding
out the remainder of the short term forecast. Bitmeal pieces of
energy aloft advect their way overtop the broad ridge of high
pressure aloft centered over the Dixieland and arcing into the
heart of our FA upwards to 594 DM at H5. This will effectively cap
off convection for much of the period for southern Ky, while
rimfire Pops occur primarily across our northern and western
peripheral counties. A frontal boundary, with hints of slightly
higher Pops, meanders its way toward said northern border by the
end of the period.

Temp (and humidity) wise, we`ll be moving from the seasonally
fantastic levels of days past to the more summer like feel thru
the short term, which by this time of year, means toward or even
slightly above climo norms.

.LONG TERM...(Thursday through Monday)
Issued at 314 PM CDT Mon Aug 22 2016

We will start out the long term with an upper level high centered
over the Gulf Coast states, with the northwestern edge of this high
nudging into our CWA. Models continue to have night and day
differences with regards to any possible rainfall on Thursday with
the ECMWF continuing to show dry conditions (not a lot of moisture
to work with) and the GFS indicating a more "dirty" ridge with some
activity possibly forming during the day. However, the main
precipitation band should be coinciding with a frontal boundary that
will be way off to our northwest at that time.

That frontal boundary will make its way into the region Thursday
night into Friday. Again, the ECMWF continues to be indicating
fairly dry conditions as the front weakens substantially as it
approaches. The GFS is also steadfast with its wetter solution. Both
models are fairly decent with regards to timing though. Given that
the GFS precip ensemble mean and the Canadian do not indicate a dry
frontal passage, gives more credence to not changing POPs too much
but definitely not go completely dry.

During that time, the upper level high which was centered over the
western Gulf Coast states at the beginning of the long term period,
will steadily shift eastward. With high pressure at the surface, any
precipitation chances for the weekend will likely be tied to any
small pieces of energy rotating around the upper high. The best
chances seem to be situated in the western sections of the CWA where
moisture appears a bit better. However, this far out in time, it is
would be wise to not get too fancy with POPs, although the going POP
strategy shows the aforementioned trend.

&&

.AVIATION...
Issued at 154 AM CDT Tue Aug 23 2016

We retain possibility of patchy shallow fog developing thru
daybreak, with KCGI most likely. Warm advection mid level clouds
will be moving in from the southwest as the morning progresses, in
advance of a disturbance sweeping by, which looks to generate
some -SHRA/TSRA chances over mainly southeast MO Today. Included
mention in KCGI terminal. Can`t be ruled out for KPAH either, but
probability too low to include with this issuance. Some guidance
hinting at lower cloud deck with MVFR cigs at KCGI and maybe KPAH
as they warm sector. Won`t pull the trigger on that yet either,
with only marginal confidence at this writing. Expect developing
light selys to veer slowly with time to light slys.

&&

.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.

&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.