Area Forecast Discussion
Issued by NWS Paducah, KY

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000
FXUS63 KPAH 110858
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
258 AM CST Sat Nov 11 2017

.SHORT TERM...(Today through Monday night)
Issued at 258 AM CST Sat Nov 11 2017

High pressure over the Appalachian Mountains early this morning
is bringing the season`s first hard freeze to some areas.
Temperatures as of 2 AM were in the upper 20s to lower 30s, and
they should fall a bit more by sunrise. The high will move east
to the Atlantic Seaboard late today, causing winds to turn
southeast. Despite the milder southeast flow, widespread high
cloudiness and the low November sun angle will limit highs to the
upper 40s and lower 50s today.

Clouds will lower and thicken tonight as a 500 mb shortwave moves
east toward the mid and upper Mississippi Valley. Some light rain
will spread east across Missouri and Illinois, possibly reaching
the lower Ohio Valley around sunrise. Clouds and south winds will
keep temps in the 40s overnight.

On Sunday, the amplifying 500 mb shortwave will move east of the
lower Ohio Valley by evening. A weak cold front will pass through
during the afternoon and early evening. The chance of showers will
diminish from west to east as the cold front and shortwave pass
by. Highs will be in the 50s.

Drier air will arrive by Monday as shortwave ridging noses in and
surface high pressure passes across Illinois. Despite abundant
sunshine Monday, highs will only be 50 to 55 under the influence
of cool high pressure.

.LONG TERM...(Tuesday through Friday)
Issued at 258 AM CST Sat Nov 11 2017

To start out the long term period, surface high pressure will be
centered to our northeast and return flow will be working in earnest
just to our west. During the day on Tuesday, a frontal boundary will
develop in the northern and central Plains states and move eastward.
While Tuesday is expected to remain dry, we will start to see an
increase in moisture and cloudiness especially in the western
counties.

By 12Z Wednesday, the front should be situated from Oklahoma up into
the western Great Lakes region. While Tuesday evening should remain
mainly dry, there will be increasing chances for precipitation
mainly across our northwestern tier counties after midnight Tuesday
night into Wednesday morning. The front will slide southeast across
the area during the day on Wednesday and rain chances will
overspread the rest of the area with fairly high POPs.

Differences in model solutions show up by Wednesday night, as it is
unclear how soon the rain may end. Models do not have a handle on
how quickly to build the surface high southward, hence shoving the
rain out of the area. In addition, there are hints that the front
may stall out over parts of the region. Still feel Wednesday evening
may be wet in many areas, especially the southern half of the
region.

The scenario becomes even more tricky for Thursday as models return
the front back north as a warm front. Timing of the front`s
progression is very challenging due to the development of another
surface low in the lee of the Rockies at that time. However, whether
the front retreats back north on Thursday or Thursday night, we will
need to have continued POPs in the forecast. We may have a brief
lull in the warm sector for a while before an upper level trough
helps push a cold front through sometime Friday.

Ahead of the front, on Thursday night into Friday before the front
comes through, dewpoints will surge into the upper 50s to possibly
lower 60s. Depending on how the upper levels end up panning out, we
could have some decent winds aloft to contend with. Could have some
instability to work with along with good mid level lapse rates.
Something we will be keeping an eye on at least. Still lots of
differences in how this whole late week system will pan out. Can
definitely see at least some isolated thunderstorms with this system.

Lots of fine tuning to be done with subsequent forecasts here, so
broadbrushed rain chances will have to do for now until we can
obtain a better handle on how this system will evolve last this
week. Right now, the first part of the weekend looks dry.

&&

.AVIATION...
Issued at 258 AM CST Sat Nov 11 2017

Widespread high clouds will persist today and tonight. Some lower
clouds should begin to arrive from the southeast this evening,
mainly in west Kentucky and southwest Indiana. Will keep cigs vfr
at this time, with a mention of scattered low clouds this evening
east of the Mississippi River. Winds will be light southeast for
most of the taf period.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&

$$

SHORT TERM...MY
LONG TERM...CW
AVIATION...MY



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