Area Forecast Discussion
Issued by NWS Paducah, KY
FXUS63 KPAH 282116
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
316 PM CST Fri Nov 28 2014
.SHORT TERM...(Tonight through Sunday night)
Issued at 315 PM CST FRI NOV 28 2014
A substantial modification in temperatures is still on track over
the weekend as the upper flow pattern becomes zonal and low level
southerly winds increase markedly. Unfortunately, the stronger
wind profile will act to bring a rapid increase in low level
moisture late tonight and early Saturday. This persists through
the weekend, so the entire period looks to be shrouded in cloud
cover. With the abundant low level moisture and weak isentropic
lift, some light rain or drizzle activity will be possible by
Saturday afternoon and Saturday night.
A better chance of rain enters the forecast Sunday and especially
Sunday night with the approach and passage of a strong cold front.
Even with the focus of the front, rain totals should remain on the
light side. The arctic air behind the front will arrive much more
quickly than we were thinking a few days back. As a result, some
of the rain may change over to light freezing rain over northern
portions of southern Illinois and southeast Missouri late Sunday
night. It is possible this area may even begin to see a light
glaze on mainly elevated and untreated surfaces by daybreak
Monday - but that is by no means a certainty at this point.
Given the strong pressure gradient between high pressure to our
east and the approaching cold front, the weekend promises to be
rather windy. South to southwest winds sustained at 15 to 20 mph
will occasionally gust as high as 25 to 30 mph both weekend days.
The period will also be characterized by a non-diurnal temperature
trend as temperatures stage a slow warming trend from late tonight
into Sunday - before plummeting behind the front Sunday night.
.LONG TERM...(Monday through Friday)
Issued at 315 PM CST FRI NOV 28 2014
Forecast confidence decent through Tuesday night, although forecast
rather tricky/complicated at the onset. From Wednesday on forecast
solutions still miles apart. Details to follow.
At the beginning of the long term period ( 12Z Monday), a cold front
is forecast to be just south and east of our CWA. The approach of a
weak H5 short wave is forecast to induce a light overrunning
precipitation event across our CWA. If forecast temperatures pan out
on Monday, there is the potential for freezing rain over the
northwest half of our CWA by the end of the day.
Temperatures over the northwest third of our CWA Monday morning will
start out below freezing so freezing rain will be possible generally
north and west of a line from Mount Carmel Illinois to Van Buren
Missouri. A NE-SW band of rain or freezing rain will generally
extend 25 miles either side of a line from Winslow Indiana to
Doniphan Missouri. Only light ice accumulations are expected.
As the colder air overspreads the region Monday afternoon,
temperatures are expected to fall to at or below freezing generally
north and west of a line from Rockport Indiana to Poplar Bluff
Missouri. Therefore freezing rain will be possible in these areas. A
band of rain or freezing rain will generally extend 25 miles either
side of a line from Owensboro Kentucky to Bernie Missouri. Only
light ice accumulations are expected.
With the exception of the southern Pennyrile region of western
Kentucky, a narrow band of light freezing rain may linger over the
southeast sections of our CWA Monday evening. Only light ice
accumulations are expected.
With the passage of another cold front Tuesday night, there will be
a small chance for light rain over the far southeast sections of our
CWA where moisture will be a little deeper.
Wednesday looks dry for now but beyond that models are still in
total disagreement, and for the sake of not going into every little
detail/model difference, and in an effort to go with some type of
blend, will have some measure of precipitation over all or part of
our CWA from Wednesday night through the end of the period. Whew!
With the exception of a rain/snow mix over the western and
northwestern sections of our CWA Wednesday night, all other
precipitation is expected to be liquid.
Issued at 1150 AM CST Fri Nov 28 2014
Main aviation concern through much of the forecast is wind. South
winds will gust up to 20 knots this afternoon. Low level wind
shear will develop tonight as winds increase to around 50 knots at
1700 feet AGL. A rapid increase in MVFR clouds will take place
late tonight and early Saturday morning. As ceilings continue to
lower through the morning, the development of drizzle is possible
by midday Saturday.