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FXUS63 KILX 252100

National Weather Service Lincoln IL
300 PM CST WED NOV 25 2015

.SHORT TERM...(Tonight)

High pressure is sliding off to the east coast this afternoon,
and another system is developing over the Plains.  This storm system
will slowly make its approach to the Midwest for later Thanksgiving
night.  In the meantime, scattered showers, low clouds, and drizzle
are expected later this evening and overnight, spreading as dawn
approaches.  Continued southerly winds overnight will work together
with the expansive cloud cover to keep the overnight lows mild for
the end of November.  Not much of a change in the overall forecast,
heading into a rainy holiday weekend.


.LONG TERM...(Thursday through Wednesday)

An active weather pattern will be in store for central and southeast
Illinois through the Thanksgiving weekend and into early next week.
Overall the shorter range models are generally in agreement with a
northern stream upper level trough shifting and associated cold
front shift through the Midwest Friday and upper level low/Rex block
situation developing the western states. The differences come into
play later in the weekend and into early next week with the amount
of shortwave energy that is ejected toward the middle MS valley and
when the upper low in the west begins to move out.

The approaching cold front and increasing southerly flow and deeper
moisture will produce the likelihood of light rain in the IL River
valley Thanksgiving Day, with scattered showers in the rest of
central Illinois. East central Illinois may see some light warm
advection rain in the morning, but then only a few spotty showers
during the afternoon, with mainly cloudy conditions in the
southeast. Despite the potential for rain and the clouds,
temperatures on Thanksgiving will be unseasonably mild with highs
around 60 across the whole forecast area.

The highest potential for moderate to heavy rain will move into
central IL Thursday evening, and into eastern/southeast IL late
Thursday night as the cold front moves through and area of low
pressure moving along it enhance the rainfall potential. The rain
should linger in most of the forecast area through Friday as the
front slowly sags to the southeast. Temperatures on Friday should be
warmest in the morning, with readings slowly falling during the day
as the cooler air filters in. Forecast soundings indicate that the
western edge of the precipitation shield could see a change to light
freezing rain or snow north of a Rushville-Bloomington line Friday
night. Very little or no accumulation is anticipated from this brief
change over.

Rainfall totals of 1.00 to 1.50 inches are anticipated by Saturday
morning, with the highest amounts staying in southern IL or west of
the MS River. Much of the snow cover has melted in the northern part
of the forecast area, so the impact of up to 1.50" of rain should
not be as great on area streams/creeks.

The first piece of shortwave energy coming out of the western U.S.
upper low is expected to interact with the nearly stationary front
south of the Ohio River valley, and may in fact push it a bit
farther north later Saturday into Sunday. This will keep the chance
of rain in southeast IL through the weekend, and move it back into
parts of central IL by Sunday morning.

There is a lot of uncertainty with the movement of the western U.S.
upper low late in the weekend and into early next week. The European
model is quite complex and quicker with the low, while the GFS is
slower. Prefer the slower GFS solution, especially since this upper
level pattern is fairly complex. The result would be a continuation
of unsettled weather and a trend toward cooler temperatures Monday
into early Tuesday. Could see a change from rain to light snow or a
mix of rain/snow in central Illinois Monday night as temperatures
dip below freezing and colder temperatures aloft approach the region.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)

Main issues for aviation concerns is the timing of the
deteriorating conditions across Central Illinois. Mid and low
clouds out there now...spreading across the terminals in the next
couple hours, but still VFR. Very gusty southerly winds, gusting
to 25kts. As sunset approaches, cigs fall and stay down overnight.
Big issues with the forecast is the timing. Time heights pull the
cigs to MVFR between 03z-06z. Have tried to develop a trend in the
forecast. Showers starting later this evening and spreading east
ahead of the main system. Showers more scattered in nature
initially and not willing to go predominate for any given period
at this point.


.ILX Watches/Warnings/Advisories...


LONG TERM...Miller
AVIATION...HJS is the U.S. government's official web portal to all federal, state and local government web resources and services.