Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 302035

Area Forecast Discussion
National Weather Service Lincoln IL
235 PM CST Wed Nov 30 2016

.SHORT TERM...(This evening through Thursday)
ISSUED AT 225 PM CST Wed Nov 30 2016

After a brief bout of sunshine earlier this morning, clouds moved
in as moisture wrapped around the large low pressure system to the
north/northwest.  The same system has been driving the weather for
the last few days will only progress slowly eastward through
tomorrow. Deep cyclonic flow combined with low level moisture should
keep the clouds in place tonight and into tomorrow morning. Although
the temperatures are cooler, they are relatively close to the
climatological normal. The low clouds and low level moisture may
result in some flurries/sprinkles, mainly north of a line from
Peoria to Bloomington, before midnight.  For tomorrow, westerly
winds will continue, with clouds remaining in place as the
temperatures climb only to the low 40s.


.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 225 PM CST Wed Nov 30 2016

Models in good agreement in moving the closed upper low at 500 mb
north of the Great Lakes Thursday night with weak upper level
ridging building over the Midwest in its wake for Friday into
Saturday. Dry weather expected to continue through Saturday across
our area as weak high pressure edges into the region. Forecast
soundings continue to show a gradual erosion of the low level
moisture as we head into Friday morning, however, we start to see
some mid and high level clouds tracking across the area at the
same time frame so no prolonged period of sunshine expected either
Friday or Saturday with seasonably cold temperatures, generally
from 40 to 45 degrees for both days.

By late Saturday, a northern stream wave is forecast to track across
the Plains and into the Midwest increasing the cloud cover with some
light precipitation developing from west to east overnight Saturday
into Sunday. With the precipitation coming in late at night and
boundary layer temperatures cooling to just above freezing, we may
see some very light snow, or a mix of light snow and rain develop
initially, with any mix quickly changing over to light rain during
the morning hours of Sunday as temperatures warm into the upper 30s
to lower 40s. Light rain should continue off and on during the day
Sunday and then POPs will lower quickly towards evening as the upper
trof shifts across the Great Lakes.

As the upper trof shifts to the east, the closed low at 500 mb over
the southwest U.S., which has not been handled well by the medium
range models, starts to eject northeast into the southern Plains on
Monday with another round of precip expected again Monday night into
Tuesday as the trof shifts across the Midwest. Once again, due to
the timing of the precip arrival on Monday night, we may see a
mix of rain and snow based on model consensus, however, just based
off the soundings, which appear warmer than what we saw 24 hours
ago, the trend may be for more rain than snow, especially if the
12z ECMWF verifies. Any mix we see overnight will become all rain
by Tuesday morning with the bulk of the precip shifting off to our
northeast with the upper trof by evening as another shortwave
drops into the southern Rockies late Tuesday threatening our area
with more rain later on Wednesday.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1157 AM CST Wed Nov 30 2016

Not changing much of the forecast as a deep low centered over
MN/WI border moves cloud cover in place this morning. More MVFR
cigs expected through the night as moisture wraps around the storm
system. Expect cloudy overnight and into the morning. Guidance
show SPI and DEC potentially on the edge of the MVFR to VFR
transition... but not enough confidence to bring cigs above 3000
ft with the low/cyclonic flow that close. Southwesterly wind
continues throughout.




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