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Area forecast discussion 
National Weather Service Lincoln Illinois
1143 am CST Fri Dec 26 2014

issued at 1033 am CST Friday Dec 26 2014

High pressure sliding off to the east leaving much of the Midwest
with southerly winds, and somewhat gusty with an increasing
gradient in the midlevels as well as at the sfc. Warm temps
expected with the temperatures climbing a bit quicker than
Standard diurnal curve. Have bumped up the highs to a degree or
two more than yesterdays maxt, and adjusted the hourlys as well.
Some minor mid/high level clouds off to the NW, but little impact
so far. All in all, minor updates to the forecast.


Short term...(today)
issued at 330 am CST Friday Dec 26 2014

A slow moving cold front, currently extending from the western Great
Lakes into to southern High Plains, will continue to creep toward
central and southeast Illinois today. Cloud cover will gradually
increase from the northwest with the approach of the front.
Southerly winds, gusting to near 25 mph at times today, will provide
the region with another unseasonably mild day. High temperatures
should peak out near 50 degrees area wide.


Long term...(tonight through thursday)
issued at 330 am CST Friday Dec 26 2014

00z forecast models continue slower trend of bringing in light rain
chances from the west tonight and most areas could stay dry this
evening with just small pops in western counties later this evening.
Have chances of light rain spreading east across central/eastern Illinois
during overnight and milder lows in the low to mid 40s tonight with
south winds 8-15 mph. 1008 mb low pressure over NW Texas at sunset
will eject quickly NE to southeast WI by dawn Sat, and into northern
lower Michigan by noon Sat. This will pull a cold front se through central
Illinois during the day Sat with likely chances of light rain showers. One
more mild day Sat in the upper 40s/lower 50s (except mid 40s NW of
Illinois river). Cold front pushes se of Wabash River by sunset Sat and
pushes into mid Tennessee by dawn Sunday as another low pressure lifts NE
along it from southern MS River Valley. Have light rain chances
lingering over southeast Illinois Sat night, and could mix in with a
little bit of light snow overnight Sat night before ending but no
accumulation expected. Lows Sat night range from mid 20s over Illinois
River valley to lower 30s in southeast Illinois.

Forecast models continue to show strong Arctic high pressure
settling southward from Canadian rockies into Front Range of US
rockies from Mon-Wed and ushering in colder air into Illinois with below
normal temps by middle of next week. Upper level trof digging
southward into the Great Lakes and Ohio River valley by middle of
next week to also help bring in cooler temps while best chances of
scattered light snow showers appears closer to the Great Lakes
region. Tue night and Wed should be the coldest time next week with
upper single digit and teens for lows Tue night. Just beyond the 7
day forecast, forecast models in agreement in showing a strong low
pressure system ejecting NE from the Southern Plains into the Ohio
River valley by next Sat and this could bring more significant
precipitation to central/southeast IL, though GFS model has US on NW
fringe of this storm system and is colder than the European model (ecmwf) model.
Still a lot of time for forecast models to reflect better idea of
forecast for next weekend with this storm system.


Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1132 am CST Friday Dec 26 2014
not much of a change in the forecast for this round of tafs.
Increasing llvl MVFR clouds this evening and then into the
overnight dropping the cigs and bringing in the precip. Bigger
concern than the precip is the wind shear at around 2000 ft. The
forecast soundings backing down a bit in the 12z run, and have
reduced the kts by 5...but still in the 30-40kt range out of the
SW with southerly at the sfc. Forecast soundings still saturated
only in the low levels early, pointing to more of a drizzle event,
and prefer to keep the predominant dz particularly with the better
energy associated with the sfc system shunting across the region
to the north. That being said, it is still a front. And needed a
tempo to at least depict the chances for dropping to IFR, so
included a -ra in the tempo.


Ilx watches/warnings/advisories...


short term...Bak
long term...07

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