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fxus63 kilx 111109 
afdilx 


Area forecast discussion 
National Weather Service Lincoln Illinois 
609 am CDT Sat Oct 11 2008 


Discussion... 
issued 325 am CDT Sat Oct 11 2008 


00z short range models in good agreement through Monday with a dry 
and unseasonably mild weather pattern continuing next three days. 
Models then diverge with handling next weather system ejecting out 
of the desert SW starting Monday night. NCEP confidence below normal 
next work week and appeared to use a blend of the GFS and NAM 
models which is in between the faster European model (ecmwf) and slower Gem/UKMET 
camps. 


08z/3 am surface map shows 1030 mb high pressure over southeast Ontario 
into New York and ridging across the Great Lakes region while a cold 
front extended from southern Minnesota through eastern Nebraska into northwest 
Kansas. Light southeast winds over central Illinois between these weather systems. 
Patches of ac and cirrus clouds over Illinois with mostly clear to partly 
cloudy skies early this morning. These clouds ahead of a weak 
short wave near the MO/Illinois border and lifting north-northeast. Temperatures were in the 
low to middle 50s and dewpoints in the upper 40s and lower 50s. Aloft 
a strong upper level ridge extended from the Gulf of Mexico 
northward across the Ohio Valley into the Great Lakes. Strong upper 
level low/trough was over the western U.S. And central Canada with 
544 dm 500 mb low along the Nevada/California border and 548 dm low in central 
Saskatchewan. 


Short term...today through Monday. 


Large high pressure drifts over New England today while cold front 
stays over the Central Plains due to strong upper level ridge 
building northward over the eastern states today. 500 mb heights 
elevating above 588 dm over Illinois and 850 mb temperatures near 16c. Curule 
shows scattered cumulus clouds by afternoon over western Illinois closer 
to the MS river. Should be a mostly sunny day across central/southeast Illinois 
with southeast winds 5 to 10 miles per hour. Mild highs in the lower 80s and 
Lawrenceville near 85f. Well above normal highs in the upper 60s 
to near 70f...but shy of record highs in the upper 80s and lower 
90s. 


Fair skies and southeast winds less than 10 miles per hour allows temperatures to cool into 
the middle to upper 50s eastern Illinois and around 60f western Illinois. Models 
build upper level heights over Illinois to 591 dm or even higher Sunday 
with high pressure staying over New England and Middle Atlantic 
States and cold front over the Central Plains. Illinois to again enjoy 
mostly sunny skies with south-southeast winds 5 to 15 miles per hour and warm highs in 
the low to middle 80s. Lows around 60f Sunday night with some 
increasing clouds by overnight into Monday as skies become partly 
cloudy. Most models continue to keep central/southeast Illinois dry Monday with 
warm highs in the upper 70s and lower 80s...warmest in eastern Illinois. 


Long term...Monday night through Friday. 


00z NAM and GFS models bring cold front into far northwest Illinois by midnight 
Monday night and into central Illinois late Monday night. Quantitative precipitation forecast is along and 
behind the front with strong upper level trough/short wave over the 
central/northern plains. Kept chance of showers and thunderstorms 
west of I-57 Monday night especially after midnight with eastern Illinois 
east of Highway 51 from Bloomington to Decatur staying dry Monday 
night. Cold front appears to go through eastern/southeast Illinois during Tuesday 
especially in the morning with good chance of convection Tuesday 
across the area and likely probability of precipitation from I-55 northwest. Brunt of upper level 
energy passes north of Illinois over Minnesota/WI with a weakening tail of 
short wave energy moving southeast across Illinois Tuesday. Mostly cloudy skies and 
cooler highs ranging from the lower 60s west of Peoria and 
Springfield to 70 to 75f over eastern Illinois. Big differences with 
extended models Wednesday with European model (ecmwf) showing overrunning quantitative precipitation forecast into MO/Illinois 
with frontal boundary near the Ohio River while GFS has MO/Illinois dry 
with high pressure ridge building in and Gem is dry over Illinois by Wednesday 
too. Due to vast differences in extended model solutions and 
jumping around from previous model runs...decided to leave small 
chances of showers Wednesday and seasonable highs in the middle to upper 60s. 


Huettl 
&& 


Aviation... 
issued 608 am CDT Sat Oct 11 2008 


VFR conditions will continue next 24hrs at all taf sites. Cirrus 
clouds will continue to push northeast out of the area. Models 
indicate some low level moisture...so some scattered cumulus is 
possible today. BUFKIT supports this thought as well. Moisture is 
limited enough to keep any cloud cover scattered and not broken. Light 
winds will be more southerly today with highest winds at spi and 
pia...then they will become light and easterly around sunset. 


Auten 
&& 


Ilx watches/warnings/advisories... 
none. 
&& 


$$