497 
FXUS63 KILX 090838
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
338 AM CDT Sun Apr 9 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 337 AM CDT Sun Apr 9 2017

Another breezy day ahead along with even warmer high temperatures 
of 75-80F, despite more cloud cover today. 1020 mb high pressure 
over the mid Atlantic states early this morning will push off the 
East coast during the day, while 996 mb surface low pressure over sw 
Nebraska moves into west central Iowa by sunset. South winds to gust 
from 30-40 mph today and be strongest in late morning and afternoon 
hours. Partly to mostly cloudy skies expected today with more 
sunshine possible in southeast IL while cloudier skies over the IL 
river valley. Mild lows in the upper 50s and lower 60s tonight which 
is actually close to normal highs for early April. Low pressure to 
weaken to 1001 mb by sunrise Mon as it tracks ne into central WI. 
Have 20-30% chance of showers and thunderstorms moving into far NW 
CWA late this evening and across the IL river valley overnight. SPC 
day1 outlook keeps slight to marginal risk of severe storms west/nw 
of IL through sunrise Monday.

&&

.LONG TERM...(Monday through Saturday)
ISSUED AT 337 AM CDT Sun Apr 9 2017

An upper level trof over the central/northern Rockies to move 
east into the Midwest on Monday and have an associated cold front 
move into nw IL late Monday afternoon. SPC day2 outlook continues a 
marginal risk of severe thunderstorms Monday afternoon into mid 
Monday evening east of the IL river, with a slight risk of severe 
storms over Champaign, Vermilion, eastern McLean, eastern DeWitt and 
northern Piatt counties. Primarily for damaging wind gust with 
MLCAPES peaking around 1000 j/kg and unidirectional wind fields. 
Weakening surface low pressure tracks into northern lower MI by 
midday Monday and then pulls a cold front se into the IL river 
valley later Monday afternoon and thru rest of central/southeast IL 
during Mon evening. Highest chances of convection continue east of 
the IL river on Monday afternoon/evening, then just isolated showers 
possible in southeast IL overnight Monday night. Breezy sw winds on 
Monday ahead of cold front bring another mild spring day in the low 
to mid 70s. Lows Mon night range from around 40F nw of the IL river, 
to the lower 50s se of I-70. 

Dry weather returns to the area Tuesday through Wednesday as Pacific 
high pressure moves east into IL Tue evening and over the ohio river 
valley and eastern great lakes by sunset Wed. Temps cool closer to 
normal on Tue and Tue night, with highs Tue around 60F northern CWA 
and mid 60s along and south of I-70 with partly to mostly sunny 
skies. Lows Tue night around 40F northern CWA and near 45F by 
Lawrenceville. Winds become se on Wed but fairly light on back side 
of high pressure, with a fair amount of sunshine, though more clouds 
moving into the IL river valley Wed afternoon. Milder highs Wed in 
the mid to upper 60s with Lawrenceville near 70F. 

Medium range models continue to show a weak frontal boundary pushing 
se into IL around Thu, though timing and associated qpf along front 
differ between models. The front does appear to be stalling out near 
southern IL Thu night/Fri as upper level ridge builds into IL and 
have surface high pressure north over Great Lakes region and also 
south over the southeast states. Have increasing chances of showers 
and thunderstorms nw of I-70 overnight Wed night and then carried 30-
50% chance of showers and possible thunderstorms on Thu with frontal 
boundary nearby. Highs Thu in the upper 60s/lower 70s, mildest in 
southeast IL with Lawrenceville nearing mid 70s. Have isolated 
convection in southeast IL on Thu evening, then dry rest of Thu 
night. But chances of showers and isolated thunderstorms appears to 
return over west central/sw CWA by Fri afternoon and over most of 
area Fri night and Sat as front lifts back ne as a warm front. Highs 
Fri in the mid to upper 60s in central IL and lower 70s in southeast 
IL, warm into the 70s on Saturday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1255 AM CDT Sun Apr 9 2017

Tight pressure gradient will remain over central IL during the next
24 hours thru Sunday evening, with 1020 mb high pressure over the
mid Atlantic states and drifting off the mid Atlantic coast 
during Sunday. Meanwhile 997 mb surface low pressure along the 
western KS/NE border to track into east central Nebraska by 18Z 
Sunday, and into north central IA and se MN by 06Z/Mon. LLWS will
continue until 10-12Z Sunday with 1.5-2k ft SSW winds of 45-50 
kts. LLWS will return again between 02-03Z Monday with 2k ft SW 
winds 40-50 kts, strongest at CMI. Southerly winds at night will 
be 11-16 kts and increase to 17-22 kts with gusts of 27-32 kts 
during daytime after 14Z/9 am. A blanket of thick cirrus clouds 
of 20-25k ft cover central IL while lower clouds of 5-8k ft were 
over IA. Models have slowed arrival of these lower clouds in 
central IL and spread into PIA between 09-10Z and over rest of 
central IL between 11-14Z as southerly winds increase. VFR ceilings
could lower to MVFR of 2.5-3k ft after sunset Sunday evening 
especially at PIA. 

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...07
LONG TERM...07
AVIATION...07