Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 171150

Area Forecast Discussion
National Weather Service Lincoln IL
550 AM CST Wed Jan 17 2018

.SHORT TERM...(Today and tonight)
ISSUED AT 338 AM CST Wed Jan 17 2018

Another frigid morning across central and southeast IL with 1043
mb arctic high pressure extending from the Ozarks into central
Texas per 09Z/3 am surface analysis. Stratocumulus clouds of
1.5-2.5k ft were in southeast Lawrence county and slowly drifting
SSE. Temperatures mostly in the single digits above zero with a
few cities like Galesburg, Macomb, Springfield and Champaign a
degree or 2 below zero. Lawrenceville was at 8F and on edge of
stratocumulus cloud deck. Westerly winds of 6-13 mph was giving
wind chills of 5 to 15 below zero early this morning, with
Champaign wind chill of 18 below and 17 below at Bloomington and
Macomb. Aloft a strong mid/upper level trof extended from the
eastern Great Lakes into western parts of KY/TN and will be
shifting eastward into the central Appalachians by sunset, and
take stratocumulus clouds out of far se IL early this morning.

00Z forecast model show strong arctic high pressure drifting into
western TN and eastern AR by sunset and to provided another cold
day to central/se IL despite a fair amount of sunshine. Few to
scattered mid level clouds over the upper MS river valley to pass
se across central IL this afternoon. West winds of 7-13 mph to
still give wind chills of 5 to 15 below zero thru about 10 am

High pressure settles over the TN and lower MS river valleys
during tonight and develops a sw flow over central/se IL with fair
skies. Lows tonight of 10-15F with wind chills of 5 above to 5
below zero.

.LONG TERM...(Thursday through Tuesday)
ISSUED AT 338 AM CST Wed Jan 17 2018

High pressure will be sprawled across the southeast states Thu/Fri
and increasing sw flow to modify temperatures with a fair amount
of sunshine both days. Temps rise closer to normal on Thu with
highs of 32-38F (coolest near IN border) and above normal on
Friday with highs in the low to mid 40s, some upper 30s along the
IN border. Lows Thu night generally in the lower 20s, with lows
Fri night near or just below freezing.

Medium range models continue to dig a strong upper level trof
along the Pacific coast Friday and Friday night and over the
Rockies by Sat night. Skies become mostly cloudy on Saturday as
IL gets in a sw upper level flow. GFS appears too damp on Saturday
and prefer the drier ECMWF model solution and kept most of CWA
dry thru Saturday. Highs Saturday in the mid to upper 40s, with
50F at Jacksonville. Have isolated showers possible Sat evening,
then 30-40% chance of showers overnight Sat night. Any mixed
precipitation appears to be just north of CWA by overnight Sat
night. Lows Sat night above freezing, in the upper 30s and lower

Models have trended slower ejecting surface low pressure from OK
panhandle at dawn Sunday ne into southeast IA by dawn Monday, with
cold front moving east over IL late Sunday night into early Monday
morning. Chances of rain showers on Sunday with lowest pops of
20-30% in southeast IL and highest pops of 40-50% over IL river
valley. Highs Sunday in the low to mid 50s and will be mildest day
in the next 7. Likely to categorical pops of showers Sunday night
with isolated thunderstorms Sunday evening in se MO and sw IL,
from I-64 south. Strong surface low ejects ne across the western
great lakes Monday with deep upper level trof keeping chances of
showers over IL along with temps cooling with brisk west winds.
Scattered light rain showers could be mixed with light snow nw of
IL river and north of Peoria. Highs Monday mostly in the lower
40s, but range from 38F at Galesburg to 45F in Lawrenceville.

Dry weather returns to the prairie state Monday night through Wed
as Pacific high pressure drifts east into the nations mid section
by Wed. Temps still a bit above normal Tue/Wed with highs Tue in
upper 30s/lower 40s, and 30s on Wed in central IL with lower 40s
in southeast IL from I-70 south. Lows in the 20s Monday and
Tuesday nights.

Climate Prediction Center`s (CPC) 8-14 Day Outlook for Jan 24-30
continues to trend toward a milder and wetter wx pattern. CPC has
a 35-45% chance of above normal temperatures and a 50-55% chance
of above normal precipitation over central and southeast IL during
the last week of January. This may offset bitter cold conditions
that we have experienced much of the past 3.5 weeks since
Christmas eve. In fact only 4 of the past 24 days had above normal
temperatures from Jan 8-11th.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 550 AM CST Wed Jan 17 2018

DEC airport will continue to have ceilings around 300 ft and
vsbys around 3 miles at times until about 14Z/9 am until WNW wind
around 10 kts shift west toward mid morning. Other central IL
airports may see few clouds with bases of 500-1k ft this morning.
Otherwise VFR conditions expected to prevail across the area
through 12Z/6 am Thu. A strong 1043 mb arctic high pressure from
central Texas into the Ozarks will drift into the TN and lower MS
river valley during tonight, bringing fair wx to central IL. Few-
scattered mid/high clouds will stream se across central IL this
afternoon and diminish during the evening. West winds of 8-13 kts
this morning will become SW during midday and continue through
tonight. Added LLWS for I-74 TAF sites by overnight, starting at
PIA at 04Z, BMI at 05Z and CMI at 06Z with 1800 ft sw winds of
39-44 kts.





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