Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 220839

Area Forecast Discussion
National Weather Service Lincoln IL
339 AM CDT Wed Mar 22 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 338 AM CDT Wed Mar 22 2017

Cool high pressure will influence the weather across the CWA today,
but move east allowing winds to become more southerly by this
evening. A weather system will begin developing out west tonight,
but not bring any precip to the area until after the overnight hours
tonight. Currently, satellite trends indicate scattered to broken
low clouds advecting into the area from Lake Michigan. HiRes models
pick up on the cloud cover but dissipate it over the CWA early this
morning. Based on satellite trends and comparing current model
forecast to current observation, believe models are too aggressive
to dissipating this area of lower clouds this morning. These clouds
will move west/southwest and eventually diminish this afternoon.
However, high and mid clouds will move over the area later this
afternoon and into tonight. So expecting a partly to mostly cloudy
sky through tonight. Afternoon highs will be cooler than past couple
of days. Overnight lows will once again drop to around freezing or
below. Current freezing warning in the southeast will remain in
place for this morning. Cloud cover overnight should keep temps in
the southeast around 32 so do not think another freeze warning will
be needed at this time.


.LONG TERM...(Thursday through Tuesday)
ISSUED AT 338 AM CDT Wed Mar 22 2017

A progressive upper level pattern will be in store for the Midwest
the next few days resulting in a return to warmer temperatures.
Upper level ridge will shift east over IL Thu afternoon and then
shift into the eastern states thereafter, resulting in several upper
level shortwave trofs moving across the area. This will give central
IL a period of unsettled weather into early next week. In fact CPC 8-
14 day outlook from Mar 29th - Apr 4th favors a continue mild and
wet pattern over central IL, with a 60% chance of above normal
temperatures and a 55% chance of above normal precipitation.

After a chilly day today and tonight, temperatures are projected to
moderate closer to normal on Thu with highs ranging from around 50F
from I-74 ne and mid 50s from Jacksonville and Robinson sw. 1038 mb
Canadian high pressure over northeast MN and sw Ontario, will settle
se into the mid Atlantic states by midday Thu and beginning a warm
air advection pattern over IL. Latest models continue to show light
qpf lifting ne over central IL during Thu. Mainly looks like chance
pops of light rain showers, though could be a mix nw of IL river
early Thu morning it precipitation arrives that quickly. Showers
shift north of CWA by Thu evening with a warm front. Temps will not
cool but a few degrees for lows Thu night in the upper 40s to around

Breezy south winds Friday gusting 25-30 mph will warm temps into the
70-75F range with a few upper 60s near the IN border, while areas
near Springfield and Jacksonville near 75F. Partly to mostly cloudy
skies expected Friday and just have a slight chance of showers and
thunderstorms late Fri afternoon from Galesburg to Rushville west.
00Z Mar 22 models develop a strong cutoff upper level low in
southeast CO by dawn Friday and moves into central MO as it
gradually weakens by sunset Sat. Models have trended drier on Fri
evening over central and eastern IL and have lower pops then. Think
areas east of I-57 will not see showers and possible thunderstorms
until after midnight Fri night, while convection moves into the IL
river valley during mid/late Friday evening. SPC keeps slight to
marginal risk of severe storms sw of IL Friday night. Best
chances of showers and a few thunderstorms over CWA is late Fri
night and Saturday with cloudy skies. Mild lows Fri night mostly
in the mid 50s. Highs Sat range from low to mid 60s northern CWA
to near 70F by Lawrenceville.

Weakening cutoff upper level low and nearby surface low moves into
the IL river valley Sunday morning and toward southern lower MI by
midnight Sunday night. This will likely keep showers around Sat
night along with isolated thunderstorms Sat evening. Then chance of
rain showers still on Sunday, though diminishing from sw to ne
during Sunday afternoon. Highs Sunday range from around 60F northern
CWA to upper 60s in southeast IL.

Another upper level trof and low pressure system ejects ne into the
mid MS river valley by early Monday evening, spreading rain showers
back ne into central IL during Monday, especially Monday afternoon
and continues Monday night. Highs Monday in the lower 60s nw CWA and
upper 60s to near 70F in southeast IL. Could be a few isolated light
rain showers lingering Tue over eastern IL as upper level trof exits
ne into the central Great Lakes. Highs Tue in the upper 50s/lower
60s in central IL and mid 60s south of I-70, so temps still above
normal levels for late March.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1100 PM CDT Tue Mar 21 2017

Watching a band of MVFR cigs coming off Lake Michigan into
northeast Illinois late this evening. Based on its present
movement, the leading edge of the lower cloud deck will
reach BMI and PIA between 07z-10z. Will handle with a tempo
group in those time frames for both BMI and PIA, and keep
mainly VFR conditions for our other TAF sites. Any lower
clouds should dissipate by mid morning on Wednesday as
high pressure builds in from the northwest with VFR conditions
prevailing at all sites for the remainder of the forecast
period. Surface flow will be northeast at 10 to 15 kts for
the rest of the night with gusts around 20 kts at times.
Winds should veer more into an easterly direction on Wed.
with speeds continuing at 10 to 15 kts.


Freeze Warning until 9 AM CDT this morning for ILZ066>068-



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