Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 201808

Area Forecast Discussion
National Weather Service Lincoln IL
108 PM CDT Mon Mar 20 2017

Issued at 1051 AM CDT Mon Mar 20 2017
Storms exited to the east this morning, and temperatures quickly
warmed as the winds moved around to more southerly. Clouds are
slowly filling in across the area...with some additional
convection building to the north. Scattered showers and
thunderstorms will remain possible through the afternoon hours,
mainly east of I-55 until the front to the NW finally drifts
through Central Illinois. Some minor updates to the PoPs, but no
major updates anticipated at this time.


.SHORT TERM...(Today and tonight)
ISSUED AT 337 AM CDT Mon Mar 20 2017

Strong to severe thunderstorms with hail (ranging from pea size to
golf ball size at Galesburg), frequent lightning and heavy rains
were east affected our northern CWA and into northern IL since
1245 am and were now moving east of Peoria. This area of storms
should pass east of Marshall, Woodford and Mclean counties by 6 am
with some backbuilding. Latest HRRR model shows some of this
convection moving into Champaign, Vermilion and Edgar counties
during early and mid morning as it weakens since getting further
away from low level jet and MUCAPES lowering early this morning.

1009 mb surface low pressure near the nw tip of MO will track so
southeast of St Louis by sunset today and pull a cold front
southward across central IL this afternoon and toward I-70 by early
evening. Showers and thunderstorms will gradually shift into
southeast IL during today and linger southeast of I-70 this evening
as cold front continues to press southward through that area. The
cold front to push into central KY by dawn Tue with convection
shifting south of highway 50 by overnight. Milder highs today range
from lower 60s from I-74 ne and lower 70s from Jacksonville and
Lawrenceville sw with lower 80s by St Louis. Cooler lows tonight in
the upper 30s over central IL and lower 40s in southeast IL.

.LONG TERM...(Tuesday through Sunday)
ISSUED AT 337 AM CDT Mon Mar 20 2017

Cooler highs Tue range from lower 50s from I-74 north, to upper 50s
to near 60F in southeast IL. A short wave ejecting ESE from the
northern Rockies quickly tracks into central IL by sunset Tue. This
to likely spread a band of rain showers into central IL during Tue
afternoon and shifting into areas south of I-72 Tue evening before
ending by overnight Tue night. Cooler lows Tue night in the upper
20s ne CWA and lower 30s SW CWA.

1037 mb high pressure builds southeast into lower MI by sunset Wed
and brings more sunshine but below normal temperatures to central
and southeast IL. Wed will be the coolest day this week, similar to
this past Saturday, with highs in the low to mid 40s, coolest from I-
74 ne. Lows Wed night again below freezing, ranging from upper 20s
to around 30F.

00Z forecast models continue to show strong low pressure developing
over eastern CO by sunset Thu and have trended slower with ejecting
it into the central plains late this week with a cutoff upper level
low moving toward central or southern IL by sunset Sat. Have chance
of light rain showers over northern CWA Thu afternoon/evening with
highs Thu in the low to mid 50s. Warmer on Friday with highs 65-70F
and have it dry Friday morning with chance of showers/thunderstorms
west of I-57 Friday afternoon. Best chances of showers and
thunderstorms spreads east across area during Friday night and
continues on Saturday, though thunder chances shift into southeast
CWA by Sat afternoon. Highs Sat range from upper 50s nw of IL river,
to the mid 60s in southeast IL.  During Sat night have just slight
chance of showers nw of IL river while likely chances of showers in
southeast IL with isolated thunderstorms Sat evening in far
southeast IL. Lingered chances of showers on Sunday especially
Sunday morning. Turning a bit cooler with highs in the lower to mid
50s in central IL and upper 50s to near 60F in southeast IL.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 100 PM CDT Mon Mar 20 2017

Conflicting forecasts across the models mishandling low level
precip this afternoon. Have tried to adjust the forecasts for less
clouds early...and a gradual shift to more northerly winds behind
a surface boundary/front laid out across the Midwest. For the most
part, scattered clouds...but bkn anticipated closer to sunset in
most TAF sites because of proximity to the stalled boundary.
Forecast confidence is low considering that the low cigs may be
more confined to the location of the boundary given most recent
model runs.




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