Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 270432
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1132 PM CDT Thu Apr 26 2018

.UPDATE...
Issued at 911 PM CDT Thu Apr 26 2018

Mostly clear skies across the area with winds light and variable.
Expecting this to continue as a dry frontal boundary moves into
the area from the northwest overnight. Current forecast has a good
handle on this for the rest of the night. So no update planned at
this time.

&&

.SHORT TERM...(This evening through Friday)
ISSUED AT 239 PM CDT Thu Apr 26 2018

A weak cold front currently extending from northern Wisconsin to
Kansas will push across central Illinois tonight. The front will
be moisture-starved, so little more than a band of mid/high clouds
is expected with FROPA. Low temperatures will drop into the lower
to middle 40s.

Once the front passes, skies will become mostly sunny by Friday
morning. Meanwhile, a short-wave trough evident on 19z/2pm water
vapor imagery over western Manitoba will drop southeastward and
amplify over the Great Lakes on Friday. As it does, it will push a
stronger cold front into north-central Illinois by late in the
day. While the airmass ahead of the boundary will remain quite
dry, favorable upper dynamics and convergence along the front
will support at least isolated convection during the late
afternoon and evening. While most synoptic models tend to keep
any precip further N/NE in the Chicago area, several CAMs suggest
development further southwest along the front into the northern
KILX CWA between 21z Fri and 00z Sat. Based on this, have included
slight chance PoPs for showers along/north of a Canton to
Bloomington line late Friday afternoon. High temperatures will
reach the middle to upper 60s.

.LONG TERM...(Friday night through Thursday)
ISSUED AT 239 PM CDT Thu Apr 26 2018

A few showers will linger into Friday evening along the advancing
front, primarily impacting locations along/north of a Lincoln to
Danville line. The front will quickly sink into the Ohio River
Valley, allowing a chilly airmass to settle into the region this
weekend. With 850mb temps progged to drop into the 0 to -4C
range, highs will remain in the middle to upper 50s on Saturday.
As a 1028mb high builds southward into Illinois, winds will become
light/variable Saturday night...allowing excellent radiational
cooling conditions to develop. Overnight lows will drop into the
lower to middle 30s, sufficiently cold to support frost
development. Have included areas of frost in the forecast
accordingly, and will need to monitor future temp/wind forecasts
for the possibility of a Frost Advisory across parts of the CWA.

Once the high shifts east of the region, southerly flow will
signal a major warming trend for early next week. As upper heights
rise, temperatures will soar well into the 70s on Monday...then
will reach the upper 70s and lower 80s by Tuesday. A western CONUS
upper trough will translate eastward and will eventually flatten
the prevailing ridge over the Midwest: however, the speed of this
process still remains somewhat in question. Model consensus
suggests the trough and its associated frontal boundary will
likely not impact central Illinois until Tuesday night at the
earliest...with the best rain chances arriving Wednesday/Thursday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1132 PM CDT Thu Apr 26 2018

VFR conditions will prevail at all TAF sites next 24hrs. Cirrus
will continue over the area overnight...followed by some few mid
clouds that are over northwest IL and eastern IA. Clear skies are
expected most of the day tomorrow, but models are bringing in some
moisture around 8kft late tomorrow afternoon through tomorrow
night. Winds will remain variable overnight but become northwest
once a dry cold front comes late tonight...then westerly winds are
expected tomorrow afternoon with some gusts to around 20 kts,
followed by lighter winds during the evening.

&&

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

$$

UPDATE...Auten
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten



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