Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 271149
AFDILX

Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
649 AM CDT Sat Sep 27 2014

.SHORT TERM...(Today)
ISSUED AT 313 AM CDT SAT SEP 27 2014

Weak low pressure centered over south-central Iowa will retrograde
slow to the northwest today, but upper level moisture streaming
around the south side of the low will push varying amounts of cirrus
clouds into central Illinois today. Sunshine should still prevail
for the most part, as the overall air mass remains nearly unchanged
from yesterday. That will mean another day of lower 80s for highs
with light east to southeast winds, generally less than 10 mph.

Patchy ground fog early this morning near the Wabash River should
dissipate quickly after sunrise.

&&

.LONG TERM...(Tonight through Friday)
ISSUED AT 313 AM CDT SAT SEP 27 2014

Upper low expected to weaken into a broad wave by Sunday before
dropping southeast across the state. Looks to be a dry passage,
because although moisture will be spreading northeast out of the
southeast states, the wave should be past us before the moisture
gets this far north.

Main challenge for this part of the forecast is with the midweek
system. Latest ECMWF and GFS are in reasonable agreement with the
evolution of the upper low currently near San Francisco, lifting it
into South Dakota by Tuesday evening. Main surface cyclone will be
drawn northward into Manitoba on Wednesday, with its trailing front
hanging up to our northwest. Have mentioned some token 20% PoP`s
northwest of the Illinois River on Wednesday, but rain chances will
more likely hold off until late Wednesday night as a deep long wave
trough emerges on the Plains and forms a surface low over the
Oklahoma area at the trail end of the stationary front. The models
start to diverge with respect to this low, with the GFS much deeper,
but the general trend on both models is to slow the passage of the
front down a bit. Areas east of I-57 may remain dry through most of
Thursday afternoon, with the main daytime threat west of I-55 and
everywhere Thursday night with the passage of the front. Bulk of the
rain should be out of the area by late Friday morning, but we may
see some wraparound showers as a strong secondary shortwave moves
into the region.

Temperatures expected to stay above normal into early next week with
highs lower-mid 80s, before cooling off a bit. As the late week
shortwave arrives, a more prominent surge of cooler air will arrive
for Friday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 649 AM CDT SAT SEP 27 2014

VFR conditions are expected to continue the next 24 hours. The
only clouds of note will be cirrus streaming into IL from the
south, as a weak upper level disturbance across extreme southern
Iowa tracks slowly northwest away from our area. A weak pressure
gradient across Illinois will help keep surface winds in the 4 to
8 kt range from the east to southeast today and tonight.

&&

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

$$

SHORT TERM...SHIMON
LONG TERM...GEELHART
AVIATION...SHIMON







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