Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 180601
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
101 AM CDT Thu May 18 2017

.UPDATE...
Issued at 914 PM CDT Wed May 17 2017

Moisture channel imagery now shows upper low has rotated into
north central IL with trailing tail of convection extending
southward into west central IL. CIN in the SPC mesoanalysis has
spread back into west central IL, with limited low level
convergence, on the storm outflow. Main upper dynamics pushing to
the northeast, northeast of area.

Surface winds remain a concern, as the strong winds are slow to
diminish this evening. Dust picked up by the strong winds has
produced "dust storm" type impact over much of CWA during the
evening, with visibilities below 1/4 mile and brown out conditions
over many parts of central IL. Decided to extend the wind advisory
into the early morning hours, as though the winds may drop below
criteria, the impact of the dust closed roads in the region has
been a major problem. Many accidents and IL State Police have been
in contact with WFO, so for extreme safety cncerns, extended the
advisory and highlighted the impacts of the winds producing low
visibility dust conditions. Also issued SPS, also advising to
limit travel to only necessary due to the darkness and the dust
making driving dangerous.

&&

.SHORT TERM...(This evening through Thursday)
ISSUED AT 252 PM CDT Wed May 17 2017

Mositure chnnal satellite loop shows the upper low rotating
northeast across KS into the northwest tip of MO by this
afternoon. Instability beneath upper low with surface convergence
is strongest over northern MO rotating into IA. Cap over IL seen
in morning soundings and in the SPC isntability mesoanalysis shows
minor convection developed so far is not surface based. Progs do
show small period early this evening when surface based convection
still possible in western IL, but then window will close by mid
evening. With the movement of the upper closed low to the
northeast, dragging the surface front to approach IL overnight,
will be continued chance of mainly elevated convection. Minor
chance of severe winds possible in the northwest part of CWA, due
to strong winds above surface and a chance of a stronger storm
bringing those winds down to surface. However that window gets
smaller as evening progresses and the lack of low level
convergence in area making it more difficult for significant
convection to form.

As for Thursday, the upper low moves off to north and all but the
south parts of warning area is dry.

.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 252 PM CDT Wed May 17 2017

In the long range, the next system begins on Friday morning as
overrunning over the front that will stall over southern IL late
Thursday. Showers and storms move back into the area Friday,
continuing through Saturday and finally exiting on Sunday, after
the front moves through region Saturday night. Will have to watch
system for possible periods of heavy rain. Models are not totally
in align yet on timing and pcpn amounts.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1259 AM CDT Thu May 18 2017

SW winds 15-25 kts and gusts 25-35 kts early overnight to
gradually diminish. These winds could pick back up for a time Thu
morning before diminishing again during Thu afternoon as low
pressure pulls away from IL. VFR conditions expected to continue
across the central IL airports through 06Z/1 am Thu night.
Isolated showers and thunderstorms have lifting ne of central IL
in northeast IL. Another area of convection was in southeast MO
and lifting ne toward southeast IL and these should stay south of
I-70. Just scattered mid level clouds of 7-12k ft to occur into
the morning, then scattered cumulus clouds with bases of 4-6k ft
appear by afternoon. A 996 mb surface low presure over southeast
MN near WI border has cold front through nw IA and far southeast
NE. This front to move se to PIA around 22Z and reach CMI and DEC
around 02Z/Thu. Could see broken 5-6k ft clouds behind the front
along with wind shift to north around 10 kts and few higher gusts.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 4 AM CDT early this morning for ILZ027>031-
036>038-040>057-061>063-066>068-071>073.

&&

$$

UPDATE...Goetsch
SHORT TERM...Goetsch
LONG TERM...Goetsch
AVIATION...07



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