Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 242301

Area Forecast Discussion
National Weather Service Lincoln IL
601 PM CDT Sat Mar 24 2018

.SHORT TERM...(This evening through Sunday)
ISSUED AT 314 PM CDT Sat Mar 24 2018

Surface low moving into southwestern IL this afternoon as a short
wave aloft drops into the trough just to the east. Although the
fronts associated with the system have remained well to the north,
the short wave has had more than enough energy to lift relatively
rich RH into a prolonged winter storm for areas north of I-74.
Winter Storm warning will continue as some of the visibilities
sporadically drop in still intermittent heavier snowfall. A wintry
mix is the dividing line... generally along or just south of a
line from PIA to BMI to CMI. Visibilities further reduced by
strong winds gusting in excess of 35mph. These winds will
continue, eventually becoming more northeasterly. A short break is
in store for the area in the late afternoon before a weaker round
of precip drops southward in behind the low as it shifts to the
east. The airmass to the NE is far more dry at the surface, with
dewpoints in the teens in southern MI and northern IN. This dry
air advecting into the region is what should be working on
clearing the skies per HRRR et al. The erosion of the moisture is
already evident on the radar mosaic in the region. Models have the
sky cover breaking up by midnight and moving the drier air into
place to avoid any significant visibility drops. Think that the
erosion of the cloud cover may be slightly overdone... and have
kept some of the clouds in place through the overnight in the

.LONG TERM...(Sunday night through Saturday)
ISSUED AT 314 PM CDT Sat Mar 24 2018

Moving into the extended, a quiet end to the weekend as sunny
skies return, albeit with a cooler airmass and temps only climbing
into the upper 30s/lower 40s. The weak ridging aloft shifts to the
east and the flow into the region becomes more southwesterly
aloft. Weak warm advection as well as increasing available
moisture sets up the region for another bout of precip, dominating
the forecast with pops from Monday through Tuesday night. In that
time frame, the warm air advection brings the highs up to near 60
for Tuesday, even as the rain continues. By Wednesday early, the
front is moving through, limiting the highs to the 50s. The
forecast dries out for a couple days at least with more seasonable
temperatures. Both the GFS and ECMWF are hinting at a secondary
wave diving into the more broadscale trof over the CONUS, bringing
more precip to wrap up the work week into next weekend.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 600 PM CDT Sat Mar 24 2018

Precipitation winding down this evening across central Illinois as
shortwave pushes southeast of area and drier air evident over
northeast IL advects into terminals. Any precipitation should end
fairly early in the TAF period, but MVFR Cigs will likely linger
well into the night. High pressure over southern Quebec will
ridge into the area Sunday giving a brief respite prior to the
next weather system. Winds should remain in the 10-20 kt range.


Winter Storm Warning until 10 PM CDT this evening for ILZ027>031-



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