Area Forecast Discussion
Issued by NWS Central Illinois
FXUS63 KILX 031721
Area Forecast Discussion
National Weather Service Lincoln IL
1121 AM CST Mon Mar 3 2014
ISSUED 931 AM CST Mon Mar 3 2014
Wind chill advisory was dropped an hour early, as all sites have
seen wind chills rise out of advisory criteria. However, will
still see them below zero for a couple more hours. Otherwise, the
forecast is largely on track, with high pressure ridge starting to
nudge into our area from the west.
ISSUED 1120 AM CST Mon Mar 3 2014
VFR conditions to prevail next 24 hours. Northeast winds to
gradually turn more southeast overnight as high pressure drifts
off to the northeast. An upper disturbance sliding off to the
north will bring ceilings down to about 10KFT overnight, before
skies clear again Tuesday morning, but no precipitation is
expected this far south.
ISSUED 317 AM CST Mon Mar 3 2014
SHORT TERM...Today through Wednesday
At 08Z/2AM 1039 MB Arctic high was centered over eastern Nebraska.
Deep mid-level moisture plume noted on W/V imagery spreading up
the Ohio Valley ahead of eastward advancing southern MO trough.
Snow associated with this feature has now slipped south of the CWA
after bringing minor accumulations south of I-70 last evening.
Northwest low level flow east of the sfc high continued to produce
cold advection with readings mainly in the single digits above
zero, but now slipping below zero NW of the IL river (-9F at GBG)
where cirrus was beginning to thin and shift off to the east.
Still expecting readings to dip below zero along/west of I-55 and
with NW winds near 10 mph, -15 to -25F wind chills are expected
into mid- morning, and will continue wind chill advisory until 10 AM
Surface ridge shifts over the area today, producing mostly sunny
skies but bitterly cold air (by March standards). Low level
thermal profiles support highs in the teens for much of the CWA,
which is around 30-35 degrees below normal. This would produce
record low highs for the date, see climate section below. Expect a
quick temp drop-off this evening under clear skies as ridge slides
off to the east. Increasing clouds after midnight associated with
a shortwave passing through the Great Lakes, along with developing
light return flow should cause temps to steady out or rise late.
Tuesday will be a day between shortwaves, and will see the start
of a week-long thermal moderation, with most areas getting well into
the 20s, or only 20 degrees below normal. By late day the next
northern stream wave will increase clouds, taking a farther south
track, and bringing a slight chance of light snow to the northern
CWA Tuesday night. Best forcing and moisture lines up across the
northern CWA on Wednesday and have introduced chance pops for
light snow. Fair amount of model spread in timing with this wave
and will linger slight chance pops into Wed night. Slow temp
moderation continues through mid week as height gradually rise.
LONG TERM...Thursday through Sunday
Next system of interest will bring a better chance for more
widespread precip later Friday and especially Saturday, when a
stronger shortwave/trough interacts with a tightening baroclinic
zone across the Midwest. Warm advection ahead of this system will
bring a nice warm up Friday, with +4-8 C 850 MB temps translating
to highs of 40-50. Precip type looks to start as rain, possibly
transitioning to a rain/snow mix on Saturday over the northwest
half. Low confidence in timing at this point, as GFS is about 12
hours faster than ECMWF, so will keep pops low. High pressure then
returns for the last half of the weekend, resulting in dry weather.