Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 271943

Area Forecast Discussion
243 PM CDT Fri Mar 27 2015

.SHORT TERM...(Tonight)

Persistent area of snow showers that originated in northeast
Illinois off Lake Michigan early this morning passed through much of
east central Illinois east of I-57 earlier today. Webcams showed
some light accumulations around Danville from some of the heavier
showers. Most of these showers were in Indiana by 2 pm, although
some light snow showers linger just west of the border as well. Dry
air has been spreading over more and more of central Illinois as
time goes on, with dew points down to around 10 degrees from Peoria
north and west, where skies have been largely clear the last few

The clouds are very cellular/diurnal in nature on visible satellite,
and most areas should become mostly clear by sunset with loss of
daytime heating. However, cirrus has been overspreading western Iowa
and northwest Missouri ahead of the next shortwave. This should
spread into western parts of the forecast area overnight, but any
associated precipitation will remain west of the Mississippi River.
With lesser cloud cover across the east, lows should reach the upper
teens, while low-mid 20s prevail across the west half of the CWA.


.LONG TERM...(Saturday through Friday)

Short wave trof forecast by models to pass to our west on Saturday
keeping the bulk of the clouds and any associated precip out of our
area. Another chilly day expected as the center of the cold air mass
will be shifting just to our north in the morning, and then off
to east central Indiana by evening. Coolest temperatures will be
across east central Illinois where afternoon readings will struggle
to reach 40 degrees. Looks like a fast drop in temperatures tomorrow
evening before a return southerly flow sets up over west central
Illinois late in the evening. A gusty south wind on Sunday should
help bring in some warmer air to the forecast area ahead of the
next shortwave and attendant frontal boundary. Wind gusts may
approach 40 mph over parts of central Illinois on Sunday with rain
chances increasing from west to east during the morning and then
continuing into Sunday evening. Very narrow window of opportunity
for a mix of rain and snow Sunday morning across the far north but
latest model trends were backing off that idea as the precip was a
bit slower to get in plus 2 meter temps were warming during the
early morning hours. If that trend continues, we could probably
leave the mention of rain/snow out in the north.

The threat of rain will end from west to east Sunday evening as the
shortwave shifts quickly away from our area with a weak area of high
pressure tracking to our south on Monday. Another quick moving
shortwave will track across the upper Great Lakes late Monday into
early Tuesday taking the bulk of the lift and rain threat to our
north Monday night into Tuesday morning. Southerly winds ahead of
this wave should help push temps into the 60s most areas Monday
afternoon with overnight lows not expected to drop much below the
low to mid 40s. Quiet weather is then expected to push into our area
for Tuesday afternoon thru most of Wednesday before a stronger upper
wave and surface low start to affect our area late Wednesday into
Thursday, and possibly beyond. Models showing quite a large spread
with respect to the handling of the upper pattern out over the
western U.S. with the latest ECMWF more aggressive in pushing the
upper trof east into the Midwest by the end of next week bringing
periodic chances for showers and thunderstorms, while the GFS was
holding the upper low out over the central Rockies. Looks like a
rather unsettled weather pattern for the second half of next week
with significant timing differences seen with respect to the
individual shortwaves ejecting out of the longwave trof and even
disagreement in how quickly the large upper trof ejects east into
our area.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)

Main forecast concern is for brief MVFR conditions at KCMI. Area
of snow showers in east central Illinois has been shifting more
into Indiana and should largely be out of the area by 19Z, but
some lower ceilings around 2500 feet are still upstream, being
influenced by flow off Lake Michigan. Am expecting ceilings to
lift above 3000 feet after an hour or two.

Otherwise, VFR conditions will be prevailing over central Illinois
the next 24 hours. Any lingering clouds this afternoon should be
diminishing late afternoon as daytime heating diminishes. Winds
will remain gusty out of the north for a few more hours, then
become light and gradually turn easterly tonight, as high pressure
settles into the Great Lakes region.




SHORT TERM...Geelhart
AVIATION...Geelhart is the U.S. government's official web portal to all federal, state and local government web resources and services.