Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 141110

Area Forecast Discussion
National Weather Service Lincoln IL
610 AM CDT Mon Apr 14 2014

ISSUED 300 AM CDT Mon Apr 14 2014

SHORT TERM...Today through Wednesday

07z/2am surface analysis shows cold front just west of the
Illinois River, with main area of rain well east of the boundary
across Kentucky and Indiana. Front will progress eastward through
the region early this morning, exiting the E/SE KILX CWA between
12z and 15z. With deepest fetch of moisture displaced well to
the east and deformation zone precip across Iowa shifting
northeastward into Wisconsin, a distinct lull in precip chances
will occur across central Illinois this morning. Forecast
soundings show a relatively shallow layer of low-level moisture in
place, resulting in overcast conditions and perhaps a few
scattered showers. Better precip chances will return this
afternoon/evening as a northern stream short-wave currently
pushing through the Dakotas approaches from the northwest. As
synoptic lift increases and soundings moisten, showers will become
more numerous across the area. Enough cold air will arrive aloft
to support a rain/snow mix across the western half of the CWA this
afternoon, although air temps in the upper 30s and warm ground
conditions will prevent any snow accumulation. Once the sun goes
down and temps begin to drop, the precip will change to
predominantly snow this evening before shifting eastward and
coming to an end by midnight. A minor accumulation of a couple
tenths of an inch will be possible, especially across the NE CWA
around Champaign and Danville. Once precip ends, skies will clear
from west to east overnight. Numeric guidance is showing very cold
low temps dipping into the lower to middle 20s: however, think
initial cloud cover and continued brisk northwesterly winds will
keep readings from dropping quite that low. Instead, will forecast
lows mainly in the upper 20s and lower 30s.

High pressure will build into the Midwest on Tuesday, resulting in
diminishing winds and a return to sunny skies. Despite sunshine,
afternoon high temperatures will remain well below normal for this
time of year in the 40s. Once high pushes eastward, a strong
southerly return flow will develop on Wednesday. Forecast
soundings and numeric guidance suggest wind gusts potentially
reaching 35 mph by afternoon. Given ample sunshine and strong
southerly flow, high temperatures will rebound well into the 50s.

LONG TERM...Thursday through Sunday

The extended forecast will be characterized by a warmer/wetter
pattern. Once deep upper trough initially in place over the Great
Lakes/Midwest shifts eastward, a progressive zonal flow will take
hold across the CONUS for the end of this week into early next
week. The end result will be a return to near normal temperatures
in the 60s with periodic chances for rain. After a warm/dry day on
Thursday, the first in a series of systems will track into the
region Thursday night into Friday. Models are in fairly good
agreement with the timing and track of this feature, with the
ECMWF/GEM remaining just slightly slower than the GFS. Will
continue with chance PoPs across the western half of the CWA
Thursday night, then across the board on Friday. Another warm/dry
day will be on tap in the wake of this system on Saturday. After
that, model discrepancies still exist concerning potential
disturbance on Easter. All models show a 500mb wave passing
through the Midwest on Sunday. The difference is that the GFS
remains dry with this feature, while both the ECMWF and GEM are
developing showers. While moisture will be somewhat lacking due
to limited return flow from the Gulf of Mexico, think strength of
upper wave and good agreement between the ECMWF/GEM warrants a
mention of showers for Easter Sunday.



ISSUED 610 AM CDT Mon Apr 14 2014

Cold front has passed all of the TAF sites, and northwest winds
will gradually become more northerly while still gusting from
25-30 knots into early evening. Have had some showers redevelop in
central Illinois moving northeast, but there will be a period of
drier weather through about early afternoon, at which point rain
showers will become more numerous. Colder air spilling into the
area will start to switch the precipitation to a rain/snow mix mid
to late afternoon at most TAF sites, although perhaps holding off
at KCMI til closer to 00Z. The precipitation will become all snow
for a time before ending mid to late evening. MVFR ceilings will
be persistent until late evening, then break up once the
precipitation ends.




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