Area Forecast Discussion
Issued by NWS Central Illinois

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000
FXUS63 KILX 291744
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1244 PM CDT FRI APR 29 2016

.UPDATE...
Issued at 1038 AM CDT Fri Apr 29 2016

15z/10am surface analysis shows stationary frontal boundary
extending from West Virginia southwestward to an area of low
pressure over the Texas panhandle. Meanwhile, high pressure over
southern Canada dominates the weather across the Great
Lakes/Midwest. This high will gradually shift off to the east,
allowing the front to slowly lift northward tonight. In the
meantime, cool/dry weather will be on tap across central Illinois
for the remainder of the day. Quite a bit of low cloudiness
continues to blanket the northern two-thirds of the KILX CWA:
however, the HRRR suggests this cloud cover will scatter as the
day progresses. End result will be a partly to mostly cloudy day.
Highs will mainly be in the lower to middle 60s, but will top out
around 70 degrees south of I-70 where sunshine will be more
prevalent.

&&

.SHORT TERM...(Today)
ISSUED AT 342 AM CDT Fri Apr 29 2016

Quiet conditions are expected across central and southeast Illinois
today. We will be between weather systems, although there will be a
fair amount of cloud cover across the area. Expect light winds and
slightly cooler than normal temperatures. Daytime highs will top out
in the 60s at most locations.

.LONG TERM...(Tonight through Thursday)
ISSUED AT 342 AM CDT Fri Apr 29 2016

Deep trof over the western half of the CONUS will eject out another
low for the Midwest this weekend. Same kind of set up with a slow
moving system keeping much of the Midwest wet, and putting in excess
of an inch of rain anticipated for Central Illinois. A slower trend
in the models as the precip spreads from southwest to northeast
overnight tonight...mainly after midnight.  The region sets up for
mainly a warm sector event from the developing low to the west.
Southerly flow of warm moisture feeding into the ongoing
precipitation for Saturday and Saturday night.  Precip slowly
decreasing through Sunday night as the upper low finally progresses
through the region. Sunday night will have some clearing of the
precip with drier air wrapping around the system.

Models have had several problems...the 00z runs for the last three
nights have been different. Models are still not in agreement with
handling the pattern shift with the shearing out of the energy
remaining in the trof in the southwest. It seems an attempt at more
northwesterly flow ...but so far, the lack of gradient aloft is weak
at best, with no consistency for the energy trying to dig out a trof
over the Great Lakes.  Remaining forecast is dry for now...with some
slight chances creeping in mid/end week.  Temperatures are moderate
and holding near seasonal.  Confidence in forecast for next week
remains weak and highly conditional.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1244 PM CDT Fri Apr 29 2016

MVFR ceilings persist at the central Illinois terminals early this
afternoon: however the HRRR continues to suggest these will
scatter over the next 2-3 hours. Have noted a gradual thinning of
the low clouds on visible satellite, so will follow the HRRR and
scatter the ceilings between 21z and 22z. A high overcast from
convective blowoff upstream will remain through the late
afternoon and evening, before clouds once again begin lowering
tonight as a warm front lifts northward into the area. Models
still disagree as to how quickly the lower clouds and precip will
return, with the NAM being the fastest. Based on a continued dry
E/NE low-level flow north of the front, think the slower GFS/Rapid
Refresh is the way to go. As such, have delayed IFR ceilings and
predominant rain until 09z at KSPI and 12z at the I-74 terminals.
Modest elevated instability suggests the potential for a few
embedded thunderstorms, so have included VCTS between 12z and 18z
as the initial surge of warm advection precip moves through. Winds
will be from the northeast at 5 to 10kt early this afternoon, then
will veer to the southeast and increase to between 15 and 20kt by
Saturday morning.

&&

.ILX Watches/Warnings/Advisories...
NONE.
&&

$$

UPDATE...Barnes
SHORT TERM...BAK
LONG TERM...HJS
AVIATION...Barnes


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