Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 280839
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
339 AM CDT SAT MAY 28 2016

.SHORT TERM...(Today)
ISSUED AT 339 AM CDT Sat May 28 2016

Deep southwesterly flow remains in place across the Midwest this
morning, with several subtle short-waves embedded within the flow.
Despite presence of deep-layer moisture and at least weak synoptic
lift, very little precip is currently occurring across the area.
High-res models such as the HRRR and NAM12 are suggesting scattered
showers will develop across east-central Illinois later this
morning.  Meanwhile further west, a nearly stationary frontal
boundary draped from Wisconsin to Oklahoma will begin to edge
eastward this afternoon.  Scattered showers and thunderstorms will
develop along/ahead of the front, with all models keeping the bulk
of this precipitation west of the I-55 corridor.  End result will be
a partly to mostly cloudy day with widely scattered showers and
thunderstorms.  Will therefore maintain just low chance PoPs through
the day.  High temperatures will top out in the upper 70s and lower
80s.

&&

.LONG TERM...(Tonight through Friday)
ISSUED AT 339 AM CDT Sat May 28 2016

Complicated forecast issues remain in place for the next week or so
as the models continue to struggle with handling the pattern shifts
over the CONUS.  Showery/thunderstorm activity is more the rule than
the exception...but pinning down time frames is problematic.
Temperatures in the forecast remain more summer-like and several
degrees above normal with southwesterly flow aloft and southerly
winds at the surface continuing to feed warm air into the region.
That being said, any one days high temperatures will fall prey to
any shower/cloud activity that could dampen the diurnal curve.

Slow open h5 wave over the Plains this morning on sat imagery slowly
rotating through the broad scale trof over the western half of the
CONUS.  Southwesterly flow keeping WAA active through the region and
setting up for the potential of short wave rippling through the
region.  The models have been struggling with the current weather
pattern that is slow to shift eastward...but upping the pops
overnight tonight as the main wave passes through. Sunday will
slowly clear...but have delayed the chance pops in the far eastern
portions of the state somewhat.  For the next week... pops are off
and on as a loosely defined flow pattern sets up for parts of the
Midwest and southeastern parts of the country.  Showery activity
with a strong diurnal component expected through midweek until a low
dips into the Northern Plains/Upper Midwest, dragging a frontal
boundary expected to scour out some of the chances for a couple days
towards the end of the week.  With current model performance when
handling the active pattern so far...confidence overall in the
forecast is relatively low.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1159 PM CDT Fri May 27 2016

Scattered showers can be expected overnight into early Saturday
morning at central and eastern IL TAF sites. MVFR ceilings are
expected to accompany the showers, particularly at PIA and BMI
where lower clouds and rainfall have prevailed already this
evening. Could see a brief period of MVFR ceilings at CMI, but
will hold off for now as the best low level moisture flow will be
to the west.

Many of the short range models are showing a break in the rain
potential by mid-late Saturday morning. However, similar to today,
an increase in south-southwest winds are expected as the cloud
heights rise and mixing maximizes.

The latest NAM is pointing to the best instability, lift and
potential for scattered t-storms in NW and northern IL, so only
west with VCTS for PIA and kept the convection out of the rest of
central IL for now.


&&

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

$$

SHORT TERM...Barnes
LONG TERM...HJS
AVIATION...Miller


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