Area Forecast Discussion
Issued by NWS Central Illinois

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382
FXUS63 KILX 040820
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
320 AM CDT WED MAY 4 2016

.SHORT TERM...(Today)
ISSUED AT 320 AM CDT Wed May 4 2016

A band of showers and a few thunderstorms is diving across central
and southeast Illinois early this morning. This convection lies just
ahead of a strong cold front, that is driven by a vigorous upper
wave diving into the Midwest. The rapid movement of this
front/precipitation will have the rainfall completely out of the
forecast area by mid-morning. It will be noticeable cooler across
the region today behind the front, with many areas only seeing high
temperatures in the 50s. Northerly post-frontal winds gusting to 30
mph at times will also make it feel cooler. Peak afternoon heating
and very chilly air aloft will combine to produce steep lapse rates
later today. This should allow a few showers or a thunderstorm to
pop this afternoon. However, coverage should not be significant and
have limited Slight Chance afternoon PoPs to roughly the eastern
half of the forecast area.

&&

.LONG TERM...(Tonight through Tuesday)
ISSUED AT 320 AM CDT Wed May 4 2016

Upper ridging currently along the Rockies will be edging eastward
the next couple days, but pattern overall will be rather blocky,
with closed lows on either side of it. No real breakdown expected
until this weekend, when an upper wave will drop southeast from
Hudson Bay and finally boot the eastern low out of the way. However,
the western one will remain in the picture until Monday, with a
surface boundary extending eastward into the Midwest.

Longer range models are in decent agreement with pushing the front
through the area by Saturday evening, with scattered showers and
thunderstorms during the day and evening hours, before diminishing.
After that, the boundary becomes parallel to the upper flow between
what`s left of the ridge and shortwaves rotating through the Great
Lakes region. The GFS hangs onto this until late Monday night before
the front and associated rain chances lift back north. Meanwhile,
the ECMWF is much more aggressive in pushing it back beginning
Sunday evening as the lingering ridge axis slides overhead. Leaned
more toward the latter solution, although not quite as wet, and have
chance PoP`s over most of the forecast area Sunday night and Monday.
With the remnants of the western low only into the central Plains by
Tuesday, rain chances will be steadily increasing with time early
next week.

A warming trend will commence on Thursday, with highs mostly in the
mid 60s. As the thermal ridge builds east late in the week, a couple
days are expected with temperatures reaching near 80 degrees, before
the front pushes through. However, with the main troughing remaining
near the Great Lakes, temperatures behind the front should not be
especially cooler.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1203 PM CDT Wed May 4 2016

VFR conditions will prevail at all TAF sites next 24hrs. Sfc front
will drop quickly through the CWA early this morning and radar
indicates thunderstorms along with showers. So have changed to
VCTS with TEMPO group at all sites for thunderstorms. Once the
pcpn moves south skies will scatter out some. However, with the
500mb trough, additional clouds and VCSH will be seen at
DEC/CMI/BMI in the afternoon. Skies will scatter out and clear
after sunset at all sites. Winds will become northwesterly just
behind the front and then northerly during the day and into the
afternoon. Wind speeds will increase and gust to 23-26kts at all
sites. Winds speeds will decrease in the evening.


&&

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

$$

SHORT TERM...BAK
LONG TERM...Geelhart
AVIATION...Auten



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