Area Forecast Discussion
Issued by NWS Chicago, IL

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FXUS63 KLOT 211114

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
614 AM CDT SAT MAY 21 2016


Today through Monday...

300 am...Showers over the far southeast cwa expected to persist
through about 12z as they slowly rotate to the east and begin to
dissipate some. Back edge of the mid/high clouds over northwest
IL will slowly move east this morning with skies becoming mostly
sunny. A weak trough will move across the upper lakes later this
afternoon into tonight and some models continue to suggest
isolated showers developing perhaps as far south as southern WI
this afternoon. Confidence is very low of precip developing this
afternoon and have stayed dry. High temps will rebound into the
mid 70s across much of the cwa with cooler temps along the lake as
winds remain north/northeasterly.

High pressure will move across the lakes region Sunday. This will
maintain onshore flow with cooler temps along the lakeshore but
temps further inland should warm well into the 70s with some
western areas likely reaching 80. As the high slowly drifts east
Monday...winds will turn more southerly and this should keep any
lake cooling along the IL shore and perhaps not too far inland.
Highs should reach around 80 at most locations Monday...perhaps
some lower 80s western areas. cms



Monday night through Friday...

300 am...High pressure slowly moving east/southeast Monday night
and Tuesday will delay the moisture return as well as the chance
of thunderstorms. Monday night now looking dry for much of the
area and backed off to just slight chance pops in the far west
overnight. Much of this activity is then progged to lift north
across the western lakes during the day Tuesday...which could end
up being dry locally. While slower...dewpoints do increase into
the lower 60s by Tuesday afternoon and with less precip high temps
will probably reach 80. Southwesterly winds appear strong enough
to prevent any lake cooling but lower confidence from this

Precip chances increase Tuesday night into Wednesday but still not
too confident on timing/duration and there could be various waves
of showers/thunderstorms through the end of the week with high
chance pops from Tuesday night onward. Dewpoints expected to surge
into the upper 60s Wednesday...though likely aided by possible
precip Tuesday humidity levels will begin to feel much
more summer-like. If there are dry periods combined with some
partial sunshine during the day...highs could easily reach the
lower/mid 80s each day in the extended. cms



A quiet weather weekend for regional airports as high pressure
prevails. The center of this high will remain to the west of the
area winds will again be northeasterly. For Chicago
airports this means the lake component again and that looks to
boost speeds to 10-11 kt by early afternoon with high confidence.
Prior to that increase...the direction may wobble between 350 and
020 degrees but speeds will be light. Clouds will be VFR with some
high based cumulus expected by RFD. Winds become light and
variable tonight into early Sunday morning.



104 AM CDT

Quiet conditions over lake Michigan will continue through the
weekend with nearby expansive high pressure centered across the
Mississippi River Valley. This high center will move over the
lake Sunday afternoon and evening bringing light and variable to
near calm conditions over the open waters during that period.
Next week brings southerly flow for much if not all of it. We
are not seeing any strong wind periods during at least the first
half of the week. The latter half becomes more uncertain as
computer model guidance indicates the likelihood of one...maybe a
couple...low pressure centers tracking into the western Great
Lakes but significantly varied low magnitude and timing at this






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