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000
FXUS63 KLOT 281447
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
947 AM CDT TUE JUN 28 2016

.UPDATE...
940 AM CDT

Main updates this morning were to increase cloud cover through
midday/early afternoon, with mostly cloudy skies likely for most
areas this morning. Visible satellite showing low stratus steadily
moving south through northern Illinois and northwest Indiana,
while diurnal develoment has blossomed over the last hour.
Although there may be some erosion to the edges of the main cloud
shield, anticipate the bulk of this moisture to hold together
while drifting south into early afternoon. Do clear skies going
into mid afternoon, but could see some locations south of I80
holding onto these clouds slightly longer into the late afternoon.
Have made little changes to temps at this point but with the
thicker clouds in place, could see some locations needing some
minor lower adjusments.

Rodriguez

&&

.SHORT TERM...
240 AM CDT

Through tonight...

Northerly winds have pushed much drier air south across Northern
Illinois early this morning, and expect prior to daybreak temps to
fall to a 56-62 deg range. IR imagery is showing a stratus deck
drifting south across Lake Michigan, and approaching Northeast
Illinois. Expect the stratus layer to be focused east of a
Rockford/Kankakee line through this afternoon, then with high
pressure building in from the Northwest this will steadily erode the
low clouds. With a continued North to Northeast surface flow, temps
will remain unseasonably cool today with highs mainly in the lower
to middle 70s. The exception will be areas adjacent to Lake
Michigan, where the day will start in the mid 60s and likely not
warm much beyond that point if at all.

As high pressure builds overhead tonight expect the dry air, light
winds, near cloudless skies to produce an optimal cooling
opportunity. Thus expect surface temps to fall easily into the lower
50s with a few upper 40s away from Lake Michigan and the urban heat
island. Closer to Lake Michigan temps will hold several degrees
warmer in the upper 50s/around 60.

Beachler

&&

.LONG TERM...
240 AM CDT

Wednesday through Monday...

High pressure arrives overhead early
Wed, with continued near cloudless skies. 500mb trough axis will be
pivoting east, with a continued northwest longwave flow over the
Great Lakes region. Temps will start to moderate slightly Wednesday,
with highs returning to the middle/upper 70s; however, with an
expected light onshore flow for far Northeast Illinois temperatures
will remain around 70 to the lower 70s.

Surface ridge will slowly drift east/southeast late Wed night, but
expect the influence to linger through much of Wed ngt keeping
clouds to a minimum and allowing lows to fall into the middle/upper
50s for another night. A weak mid-lvl vort maxima will slide over
the region Thur morning; however, the main focus will be on a
stronger lobe of vorticity progged to dive south from
Manitoba/Western Ontario Thur morning. This will enhance a frontal
boundary that will become oriented from Lake Superior southwest
through the Central Plains midday Thursday. Expect this frontal
boundary to develop a few showers/thunderstorms by Thur afternoon.
Highs Thur will continue to moderate slightly, reaching around 80
for highs. Confidence on precip coverage for Thur remains low, and
could see some lingering impact from the broad surface ridge. Plus
the better dynamics/forcing will be displaced well to the north
across Northern Lake Michigan.

Friday through Monday: Ensembles begin to weaken the high amplitude
500mb ridge across the Western CONUS into Western Canada, but
maintain a weak northwest flow through the Upper Midwest/Great Lakes
region. Another frontal boundary will arrive early Friday, with
surface ridging diving south from Manitoba. This will bring temps
back to the 70s for much of the area, with a weak onshore component
for areas adjacent to Lake Michigan. This late week surface ridge
will then remain over the Great Lakes through the weekend, drifting
east by early next week with flow turning Southwest and allowing
increased chances for precip and temps returning to the 80s by early
next week. Forecast guidance has slowed the return of much warmer
air until closer to the middle of next week.

Beachler

&&

.AVIATION...
For the 12Z TAFs...

The main cold front has pushed inland through KORD, KMDW, KDPA,
KGYY. KRFD should see little impact from the fropa as the air mass
becomes modified by the time the front reaches there. Winds have
turning nely- nnely and increased to 10-15 kt. The stratocu deck
with mvfr cigs has also pushed inland with bases arnd 1.8-2.5 kft.
Expect that winds should remain nely- nnely through the day, but
speeds should begin to diminish to below 10 kt by late afternoon.
With daytime warming, bases should lift to vfr by late morning or
early afternoon. As high pressure builds across the region this
evening, winds should becm lgt/vrbl with skies becmg skc overnight
tonight.

&&

.MARINE...
400 AM CDT

Main concern remains brisk northerly winds behind a cold front.
North winds of 15-25 kt will persist through through the day
today. With high pressure beginning to build in from the west
tonight, winds should gradually diminish but remain northerly. The
persistent north fetch even with wind speeds diminishing whould
keep choppy conditions over the south end of the lake through
Tuesday night. Thus, the small craft advisory will continue
unchanged.

As the high pressure builds across the western Great Lakes tonight
and Wednesday, winds will diminish Tuesday night. After a period
of west to southwest winds Wednesday and Thursday, another cold
front will cross the lake Thursday night, with brisk northerly
winds returning on Friday. Winds will then diminish by Saturday
as another area of high pressure builds across the Great Lakes
region.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 281130
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
630 AM CDT TUE JUN 28 2016

.SHORT TERM...
240 AM CDT

Through tonight...

Northerly winds have pushed much drier air south across Northern
Illinois early this morning, and expect prior to daybreak temps to
fall to a 56-62 deg range. IR imagery is showing a stratus deck
drifting south across Lake Michigan, and approaching Northeast
Illinois. Expect the stratus layer to be focused east of a
Rockford/Kankakee line through this afternoon, then with high
pressure building in from the Northwest this will steadily erode the
low clouds. With a continued North to Northeast surface flow, temps
will remain unseasonably cool today with highs mainly in the lower
to middle 70s. The exception will be areas adjacent to Lake
Michigan, where the day will start in the mid 60s and likely not
warm much beyond that point if at all.

As high pressure builds overhead tonight expect the dry air, light
winds, near cloudless skies to produce an optimal cooling
opportunity. Thus expect surface temps to fall easily into the lower
50s with a few upper 40s away from Lake Michigan and the urban heat
island. Closer to Lake Michigan temps will hold several degrees
warmer in the upper 50s/around 60.

Beachler

&&

.LONG TERM...
240 AM CDT

Wednesday through Monday...

High pressure arrives overhead early
Wed, with continued near cloudless skies. 500mb trough axis will be
pivoting east, with a continued northwest longwave flow over the
Great Lakes region. Temps will start to moderate slightly Wednesday,
with highs returning to the middle/upper 70s; however, with an
expected light onshore flow for far Northeast Illinois temperatures
will remain around 70 to the lower 70s.

Surface ridge will slowly drift east/southeast late Wed night, but
expect the influence to linger through much of Wed ngt keeping
clouds to a minimum and allowing lows to fall into the middle/upper
50s for another night. A weak mid-lvl vort maxima will slide over
the region Thur morning; however, the main focus will be on a
stronger lobe of vorticity progged to dive south from
Manitoba/Western Ontario Thur morning. This will enhance a frontal
boundary that will become oriented from Lake Superior southwest
through the Central Plains midday Thursday. Expect this frontal
boundary to develop a few showers/thunderstorms by Thur afternoon.
Highs Thur will continue to moderate slightly, reaching around 80
for highs. Confidence on precip coverage for Thur remains low, and
could see some lingering impact from the broad surface ridge. Plus
the better dynamics/forcing will be displaced well to the north
across Northern Lake Michigan.

Friday through Monday: Ensembles begin to weaken the high amplitude
500mb ridge across the Western CONUS into Western Canada, but
maintain a weak northwest flow through the Upper Midwest/Great Lakes
region. Another frontal boundary will arrive early Friday, with
surface ridging diving south from Manitoba. This will bring temps
back to the 70s for much of the area, with a weak onshore component
for areas adjacent to Lake Michigan. This late week surface ridge
will then remain over the Great Lakes through the weekend, drifting
east by early next week with flow turning Southwest and allowing
increased chances for precip and temps returning to the 80s by early
next week. Forecast guidance has slowed the return of much warmer
air until closer to the middle of next week.

Beachler

&&

.AVIATION...
For the 12Z TAFs...

The main cold front has pushed inland through KORD, KMDW, KDPA,
KGYY. KRFD should see little impact from the fropa as the air mass
becomes modified by the time the front reaches there. Winds have
turning nely- nnely and increased to 10-15 kt. The stratocu deck
with mvfr cigs has also pushed inland with bases arnd 1.8-2.5 kft.
Expect that winds should remain nely- nnely through the day, but
speeds should begin to diminish to below 10 kt by late afternoon.
With daytime warming, bases should lift to vfr by late morning or
early afternoon. As high pressure builds across the region this
evening, winds should becm lgt/vrbl with skies becmg skc overnight
tonight.

&&

.MARINE...
400 AM CDT

Main concern remains brisk northerly winds behind a cold front.
North winds of 15-25 kt will persist through through the day
today. With high pressure beginning to build in from the west
tonight, winds should gradually diminish but remain northerly. The
persistent north fetch even with wind speeds diminishing whould
keep choppy conditions over the south end of the lake through
Tuesday night. Thus, the small craft advisory will continue
unchanged.

As the high pressure builds across the western Great Lakes tonight
and Wednesday, winds will diminish Tuesday night. After a period
of west to southwest winds Wednesday and Thursday, another cold
front will cross the lake Thursday night, with brisk northerly
winds returning on Friday. Winds will then diminish by Saturday
as another area of high pressure builds across the Great Lakes
region.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 281130
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
630 AM CDT TUE JUN 28 2016

.SHORT TERM...
240 AM CDT

Through tonight...

Northerly winds have pushed much drier air south across Northern
Illinois early this morning, and expect prior to daybreak temps to
fall to a 56-62 deg range. IR imagery is showing a stratus deck
drifting south across Lake Michigan, and approaching Northeast
Illinois. Expect the stratus layer to be focused east of a
Rockford/Kankakee line through this afternoon, then with high
pressure building in from the Northwest this will steadily erode the
low clouds. With a continued North to Northeast surface flow, temps
will remain unseasonably cool today with highs mainly in the lower
to middle 70s. The exception will be areas adjacent to Lake
Michigan, where the day will start in the mid 60s and likely not
warm much beyond that point if at all.

As high pressure builds overhead tonight expect the dry air, light
winds, near cloudless skies to produce an optimal cooling
opportunity. Thus expect surface temps to fall easily into the lower
50s with a few upper 40s away from Lake Michigan and the urban heat
island. Closer to Lake Michigan temps will hold several degrees
warmer in the upper 50s/around 60.

Beachler

&&

.LONG TERM...
240 AM CDT

Wednesday through Monday...

High pressure arrives overhead early
Wed, with continued near cloudless skies. 500mb trough axis will be
pivoting east, with a continued northwest longwave flow over the
Great Lakes region. Temps will start to moderate slightly Wednesday,
with highs returning to the middle/upper 70s; however, with an
expected light onshore flow for far Northeast Illinois temperatures
will remain around 70 to the lower 70s.

Surface ridge will slowly drift east/southeast late Wed night, but
expect the influence to linger through much of Wed ngt keeping
clouds to a minimum and allowing lows to fall into the middle/upper
50s for another night. A weak mid-lvl vort maxima will slide over
the region Thur morning; however, the main focus will be on a
stronger lobe of vorticity progged to dive south from
Manitoba/Western Ontario Thur morning. This will enhance a frontal
boundary that will become oriented from Lake Superior southwest
through the Central Plains midday Thursday. Expect this frontal
boundary to develop a few showers/thunderstorms by Thur afternoon.
Highs Thur will continue to moderate slightly, reaching around 80
for highs. Confidence on precip coverage for Thur remains low, and
could see some lingering impact from the broad surface ridge. Plus
the better dynamics/forcing will be displaced well to the north
across Northern Lake Michigan.

Friday through Monday: Ensembles begin to weaken the high amplitude
500mb ridge across the Western CONUS into Western Canada, but
maintain a weak northwest flow through the Upper Midwest/Great Lakes
region. Another frontal boundary will arrive early Friday, with
surface ridging diving south from Manitoba. This will bring temps
back to the 70s for much of the area, with a weak onshore component
for areas adjacent to Lake Michigan. This late week surface ridge
will then remain over the Great Lakes through the weekend, drifting
east by early next week with flow turning Southwest and allowing
increased chances for precip and temps returning to the 80s by early
next week. Forecast guidance has slowed the return of much warmer
air until closer to the middle of next week.

Beachler

&&

.AVIATION...
For the 12Z TAFs...

The main cold front has pushed inland through KORD, KMDW, KDPA,
KGYY. KRFD should see little impact from the fropa as the air mass
becomes modified by the time the front reaches there. Winds have
turning nely- nnely and increased to 10-15 kt. The stratocu deck
with mvfr cigs has also pushed inland with bases arnd 1.8-2.5 kft.
Expect that winds should remain nely- nnely through the day, but
speeds should begin to diminish to below 10 kt by late afternoon.
With daytime warming, bases should lift to vfr by late morning or
early afternoon. As high pressure builds across the region this
evening, winds should becm lgt/vrbl with skies becmg skc overnight
tonight.

&&

.MARINE...
400 AM CDT

Main concern remains brisk northerly winds behind a cold front.
North winds of 15-25 kt will persist through through the day
today. With high pressure beginning to build in from the west
tonight, winds should gradually diminish but remain northerly. The
persistent north fetch even with wind speeds diminishing whould
keep choppy conditions over the south end of the lake through
Tuesday night. Thus, the small craft advisory will continue
unchanged.

As the high pressure builds across the western Great Lakes tonight
and Wednesday, winds will diminish Tuesday night. After a period
of west to southwest winds Wednesday and Thursday, another cold
front will cross the lake Thursday night, with brisk northerly
winds returning on Friday. Winds will then diminish by Saturday
as another area of high pressure builds across the Great Lakes
region.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO



  [top]

000
FXUS63 KILX 281122
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
622 AM CDT TUE JUN 28 2016

.SHORT TERM...(Today)
ISSUED AT 306 AM CDT Tue Jun 28 2016

Low cloud cover associated with a shortwave dropping out of the
upper Midwest will approach central IL by morning bringing scattered
to broken cloud cover for a good portion of the day mainly from
around I-55 eastward. A continuation of cooler air pushing into the
area in northerly low level flow should result in highs today
reaching only the mid to upper 70s along I-74 and just north...to
the lower 80s from Jacksonville through Effingham. Some mid 80s will
be possible south of I-70. Dewpoints in the 50s over northern IL and
southern WI currently will also push southward resulting in drier
than normal mid 50s to around 60 degree dewpoints over the central
IL forecast area by afternoon for very pleasant conditions. Expect
northerly breezes around 10 mph through the day.

.LONG TERM...(Tonight through Monday)
ISSUED AT 306 AM CDT Tue Jun 28 2016

Latest model runs show little change in the projected upper air
pattern for the week, with a broad scale trough over the eastern
U.S. through Thursday and a dry air mass. A more significant
shortwave will swing across the northern Great Lakes Thursday
night and Friday, bringing a reinforcing shot of cooler and drier
air. Late in the weekend, the GFS and ECMWF show a trend of the
hotter air mass over the Rockies shifting eastward toward the
central CONUS, with its effects being felt over our area just
beyond the current forecast period.

The main forecast concerns are with precipitation chances beginning
Thursday night, as the shortwave brings a cold front across the
Midwest. The GFS and ECMWF are most consistent in the timing of the
frontal passage between midnight and late morning Friday, although
the former model is more meager with the rain chances. The NAM
appears to develop some convective feedback at the tail end of its
run and was not used. However, both it and the GFS advect some
significant moisture into the area ahead of the system, with
precipitable water values over the south half of Illinois reaching
the 1.5-2 inch range Thursday night. Have increased rain chances
over most of the forecast area to 40-50% for Thursday night.

Some showers will linger into Friday over the southeast CWA. At that
point, the front starts to hang up to our south as it becomes
parallel to the upper flow. The GFS and ECMWF both bring periodic
surges of showers and some thunderstorms along the boundary through
the weekend, which may affect the southern portions of the forecast
area. An area of high pressure over the Great Lakes will block the
northward migration of this rain, but the ECMWF is not quite as
strong as the GFS with it and thus gets some rain almost up to I-72.
Currently am leaning toward the GFS solution and will limit the 30%
PoP`s to areas south of I-70 Saturday and Saturday night. Model
discrepancy widens later in the holiday weekend, leading to more
significant uncertainty with the rain chances for the 4th of July
holiday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 622 AM CDT Tue Jun 28 2016

VFR conditions expected for the next 24 hours. An area of cloud
cover from the north expected to affect KBMI and KCMI and
potentially KDEC starting around 18Z. However, given recent trends
and model forecasts this is likely to thin and lift somewhat
before reaching the area so have only included SCT050-060 in TAFs.
Winds N up to 10 kts...decreasing in the evening.

&&

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

&&

$$

SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton




000
FXUS63 KILX 281122
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
622 AM CDT TUE JUN 28 2016

.SHORT TERM...(Today)
ISSUED AT 306 AM CDT Tue Jun 28 2016

Low cloud cover associated with a shortwave dropping out of the
upper Midwest will approach central IL by morning bringing scattered
to broken cloud cover for a good portion of the day mainly from
around I-55 eastward. A continuation of cooler air pushing into the
area in northerly low level flow should result in highs today
reaching only the mid to upper 70s along I-74 and just north...to
the lower 80s from Jacksonville through Effingham. Some mid 80s will
be possible south of I-70. Dewpoints in the 50s over northern IL and
southern WI currently will also push southward resulting in drier
than normal mid 50s to around 60 degree dewpoints over the central
IL forecast area by afternoon for very pleasant conditions. Expect
northerly breezes around 10 mph through the day.

.LONG TERM...(Tonight through Monday)
ISSUED AT 306 AM CDT Tue Jun 28 2016

Latest model runs show little change in the projected upper air
pattern for the week, with a broad scale trough over the eastern
U.S. through Thursday and a dry air mass. A more significant
shortwave will swing across the northern Great Lakes Thursday
night and Friday, bringing a reinforcing shot of cooler and drier
air. Late in the weekend, the GFS and ECMWF show a trend of the
hotter air mass over the Rockies shifting eastward toward the
central CONUS, with its effects being felt over our area just
beyond the current forecast period.

The main forecast concerns are with precipitation chances beginning
Thursday night, as the shortwave brings a cold front across the
Midwest. The GFS and ECMWF are most consistent in the timing of the
frontal passage between midnight and late morning Friday, although
the former model is more meager with the rain chances. The NAM
appears to develop some convective feedback at the tail end of its
run and was not used. However, both it and the GFS advect some
significant moisture into the area ahead of the system, with
precipitable water values over the south half of Illinois reaching
the 1.5-2 inch range Thursday night. Have increased rain chances
over most of the forecast area to 40-50% for Thursday night.

Some showers will linger into Friday over the southeast CWA. At that
point, the front starts to hang up to our south as it becomes
parallel to the upper flow. The GFS and ECMWF both bring periodic
surges of showers and some thunderstorms along the boundary through
the weekend, which may affect the southern portions of the forecast
area. An area of high pressure over the Great Lakes will block the
northward migration of this rain, but the ECMWF is not quite as
strong as the GFS with it and thus gets some rain almost up to I-72.
Currently am leaning toward the GFS solution and will limit the 30%
PoP`s to areas south of I-70 Saturday and Saturday night. Model
discrepancy widens later in the holiday weekend, leading to more
significant uncertainty with the rain chances for the 4th of July
holiday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 622 AM CDT Tue Jun 28 2016

VFR conditions expected for the next 24 hours. An area of cloud
cover from the north expected to affect KBMI and KCMI and
potentially KDEC starting around 18Z. However, given recent trends
and model forecasts this is likely to thin and lift somewhat
before reaching the area so have only included SCT050-060 in TAFs.
Winds N up to 10 kts...decreasing in the evening.

&&

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

&&

$$

SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton




000
FXUS63 KLOT 280908
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
408 AM CDT TUE JUN 28 2016

.SHORT TERM...
240 AM CDT

Through tonight...

Northerly winds have pushed much drier air south across Northern
Illinois early this morning, and expect prior to daybreak temps to
fall to a 56-62 deg range. IR imagery is showing a stratus deck
drifting south across Lake Michigan, and approaching Northeast
Illinois. Expect the stratus layer to be focused east of a
Rockford/Kankakee line through this afternoon, then with high
pressure building in from the Northwest this will steadily erode the
low clouds. With a continued North to Northeast surface flow, temps
will remain unseasonably cool today with highs mainly in the lower
to middle 70s. The exception will be areas adjacent to Lake
Michigan, where the day will start in the mid 60s and likely not
warm much beyond that point if at all.

As high pressure builds overhead tonight expect the dry air, light
winds, near cloudless skies to produce an optimal cooling
opportunity. Thus expect surface temps to fall easily into the lower
50s with a few upper 40s away from Lake Michigan and the urban heat
island. Closer to Lake Michigan temps will hold several degrees
warmer in the upper 50s/around 60.

Beachler

&&

.LONG TERM...
240 AM CDT

Wednesday through Monday...

High pressure arrives overhead early
Wed, with continued near cloudless skies. 500mb trough axis will be
pivoting east, with a continued northwest longwave flow over the
Great Lakes region. Temps will start to moderate slightly Wednesday,
with highs returning to the middle/upper 70s; however, with an
expected light onshore flow for far Northeast Illinois temperatures
will remain around 70 to the lower 70s.

Surface ridge will slowly drift east/southeast late Wed night, but
expect the influence to linger through much of Wed ngt keeping
clouds to a minimum and allowing lows to fall into the middle/upper
50s for another night. A weak mid-lvl vort maxima will slide over
the region Thur morning; however, the main focus will be on a
stronger lobe of vorticity progged to dive south from
Manitoba/Western Ontario Thur morning. This will enhance a frontal
boundary that will become oriented from Lake Superior southwest
through the Central Plains midday Thursday. Expect this frontal
boundary to develop a few showers/thunderstorms by Thur afternoon.
Highs Thur will continue to moderate slightly, reaching around 80
for highs. Confidence on precip coverage for Thur remains low, and
could see some lingering impact from the broad surface ridge. Plus
the better dynamics/forcing will be displaced well to the north
across Northern Lake Michigan.

Friday through Monday: Ensembles begin to weaken the high amplitude
500mb ridge across the Western CONUS into Western Canada, but
maintain a weak northwest flow through the Upper Midwest/Great Lakes
region. Another frontal boundary will arrive early Friday, with
surface ridging diving south from Manitoba. This will bring temps
back to the 70s for much of the area, with a weak onshore component
for areas adjacent to Lake Michigan. This late week surface ridge
will then remain over the Great Lakes through the weekend, drifting
east by early next week with flow turning Southwest and allowing
increased chances for precip and temps returning to the 80s by early
next week. Forecast guidance has slowed the return of much warmer
air until closer to the middle of next week.

Beachler

&&

.AVIATION...
For the 06Z TAFs...

the main cold front continues to push quickly south down the lake
into northeastern IL. 06Z obs show that the front has pushed
through KUGN and is approaching KPWK. Expect that the front will
reach KORD by arnd 0630Z. Winds should shift nnely for several
hours with gusts near 20kt. by late morning winds should trend to
nly-nnwl and drop off 10-12 kt through late afternoon and then
diminish to lgt/vrbl in the evening as high pressure builds over
the region.

Latest satellite imagery indicates a ragged area of stratocu
behind the front, with the most extensive cloud cover still in
central to northern WI. Expect that the lower clouds should filter
in following the fropa, but the lowest cloud cover should not move
in until after 12z. Confidence regarding prevailing bases is low,
but upstream obs do show mvfr conditions and there is moderate
confidence that mvfr cigs will move in through the morning hours
and then lift to vfr by early afternoon.

&&

.MARINE...
400 AM CDT

Main concern remains brisk northerly winds behind a cold front.
North winds of 15-25 kt will persist through through the day
today. With high pressure beginning to build in from the west
tonight, winds should gradually diminish but remain northerly. The
persistent north fetch even with wind speeds diminishing whould
keep choppy conditions over the south end of the lake through
Tuesday night. Thus, the small craft advisory will continue
unchanged.

As the high pressure builds across the western Great Lakes tonight
and Wednesday, winds will diminish Tuesday night. After a period
of west to southwest winds Wednesday and Thursday, another cold
front will cross the lake Thursday night, with brisk northerly
winds returning on Friday. Winds will then diminish by Saturday
as another area of high pressure builds across the Great Lakes
region.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KILX 280807
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
307 AM CDT TUE JUN 28 2016

.SHORT TERM...(Today)
ISSUED AT 306 AM CDT Tue Jun 28 2016

Low cloud cover associated with a shortwave dropping out of the
upper Midwest will approach central IL by morning bringing scattered
to broken cloud cover for a good portion of the day mainly from
around I-55 eastward. A continuation of cooler air pushing into the
area in northerly low level flow should result in highs today
reaching only the mid to upper 70s along I-74 and just north...to
the lower 80s from Jacksonville through Effingham. Some mid 80s will
be possible south of I-70. Dewpoints in the 50s over northern IL and
southern WI currently will also push southward resulting in drier
than normal mid 50s to around 60 degree dewpoints over the central
IL forecast area by afternoon for very pleasant conditions. Expect
northerly breezes around 10 mph through the day.

&&

.LONG TERM...(Tonight through Monday)
ISSUED AT 306 AM CDT Tue Jun 28 2016

Latest model runs show little change in the projected upper air
pattern for the week, with a broad scale trough over the eastern
U.S. through Thursday and a dry air mass. A more significant
shortwave will swing across the northern Great Lakes Thursday
night and Friday, bringing a reinforcing shot of cooler and drier
air. Late in the weekend, the GFS and ECMWF show a trend of the
hotter air mass over the Rockies shifting eastward toward the
central CONUS, with its effects being felt over our area just
beyond the current forecast period.

The main forecast concerns are with precipitation chances beginning
Thursday night, as the shortwave brings a cold front across the
Midwest. The GFS and ECMWF are most consistent in the timing of the
frontal passage between midnight and late morning Friday, although
the former model is more meager with the rain chances. The NAM
appears to develop some convective feedback at the tail end of its
run and was not used. However, both it and the GFS advect some
significant moisture into the area ahead of the system, with
precipitable water values over the south half of Illinois reaching
the 1.5-2 inch range Thursday night. Have increased rain chances
over most of the forecast area to 40-50% for Thursday night.

Some showers will linger into Friday over the southeast CWA. At that
point, the front starts to hang up to our south as it becomes
parallel to the upper flow. The GFS and ECMWF both bring periodic
surges of showers and some thunderstorms along the boundary through
the weekend, which may affect the southern portions of the forecast
area. An area of high pressure over the Great Lakes will block the
northward migration of this rain, but the ECMWF is not quite as
strong as the GFS with it and thus gets some rain almost up to I-72.
Currently am leaning toward the GFS solution and will limit the 30%
PoP`s to areas south of I-70 Saturday and Saturday night. Model
discrepancy widens later in the holiday weekend, leading to more
significant uncertainty with the rain chances for the 4th of July
holiday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1148 PM CDT Mon Jun 27 2016

Quiet/VFR aviation weather conditions expected across the central
Illinois terminals through the 06Z TAF valid time. The main
potential fly in the ointment is enhanced low-level moisture that
is forecast to stream toward the area as the flow is at least
partially off Lake Michigan. This will likely result in MVFR CIGs
near the area on Tuesday, with KBMI & KCMI the most likely to be
impacted. At this point, have only included scattered low clouds
there, but this threat will need to be watched. Expect winds AOB
10 kts through the period.


&&

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

$$

SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Bak




000
FXUS63 KLOT 280740
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
240 AM CDT TUE JUN 28 2016

.SHORT TERM...
240 AM CDT

Through tonight...

Northerly winds have pushed much drier air south across Northern
Illinois early this morning, and expect prior to daybreak temps to
fall to a 56-62 deg range. IR imagery is showing a stratus deck
drifting south across Lake Michigan, and approaching Northeast
Illinois. Expect the stratus layer to be focused east of a
Rockford/Kankakee line through this afternoon, then with high
pressure building in from the Northwest this will steadily erode the
low clouds. With a continued North to Northeast surface flow, temps
will remain unseasonably cool today with highs mainly in the lower
to middle 70s. The exception will be areas adjacent to Lake
Michigan, where the day will start in the mid 60s and likely not
warm much beyond that point if at all.

As high pressure builds overhead tonight expect the dry air, light
winds, near cloudless skies to produce an optimal cooling
opportunity. Thus expect surface temps to fall easily into the lower
50s with a few upper 40s away from Lake Michigan and the urban heat
island. Closer to Lake Michigan temps will hold several degrees
warmer in the upper 50s/around 60.

Beachler

&&

.LONG TERM...
240 AM CDT

Wednesday through Monday...

High pressure arrives overhead early
Wed, with continued near cloudless skies. 500mb trough axis will be
pivoting east, with a continued northwest longwave flow over the
Great Lakes region. Temps will start to moderate slightly Wednesday,
with highs returning to the middle/upper 70s; however, with an
expected light onshore flow for far Northeast Illinois temperatures
will remain around 70 to the lower 70s.

Surface ridge will slowly drift east/southeast late Wed night, but
expect the influence to linger through much of Wed ngt keeping
clouds to a minimum and allowing lows to fall into the middle/upper
50s for another night. A weak mid-lvl vort maxima will slide over
the region Thur morning; however, the main focus will be on a
stronger lobe of vorticity progged to dive south from
Manitoba/Western Ontario Thur morning. This will enhance a frontal
boundary that will become oriented from Lake Superior southwest
through the Central Plains midday Thursday. Expect this frontal
boundary to develop a few showers/thunderstorms by Thur afternoon.
Highs Thur will continue to moderate slightly, reaching around 80
for highs. Confidence on precip coverage for Thur remains low, and
could see some lingering impact from the broad surface ridge. Plus
the better dynamics/forcing will be displaced well to the north
across Northern Lake Michigan.

Friday through Monday: Ensembles begin to weaken the high amplitude
500mb ridge across the Western CONUS into Western Canada, but
maintain a weak northwest flow through the Upper Midwest/Great Lakes
region. Another frontal boundary will arrive early Friday, with
surface ridging diving south from Manitoba. This will bring temps
back to the 70s for much of the area, with a weak onshore component
for areas adjacent to Lake Michigan. This late week surface ridge
will then remain over the Great Lakes through the weekend, drifting
east by early next week with flow turning Southwest and allowing
increased chances for precip and temps returning to the 80s by early
next week. Forecast guidance has slowed the return of much warmer
air until closer to the middle of next week.

Beachler

&&

.AVIATION...
For the 06Z TAFs...

the main cold front continues to push quickly south down the lake
into northeastern IL. 06Z obs show that the front has pushed
through KUGN and is approaching KPWK. Expect that the front will
reach KORD by arnd 0630Z. Winds should shift nnely for several
hours with gusts near 20kt. by late morning winds should trend to
nly-nnwl and drop off 10-12 kt through late afternoon and then
diminish to lgt/vrbl in the evening as high pressure builds over
the region.

Latest satellite imagery indicates a ragged area of stratocu
behind the front, with the most extensive cloud cover still in
central to northern WI. Expect that the lower clouds should filter
in following the fropa, but the lowest cloud cover should not move
in until after 12z. Confidence regarding prevailing bases is low,
but upstream obs do show mvfr conditions and there is moderate
confidence that mvfr cigs will move in through the morning hours
and then lift to vfr by early afternoon.

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

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000
FXUS63 KLOT 280610
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
110 AM CDT TUE JUN 28 2016

.UPDATE...

The synoptically enhanced lake breeze/front...still somewhat
visible on doppler and tdwr radars continues to march
southwestward this evening. Winds will shift to north-northeast
area wide overnight. The pressure gradient is not super strong
initially behind the front thus mitigating the winds behind the
initial surge, but the gradient will increase more significantly
late tonight across southern Lake Michigan, closer to the actual
cold frontal boundary. Temperatures have already fallen into the
upper 60s to low 70s, and that trend will continue with readings
likely bottoming out in the mid 60s downtown to the upper 50s in
outlying areas. Guidance still suggests some broken cloudiness
seen on the early autumn- like satellite imagery behind the front
to move into the local area overnight into early Tuesday. Beach
conditions will remain hazardous through the evening.

KMD

&&

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens Celsius will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this occurs.
The later frontal timing of the ECMWF and also lower instability
would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 06Z TAFs...

the main cold front continues to push quickly south down the lake
into northeastern IL. 06Z obs show that the front has pushed
through KUGN and is approaching KPWK. Expect that the front will
reach KORD by arnd 0630Z. Winds should shift nnely for several
hours with gusts near 20kt. by late morning winds should trend to
nly-nnwl and drop off 10-12 kt through late afternoon and then
diminish to lgt/vrbl in the evening as high pressure builds over
the region.

Latest satellite imagery indicates a ragged area of stratocu
behind the front, with the most extensive cloud cover still in
central to northern WI. Expect that the lower clouds should filter
in following the fropa, but the lowest cloud cover should not move
in until after 12z. Confidence regarding prevailing bases is low,
but upstream obs do show mvfr conditions and there is moderate
confidence that mvfr cigs will move in through the morning hours
and then lift to vfr by early afternoon.

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

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000
FXUS63 KLOT 280610
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
110 AM CDT TUE JUN 28 2016

.UPDATE...

The synoptically enhanced lake breeze/front...still somewhat
visible on doppler and tdwr radars continues to march
southwestward this evening. Winds will shift to north-northeast
area wide overnight. The pressure gradient is not super strong
initially behind the front thus mitigating the winds behind the
initial surge, but the gradient will increase more significantly
late tonight across southern Lake Michigan, closer to the actual
cold frontal boundary. Temperatures have already fallen into the
upper 60s to low 70s, and that trend will continue with readings
likely bottoming out in the mid 60s downtown to the upper 50s in
outlying areas. Guidance still suggests some broken cloudiness
seen on the early autumn- like satellite imagery behind the front
to move into the local area overnight into early Tuesday. Beach
conditions will remain hazardous through the evening.

KMD

&&

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens Celsius will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this occurs.
The later frontal timing of the ECMWF and also lower instability
would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 06Z TAFs...

the main cold front continues to push quickly south down the lake
into northeastern IL. 06Z obs show that the front has pushed
through KUGN and is approaching KPWK. Expect that the front will
reach KORD by arnd 0630Z. Winds should shift nnely for several
hours with gusts near 20kt. by late morning winds should trend to
nly-nnwl and drop off 10-12 kt through late afternoon and then
diminish to lgt/vrbl in the evening as high pressure builds over
the region.

Latest satellite imagery indicates a ragged area of stratocu
behind the front, with the most extensive cloud cover still in
central to northern WI. Expect that the lower clouds should filter
in following the fropa, but the lowest cloud cover should not move
in until after 12z. Confidence regarding prevailing bases is low,
but upstream obs do show mvfr conditions and there is moderate
confidence that mvfr cigs will move in through the morning hours
and then lift to vfr by early afternoon.

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014 UNTIL 4 AM Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002 UNTIL 4 AM Wednesday.

LM...Small Craft Advisory...NEARSHORE WATERS
     UNTIL 4 AM Wednesday.

&&

$$

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000
FXUS63 KILX 280450
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1150 PM CDT MON JUN 27 2016

.UPDATE...
Issued at 857 PM CDT Mon Jun 27 2016

Quiet weather is expected across central and southeast Illinois
overnight as high pressure begins to build into the area.
Noticeably cooler and less humid air will also spread into the
region on northerly winds. Going forecast has this benign scenario
handled well, and only minor tweaks are needed to the hourly
forecast trends.

&&

.SHORT TERM...(Tonight)
ISSUED AT 240 PM CDT Mon Jun 27 2016

Cooler and drier air will push into Illinois overnight. Dew points
in the upper 50s currently north of I-80 will spread southward as
far south as I-70 by morning. A few clouds may spread over east
central Illinois by sunrise but otherwise clear skies and slightly
cooler than normal lows can be expected.

.LONG TERM...(Tuesday through Monday)
ISSUED AT 240 PM CDT Mon Jun 27 2016

500 mb trof axis to shift to our east Tuesday morning allowing
cooler and much drier air to filter across the forecast area during
the day. Surface high pressure will then build southeast into the
region through midweek bringing pleasant weather conditions to the
forecast area. Once we get into Thursday, we start seeing some model
differences with respect to a vigorous shortwave forecast to track
southeast into the lower Great Lakes bringing the threat for
scattered showers and thunderstorms to parts of the area, especially
later in the day and Thursday night. Latest ECMWF following the 00z
run of last night in bringing precip to our northwest by late in the
day Thursday and then with the more favorable dynamics shifting well
to our north, precip diminishes as it heads into central Illinois
Thursday night. The GFS was much more aggressive with the rain threat
with the shortwave late Thursday into Friday before the low level
baroclinic zone gets shunted south of the forecast area as we head
into the weekend with another surface high shifting southeast into
the region at this time. Based on the forecast 500 mb pattern over
the lower 48, with the longwave trof and stronger confluent zone
over the Great Lakes, the higher chances for showers and storms will
be confined over mainly the southern portions of the forecast area.

Temperatures will be at their coolest on Tuesday with highs only
rising into the middle 70s far north to possibly the mid 80s over
extreme southeast Illinois. After that, look for temperatures to
start edging slowly back into the 80s over the entire forecast area
starting on Thursday and continuing through the holiday weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1148 PM CDT Mon Jun 27 2016

Quiet/VFR aviation weather conditions expected across the central
Illinois terminals through the 06Z TAF valid time. The main
potential fly in the ointment is enhanced low-level moisture that
is forecast to stream toward the area as the flow is at least
partially off Lake Michigan. This will likely result in MVFR CIGs
near the area on Tuesday, with KBMI & KCMI the most likely to be
impacted. At this point, have only included scattered low clouds
there, but this threat will need to be watched. Expect winds AOB
10 kts through the period.

&&

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

$$

UPDATE...Bak
SHORT TERM...Barker
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KLOT 280229
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
929 PM CDT MON JUN 27 2016

.UPDATE...915 PM CDT

The synoptically enhanced lake breeze/front...still somewhat
visible on doppler and tdwr radars continues to march
southwestward this evening. Winds will shift to north-northeast
area wide overnight. The pressure gradient is not super strong
initially behind the front thus mitigating the winds behind the
initial surge, but the gradient will increase more significantly
late tonight across southern Lake Michigan, closer to the actual
cold frontal boundary. Temperatures have already fallen into the
upper 60s to low 70s, and that trend will continue with readings
likely bottoming out in the mid 60s downtown to the upper 50s in
outlying areas. Guidance still suggests some broken cloudiness
seen on the early autumn- like satellite imagery behind the front
to move into the local area overnight into early Tuesday. Beach
conditions will remain hazardous through the evening.

KMD

&&

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens Celsius will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this occurs.
The later frontal timing of the ECMWF and also lower instability
would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 00Z TAFs...

642 pm...Lake boundary/cold front now west of ord/mdw with
east/northeast winds now expected the rest of the evening. Speeds
may diminish some this evening but will increase again overnight
as the main cold front moves across the area. Guidance shows winds
trending back northerly or north/northwest Tuesday morning and not
sure how long this may persist before turning back northeasterly
by late morning or early afternoon. Could also be a lull in the
wind speeds/gusts Tuesday morning...but should see 10kts or more
once winds turn more northeasterly with some gust potential into
Tuesday afternoon/evening.

Confidence regarding low clouds is low. If low clouds develop...
they`ll likely be close to 1kft overnight. Better chance for mvfr
cigs appear to be Tuesday morning...which will then slowly lift by
Tuesday afternoon. Trends will need to be monitored to possibly
include a bkn low mvfr cig with the 03z update. cms

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014...1 AM Tuesday TO 4 AM
     Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002...1 AM Tuesday TO 4 AM
     Wednesday.

LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 280219
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
919 PM CDT MON JUN 27 2016

.UPDATE...
915 PM CDT

The synoptic cold front...still somewhat visible on doppler and
tdwr radars continues to march southwestward this evening. Winds
will shift to north-northeast area wide overnight. The pressure
gradient is not super strong initially behind the front thus
mitigating the winds behind the initial surge, but the gradient
will increase more significantly late tonight across southern Lake
Michigan. Temperatures have already fallen into the upper 60s to
low 70s, and that trend will continue with readings likely
bottoming out in the mid 60s downtown to the upper 50s in outlying
areas. Guidance still suggests some broken cloudiness seen on the
early autumn- like satellite imagery behind the front to move into
the local area overnight into early Tuesday. Beach conditions will
remain hazardous through the evening.

KMD

&&

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens Celsius will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this occurs.
The later frontal timing of the ECMWF and also lower instability
would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 00Z TAFs...

642 pm...Lake boundary/cold front now west of ord/mdw with
east/northeast winds now expected the rest of the evening. Speeds
may diminish some this evening but will increase again overnight
as the main cold front moves across the area. Guidance shows winds
trending back northerly or north/northwest Tuesday morning and not
sure how long this may persist before turning back northeasterly
by late morning or early afternoon. Could also be a lull in the
wind speeds/gusts Tuesday morning...but should see 10kts or more
once winds turn more northeasterly with some gust potential into
Tuesday afternoon/evening.

Confidence regarding low clouds is low. If low clouds develop...
they`ll likely be close to 1kft overnight. Better chance for mvfr
cigs appear to be Tuesday morning...which will then slowly lift by
Tuesday afternoon. Trends will need to be monitored to possibly
include a bkn low mvfr cig with the 03z update. cms

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014...1 AM Tuesday TO 4 AM
     Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002...1 AM Tuesday TO 4 AM
     Wednesday.

LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KILX 280159
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
859 PM CDT MON JUN 27 2016

.UPDATE...
Issued at 857 PM CDT Mon Jun 27 2016

Quiet weather is expected across central and southeast Illinois
overnight as high pressure begins to build into the area.
Noticeably cooler and less humid air will also spread into the
region on northerly winds. Going forecast has this benign scenario
handled well, and only minor tweaks are needed to the hourly
forecast trends.

&&

.SHORT TERM...(Tonight)
ISSUED AT 240 PM CDT Mon Jun 27 2016

Cooler and drier air will push into Illinois overnight. Dew points
in the upper 50s currently north of I-80 will spread southward as
far south as I-70 by morning. A few clouds may spread over east
central Illinois by sunrise but otherwise clear skies and slightly
cooler than normal lows can be expected.

.LONG TERM...(Tuesday through Monday)
ISSUED AT 240 PM CDT Mon Jun 27 2016

500 mb trof axis to shift to our east Tuesday morning allowing
cooler and much drier air to filter across the forecast area during
the day. Surface high pressure will then build southeast into the
region through midweek bringing pleasant weather conditions to the
forecast area. Once we get into Thursday, we start seeing some model
differences with respect to a vigorous shortwave forecast to track
southeast into the lower Great Lakes bringing the threat for
scattered showers and thunderstorms to parts of the area, especially
later in the day and Thursday night. Latest ECMWF following the 00z
run of last night in bringing precip to our northwest by late in the
day Thursday and then with the more favorable dynamics shifting well
to our north, precip diminishes as it heads into central Illinois
Thursday night. The GFS was much more aggressive with the rain threat
with the shortwave late Thursday into Friday before the low level
baroclinic zone gets shunted south of the forecast area as we head
into the weekend with another surface high shifting southeast into
the region at this time. Based on the forecast 500 mb pattern over
the lower 48, with the longwave trof and stronger confluent zone
over the Great Lakes, the higher chances for showers and storms will
be confined over mainly the southern portions of the forecast area.

Temperatures will be at their coolest on Tuesday with highs only
rising into the middle 70s far north to possibly the mid 80s over
extreme southeast Illinois. After that, look for temperatures to
start edging slowly back into the 80s over the entire forecast area
starting on Thursday and continuing through the holiday weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 632 PM CDT Mon Jun 27 2016

Quiet/VFR aviation weather conditions expected across the central
Illinois terminals through the 00Z TAF valid time. The main
potential fly in the ointment is enhanced low-level moisture that
is forecast to stream toward the area as the flow is at least
partially off Lake Michigan. This will likely result in MVFR CIGs
near the area on Tuesday, with KCMI the most likely to be
impacted. At this point, have only included scattered low clouds
there, but this threat will need to be watched. Expect winds AOB
10 kts through the period.


&&

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

$$

UPDATE...Bak
SHORT TERM...Barker
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KLOT 272342
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
642 PM CDT MON JUN 27 2016

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens celsisus will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GGEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this
occurs. The later frontal timing of the ECMWF and also lower
instability would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 00Z TAFs...

642 pm...Lake boundary/cold front now west of ord/mdw with
east/northeast winds now expected the rest of the evening. Speeds
may diminish some this evening but will increase again overnight
as the main cold front moves across the area. Guidance shows winds
trending back northerly or north/northwest Tuesday morning and not
sure how long this may persist before turning back northeasterly
by late morning or early afternoon. Could also be a lull in the
wind speeds/gusts Tuesday morning...but should see 10kts or more
once winds turn more northeasterly with some gust potential into
Tuesday afternoon/evening.

Confidence regarding low clouds is low. If low clouds develop...
they`ll likely be close to 1kft overnight. Better chance for mvfr
cigs appear to be Tuesday morning...which will then slowly lift by
Tuesday afternoon. Trends will need to be monitored to possibly
include a bkn low mvfr cig with the 03z update. cms

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014...1 AM Tuesday TO 4 AM
     Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002...1 AM Tuesday TO 4 AM
     Wednesday.

LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 272342
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
642 PM CDT MON JUN 27 2016

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens celsisus will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GGEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this
occurs. The later frontal timing of the ECMWF and also lower
instability would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 00Z TAFs...

642 pm...Lake boundary/cold front now west of ord/mdw with
east/northeast winds now expected the rest of the evening. Speeds
may diminish some this evening but will increase again overnight
as the main cold front moves across the area. Guidance shows winds
trending back northerly or north/northwest Tuesday morning and not
sure how long this may persist before turning back northeasterly
by late morning or early afternoon. Could also be a lull in the
wind speeds/gusts Tuesday morning...but should see 10kts or more
once winds turn more northeasterly with some gust potential into
Tuesday afternoon/evening.

Confidence regarding low clouds is low. If low clouds develop...
they`ll likely be close to 1kft overnight. Better chance for mvfr
cigs appear to be Tuesday morning...which will then slowly lift by
Tuesday afternoon. Trends will need to be monitored to possibly
include a bkn low mvfr cig with the 03z update. cms

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ014...1 AM Tuesday TO 4 AM
     Wednesday.

IN...Beach Hazards Statement...INZ001-INZ002...1 AM Tuesday TO 4 AM
     Wednesday.

LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

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000
FXUS63 KILX 272336
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
636 PM CDT MON JUN 27 2016

.SHORT TERM...(Tonight)
ISSUED AT 240 PM CDT Mon Jun 27 2016

Cooler and drier air will push into Illinois overnight. Dew points
in the upper 50s currently north of I-80 will spread southward as
far south as I-70 by morning. A few clouds may spread over east
central Illinois by sunrise but otherwise clear skies and slightly
cooler than normal lows can be expected.

.LONG TERM...(Tuesday through Monday)
ISSUED AT 240 PM CDT Mon Jun 27 2016

500 mb trof axis to shift to our east Tuesday morning allowing
cooler and much drier air to filter across the forecast area during
the day. Surface high pressure will then build southeast into the
region through midweek bringing pleasant weather conditions to the
forecast area. Once we get into Thursday, we start seeing some model
differences with respect to a vigorous shortwave forecast to track
southeast into the lower Great Lakes bringing the threat for
scattered showers and thunderstorms to parts of the area, especially
later in the day and Thursday night. Latest ECMWF following the 00z
run of last night in bringing precip to our northwest by late in the
day Thursday and then with the more favorable dynamics shifting well
to our north, precip diminishes as it heads into central Illinois
Thursday night. The GFS was much more aggressive with the rain threat
with the shortwave late Thursday into Friday before the low level
baroclinic zone gets shunted south of the forecast area as we head
into the weekend with another surface high shifting southeast into
the region at this time. Based on the forecast 500 mb pattern over
the lower 48, with the longwave trof and stronger confluent zone
over the Great Lakes, the higher chances for showers and storms will
be confined over mainly the southern portions of the forecast area.

Temperatures will be at their coolest on Tuesday with highs only
rising into the middle 70s far north to possibly the mid 80s over
extreme southeast Illinois. After that, look for temperatures to
start edging slowly back into the 80s over the entire forecast area
starting on Thursday and continuing through the holiday weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 632 PM CDT Mon Jun 27 2016

Quiet/VFR aviation weather conditions expected across the central
Illinois terminals through the 00Z TAF valid time. The main
potential fly in the ointment is enhanced low-level moisture that
is forecast to stream toward the area as the flow is at least
partially off Lake Michigan. This will likely result in MVFR CIGs
near the area on Tuesday, with KCMI the most likely to be
impacted. At this point, have only included scattered low clouds
there, but this threat will need to be watched. Expect winds AOB
10 kts through the period.

&&

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

$$

SHORT TERM...Barker
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KLOT 272005
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
305 PM CDT MON JUN 27 2016

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens celsisus will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GGEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this
occurs. The later frontal timing of the ECMWF and also lower
instability would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 18Z TAFs...

Main forecast concerns/challenges this TAF period are with a wind
shift to the northeast at/above 10 KT this evening, and then with
MVFR ceilings tonight.

VFR conditions ongoing across the terminals early this afternoon,
with these conditions expected to persist through this afternoon
and evening. Upstream front dropping down the lake this afternoon
will allow for an increase in cloud cover tonight as well as a
wind shift, but any precip to stay to the north and northeast. Did
push up arrival of north/northeast winds with a wind shift to the
northeast this evening ahead of the front, and then increased
speeds later in the night with the arrival of the front.
Confidence is higher with this wind shift but lower with the exact
timing as some guidance is indicating an earlier northeast wind
shift, as early as 22-23z for areas near the lake. Feel that the
current stronger westerly winds should hold this shift until later
in the evening when the winds diminish. However, will continue to
monitor what the winds at observation points in eastern Wisconsin
do over the next couple of hours to try and gain a better handle
on trends. Upstream MVFR ceilings will likely continue to move
down towards the terminals, and have maintained this in the TAFs.

Rodriguez

&&

.MARINE...
305 PM CDT

Main concern is with gusty northerly winds behind a cold front
tonight and Tuesday. North winds of 15-25 kt are in store, which
will yield building waves and conditions hazardous for small craft
late tonight through late Tuesday night for the Illinois and
Indiana nearshore waters. As the winds quickly increase this
evening, a few 30 kt gusts are possible over the northern portion
of the lake, and a few 30 kt gusts may occur Tuesday afternoon
over the southern half of the lake.

High pressure building in will cause winds to quickly diminish
from north to south Tuesday night. After a period of west to
southwest winds Wednesday and Thursday, the next cold front will
cross the lake Thursday night, with brisk northerly winds on
Friday. For now, mentioned 15-20 kt winds in the GLF forecast, but
will have to monitor for gusts up to 25 kt and conditions
hazardous for small craft. Winds will again quickly diminish by
Saturday as high pressure builds across the Great Lakes region.

RC

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

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000
FXUS63 KILX 271945
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
245 PM CDT MON JUN 27 2016

.SHORT TERM...(Tonight)
ISSUED AT 240 PM CDT Mon Jun 27 2016

Cooler and drier air will push into Illinois overnight. Dew points
in the upper 50s currently north of I-80 will spread southward as
far south as I-70 by morning. A few clouds may spread over east
central Illinois by sunrise but otherwise clear skies and slightly
cooler than normal lows can be expected.

&&

.LONG TERM...(Tuesday through Monday)
ISSUED AT 240 PM CDT Mon Jun 27 2016

500 mb trof axis to shift to our east Tuesday morning allowing
cooler and much drier air to filter across the forecast area during
the day. Surface high pressure will then build southeast into the
region through midweek bringing pleasant weather conditions to the
forecast area. Once we get into Thursday, we start seeing some model
differences with respect to a vigorous shortwave forecast to track
southeast into the lower Great Lakes bringing the threat for
scattered showers and thunderstorms to parts of the area, especially
later in the day and Thursday night. Latest ECMWF following the 00z
run of last night in bringing precip to our northwest by late in the
day Thursday and then with the more favorable dynamics shifting well
to our north, precip diminishes as it heads into central Illinois
Thursday night. The GFS was much more aggressive with the rain threat
with the shortwave late Thursday into Friday before the low level
baroclinic zone gets shunted south of the forecast area as we head
into the weekend with another surface high shifting southeast into
the region at this time. Based on the forecast 500 mb pattern over
the lower 48, with the longwave trof and stronger confluent zone
over the Great Lakes, the higher chances for showers and storms will
be confined over mainly the southern portions of the forecast area.

Temperatures will be at their coolest on Tuesday with highs only
rising into the middle 70s far north to possibly the mid 80s over
extreme southeast Illinois. After that, look for temperatures to
start edging slowly back into the 80s over the entire forecast area
starting on Thursday and continuing through the holiday weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1211 PM CDT Mon Jun 27 2016

Cold front now over northern Illinois will push through the
terminals this afternoon and evening. some scattered cumulus may
occur along and near the front. A second cold front currently over
the Upper Mississippi Valley will be accompanied by a
reinforcement of low-level moisture off lake Michigan as north
winds gain an easterly component in its wake. may bring some MVFR
clouds to KCMI late tonight. Light winds associated with the
frontal passages should mix boundary-layer sufficiently to keep
vsbys from dropping tonight.


&&

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

$$

SHORT TERM...Barker
LONG TERM...Smith
AVIATION...Barker




000
FXUS63 KLOT 271943
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
243 PM CDT MON JUN 27 2016

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
243 PM CDT

Tuesday night through Monday...

The weather pattern will be primarily quiet through the extended
period, with the minor exception of potential thunderstorms
Thursday and Thursday night. This is the main forecast concern.

Cool high pressure will result in clear skies, winds going calm
and fairly chilly overnight lows Tuesday night in the lower-mid
50s away from Chicago and upper 50s to around 60 in and near the
city. This will be followed by a beautiful day Wednesday, with
highs slightly below seasonable. Other than some afternoon cumulus
development due to a weak midlevel disturbance, there will be
plenty of sunshine, with highs warming to the upper 70s to around
80 inland. Early lake breeze formation will keep lakeshore areas
in the lower 70s.

After a quiet and slightly milder night Wednesday night,
attention turns to a cold frontal boundary approaching the mid and
upper MS valley. Ahead of the front, 925 mb temperatures in the
upper teens celsisus will support surface temperatures warming to
the upper 70s to lower 80s. Afternoon dewpoints will likely rise
to the upper 50s to lower 60s range. Though a shower cannot be
ruled out west of I-55 in the morning, main period of concern is
the afternoon and evening.

There is uncertainty on timing of the approaching front, with the
12z GFS/GGEM quicker than the ECMWF, as well as dewpoints and
associated instability by the late afternoon. Global models are in
decent agreement on a sheared wave trailing from main trough
across the northern Lakes swinging across northern Illinois during
the evening as surface cold front translates southeast. GFS
dewpoints are very likely overdone, but even forecast dewpoints in
grids could yield some minor instability. Should isolated or
widely scattered storms or clusters of storms develop in far
northern Illinois (mainly north of I-88) during the late afternoon
and early evening during more favored diurnal period, 30-35 kt NW
flow at 500 mb could support some storm organization. Coupled with
steep low level lapse rates, have some concern for an isolated
strong or marginally severe storm (mainly along/north of I-88 as
mentioned above), with gusty winds the main threat if this
occurs. The later frontal timing of the ECMWF and also lower
instability would result in little to no strong/severe threat.

The front will be through most if not all of the CWA by Friday
morning, keeping threat for any additional convection in at most
far southeast CWA. The rest of the area will be dry and cooler
with steady northerly winds keeping the shore coolest. Will need
to watch for strength of northerly winds and resulting wave
heights with regard to hazardous swim conditions on Friday.
Surface high pressure locking over the central Great Lakes will
result in a very pleasant Independence Day holiday weekend with
primarily dry conditions. Temperatures will start out a bit below
normal under influence of troughing south of Hudson Bay, and then
moderate close to normal by July 4th as mid and upper ridging
builds northward. Onshore flow through the weekend will result in
cooler temperatures along the lakeshore.

RC

&&

.AVIATION...
For the 18Z TAFs...

Main forecast concerns/challenges this TAF period are with a wind
shift to the northeast at/above 10 KT this evening, and then with
MVFR ceilings tonight.

VFR conditions ongoing across the terminals early this afternoon,
with these conditions expected to persist through this afternoon
and evening. Upstream front dropping down the lake this afternoon
will allow for an increase in cloud cover tonight as well as a
wind shift, but any precip to stay to the north and northeast. Did
push up arrival of north/northeast winds with a wind shift to the
northeast this evening ahead of the front, and then increased
speeds later in the night with the arrival of the front.
Confidence is higher with this wind shift but lower with the exact
timing as some guidance is indicating an earlier northeast wind
shift, as early as 22-23z for areas near the lake. Feel that the
current stronger westerly winds should hold this shift until later
in the evening when the winds diminish. However, will continue to
monitor what the winds at observation points in eastern Wisconsin
do over the next couple of hours to try and gain a better handle
on trends. Upstream MVFR ceilings will likely continue to move
down towards the terminals, and have maintained this in the TAFs.

Rodriguez

&&

.MARINE...
345 AM CDT

Another cold front will surge down the lake Monday night with
winds turning north and increasing to 15-25 kt. Occasional gusts
to 30 kt are possible over the southern half of the lake Tuesday
afternoon. A small craft advisory will likely be needed for late
Monday night through Tuesday night, but will hold off on hoisting
the advisory for now as there is still some question as to when
the stronger winds and higher waves will build over the south end
of the lake. High pressure will spread over the western Great
Laked Tuesday night allowing winds and waves to subside. High
pressure will remain over the region through mid week and then
shifts southeast Thursday. Winds will become southwest behind the
high. A cold front/low pressure trough combo will push down the
lake Thursday night with winds becoming north again behind it.
Another high will build over the lake Friday night into Saturday.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

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000
FXUS63 KLOT 271931
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
231 PM CDT MON JUN 27 2016

.SHORT TERM...
231 PM CDT

Through Tuesday...

Generally sunny skies with temps in the upper 80s still ongoing
this afternoon, while continued stream of drier air moves through
the area. With reinforcing pushes of drier and cooler air
occurring this afternoon into the evening, most locations have
reached the warmest temps of the day and will see temps fall over
the next several hours. Expect increasing cloud cover currently
being observed to the north spread south this evening and
overnight, but with any upstream showers to likely slide just to
the north and northeast of the area. Still anticipating a quick
transition to north and northeast winds late this afternoon into
the early evening, with most short term guidance showing this
solution. This seems reasonable given the substantial weakening
occurring in the surface gradient, and with upstream obs beginning
to show this trend. With temps in the 80s this afternoon,
locations near the lake will feel this wind shift the most with a
quick transition to cooler temps off the lake. Do think there will
be some possible stronger speeds with this wind shift, but with
the prevailing strong winds not anticipated until later tonight.
High pressure will help erode lingering cloud cover on Tuesday but
with a cooler air mass in place, temps will stay in the 70s inland
and 60s near the lake.

Rodriguez

&&

.LONG TERM...
208 AM CDT

Tuesday through Sunday...

500mb trough axis will be overhead of the
Great Lakes tuesday, with broad surface ridging centered over the
Upper Midwest Tue, which will maintain a better pressure gradient
and higher winds for Lake Michigan Northern Illinois. In addition
much cooler air aloft will cover the Great Lakes region, with
surface temps struggling to warm beyond the low/mid 70s. With an
onshore component, areas adjacent to Lake Michigan may remain in
the 60s Tuesday.

High pressure will become centered over Northern Illinois Tue ngt,
which will setup for a cool overnight as Td`s will be in the upper
40s to lower 50s. Expect temps prior to daybreak Wed to be around 50-
54, but could see a few areas further radiate into the upper 40s.
Then surface temps will begin to rebound Wed, as highs reach into
the mid/upr 70s. A lake breeze/onshore flow may keep areas adjacent
to Lake Michigan in the upper 60s/around 70.

Thursday through Sunday: Ensembles continue to demonstrate minimal
spread in the high amplitude ridge building across Western
CONUS/Canada mid-week, then beginning to spill east towards Manitoba
Fri/Sat. This will mainly keep the Upper Midwest/Great Lakes region
in a quasi-northwest flow through the current extended periods. Then
heading towards the last periods into early the following week, the
ridging slides east across the Upper Midwest/Great Lakes.

Broad surface ridging will remain through Thur morning, then a
frontal boundary is progged to bring a chance for
showers/thunderstorms late Thursday/Friday. With another dry stretch
to start the weekend, before temps begin to warm for the second half
of the weekend into early next week to the 80s. The heat and
humidity returns for early next week.

Beachler

&&

.AVIATION...
For the 18Z TAFs...

Main forecast concerns/challenges this TAF period are with a wind
shift to the northeast at/above 10 KT this evening, and then with
MVFR ceilings tonight.

VFR conditions ongoing across the terminals early this afternoon,
with these conditions expected to persist through this afternoon
and evening. Upstream front dropping down the lake this afternoon
will allow for an increase in cloud cover tonight as well as a
wind shift, but any precip to stay to the north and northeast. Did
push up arrival of north/northeast winds with a wind shift to the
northeast this evening ahead of the front, and then increased
speeds later in the night with the arrival of the front.
Confidence is higher with this wind shift but lower with the exact
timing as some guidance is indicating an earlier northeast wind
shift, as early as 22-23z for areas near the lake. Feel that the
current stronger westerly winds should hold this shift until later
in the evening when the winds diminish. However, will continue to
monitor what the winds at observation points in eastern Wisconsin
do over the next couple of hours to try and gain a better handle
on trends. Upstream MVFR ceilings will likely continue to move
down towards the terminals, and have maintained this in the TAFs.

Rodriguez

&&

.MARINE...
345 AM CDT

Another cold front will surge down the lake Monday night with
winds turning north and increasing to 15-25 kt. Occasional gusts
to 30 kt are possible over the southern half of the lake Tuesday
afternoon. A small craft advisory will likely be needed for late
Monday night through Tuesday night, but will hold off on hoisting
the advisory for now as there is still some question as to when
the stronger winds and higher waves will build over the south end
of the lake. High pressure will spread over the western Great
Laked Tuesday night allowing winds and waves to subside. High
pressure will remain over the region through mid week and then
shifts southeast Thursday. Winds will become southwest behind the
high. A cold front/low pressure trough combo will push down the
lake Thursday night with winds becoming north again behind it.
Another high will build over the lake Friday night into Saturday.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

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000
FXUS63 KLOT 271747
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1247 PM CDT MON JUN 27 2016

.UPDATE...
1035 AM CDT

No real big changes to going forecast for much of today, however,
did speed up the arrival of the next front later tonight. In the
near term, temps have quickly jumped up to the 80s this morning
under sunny skies, while drier air pushes across the CWA. This
drier air will allow for continued sunshine today while northwest
winds steadily increase into the afternoon. Lake influence will
likely allow for a more northerly direction over the lake out
ahead of this next front this afternoon, and while this front
easily slides down the lake, expect a north northeast wind to push
onshore by early this evening. Some guidance a little quicker with
this transition and can`t completely argue with this solution.
Will continue to monitor this possibility, and if it were to
occur, then flow off the lake could occur as soon as 22/23z. Then,
with persistent CAA tonight, a likely increase in speeds will
occur.

Rodriguez

&&

.SHORT TERM...
208 AM CDT

Through tonight...

Early this morning Td`s were in the lower to middle 60s, with a few
areas of Northwest Indiana lingering in the upper 60s. IR imagery
continues to show the channel of higher based clouds stretching
along and east of a Central Missouri/East Central Illinois/Southern
Lower Michigan line. Underneath this channel of clouds Td`s continue
to be higher, or around 70-73 degrees. The next frontal boundary,
that will shift winds to the Northwest and usher in much
drier/cooler air, remains well upstream of the Northern Illinois. So
prior to the arrival of this boundary, warm air aloft remains and
expect the lack of solar shielding will likely lead to another very
warm day with highs approaching 90 degrees across many portions of
Northern Illinois. Leading edge of high pressure will help to
providing increased mixing this afternoon, and should slowly push
Td`s down to the upper 50s. With the secondary boundary sliding
south across Lake Michigan/Wisconsin, clouds will be on the increase
this evening/overnight, but expect this to be confined to Northeast
Illinois/Northwest Indiana. But with winds turning North, surface
temps overnight will radiate into the upper 50s to lower 60s. With
winds turning Northerly, expect dangerous rip-currents to develop
late tonight through daybreak Tuesday from the building waves in the
surf zone of Lake Michigan.

Beachler

&&

.LONG TERM...
208 AM CDT

Tuesday through Sunday...

500mb trough axis will be overhead of the
Great Lakes tuesday, with broad surface ridging centered over the
Upper Midwest Tue, which will maintain a better pressure gradient
and higher winds for Lake Michigan Northern Illinois. In addition
much cooler air aloft will cover the Great Lakes region, with
surface temps struggling to warm beyond the low/mid 70s. With an
onshore component, areas adjacent to Lake Michigan may remain in
the 60s Tuesday.

High pressure will become centered over Northern Illinois Tue ngt,
which will setup for a cool overnight as Td`s will be in the upper
40s to lower 50s. Expect temps prior to daybreak Wed to be around 50-
54, but could see a few areas further radiate into the upper 40s.
Then surface temps will begin to rebound Wed, as highs reach into
the mid/upr 70s. A lake breeze/onshore flow may keep areas adjacent
to Lake Michigan in the upper 60s/around 70.

Thursday through Sunday: Ensembles continue to demonstrate minimal
spread in the high amplitude ridge building across Western
CONUS/Canada mid-week, then beginning to spill east towards Manitoba
Fri/Sat. This will mainly keep the Upper Midwest/Great Lakes region
in a quasi-northwest flow through the current extended periods. Then
heading towards the last periods into early the following week, the
ridging slides east across the Upper Midwest/Great Lakes.

Broad surface ridging will remain through Thur morning, then a
frontal boundary is progged to bring a chance for
showers/thunderstorms late Thursday/Friday. With another dry stretch
to start the weekend, before temps begin to warm for the second half
of the weekend into early next week to the 80s. The heat and
humidity returns for early next week.

Beachler

&&

.AVIATION...
For the 18Z TAFs...

Main forecast concerns/challenges this TAF period are with a wind
shift to the northeast at/above 10 KT this evening, and then with
MVFR ceilings tonight.

VFR conditions ongoing across the terminals early this afternoon,
with these conditions expected to persist through this afternoon
and evening. Upstream front dropping down the lake this afternoon
will allow for an increase in cloud cover tonight as well as a
wind shift, but any precip to stay to the north and northeast. Did
push up arrival of north/northeast winds with a wind shift to the
northeast this evening ahead of the front, and then increased
speeds later in the night with the arrival of the front.
Confidence is higher with this wind shift but lower with the exact
timing as some guidance is indicating an earlier northeast wind
shift, as early as 22-23z for areas near the lake. Feel that the
current stronger westerly winds should hold this shift until later
in the evening when the winds diminish. However, will continue to
monitor what the winds at observation points in eastern Wisconsin
do over the next couple of hours to try and gain a better handle
on trends. Upstream MVFR ceilings will likely continue to move
down towards the terminals, and have maintained this in the TAFs.

Rodriguez

&&

.MARINE...
345 AM CDT

Another cold front will surge down the lake Monday night with
winds turning north and increasing to 15-25 kt. Occasional gusts
to 30 kt are possible over the southern half of the lake Tuesday
afternoon. A small craft advisory will likely be needed for late
Monday night through Tuesday night, but will hold off on hoisting
the advisory for now as there is still some question as to when
the stronger winds and higher waves will build over the south end
of the lake. High pressure will spread over the western Great
Laked Tuesday night allowing winds and waves to subside. High
pressure will remain over the region through mid week and then
shifts southeast Thursday. Winds will become southwest behind the
high. A cold front/low pressure trough combo will push down the
lake Thursday night with winds becoming north again behind it.
Another high will build over the lake Friday night into Saturday.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KILX 271712
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1212 PM CDT MON JUN 27 2016

.UPDATE...
Issued at 1031 AM CDT Mon Jun 27 2016

No significant changes this morning in ongoing forecast.

Cold front on schedule moving into Illinois late this morning.
Substantially lower dew points should filter into the region in
its wake. However, current forecast in the lower 90s ahead of the
boundary still looks reasonable given 12z KILX sounding and latest
LAMP and NAM guidance.

&&

.SHORT TERM...(Today)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Any remaining chance of showers or thunderstorms should push south
of the central/SE Illinois forecast area by daybreak as a weak cold
front continues to push southward. Drier air behind the front is
resulting in mostly mid 60s dewpoints north of I-72 and this should
filter throughout the forecast area by afternoon. Early this
morning, however a few areas of fog are developing where
precipitation was prevalent and cloud cover is dissipating. These
include Schuyler county to around Springfield southward, as well as
from northern Moultrie county through Champaign and Danville. Have
added patchy fog to the forecast for this morning in these areas,
however don`t expect any dense fog to become prevalent as the
evening sounding shows a rather unfavorable moisture profile with
mixing ratio decreasing with height. Today`s high should range from
the upper 80s to around 90 along the I-74 corridor, to the low
90s to the south as the air mass hasn`t changed too dramatically
since yesterday, and more sunshine will take place. The more
noticeable difference will be less humidity resulting in heat
index peaking around the upper 80s to low 90s compared with
yesterday`s 95 to 100 degree values.

.LONG TERM...(Tonight through Sunday)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Secondary cold front will push through the forecast area this
evening, marking the start of an extended period of less humid
conditions which will last into the holiday weekend. As a broad
upper troughing pattern persists over the Midwest, periodic surges
of cooler air will drop southward out of Manitoba and Ontario. Low
temperatures by Wednesday morning are expected to be as cool as the
lower 50s over the northeast CWA, and while highs return to the
lower 80s by late week, humidity levels will be fairly comfortable
for this time of year.

High pressure will keep the region for a good part of the next
several days. The main period of concern will be from Thursday night
into the weekend. A strong shortwave will swing through the Great
Lakes, bringing a frontal boundary into the forecast area by early
Friday. The GFS is somewhat wetter with its solution, while the
ECMWF keeps most of the precipitation threat closer to the Great
Lakes. Currently thinking that shower/storms should be more
scattered and will limit PoP`s to about 35-40% at best. More of a
discrepancy sets up into the weekend, as the frontal boundary south
of us becomes parallel to the upper flow. Both extended models show
some fairly widespread showers Saturday and Saturday night along the
front, extending as far north as central Illinois. However, by this
point, high pressure over the Great Lakes will result in a fairly
persistent east/northeast flow of drier air, so will keep
measurable PoP`s south of I-70 for now, with slight chances north
to about I-72.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1211 PM CDT Mon Jun 27 2016

Cold front now over northern Illinois will push through the
terminals this afternoon and evening. some scattered cumulus may
occur along and near the front. A second cold front currently over
the Upper Mississippi Valley will be accompanied by a
reinforcement of low-level moisture off lake Michigan as north
winds gain an easterly component in its wake. may bring some MVFR
clouds to KCMI late tonight. Light winds associated with the
frontal passages should mix boundary-layer sufficiently to keep
vsbys from dropping tonight.

&&

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

$$

UPDATE...Barker
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Barker




000
FXUS63 KLOT 271548
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1048 AM CDT MON JUN 27 2016

.UPDATE...
1035 AM CDT

No real big changes to going forecast for much of today, however,
did speed up the arrival of the next front later tonight. In the
near term, temps have quickly jumped up to the 80s this morning
under sunny skies, while drier air pushes across the CWA. This
drier air will allow for continued sunshine today while northwest
winds steadily increase into the afternoon. Lake influence will
likely allow for a more northerly direction over the lake out
ahead of this next front this afternoon, and while this front
easily slides down the lake, expect a north northeast wind to push
onshore by early this evening. Some guidance a little quicker with
this transition and can`t completely argue with this solution.
Will continue to monitor this possibility, and if it were to
occur, then flow off the lake could occur as soon as 22/23z. Then,
with persistent CAA tonight, a likely increase in speeds will
occur.

Rodriguez

&&

.SHORT TERM...
208 AM CDT

Through tonight...

Early this morning Td`s were in the lower to middle 60s, with a few
areas of Northwest Indiana lingering in the upper 60s. IR imagery
continues to show the channel of higher based clouds stretching
along and east of a Central Missouri/East Central Illinois/Southern
Lower Michigan line. Underneath this channel of clouds Td`s continue
to be higher, or around 70-73 degrees. The next frontal boundary,
that will shift winds to the Northwest and usher in much
drier/cooler air, remains well upstream of the Northern Illinois. So
prior to the arrival of this boundary, warm air aloft remains and
expect the lack of solar shielding will likely lead to another very
warm day with highs approaching 90 degrees across many portions of
Northern Illinois. Leading edge of high pressure will help to
providing increased mixing this afternoon, and should slowly push
Td`s down to the upper 50s. With the secondary boundary sliding
south across Lake Michigan/Wisconsin, clouds will be on the increase
this evening/overnight, but expect this to be confined to Northeast
Illinois/Northwest Indiana. But with winds turning North, surface
temps overnight will radiate into the upper 50s to lower 60s. With
winds turning Northerly, expect dangerous rip-currents to develop
late tonight through daybreak Tuesday from the building waves in the
surf zone of Lake Michigan.

Beachler

&&

.LONG TERM...
208 AM CDT

Tuesday through Sunday...

500mb trough axis will be overhead of the
Great Lakes tuesday, with broad surface ridging centered over the
Upper Midwest Tue, which will maintain a better pressure gradient
and higher winds for Lake Michigan Northern Illinois. In addition
much cooler air aloft will cover the Great Lakes region, with
surface temps struggling to warm beyond the low/mid 70s. With an
onshore component, areas adjacent to Lake Michigan may remain in
the 60s Tuesday.

High pressure will become centered over Northern Illinois Tue ngt,
which will setup for a cool overnight as Td`s will be in the upper
40s to lower 50s. Expect temps prior to daybreak Wed to be around 50-
54, but could see a few areas further radiate into the upper 40s.
Then surface temps will begin to rebound Wed, as highs reach into
the mid/upr 70s. A lake breeze/onshore flow may keep areas adjacent
to Lake Michigan in the upper 60s/around 70.

Thursday through Sunday: Ensembles continue to demonstrate minimal
spread in the high amplitude ridge building across Western
CONUS/Canada mid-week, then beginning to spill east towards Manitoba
Fri/Sat. This will mainly keep the Upper Midwest/Great Lakes region
in a quasi-northwest flow through the current extended periods. Then
heading towards the last periods into early the following week, the
ridging slides east across the Upper Midwest/Great Lakes.

Broad surface ridging will remain through Thur morning, then a
frontal boundary is progged to bring a chance for
showers/thunderstorms late Thursday/Friday. With another dry stretch
to start the weekend, before temps begin to warm for the second half
of the weekend into early next week to the 80s. The heat and
humidity returns for early next week.

Beachler

&&

.AVIATION...
For the 12Z TAFs...

Only concern through this evening will be winds. Light west winds
will persist through the morning. However, winds will begin to
ramp up by late morning as ample sunshine allows for mixing of
stronger winds aloft down to the surface. Forecast soundings
would support gusts to around 20 kt or so but if the low levels
mix deeper...which is possible given mainly clear skies and drier
air, then higher gusts, to around 25 kt may develop during the
afternoon. A cold front pushing south through Wisconsin and down
Lake Michigan will turn winds to nly-nnwly during the evening
hours. As cooler air spills in behind the front, expect an mvfr
stratocu deck to spread inland during the early morning hours.

&&

.MARINE...
345 AM CDT

Another cold front will surge down the lake Monday night with
winds turning north and increasing to 15-25 kt. Occasional gusts
to 30 kt are possible over the southern half of the lake Tuesday
afternoon. A small craft advisory will likely be needed for late
Monday night through Tuesday night, but will hold off on hoisting
the advisory for now as there is still some question as to when
the stronger winds and higher waves will build over the south end
of the lake. High pressure will spread over the western Great
Laked Tuesday night allowing winds and waves to subside. High
pressure will remain over the region through mid week and then
shifts southeast Thursday. Winds will become southwest behind the
high. A cold front/low pressure trough combo will push down the
lake Thursday night with winds becoming north again behind it.
Another high will build over the lake Friday night into Saturday.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
     LMZ745...1 AM Tuesday TO 4 AM Wednesday.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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000
FXUS63 KILX 271532
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1032 AM CDT MON JUN 27 2016

.UPDATE...
Issued at 1031 AM CDT Mon Jun 27 2016

No significant changes this morning in ongoing forecast.

Cold front on schedule moving into Illinois late this morning.
Substantially lower dew points should filter into the region in
its wake. However, current forecast in the lower 90s ahead of the
boundary still looks reasonable given 12z KILX sounding and latest
LAMP and NAM guidance.

&&

.SHORT TERM...(Today)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Any remaining chance of showers or thunderstorms should push south
of the central/SE Illinois forecast area by daybreak as a weak cold
front continues to push southward. Drier air behind the front is
resulting in mostly mid 60s dewpoints north of I-72 and this should
filter throughout the forecast area by afternoon. Early this
morning, however a few areas of fog are developing where
precipitation was prevalent and cloud cover is dissipating. These
include Schuyler county to around Springfield southward, as well as
from northern Moultrie county through Champaign and Danville. Have
added patchy fog to the forecast for this morning in these areas,
however don`t expect any dense fog to become prevalent as the
evening sounding shows a rather unfavorable moisture profile with
mixing ratio decreasing with height. Today`s high should range from
the upper 80s to around 90 along the I-74 corridor, to the low
90s to the south as the air mass hasn`t changed too dramatically
since yesterday, and more sunshine will take place. The more
noticeable difference will be less humidity resulting in heat
index peaking around the upper 80s to low 90s compared with
yesterday`s 95 to 100 degree values.

.LONG TERM...(Tonight through Sunday)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Secondary cold front will push through the forecast area this
evening, marking the start of an extended period of less humid
conditions which will last into the holiday weekend. As a broad
upper troughing pattern persists over the Midwest, periodic surges
of cooler air will drop southward out of Manitoba and Ontario. Low
temperatures by Wednesday morning are expected to be as cool as the
lower 50s over the northeast CWA, and while highs return to the
lower 80s by late week, humidity levels will be fairly comfortable
for this time of year.

High pressure will keep the region for a good part of the next
several days. The main period of concern will be from Thursday night
into the weekend. A strong shortwave will swing through the Great
Lakes, bringing a frontal boundary into the forecast area by early
Friday. The GFS is somewhat wetter with its solution, while the
ECMWF keeps most of the precipitation threat closer to the Great
Lakes. Currently thinking that shower/storms should be more
scattered and will limit PoP`s to about 35-40% at best. More of a
discrepancy sets up into the weekend, as the frontal boundary south
of us becomes parallel to the upper flow. Both extended models show
some fairly widespread showers Saturday and Saturday night along the
front, extending as far north as central Illinois. However, by this
point, high pressure over the Great Lakes will result in a fairly
persistent east/northeast flow of drier air, so will keep
measurable PoP`s south of I-70 for now, with slight chances north
to about I-72.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 619 AM CDT Mon Jun 27 2016

Generally VFR conditions expected across the central Illinois
terminals through the 12Z TAF valid time. Patchy fog may continue
until around 13Z at KSPI and KCMI. Winds W-NNW 10 kts or less
through the period.


&&

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

$$

UPDATE...Barker
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton




000
FXUS63 KILX 271119
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
619 AM CDT MON JUN 27 2016

.SHORT TERM...(Today)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Any remaining chance of showers or thunderstorms should push south
of the central/SE Illinois forecast area by daybreak as a weak cold
front continues to push southward. Drier air behind the front is
resulting in mostly mid 60s dewpoints north of I-72 and this should
filter throughout the forecast area by afternoon. Early this
morning, however a few areas of fog are developing where
precipitation was prevalent and cloud cover is dissipating. These
include Schuyler county to around Springfield southward, as well as
from northern Moultrie county through Champaign and Danville. Have
added patchy fog to the forecast for this morning in these areas,
however don`t expect any dense fog to become prevalent as the
evening sounding shows a rather unfavorable moisture profile with
mixing ratio decreasing with height. Today`s high should range from
the upper 80s to around 90 along the I-74 corridor, to the low
90s to the south as the air mass hasn`t changed too dramatically
since yesterday, and more sunshine will take place. The more
noticeable difference will be less humidity resulting in heat
index peaking around the upper 80s to low 90s compared with
yesterday`s 95 to 100 degree values.

.LONG TERM...(Tonight through Sunday)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Secondary cold front will push through the forecast area this
evening, marking the start of an extended period of less humid
conditions which will last into the holiday weekend. As a broad
upper troughing pattern persists over the Midwest, periodic surges
of cooler air will drop southward out of Manitoba and Ontario. Low
temperatures by Wednesday morning are expected to be as cool as the
lower 50s over the northeast CWA, and while highs return to the
lower 80s by late week, humidity levels will be fairly comfortable
for this time of year.

High pressure will keep the region for a good part of the next
several days. The main period of concern will be from Thursday night
into the weekend. A strong shortwave will swing through the Great
Lakes, bringing a frontal boundary into the forecast area by early
Friday. The GFS is somewhat wetter with its solution, while the
ECMWF keeps most of the precipitation threat closer to the Great
Lakes. Currently thinking that shower/storms should be more
scattered and will limit PoP`s to about 35-40% at best. More of a
discrepancy sets up into the weekend, as the frontal boundary south
of us becomes parallel to the upper flow. Both extended models show
some fairly widespread showers Saturday and Saturday night along the
front, extending as far north as central Illinois. However, by this
point, high pressure over the Great Lakes will result in a fairly
persistent east/northeast flow of drier air, so will keep
measurable PoP`s south of I-70 for now, with slight chances north
to about I-72.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 619 AM CDT Mon Jun 27 2016

Generally VFR conditions expected across the central Illinois
terminals through the 12Z TAF valid time. Patchy fog may continue
until around 13Z at KSPI and KCMI. Winds W-NNW 10 kts or less
through the period.

&&

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

&&

$$

SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton




000
FXUS63 KILX 271119
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
619 AM CDT MON JUN 27 2016

.SHORT TERM...(Today)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Any remaining chance of showers or thunderstorms should push south
of the central/SE Illinois forecast area by daybreak as a weak cold
front continues to push southward. Drier air behind the front is
resulting in mostly mid 60s dewpoints north of I-72 and this should
filter throughout the forecast area by afternoon. Early this
morning, however a few areas of fog are developing where
precipitation was prevalent and cloud cover is dissipating. These
include Schuyler county to around Springfield southward, as well as
from northern Moultrie county through Champaign and Danville. Have
added patchy fog to the forecast for this morning in these areas,
however don`t expect any dense fog to become prevalent as the
evening sounding shows a rather unfavorable moisture profile with
mixing ratio decreasing with height. Today`s high should range from
the upper 80s to around 90 along the I-74 corridor, to the low
90s to the south as the air mass hasn`t changed too dramatically
since yesterday, and more sunshine will take place. The more
noticeable difference will be less humidity resulting in heat
index peaking around the upper 80s to low 90s compared with
yesterday`s 95 to 100 degree values.

.LONG TERM...(Tonight through Sunday)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Secondary cold front will push through the forecast area this
evening, marking the start of an extended period of less humid
conditions which will last into the holiday weekend. As a broad
upper troughing pattern persists over the Midwest, periodic surges
of cooler air will drop southward out of Manitoba and Ontario. Low
temperatures by Wednesday morning are expected to be as cool as the
lower 50s over the northeast CWA, and while highs return to the
lower 80s by late week, humidity levels will be fairly comfortable
for this time of year.

High pressure will keep the region for a good part of the next
several days. The main period of concern will be from Thursday night
into the weekend. A strong shortwave will swing through the Great
Lakes, bringing a frontal boundary into the forecast area by early
Friday. The GFS is somewhat wetter with its solution, while the
ECMWF keeps most of the precipitation threat closer to the Great
Lakes. Currently thinking that shower/storms should be more
scattered and will limit PoP`s to about 35-40% at best. More of a
discrepancy sets up into the weekend, as the frontal boundary south
of us becomes parallel to the upper flow. Both extended models show
some fairly widespread showers Saturday and Saturday night along the
front, extending as far north as central Illinois. However, by this
point, high pressure over the Great Lakes will result in a fairly
persistent east/northeast flow of drier air, so will keep
measurable PoP`s south of I-70 for now, with slight chances north
to about I-72.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 619 AM CDT Mon Jun 27 2016

Generally VFR conditions expected across the central Illinois
terminals through the 12Z TAF valid time. Patchy fog may continue
until around 13Z at KSPI and KCMI. Winds W-NNW 10 kts or less
through the period.

&&

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

&&

$$

SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Onton




000
FXUS63 KLOT 271112
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
612 AM CDT MON JUN 27 2016

.SHORT TERM...
208 AM CDT

Through tonight...

Early this morning Td`s were in the lower to middle 60s, with a few
areas of Northwest Indiana lingering in the upper 60s. IR imagery
continues to show the channel of higher based clouds stretching
along and east of a Central Missouri/East Central Illinois/Southern
Lower Michigan line. Underneath this channel of clouds Td`s continue
to be higher, or around 70-73 degrees. The next frontal boundary,
that will shift winds to the Northwest and usher in much
drier/cooler air, remains well upstream of the Northern Illinois. So
prior to the arrival of this boundary, warm air aloft remains and
expect the lack of solar shielding will likely lead to another very
warm day with highs approaching 90 degrees across many portions of
Northern Illinois. Leading edge of high pressure will help to
providing increased mixing this afternoon, and should slowly push
Td`s down to the upper 50s. With the secondary boundary sliding
south across Lake Michigan/Wisconsin, clouds will be on the increase
this evening/overnight, but expect this to be confined to Northeast
Illinois/Northwest Indiana. But with winds turning North, surface
temps overnight will radiate into the upper 50s to lower 60s. With
winds turning Northerly, expect dangerous rip-currents to develop
late tonight through daybreak Tuesday from the building waves in the
surf zone of Lake Michigan.

Beachler

&&

.LONG TERM...
208 AM CDT

Tuesday through Sunday...

500mb trough axis will be overhead of the
Great Lakes tuesday, with broad surface ridging centered over the
Upper Midwest Tue, which will maintain a better pressure gradient
and higher winds for Lake Michigan Northern Illinois. In addition
much cooler air aloft will cover the Great Lakes region, with
surface temps struggling to warm beyond the low/mid 70s. With an
onshore component, areas adjacent to Lake Michigan may remain in
the 60s Tuesday.

High pressure will become centered over Northern Illinois Tue ngt,
which will setup for a cool overnight as Td`s will be in the upper
40s to lower 50s. Expect temps prior to daybreak Wed to be around 50-
54, but could see a few areas further radiate into the upper 40s.
Then surface temps will begin to rebound Wed, as highs reach into
the mid/upr 70s. A lake breeze/onshore flow may keep areas adjacent
to Lake Michigan in the upper 60s/around 70.

Thursday through Sunday: Ensembles continue to demonstrate minimal
spread in the high amplitude ridge building across Western
CONUS/Canada mid-week, then beginning to spill east towards Manitoba
Fri/Sat. This will mainly keep the Upper Midwest/Great Lakes region
in a quasi-northwest flow through the current extended periods. Then
heading towards the last periods into early the following week, the
ridging slides east across the Upper Midwest/Great Lakes.

Broad surface ridging will remain through Thur morning, then a
frontal boundary is progged to bring a chance for
showers/thunderstorms late Thursday/Friday. With another dry stretch
to start the weekend, before temps begin to warm for the second half
of the weekend into early next week to the 80s. The heat and
humidity returns for early next week.

Beachler

&&

.AVIATION...
For the 12Z TAFs...

Only concern through this evening will be winds. Light west winds
will persist through the morning. However, winds will begin to
ramp up by late morning as ample sunshine allows for mixing of
stronger winds aloft down to the surface. Forecast soundings
would support gusts to around 20 kt or so but if the low levels
mix deeper...which is possible given mainly clear skies and drier
air, then higher gusts, to around 25 kt may develop during the
afternoon. A cold front pushing south through Wisconsin and down
Lake Michigan will turn winds to nly-nnwly during the evening
hours. As cooler air spills in behind the front, expect an mvfr
stratocu deck to spread inland during the early morning hours.

&&

.MARINE...
345 AM CDT

Another cold front will surge down the lake Monday night with
winds turning north and increasing to 15-25 kt. Occasional gusts
to 30 kt are possible over the southern half of the lake Tuesday
afternoon. A small craft advisory will likely be needed for late
Monday night through Tuesday night, but will hold off on hoisting
the advisory for now as there is still some question as to when
the stronger winds and higher waves will build over the south end
of the lake. High pressure will spread over the western Great
Laked Tuesday night allowing winds and waves to subside. High
pressure will remain over the region through mid week and then
shifts southeast Thursday. Winds will become southwest behind the
high. A cold front/low pressure trough combo will push down the
lake Thursday night with winds becoming north again behind it.
Another high will build over the lake Friday night into Saturday.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 270844
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
344 AM CDT MON JUN 27 2016

.SHORT TERM...
208 AM CDT

Through tonight...

Early this morning Td`s were in the lower to middle 60s, with a few
areas of Northwest Indiana lingering in the upper 60s. IR imagery
continues to show the channel of higher based clouds stretching
along and east of a Central Missouri/East Central Illinois/Southern
Lower Michigan line. Underneath this channel of clouds Td`s continue
to be higher, or around 70-73 degrees. The next frontal boundary,
that will shift winds to the Northwest and usher in much
drier/cooler air, remains well upstream of the Northern Illinois. So
prior to the arrival of this boundary, warm air aloft remains and
expect the lack of solar shielding will likely lead to another very
warm day with highs approaching 90 degrees across many portions of
Northern Illinois. Leading edge of high pressure will help to
providing increased mixing this afternoon, and should slowly push
Td`s down to the upper 50s. With the secondary boundary sliding
south across Lake Michigan/Wisconsin, clouds will be on the increase
this evening/overnight, but expect this to be confined to Northeast
Illinois/Northwest Indiana. But with winds turning North, surface
temps overnight will radiate into the upper 50s to lower 60s. With
winds turning Northerly, expect dangerous rip-currents to develop
late tonight through daybreak Tuesday from the building waves in the
surf zone of Lake Michigan.

Beachler

&&

.LONG TERM...
208 AM CDT

Tuesday through Sunday...

500mb trough axis will be overhead of the
Great Lakes tuesday, with broad surface ridging centered over the
Upper Midwest Tue, which will maintain a better pressure gradient
and higher winds for Lake Michigan Northern Illinois. In addition
much cooler air aloft will cover the Great Lakes region, with
surface temps struggling to warm beyond the low/mid 70s. With an
onshore component, areas adjacent to Lake Michigan may remain in
the 60s Tuesday.

High pressure will become centered over Northern Illinois Tue ngt,
which will setup for a cool overnight as Td`s will be in the upper
40s to lower 50s. Expect temps prior to daybreak Wed to be around 50-
54, but could see a few areas further radiate into the upper 40s.
Then surface temps will begin to rebound Wed, as highs reach into
the mid/upr 70s. A lake breeze/onshore flow may keep areas adjacent
to Lake Michigan in the upper 60s/around 70.

Thursday through Sunday: Ensembles continue to demonstrate minimal
spread in the high amplitude ridge building across Western
CONUS/Canada mid-week, then beginning to spill east towards Manitoba
Fri/Sat. This will mainly keep the Upper Midwest/Great Lakes region
in a quasi-northwest flow through the current extended periods. Then
heading towards the last periods into early the following week, the
ridging slides east across the Upper Midwest/Great Lakes.

Broad surface ridging will remain through Thur morning, then a
frontal boundary is progged to bring a chance for
showers/thunderstorms late Thursday/Friday. With another dry stretch
to start the weekend, before temps begin to warm for the second half
of the weekend into early next week to the 80s. The heat and
humidity returns for early next week.

Beachler

&&

.AVIATION...
For the 06Z TAFs...

Only concern this period will be winds. Light west winds will
persist through the night. However, during the morning hours,
winds will begin to ramp up as a secondary cold front pushes south
through wisconsin and down Lake Michigan. Modest cold advection
and ample sunshine will allow stronger winds aloft to mix down to
the surface. Forecast soundings would support gusts to around
20 kt or so but if the low levels mix deeper...which is possible
given mainly clear skies and drier air, then higher gusts, to
around 25 kt may develop during the afternoon. Winds will turn
more to the north/northwest during the evening hours as high
pressure builds out of the northern plains and across the Upper
Mississippi Valley.

&&

.MARINE...
345 AM CDT

Another cold front will surge down the lake Monday night with
winds turning north and increasing to 15-25 kt. Occasional gusts
to 30 kt are possible over the southern half of the lake Tuesday
afternoon. A small craft advisory will likely be needed for late
Monday night through Tuesday night, but will hold off on hoisting
the advisory for now as there is still some question as to when
the stronger winds and higher waves will build over the south end
of the lake. High pressure will spread over the western Great
Laked Tuesday night allowing winds and waves to subside. High
pressure will remain over the region through mid week and then
shifts southeast Thursday. Winds will become southwest behind the
high. A cold front/low pressure trough combo will push down the
lake Thursday night with winds becoming north again behind it.
Another high will build over the lake Friday night into Saturday.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KILX 270829
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
329 AM CDT MON JUN 27 2016

.SHORT TERM...(Today)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Any remaining chance of showers or thunderstorms should push south
of the central/SE Illinois forecast area by daybreak as a weak cold
front continues to push southward. Drier air behind the front is
resulting in mostly mid 60s dewpoints north of I-72 and this should
filter throughout the forecast area by afternoon. Early this
morning, however a few areas of fog are developing where
precipitation was prevalent and cloud cover is dissipating. These
include Schuyler county to around Springfield southward, as well as
from northern Moultrie county through Champaign and Danville. Have
added patchy fog to the forecast for this morning in these areas,
however don`t expect any dense fog to become prevalent as the
evening sounding shows a rather unfavorable moisture profile with
mixing ratio decreasing with height. Today`s high should range from
the upper 80s to around 90 along the I-74 corridor, to the low
90s to the south as the air mass hasn`t changed too dramatically
since yesterday, and more sunshine will take place. The more
noticeable difference will be less humidity resulting in heat
index peaking around the upper 80s to low 90s compared with
yesterday`s 95 to 100 degree values.

&&

.LONG TERM...(Tonight through Sunday)
ISSUED AT 328 AM CDT Mon Jun 27 2016

Secondary cold front will push through the forecast area this
evening, marking the start of an extended period of less humid
conditions which will last into the holiday weekend. As a broad
upper troughing pattern persists over the Midwest, periodic surges
of cooler air will drop southward out of Manitoba and Ontario. Low
temperatures by Wednesday morning are expected to be as cool as the
lower 50s over the northeast CWA, and while highs return to the
lower 80s by late week, humidity levels will be fairly comfortable
for this time of year.

High pressure will keep the region for a good part of the next
several days. The main period of concern will be from Thursday night
into the weekend. A strong shortwave will swing through the Great
Lakes, bringing a frontal boundary into the forecast area by early
Friday. The GFS is somewhat wetter with its solution, while the
ECMWF keeps most of the precipitation threat closer to the Great
Lakes. Currently thinking that shower/storms should be more
scattered and will limit PoP`s to about 35-40% at best. More of a
discrepancy sets up into the weekend, as the frontal boundary south
of us becomes parallel to the upper flow. Both extended models show
some fairly widespread showers Saturday and Saturday night along the
front, extending as far north as central Illinois. However, by this
point, high pressure over the Great Lakes will result in a fairly
persistent east/northeast flow of drier air, so will keep
measurable PoP`s south of I-70 for now, with slight chances north
to about I-72.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1154 PM CDT Sun Jun 26 2016

Generally quiet/VFR aviation weather conditions expected across
the central Illinois terminals through the 06Z TAF valid time.
However patchy fog can`t be ruled over the next several hours.
Expect winds to be AOB 10 kts through the period.


&&

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

$$

SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Bak




000
FXUS63 KLOT 270709
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
209 AM CDT MON JUN 27 2016

.SHORT TERM...
208 AM CDT

Through tonight...

Early this morning Td`s were in the lower to middle 60s, with a few
areas of Northwest Indiana lingering in the upper 60s. IR imagery
continues to show the channel of higher based clouds stretching
along and east of a Central Missouri/East Central Illinois/Southern
Lower Michigan line. Underneath this channel of clouds Td`s continue
to be higher, or around 70-73 degrees. The next frontal boundary,
that will shift winds to the Northwest and usher in much
drier/cooler air, remains well upstream of the Northern Illinois. So
prior to the arrival of this boundary, warm air aloft remains and
expect the lack of solar shielding will likely lead to another very
warm day with highs approaching 90 degrees across many portions of
Northern Illinois. Leading edge of high pressure will help to
providing increased mixing this afternoon, and should slowly push
Td`s down to the upper 50s. With the secondary boundary sliding
south across Lake Michigan/Wisconsin, clouds will be on the increase
this evening/overnight, but expect this to be confined to Northeast
Illinois/Northwest Indiana. But with winds turning North, surface
temps overnight will radiate into the upper 50s to lower 60s. With
winds turning Northerly, expect dangerous rip-currents to develop
late tonight through daybreak Tuesday from the building waves in the
surf zone of Lake Michigan.

Beachler

&&

.LONG TERM...
208 AM CDT

Tuesday through Sunday...

500mb trough axis will be overhead of the
Great Lakes tuesday, with broad surface ridging centered over the
Upper Midwest Tue, which will maintain a better pressure gradient
and higher winds for Lake Michigan Northern Illinois. In addition
much cooler air aloft will cover the Great Lakes region, with
surface temps struggling to warm beyond the low/mid 70s. With an
onshore component, areas adjacent to Lake Michigan may remain in
the 60s Tuesday.

High pressure will become centered over Northern Illinois Tue ngt,
which will setup for a cool overnight as Td`s will be in the upper
40s to lower 50s. Expect temps prior to daybreak Wed to be around 50-
54, but could see a few areas further radiate into the upper 40s.
Then surface temps will begin to rebound Wed, as highs reach into
the mid/upr 70s. A lake breeze/onshore flow may keep areas adjacent
to Lake Michigan in the upper 60s/around 70.

Thursday through Sunday: Ensembles continue to demonstrate minimal
spread in the high amplitude ridge building across Western
CONUS/Canada mid-week, then beginning to spill east towards Manitoba
Fri/Sat. This will mainly keep the Upper Midwest/Great Lakes region
in a quasi-northwest flow through the current extended periods. Then
heading towards the last periods into early the following week, the
ridging slides east across the Upper Midwest/Great Lakes.

Broad surface ridging will remain through Thur morning, then a
frontal boundary is progged to bring a chance for
showers/thunderstorms late Thursday/Friday. With another dry stretch
to start the weekend, before temps begin to warm for the second half
of the weekend into early next week to the 80s. The heat and
humidity returns for early next week.

Beachler

&&

.AVIATION...
For the 06Z TAFs...

Only concern this period will be winds. Light west winds will
persist through the night. However, during the morning hours,
winds will begin to ramp up as a secondary cold front pushes south
through wisconsin and down Lake Michigan. Modest cold advection
and ample sunshine will allow stronger winds aloft to mix down to
the surface. Forecast soundings would support gusts to around
20 kt or so but if the low levels mix deeper...which is possible
given mainly clear skies and drier air, then higher gusts, to
around 25 kt may develop during the afternoon. Winds will turn
more to the north/northwest during the evening hours as high
pressure builds out of the northern plains and across the Upper
Mississippi Valley.

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KLOT 270539
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1239 AM CDT MON JUN 27 2016

.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
233 PM CDT

Monday night through Sunday...

The extended is much cooler thanks to another cold front that surges
down the lake Monday night. Not expecting any precip as the front
sinks south, but clouds will spread south of the lake over much if
not all of the warning area Monday. That combined with 925mb temps
of +11C to +16C will result in high temps in the 70s. Winds will be
off of the lake, so lake side temps will be in the upper 60s to
around 70.  The gusty north winds may create waves that will
increase the risk for rip currents, especially at the NW IN beaches.
Will not be issuing a beach hazards statement yet, but one may be
needed.

High pressure hangs around the region Tuesday afternoon through
Thursday, and then it will start to shift southeast Thursday
afternoon toward the Appalachians.  The high will bring sunny skies
and dry conditions, but the cooler upper level air will hang around
too.  Onshore flow will result in highs around 70 along the lake
again with highs in the mid to upper 70s elsewhere.  Thursday will
be a bit warmer with highs around 80 across the CWA.

An upper level trough axis rotates through the midwest along with a
cold front. Showers and storms are possible along the front Thursday
night into Friday morning.  Another surface high follows the cold
front and winds become northeast Friday. Highs will remain on the
cool side with highs in the mid 70s to around 80 away from the lake.
Thinking the high will keep any additional convection to our south
and west leading to a dry rest of the week. High temperatures will
also remain on the cool side for this time of year.

JEE

&&

.AVIATION...
For the 06Z TAFs...

Only concern this period will be winds. Light west winds will
persist through the night. However, during the morning hours,
winds will begin to ramp up as a secondary cold front pushes south
through wisconsin and down Lake Michigan. Modest cold advection
and ample sunshine will allow stronger winds aloft to mix down to
the surface. Forecast soundings would support gusts to around
20 kt or so but if the low levels mix deeper...which is possible
given mainly clear skies and drier air, then higher gusts, to
around 25 kt may develop during the afternoon. Winds will turn
more to the north/northwest during the evening hours as high
pressure builds out of the northern plains and across the Upper
Mississippi Valley.

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KLOT 270539
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1239 AM CDT MON JUN 27 2016

.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
233 PM CDT

Monday night through Sunday...

The extended is much cooler thanks to another cold front that surges
down the lake Monday night. Not expecting any precip as the front
sinks south, but clouds will spread south of the lake over much if
not all of the warning area Monday. That combined with 925mb temps
of +11C to +16C will result in high temps in the 70s. Winds will be
off of the lake, so lake side temps will be in the upper 60s to
around 70.  The gusty north winds may create waves that will
increase the risk for rip currents, especially at the NW IN beaches.
Will not be issuing a beach hazards statement yet, but one may be
needed.

High pressure hangs around the region Tuesday afternoon through
Thursday, and then it will start to shift southeast Thursday
afternoon toward the Appalachians.  The high will bring sunny skies
and dry conditions, but the cooler upper level air will hang around
too.  Onshore flow will result in highs around 70 along the lake
again with highs in the mid to upper 70s elsewhere.  Thursday will
be a bit warmer with highs around 80 across the CWA.

An upper level trough axis rotates through the midwest along with a
cold front. Showers and storms are possible along the front Thursday
night into Friday morning.  Another surface high follows the cold
front and winds become northeast Friday. Highs will remain on the
cool side with highs in the mid 70s to around 80 away from the lake.
Thinking the high will keep any additional convection to our south
and west leading to a dry rest of the week. High temperatures will
also remain on the cool side for this time of year.

JEE

&&

.AVIATION...
For the 06Z TAFs...

Only concern this period will be winds. Light west winds will
persist through the night. However, during the morning hours,
winds will begin to ramp up as a secondary cold front pushes south
through wisconsin and down Lake Michigan. Modest cold advection
and ample sunshine will allow stronger winds aloft to mix down to
the surface. Forecast soundings would support gusts to around
20 kt or so but if the low levels mix deeper...which is possible
given mainly clear skies and drier air, then higher gusts, to
around 25 kt may develop during the afternoon. Winds will turn
more to the north/northwest during the evening hours as high
pressure builds out of the northern plains and across the Upper
Mississippi Valley.

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KILX 270458
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1158 PM CDT SUN JUN 26 2016

.UPDATE...
Issued at 847 PM CDT Sun Jun 26 2016

While it is somewhat difficult to tell due to convectively
influenced and/or very week winds, a weak cold front appears to
lie across the forecast area between the I-72 & I-70 corridors. A
pre-frontal trof/outflow boundary has just about exited the
forecast area to the south and east. The precipitation threat has
largely ended across most of the forecast area for the rest of the
night, and will end across southeast Illinois shortly.

Current forecast is in pretty good shape. Have already updated
PoPs for earlier trends, and another tweak will be needed shortly.
Otherwise, other weather parameters only need minor tweaks for hourly
trends.

&&

.SHORT TERM...(Tonight)
ISSUED AT 300 PM CDT Sun Jun 26 2016

19z/2pm surface analysis shows cold front slowly dropping southward
toward the I-72 corridor.  Widely scattered thunderstorms have begun
to form along the boundary within the past hour and additional
development is expected for the remainder of the afternoon.  Due to
weak convergence along the front, a lack of upper-level support, and
0-6km bulk shear values of 20kt or less, think areal coverage of
storms will remain scattered in nature.  HRRR continues to develop
convection too robustly with each of its 1-hour forecasts, but it
does show the general trend of storms slowly sinking southward over
the next several hours.  Based on southward progress of front, have
gone with a dry forecast along and north of a Rantoul...to
Lincoln...to Jacksonville line by 00z/7pm.  Further south, have
continued high chance PoPs through the evening, with PoPs lingering
into the overnight hours south of I-70.  Any storms that occur late
this afternoon and evening will be slow-moving and capable of
producing localized downpours.  In addition, dry layer below 850mb
seen on LAPS soundings suggests the potential for gusty downburst
winds.

.LONG TERM...(Monday through Sunday)
ISSUED AT 300 PM CDT Sun Jun 26 2016

The cold front should be along or just south of I-70 Monday morning
with any lingering threat for showers/storms exiting our southern
counties during the morning. Somewhat drier air will slowly filter
south into our area during the day but temperatures will not show
much affect from the first cold front as afternoon temperatures
rise to around 90 far north to the lower 90s central and south. A
second cold front is slated to push south into our area later
Monday afternoon and evening but with the deeper moisture shunted
just south of our area from the first frontal boundary, will
continue to keep it dry tomorrow into tomorrow evening. A nice
refreshingly cool air mass will spill south following the second
cold front Monday night and by Tuesday we should see afternoon
temperatures range from the mid to upper 70s northeast while low
to mid 80s are expected over our far southern counties Tuesday
afternoon with most areas seeing dew points only in the mid to
upper 50s.

The upper pattern for the remainder of the week will feature a trof
over the eastern Great Lakes while upper level ridging dominates
across the western U.S. This should keep the weather on the quiet
side through most of Thursday before a secondary shortwave rotates
southeast around the eastern Great Lakes trof and brings shower and
thunderstorm chances into parts of our area. Models not showing much
agreement with respect to timing of the shortwave and any MCS
activity that translates southeast out of the Plains affecting parts
of west central through southern Illinois Thursday night into Friday
with another MCS forecast to develop along the trailing cold front
later Friday night into Saturday, affecting mainly southern
Illinois at this time. Temperatures this period are still
expected to average below normal but once we cool down into the
70s over parts of our area on Tuesday, most of the remainder of
the period we will see afternoon temperatures warm back close to
where they should be for late June/early July with afternoon
temperatures warming back into the 80 to 85 degree range starting
on Wednesday and continuing into the holiday weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1154 PM CDT Sun Jun 26 2016

Generally quiet/VFR aviation weather conditions expected across
the central Illinois terminals through the 06Z TAF valid time.
However patchy fog can`t be ruled over the next several hours.
Expect winds to be AOB 10 kts through the period.

&&

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

$$

UPDATE...Bak
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KILX 270154
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
854 PM CDT SUN JUN 26 2016

.UPDATE...
Issued at 847 PM CDT Sun Jun 26 2016

While it is somewhat difficult to tell due to convectively
influenced and/or very week winds, a weak cold front appears to
lie across the forecast area between the I-72 & I-70 corridors. A
pre-frontal trof/outflow boundary has just about exited the
forecast area to the south and east. The precipitation threat has
largely ended across most of the forecast area for the rest of the
night, and will end across southeast Illinois shortly.

Current forecast is in pretty good shape. Have already updated
PoPs for earlier trends, and another tweak will be needed shortly.
Otherwise, other weather parameters only need minor tweaks for hourly
trends.

&&

.SHORT TERM...(Tonight)
ISSUED AT 300 PM CDT Sun Jun 26 2016

19z/2pm surface analysis shows cold front slowly dropping southward
toward the I-72 corridor.  Widely scattered thunderstorms have begun
to form along the boundary within the past hour and additional
development is expected for the remainder of the afternoon.  Due to
weak convergence along the front, a lack of upper-level support, and
0-6km bulk shear values of 20kt or less, think areal coverage of
storms will remain scattered in nature.  HRRR continues to develop
convection too robustly with each of its 1-hour forecasts, but it
does show the general trend of storms slowly sinking southward over
the next several hours.  Based on southward progress of front, have
gone with a dry forecast along and north of a Rantoul...to
Lincoln...to Jacksonville line by 00z/7pm.  Further south, have
continued high chance PoPs through the evening, with PoPs lingering
into the overnight hours south of I-70.  Any storms that occur late
this afternoon and evening will be slow-moving and capable of
producing localized downpours.  In addition, dry layer below 850mb
seen on LAPS soundings suggests the potential for gusty downburst
winds.

.LONG TERM...(Monday through Sunday)
ISSUED AT 300 PM CDT Sun Jun 26 2016

The cold front should be along or just south of I-70 Monday morning
with any lingering threat for showers/storms exiting our southern
counties during the morning. Somewhat drier air will slowly filter
south into our area during the day but temperatures will not show
much affect from the first cold front as afternoon temperatures
rise to around 90 far north to the lower 90s central and south. A
second cold front is slated to push south into our area later
Monday afternoon and evening but with the deeper moisture shunted
just south of our area from the first frontal boundary, will
continue to keep it dry tomorrow into tomorrow evening. A nice
refreshingly cool air mass will spill south following the second
cold front Monday night and by Tuesday we should see afternoon
temperatures range from the mid to upper 70s northeast while low
to mid 80s are expected over our far southern counties Tuesday
afternoon with most areas seeing dew points only in the mid to
upper 50s.

The upper pattern for the remainder of the week will feature a trof
over the eastern Great Lakes while upper level ridging dominates
across the western U.S. This should keep the weather on the quiet
side through most of Thursday before a secondary shortwave rotates
southeast around the eastern Great Lakes trof and brings shower and
thunderstorm chances into parts of our area. Models not showing much
agreement with respect to timing of the shortwave and any MCS
activity that translates southeast out of the Plains affecting parts
of west central through southern Illinois Thursday night into Friday
with another MCS forecast to develop along the trailing cold front
later Friday night into Saturday, affecting mainly southern
Illinois at this time. Temperatures this period are still
expected to average below normal but once we cool down into the
70s over parts of our area on Tuesday, most of the remainder of
the period we will see afternoon temperatures warm back close to
where they should be for late June/early July with afternoon
temperatures warming back into the 80 to 85 degree range starting
on Wednesday and continuing into the holiday weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 639 PM CDT Sun Jun 26 2016

Mainly quiet/VFR aviation weather conditions expected across the
central Illinois terminals through the 00Z TAF valid time. A weak
cold front crossed the area within the past few hours, taking the
bulk of the shower/thunderstorm threat with it. However, a few
post frontal showers are possible over the next few hours across
KSPI, KDEC, and KCMI. Once the shower risk departs clouds should
gradually depart, with winds staying AOB 10 kts.


&&

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

$$

UPDATE...Bak
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KILX 270154
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
854 PM CDT SUN JUN 26 2016

.UPDATE...
Issued at 847 PM CDT Sun Jun 26 2016

While it is somewhat difficult to tell due to convectively
influenced and/or very week winds, a weak cold front appears to
lie across the forecast area between the I-72 & I-70 corridors. A
pre-frontal trof/outflow boundary has just about exited the
forecast area to the south and east. The precipitation threat has
largely ended across most of the forecast area for the rest of the
night, and will end across southeast Illinois shortly.

Current forecast is in pretty good shape. Have already updated
PoPs for earlier trends, and another tweak will be needed shortly.
Otherwise, other weather parameters only need minor tweaks for hourly
trends.

&&

.SHORT TERM...(Tonight)
ISSUED AT 300 PM CDT Sun Jun 26 2016

19z/2pm surface analysis shows cold front slowly dropping southward
toward the I-72 corridor.  Widely scattered thunderstorms have begun
to form along the boundary within the past hour and additional
development is expected for the remainder of the afternoon.  Due to
weak convergence along the front, a lack of upper-level support, and
0-6km bulk shear values of 20kt or less, think areal coverage of
storms will remain scattered in nature.  HRRR continues to develop
convection too robustly with each of its 1-hour forecasts, but it
does show the general trend of storms slowly sinking southward over
the next several hours.  Based on southward progress of front, have
gone with a dry forecast along and north of a Rantoul...to
Lincoln...to Jacksonville line by 00z/7pm.  Further south, have
continued high chance PoPs through the evening, with PoPs lingering
into the overnight hours south of I-70.  Any storms that occur late
this afternoon and evening will be slow-moving and capable of
producing localized downpours.  In addition, dry layer below 850mb
seen on LAPS soundings suggests the potential for gusty downburst
winds.

.LONG TERM...(Monday through Sunday)
ISSUED AT 300 PM CDT Sun Jun 26 2016

The cold front should be along or just south of I-70 Monday morning
with any lingering threat for showers/storms exiting our southern
counties during the morning. Somewhat drier air will slowly filter
south into our area during the day but temperatures will not show
much affect from the first cold front as afternoon temperatures
rise to around 90 far north to the lower 90s central and south. A
second cold front is slated to push south into our area later
Monday afternoon and evening but with the deeper moisture shunted
just south of our area from the first frontal boundary, will
continue to keep it dry tomorrow into tomorrow evening. A nice
refreshingly cool air mass will spill south following the second
cold front Monday night and by Tuesday we should see afternoon
temperatures range from the mid to upper 70s northeast while low
to mid 80s are expected over our far southern counties Tuesday
afternoon with most areas seeing dew points only in the mid to
upper 50s.

The upper pattern for the remainder of the week will feature a trof
over the eastern Great Lakes while upper level ridging dominates
across the western U.S. This should keep the weather on the quiet
side through most of Thursday before a secondary shortwave rotates
southeast around the eastern Great Lakes trof and brings shower and
thunderstorm chances into parts of our area. Models not showing much
agreement with respect to timing of the shortwave and any MCS
activity that translates southeast out of the Plains affecting parts
of west central through southern Illinois Thursday night into Friday
with another MCS forecast to develop along the trailing cold front
later Friday night into Saturday, affecting mainly southern
Illinois at this time. Temperatures this period are still
expected to average below normal but once we cool down into the
70s over parts of our area on Tuesday, most of the remainder of
the period we will see afternoon temperatures warm back close to
where they should be for late June/early July with afternoon
temperatures warming back into the 80 to 85 degree range starting
on Wednesday and continuing into the holiday weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 639 PM CDT Sun Jun 26 2016

Mainly quiet/VFR aviation weather conditions expected across the
central Illinois terminals through the 00Z TAF valid time. A weak
cold front crossed the area within the past few hours, taking the
bulk of the shower/thunderstorm threat with it. However, a few
post frontal showers are possible over the next few hours across
KSPI, KDEC, and KCMI. Once the shower risk departs clouds should
gradually depart, with winds staying AOB 10 kts.


&&

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

$$

UPDATE...Bak
SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KILX 262343
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
643 PM CDT SUN JUN 26 2016

.SHORT TERM...(Tonight)
ISSUED AT 300 PM CDT Sun Jun 26 2016

19z/2pm surface analysis shows cold front slowly dropping southward
toward the I-72 corridor.  Widely scattered thunderstorms have begun
to form along the boundary within the past hour and additional
development is expected for the remainder of the afternoon.  Due to
weak convergence along the front, a lack of upper-level support, and
0-6km bulk shear values of 20kt or less, think areal coverage of
storms will remain scattered in nature.  HRRR continues to develop
convection too robustly with each of its 1-hour forecasts, but it
does show the general trend of storms slowly sinking southward over
the next several hours.  Based on southward progress of front, have
gone with a dry forecast along and north of a Rantoul...to
Lincoln...to Jacksonville line by 00z/7pm.  Further south, have
continued high chance PoPs through the evening, with PoPs lingering
into the overnight hours south of I-70.  Any storms that occur late
this afternoon and evening will be slow-moving and capable of
producing localized downpours.  In addition, dry layer below 850mb
seen on LAPS soundings suggests the potential for gusty downburst
winds.

.LONG TERM...(Monday through Sunday)
ISSUED AT 300 PM CDT Sun Jun 26 2016

The cold front should be along or just south of I-70 Monday morning
with any lingering threat for showers/storms exiting our southern
counties during the morning. Somewhat drier air will slowly filter
south into our area during the day but temperatures will not show
much affect from the first cold front as afternoon temperatures
rise to around 90 far north to the lower 90s central and south. A
second cold front is slated to push south into our area later
Monday afternoon and evening but with the deeper moisture shunted
just south of our area from the first frontal boundary, will
continue to keep it dry tomorrow into tomorrow evening. A nice
refreshingly cool air mass will spill south following the second
cold front Monday night and by Tuesday we should see afternoon
temperatures range from the mid to upper 70s northeast while low
to mid 80s are expected over our far southern counties Tuesday
afternoon with most areas seeing dew points only in the mid to
upper 50s.

The upper pattern for the remainder of the week will feature a trof
over the eastern Great Lakes while upper level ridging dominates
across the western U.S. This should keep the weather on the quiet
side through most of Thursday before a secondary shortwave rotates
southeast around the eastern Great Lakes trof and brings shower and
thunderstorm chances into parts of our area. Models not showing much
agreement with respect to timing of the shortwave and any MCS
activity that translates southeast out of the Plains affecting parts
of west central through southern Illinois Thursday night into Friday
with another MCS forecast to develop along the trailing cold front
later Friday night into Saturday, affecting mainly southern
Illinoisat this time. Temperatures this period are still
expected to average below normal but once we cool down into the
70s over parts of our area on Tuesday, most of the remainder of
the period we will see afternoon temperatures warm back close to
where they should be for late June/early July with afternoon
temperatures warming back into the 80 to 85 degree range starting
on Wednesday and continuing into the holiday weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 639 PM CDT Sun Jun 26 2016

Mainly quiet/VFR aviation weather conditions expected across the
central Illinois terminals through the 00Z TAF valid time. A weak
cold front crossed the area within the past few hours, taking the
bulk of the shower/thunderstorm threat with it. However, a few
post frontal showers are possible over the next few hours across
KSPI, KDEC, and KCMI. Once the shower risk departs clouds should
gradually depart, with winds staying AOB 10 kts.

&&

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

$$

SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Bak




000
FXUS63 KLOT 262324
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
624 PM CDT SUN JUN 26 2016

.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
233 PM CDT

Monday night through Sunday...

The extended is much cooler thanks to another cold front that surges
down the lake Monday night. Not expecting any precip as the front
sinks south, but clouds will spread south of the lake over much if
not all of the warning area Monday. That combined with 925mb temps
of +11C to +16C will result in high temps in the 70s. Winds will be
off of the lake, so lake side temps will be in the upper 60s to
around 70.  The gusty north winds may create waves that will
increase the risk for rip currents, especially at the NW IN beaches.
Will not be issuing a beach hazards statement yet, but one may be
needed.

High pressure hangs around the region Tuesday afternoon through
Thursday, and then it will start to shift southeast Thursday
afternoon toward the Appalachians.  The high will bring sunny skies
and dry conditions, but the cooler upper level air will hang around
too.  Onshore flow will result in highs around 70 along the lake
again with highs in the mid to upper 70s elsewhere.  Thursday will
be a bit warmer with highs around 80 across the CWA.

An upper level trough axis rotates through the midwest along with a
cold front. Showers and storms are possible along the front Thursday
night into Friday morning.  Another surface high follows the cold
front and winds become northeast Friday. Highs will remain on the
cool side with highs in the mid 70s to around 80 away from the lake.
Thinking the high will keep any additional convection to our south
and west leading to a dry rest of the week. High temperatures will
also remain on the cool side for this time of year.

JEE

&&

.AVIATION...
For the 00Z TAFs...

624 pm...Only concern this period are the winds. A lake breeze is
slowly moving west across far southeast Cook County. Short term/
high res guidance has this continuing toward mdw before
dissipating with sunset. Confidence is very low as to how far west
this moves and whether it will reach mdw. Included a tempo for the
possibility. Medium to high confidence the lake breeze will remain
east of ord. Otherwise...gusty west/northwest winds will diminish
with sunset this evening and increase again during the mid/late
morning hours Monday. Forecast soundings would support gusts
around 20kts or so but if the low levels mix deeper...which is
possible given mainly sunny skies and drier air...then higher
gusts...possibly into the mid 20kt range may develop during the
afternoon. Winds will turn more to the north/northwest Monday
evening. cms

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 262324
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
624 PM CDT SUN JUN 26 2016

.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
233 PM CDT

Monday night through Sunday...

The extended is much cooler thanks to another cold front that surges
down the lake Monday night. Not expecting any precip as the front
sinks south, but clouds will spread south of the lake over much if
not all of the warning area Monday. That combined with 925mb temps
of +11C to +16C will result in high temps in the 70s. Winds will be
off of the lake, so lake side temps will be in the upper 60s to
around 70.  The gusty north winds may create waves that will
increase the risk for rip currents, especially at the NW IN beaches.
Will not be issuing a beach hazards statement yet, but one may be
needed.

High pressure hangs around the region Tuesday afternoon through
Thursday, and then it will start to shift southeast Thursday
afternoon toward the Appalachians.  The high will bring sunny skies
and dry conditions, but the cooler upper level air will hang around
too.  Onshore flow will result in highs around 70 along the lake
again with highs in the mid to upper 70s elsewhere.  Thursday will
be a bit warmer with highs around 80 across the CWA.

An upper level trough axis rotates through the midwest along with a
cold front. Showers and storms are possible along the front Thursday
night into Friday morning.  Another surface high follows the cold
front and winds become northeast Friday. Highs will remain on the
cool side with highs in the mid 70s to around 80 away from the lake.
Thinking the high will keep any additional convection to our south
and west leading to a dry rest of the week. High temperatures will
also remain on the cool side for this time of year.

JEE

&&

.AVIATION...
For the 00Z TAFs...

624 pm...Only concern this period are the winds. A lake breeze is
slowly moving west across far southeast Cook County. Short term/
high res guidance has this continuing toward mdw before
dissipating with sunset. Confidence is very low as to how far west
this moves and whether it will reach mdw. Included a tempo for the
possibility. Medium to high confidence the lake breeze will remain
east of ord. Otherwise...gusty west/northwest winds will diminish
with sunset this evening and increase again during the mid/late
morning hours Monday. Forecast soundings would support gusts
around 20kts or so but if the low levels mix deeper...which is
possible given mainly sunny skies and drier air...then higher
gusts...possibly into the mid 20kt range may develop during the
afternoon. Winds will turn more to the north/northwest Monday
evening. cms

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KILX 262005
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
305 PM CDT SUN JUN 26 2016

.SHORT TERM...(Tonight)
ISSUED AT 300 PM CDT Sun Jun 26 2016

19z/2pm surface analysis shows cold front slowly dropping southward
toward the I-72 corridor.  Widely scattered thunderstorms have begun
to form along the boundary within the past hour and additional
development is expected for the remainder of the afternoon.  Due to
weak convergence along the front, a lack of upper-level support, and
0-6km bulk shear values of 20kt or less, think areal coverage of
storms will remain scattered in nature.  HRRR continues to develop
convection too robustly with each of its 1-hour forecasts, but it
does show the general trend of storms slowly sinking southward over
the next several hours.  Based on southward progress of front, have
gone with a dry forecast along and north of a Rantoul...to
Lincoln...to Jacksonville line by 00z/7pm.  Further south, have
continued high chance PoPs through the evening, with PoPs lingering
into the overnight hours south of I-70.  Any storms that occur late
this afternoon and evening will be slow-moving and capable of
producing localized downpours.  In addition, dry layer below 850mb
seen on LAPS soundings suggests the potential for gusty downburst
winds.

&&

.LONG TERM...(Monday through Sunday)
ISSUED AT 300 PM CDT Sun Jun 26 2016

The cold front should be along or just south of I-70 Monday morning
with any lingering threat for showers/storms exiting our southern
counties during the morning. Somewhat drier air will slowly filter
south into our area during the day but temperatures will not show
much affect from the first cold front as afternoon temperatures
rise to around 90 far north to the lower 90s central and south. A
second cold front is slated to push south into our area later
Monday afternoon and evening but with the deeper moisture shunted
just south of our area from the first frontal boundary, will
continue to keep it dry tomorrow into tomorrow evening. A nice
refreshingly cool air mass will spill south following the second
cold front Monday night and by Tuesday we should see afternoon
temperatures range from the mid to upper 70s northeast while low
to mid 80s are expected over our far southern counties Tuesday
afternoon with most areas seeing dew points only in the mid to
upper 50s.

The upper pattern for the remainder of the week will feature a trof
over the eastern Great Lakes while upper level ridging dominates
across the western U.S. This should keep the weather on the quiet
side through most of Thursday before a secondary shortwave rotates
southeast around the eastern Great Lakes trof and brings shower and
thunderstorm chances into parts of our area. Models not showing much
agreement with respect to timing of the shortwave and any MCS
activity that translates southeast out of the Plains affecting parts
of west central through southern Illinois Thursday night into Friday
with another MCS forecast to develop along the trailing cold front
later Friday night into Saturday, affecting mainly southern Illinios
at this time. Temperatures this period are still expected to average
below normal but once we cool down into the 70s over parts of our
area on Tuesday, most of the remainder of the period we will see
afternoon temperatures warm back close to where they should be for
late June/early July with afternoon temperatures warming back
into the 80 to 85 degree range starting on Wednesday and continuing
into the holiday weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1231 PM CDT Sun Jun 26 2016

17z surface analysis shows cold front has progressed to the
Illinois River. Have therefore only mentioned VCSH at KPIA through
20z, followed by dry condtions for the remainder of the forecast.
Further east, have featured a period of VCTS at the remaining
terminals through the afternoon as scattered convection will
develop along the advancing boundary. Several models are hinting
that the most widespread precip will likely develop S/SE of the
terminals, so will not include any TEMPO groups for thunder unless
radar trends dictate. Once the front drops south of the area, high
clouds currently over Kansas/Missouri will stream northeastward
this evening. After that, forecast soundings indicate clear skies
overnight into Monday morning with light/variable winds.


&&

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

$$

SHORT TERM...Barnes
LONG TERM...Smith
AVIATION...Barnes




000
FXUS63 KLOT 261934
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
234 PM CDT SUN JUN 26 2016

.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
233 PM CDT

Monday night through Sunday...

The extended is much cooler thanks to another cold front that surges
down the lake Monday night. Not expecting any precip as the front
sinks south, but clouds will spread south of the lake over much if
not all of the warning area Monday. That combined with 925mb temps
of +11C to +16C will result in high temps in the 70s. Winds will be
off of the lake, so lake side temps will be in the upper 60s to
around 70.  The gusty north winds may create waves that will
increase the risk for rip currents, especially at the NW IN beaches.
Will not be issuing a beach hazards statement yet, but one may be
needed.

High pressure hangs around the region Tuesday afternoon through
Thursday, and then it will start to shift southeast Thursday
afternoon toward the Appalachians.  The high will bring sunny skies
and dry conditions, but the cooler upper level air will hang around
too.  Onshore flow will result in highs around 70 along the lake
again with highs in the mid to upper 70s elsewhere.  Thursday will
be a bit warmer with highs around 80 across the CWA.

An upper level trough axis rotates through the midwest along with a
cold front. Showers and storms are possible along the front Thursday
night into Friday morning.  Another surface high follows the cold
front and winds become northeast Friday. Highs will remain on the
cool side with highs in the mid 70s to around 80 away from the lake.
Thinking the high will keep any additional convection to our south
and west leading to a dry rest of the week. High temperatures will
also remain on the cool side for this time of year.

JEE

&&

.AVIATION...
For the 18Z TAFs...

A cold front is currently shifting over the eastern terminals.
This cold front will likely help focus thunderstorm development over
the next couple hours as it shifts east-southeastward into east
central Illinois and northwestern Indiana. It appears the threat of
storms at all terminal sites will remain low, with the better focus
expected to remain south of interstate 80. However, these
thunderstorms may impact southerly departure routes from the
airports this afternoon. Otherwise, expect mainly VFR conditions
this afternoon after a brief period of lower CIGs and primarily  a
west-northwest wind.

KJB

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KLOT 261934
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
234 PM CDT SUN JUN 26 2016

.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
233 PM CDT

Monday night through Sunday...

The extended is much cooler thanks to another cold front that surges
down the lake Monday night. Not expecting any precip as the front
sinks south, but clouds will spread south of the lake over much if
not all of the warning area Monday. That combined with 925mb temps
of +11C to +16C will result in high temps in the 70s. Winds will be
off of the lake, so lake side temps will be in the upper 60s to
around 70.  The gusty north winds may create waves that will
increase the risk for rip currents, especially at the NW IN beaches.
Will not be issuing a beach hazards statement yet, but one may be
needed.

High pressure hangs around the region Tuesday afternoon through
Thursday, and then it will start to shift southeast Thursday
afternoon toward the Appalachians.  The high will bring sunny skies
and dry conditions, but the cooler upper level air will hang around
too.  Onshore flow will result in highs around 70 along the lake
again with highs in the mid to upper 70s elsewhere.  Thursday will
be a bit warmer with highs around 80 across the CWA.

An upper level trough axis rotates through the midwest along with a
cold front. Showers and storms are possible along the front Thursday
night into Friday morning.  Another surface high follows the cold
front and winds become northeast Friday. Highs will remain on the
cool side with highs in the mid 70s to around 80 away from the lake.
Thinking the high will keep any additional convection to our south
and west leading to a dry rest of the week. High temperatures will
also remain on the cool side for this time of year.

JEE

&&

.AVIATION...
For the 18Z TAFs...

A cold front is currently shifting over the eastern terminals.
This cold front will likely help focus thunderstorm development over
the next couple hours as it shifts east-southeastward into east
central Illinois and northwestern Indiana. It appears the threat of
storms at all terminal sites will remain low, with the better focus
expected to remain south of interstate 80. However, these
thunderstorms may impact southerly departure routes from the
airports this afternoon. Otherwise, expect mainly VFR conditions
this afternoon after a brief period of lower CIGs and primarily  a
west-northwest wind.

KJB

&&

.MARINE...
233 PM CDT

The cold front is east of the northern half of the lake, and the
front will clear the southern end of the lake shortly. Winds will
become west behind the front. A second, stronger cold front will
surge down the lake Monday night with north winds 15-25 kt behind
it. Could see gusts to 30 kt over the southern half of the lake
Tuesday afternoon.  Will probably need a small craft late Monday
night into Tuesday evening especially over the NW IN nearshore
waters. Have less confidence about hazardous conditions over the IL
NSH zones so will hold off on a SCY for now.  High pressure builds
over the region late Tuesday with winds weakening under the
influence of the high. The high remains over the region through
mid week and then shifts southeast Thursday. Winds become
southwest behind the high. A cold front/low pressure trough combo
shift down the lake Thursday night with winds becoming north
behind it. Another high builds over the lake Friday night into
Saturday.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KLOT 261859
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
159 PM CDT SUN JUN 26 2016



.SHORT TERM...
159 PM CDT

Through Monday...

The latest surface analysis, as of 18z, places the surface cold
front from near KGYY, southwestward to KPNT. The prefrontal air
mass across Illinois and northwestern Indiana features
temperatures in the upper 80s and dew points in the low to mid
70s. Modifying the 12 utc ILX sounding suggests that this area is
uncapped with moderate instability in excess of 2500 J/KG.
Therefore, although convergence along the front is fairly weak, it
appears likely that at least some scattered thunderstorms will
develop over southern sections of the area (south of interstate 80
and east of interstate 55). This general idea seems to have
support from the CAMs (convective allowing models) and the latest
visible satellite imagery, which indicates an uptick cumulus
development ahead of the cold front.

Deep layer shear across the area is fairly unimpressive, with 0-6 KM
bulk shear of only around 20 KT. As a result, the convective active
will likely remain loosely organized storm clusters and pulse type
storms. In spite of this fact...some of the stronger storms will be
capable of producing an isolated bout or two of marginally severe
wind gusts. The other concern with these storms will be torrential
downpours. With precipitable water values around 2 inches, these
storms will be big rain makers. With an eastward movement at around
20-25 mph, there will be a small risk for some isolated flash
flooding...with rainfall rates up to 2 inches per hour. However,
widespread significant flash flooding is not anticipated...as these
storms should be moving out of the area by late afternoon.

Following these storms late this afternoon things will quiet down.
Another warm day is expected tomorrow...with less humidity. A second
stronger cold front will move across the area by early Monday
evening. This will bring much cooler weather to the area.

KJB

&&

.LONG TERM...
239 AM CDT

Monday through Saturday...

Warm air aloft will linger one more day with skies remaining
mostly sunny for much of the day. Td`s will be falling into the
upper 50s/low 60s due to increased mixing Monday. The result of
drier air and full sun with warm air aloft, should allow the surface
to quickly warm through the 80s and approach 90-92 in a few areas by
early afternoon. Some of the hi-res guidance members pivot a mid-lvl
wave southeast across Iowa late Mon afternoon, and could push some
clouds and a very minimal chance of precip into the Southern CWA aft
20z Mon. Expect the abundance of drier air and diffluent flow aloft
to inhibit this development, so will continue with a dry forecast
throughout Monday afternoon.

Tuesday through Saturday: Minimal changes for the extended periods
from prior forecasts. Ensembles continue to prog a high confidence
and minimal spread in the 500mb high-amplitude ridge building over
Western Canada through Thursday. This will maintain a quasi-
northwest flow setup for the Upper Midwest and Great Lakes regions.
Operational solutions continue to agree, with the surface ridge
remaining an influence on the Great Lakes region through at least
Wed ngt, before beginning to drift east Thursday. This will allow a
steady increase in chances for showers/thunderstorms in the final
few periods of the extended. Temperatures Tue/Wed will mainly be in
the low/mid 70s, then steadily return to the upper 70s and lower 80s
by the end of the week.

Beachler

&&

.AVIATION...
For the 18Z TAFs...

A cold front is currently shifting over the eastern terminals.
This cold front will likely help focus thunderstorm development over
the next couple hours as it shifts east-southeastward into east
central Illinois and northwestern Indiana. It appears the threat of
storms at all terminal sites will remain low, with the better focus
expected to remain south of interstate 80. However, these
thunderstorms may impact southerly departure routes from the
airports this afternoon. Otherwise, expect mainly VFR conditions
this afternoon after a brief period of lower CIGs and primarily  a
west-northwest wind.

KJB

&&

.MARINE...
300 AM CDT

A small craft advisory may be needed Monday night into Tuesday due
to strong winds and building waves.

Strong high pressure is centered over the east coast and deep low
is pressure moving into northern Ontario, with a trailing cold
front extending south across the western Great Lakes to the south
high plains. As the cold front and associated sfc trough
approaches the lake and the high remains nearly stationary, south
to southwest winds over the lake have increased to 15-25 kt. As
the front pushes across the lake today, winds will shift to more
westerly, initially arnd 15-25 kt, but diminishing a bit through
the day as weak high pressure builds in behind the front. A
secondary surge of colder air will push down the lake Monday night
while strong high pressure builds into the northern plains. Winds
will turn northerly and increase to 15-25 kt Monday night and
remain northerly through Tuesday. The long fetch of brisk north
winds should set up small craft advisory conditions for the south
end of the lake. As high pressure builds across the lake Tuesday
night through Wednesday night, winds will become relatively light
with variable direction.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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000
FXUS63 KILX 261731
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1231 PM CDT SUN JUN 26 2016

.UPDATE...
Issued at 905 AM CDT Sun Jun 26 2016

13z/8am surface analysis shows cold front extending from the
western Great Lakes into the southern Plains. The strongest
forward momentum and thus the greatest convergence along the
boundary will be focused further north across Michigan today,
while much weaker convergence will be noted further southwest
along the front into Illinois and Missouri. Due to weak
convergence, very little upper support, and 0-6km bulk shear of
only 20kt or less, do not think areal coverage of thunderstorms
will be particularly high along/ahead of the front. Models
continue to suggest a pronounced increase in storm coverage
along/south of I-72 between 18-21z: however, think this is a bit
overdone based on current satellite/radar loops and recent trends.
Have therefore decreased PoPs slightly and have gone with
scattered wording for the remainder of the day. Will be another
warm and very humid day with afternoon highs ranging from the
upper 80s north of the Peoria area...to the middle 90s south of
I-70. Heat index values will generally reach the upper 90s to
around 100, with readings in the 100 to 105 range across the far
SE KILX CWA.

&&

.SHORT TERM...(Today)
ISSUED AT 318 AM CDT Sun Jun 26 2016

A cold front currently from northern WI into north TX will continue
to progress into central IL today. Current timing has the front
reaching Galesburg just before noon and Lawrenceville around 7 p.m.
Scattered thunderstorms are centered along the frontal boundary so
should have scattered thunderstorms northwest of the Illinois River
by around sunrise...as far as I-70 by noon...and southeast of
I-70 by mid afternoon. By late afternoon, showers and
thunderstorms should be tapering off northwest of the Illinois
River as the surface boundary will be past the area and
instability will be rapidly diminishing. With daytime heating,
around 2000 J/KG MLCAPE should develop. Sfc-6 km bulk shear
profiles lining up with the axis of highest CAPE generally 20 kts
or less due to only a modest mid-level flow aloft. As a result,
SPC indicates a marginal risk of severe thunderstorms containing
hail and strong wind gusts from around the Illinois River
southeastward. Until afternoon, thunderstorms should pose little
threat for severe weather, although locally heavy rain in slow
moving storms will be a possibility as forecast precipitable water
will be around 2 inches and dewpoints as high as the mid 70s.

Temperatures should be down a few degrees today ranging from 89 in
Galesburg where thunderstorms and increased cloud cover will move in
early, to 93 in Lawrenceville. Nevertheless, conditions will be
quite humid resulting in heat index as high as 100, mainly east of
I-55.

.LONG TERM...(Tonight through Saturday)
ISSUED AT 318 AM CDT Sun Jun 26 2016

A transition toward cooler and less humid weather will take place
early this week, as the upper low currently over Lake Winnipeg opens
up and the resulting trough sweeps through the Great Lakes. A
general pattern of ridging over the western CONUS and periodic
troughs over the Great Lakes will persist into the weekend, and
although temperatures will rise later in the week, a less humid air
mass will persist much of the week.

The cold front which will move through later today should be through
the forecast area by late evening. Scattered showers and
thunderstorms will continue over southeast Illinois this evening,
then slowly diminish after midnight with the front settling a bit
further south. Model guidance is a bit mixed in terms of any
precipitation with the secondary cold front associated with the
upper trough, with the GFS and especially the NAM showing some
convection Monday evening, while the ECMWF remains dry. Will keep
the forecast dry for now, with the front expected to be through most
of the area by this point. Also, any lingering PoP`s for Tuesday
night and Wednesday have been removed, with the models continuing
the pattern of shifting the MCS track even further to our southwest.
Late in the week, the GFS is more robust with the upper trough late
Thursday night and thus more widespread with rain chances versus the
weaker ECMWF, although the latter model is more aggressive with a
shortwave advancing through the mid-Mississippi Valley later Friday
into Saturday. Right now, with the discrepancies, will limit any
rain chances to about 20% or less until some clarity emerges.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1231 PM CDT Sun Jun 26 2016

17z surface analysis shows cold front has progressed to the
Illinois River. Have therefore only mentioned VCSH at KPIA through
20z, followed by dry condtions for the remainder of the forecast.
Further east, have featured a period of VCTS at the remaining
terminals through the afternoon as scattered convection will
develop along the advancing boundary. Several models are hinting
that the most widespread precip will likely develop S/SE of the
terminals, so will not include any TEMPO groups for thunder unless
radar trends dictate. Once the front drops south of the area, high
clouds currently over Kansas/Missouri will stream northeastward
this evening. After that, forecast soundings indicate clear skies
overnight into Monday morning with light/variable winds.

&&

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

$$

UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Barnes




000
FXUS63 KILX 261731
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1231 PM CDT SUN JUN 26 2016

.UPDATE...
Issued at 905 AM CDT Sun Jun 26 2016

13z/8am surface analysis shows cold front extending from the
western Great Lakes into the southern Plains. The strongest
forward momentum and thus the greatest convergence along the
boundary will be focused further north across Michigan today,
while much weaker convergence will be noted further southwest
along the front into Illinois and Missouri. Due to weak
convergence, very little upper support, and 0-6km bulk shear of
only 20kt or less, do not think areal coverage of thunderstorms
will be particularly high along/ahead of the front. Models
continue to suggest a pronounced increase in storm coverage
along/south of I-72 between 18-21z: however, think this is a bit
overdone based on current satellite/radar loops and recent trends.
Have therefore decreased PoPs slightly and have gone with
scattered wording for the remainder of the day. Will be another
warm and very humid day with afternoon highs ranging from the
upper 80s north of the Peoria area...to the middle 90s south of
I-70. Heat index values will generally reach the upper 90s to
around 100, with readings in the 100 to 105 range across the far
SE KILX CWA.

&&

.SHORT TERM...(Today)
ISSUED AT 318 AM CDT Sun Jun 26 2016

A cold front currently from northern WI into north TX will continue
to progress into central IL today. Current timing has the front
reaching Galesburg just before noon and Lawrenceville around 7 p.m.
Scattered thunderstorms are centered along the frontal boundary so
should have scattered thunderstorms northwest of the Illinois River
by around sunrise...as far as I-70 by noon...and southeast of
I-70 by mid afternoon. By late afternoon, showers and
thunderstorms should be tapering off northwest of the Illinois
River as the surface boundary will be past the area and
instability will be rapidly diminishing. With daytime heating,
around 2000 J/KG MLCAPE should develop. Sfc-6 km bulk shear
profiles lining up with the axis of highest CAPE generally 20 kts
or less due to only a modest mid-level flow aloft. As a result,
SPC indicates a marginal risk of severe thunderstorms containing
hail and strong wind gusts from around the Illinois River
southeastward. Until afternoon, thunderstorms should pose little
threat for severe weather, although locally heavy rain in slow
moving storms will be a possibility as forecast precipitable water
will be around 2 inches and dewpoints as high as the mid 70s.

Temperatures should be down a few degrees today ranging from 89 in
Galesburg where thunderstorms and increased cloud cover will move in
early, to 93 in Lawrenceville. Nevertheless, conditions will be
quite humid resulting in heat index as high as 100, mainly east of
I-55.

.LONG TERM...(Tonight through Saturday)
ISSUED AT 318 AM CDT Sun Jun 26 2016

A transition toward cooler and less humid weather will take place
early this week, as the upper low currently over Lake Winnipeg opens
up and the resulting trough sweeps through the Great Lakes. A
general pattern of ridging over the western CONUS and periodic
troughs over the Great Lakes will persist into the weekend, and
although temperatures will rise later in the week, a less humid air
mass will persist much of the week.

The cold front which will move through later today should be through
the forecast area by late evening. Scattered showers and
thunderstorms will continue over southeast Illinois this evening,
then slowly diminish after midnight with the front settling a bit
further south. Model guidance is a bit mixed in terms of any
precipitation with the secondary cold front associated with the
upper trough, with the GFS and especially the NAM showing some
convection Monday evening, while the ECMWF remains dry. Will keep
the forecast dry for now, with the front expected to be through most
of the area by this point. Also, any lingering PoP`s for Tuesday
night and Wednesday have been removed, with the models continuing
the pattern of shifting the MCS track even further to our southwest.
Late in the week, the GFS is more robust with the upper trough late
Thursday night and thus more widespread with rain chances versus the
weaker ECMWF, although the latter model is more aggressive with a
shortwave advancing through the mid-Mississippi Valley later Friday
into Saturday. Right now, with the discrepancies, will limit any
rain chances to about 20% or less until some clarity emerges.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1231 PM CDT Sun Jun 26 2016

17z surface analysis shows cold front has progressed to the
Illinois River. Have therefore only mentioned VCSH at KPIA through
20z, followed by dry condtions for the remainder of the forecast.
Further east, have featured a period of VCTS at the remaining
terminals through the afternoon as scattered convection will
develop along the advancing boundary. Several models are hinting
that the most widespread precip will likely develop S/SE of the
terminals, so will not include any TEMPO groups for thunder unless
radar trends dictate. Once the front drops south of the area, high
clouds currently over Kansas/Missouri will stream northeastward
this evening. After that, forecast soundings indicate clear skies
overnight into Monday morning with light/variable winds.

&&

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

$$

UPDATE...Barnes
SHORT TERM...Onton
LONG TERM...Geelhart
AVIATION...Barnes




000
FXUS63 KLOT 261728
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1228 PM CDT SUN JUN 26 2016

.UPDATE...

1101 AM CDT

UPDATED THE FORECAST THIS MORNING TO LOWER POPS, ESPECIALLY OVER THE
NORTHERN HALF OF THE AREA THIS AFTERNOON. A LINE OF LIGHT WEAKENING
SHOWERS IS HEADING TOWARDS THE CHICAGO METRO, BUT NO MORE THAN A
QUICK LIGHT SHOWER IS EXPECTED WITH THIS ACTIVITY. AN OUTFLOW
BOUNDARY FROM SOME EARLY THUNDERSTORMS OVER NORTHWESTERN INDIANA,
HAS PUSHED OVER MY FAR SOUTHEAST, OVER PORTIONS OF BENTON COUNTY. A
FEW SHOWERS AND STORMS DEVELOPED ALONG THIS BOUNDARY, BUT HAVE
ALREADY MOVED EAST OF THE AREA OVER THE COUPLE HOURS.
MEANWHILE, THE SURFACE COLD FRONT ITSELF APPEARS TO NOW BE MOVING
TOWARDS THE FAR WESTERN PORTIONS OF THE CHICAGO METRO AREA. GIVEN
THAT CONDITIONS OVER THE SOUTHEASTERN Quadrant OF MY CWA HAVE
CLEARED, AND ARE WARMING THROUGH THE 80S WITH DEW POINTS INTO THE
LOW 70S, EXPECT THAT SOME ADDITIONAL STORMS WILL DEVELOP BY EARLY
THIS AFTERNOON. ITS EVEN POSSIBLE THAT THE CURRENT LINE OF LIGHT
SHOWERS COULD BEGIN TO BUILD INTO STORMS AS THEY MOVE FARTHER EAST
INTO THE BETTER INSTABILITY AXIS OVER EAST CENTRAL ILLINOIS INTO
NORTHWESTERN INDIANA.

IT CURRENTLY APPEARS THE FAVORED AREAS FOR THUNDERSTORMS THIS
AFTERNOON WILL BE MAINLY SOUTH OF INTERSTATE 80 AND EAST OF
INTERSTATE 55, WITH THE BEST CHANCES OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA. THESE STORMS WILL BE Capable OF PRODUCING
ISOLATED MARGINALLY SEVERE WIND GUSTS TO 60 MPH, AND VERY HEAVY
RAINFALL. WITH PWATS UP AROUND 2 INCHES THESE STORMS COULD DROP A
QUICK 1 TO 2 INCHES OVER THE AREAS THEY IMPACT.  AS SUCH, THERE IS A
LOW THREAT FOR SOME MINOR Localized FLOODING. THE DECENT MOVEMENT TO
THE STORMS SHOULD LIMIT THE THREAT OF SIGNIFICANT FLASH FLOODING.

KJB

&&

.SHORT TERM...
239 AM CDT

Through tonight...

Robust shortwave over Manitoba Canada continues to drift east
towards Ontario, with a frontal boundary stretching south through
Wisconsin and bending southwest through Missouri. Along and ahead of
this boundary considerable atmospheric moisture is present, with Td`s
mainly in the lower 70s across much of Eastern Iowa/Western Illinois
stretching north into Southern Wisconsin. The light southerly flow
this morning will hold the PWATs around 2", but with some mixing
progged for midday/afternoon, it is possible Td`s may come down
slightly or into the upper 60s to around 70 degrees. Additionally
within the warm/moist channel, thunderstorms continue to feed
northeast across Eastern Iowa into West Central Wisconsin. Skies
continue to be mostly clear early this morning over Northeast IL;
however, upon daybreak clouds will begin to thicken from west to
east.

Low level convergence will remain minimal today, as the better
dynamics remain displaced well north of Illinois. Instability
coupled with a weak lobe of vorticity drifting east later this
morning should allow thunderstorms to develop, although challenges
remain with placement and timing. Most operational guidance members
continue to point towards areas along and east of Pontiac to Gary
line with the highest probs from 17z through 22z, so have adjusted
POPs accordingly to reflect this. Meanwhile west of this area
chances diminish due to the timing of the vort lobe and instability
development. Depending on the timing of convective development,
given the abundance of low-level moisture and minimal shear, storms
will likely be slow-moving and could easily produce heavy downpours.
This may translate to heavy rain producing storms, and localized
flooding. Temperatures today are progged to be very warm/humid;
however, given the thick cloud cover progged to arrive by late
morning through the afternoon, this may keep sfc temps from
returning to the 90s in many areas. Heat indices will range from 92-
99.

Upon frontal passage flow will turn westerly as skies begin to thin
due to the growing influence from an approaching surface ridge over
Central Canada. This will keep the overnight period dry, but the
lack of cooler air aloft will still produce lows in the mid/upr 60s
to around 70 closer to Lake Michigan.

Beachler

&&

.LONG TERM...
239 AM CDT

Monday through Saturday...

Warm air aloft will linger one more day with skies remaining
mostly sunny for much of the day. Td`s will be falling into the
upper 50s/low 60s due to increased mixing Monday. The result of
drier air and full sun with warm air aloft, should allow the surface
to quickly warm through the 80s and approach 90-92 in a few areas by
early afternoon. Some of the hi-res guidance members pivot a mid-lvl
wave southeast across Iowa late Mon afternoon, and could push some
clouds and a very minimal chance of precip into the Southern CWA aft
20z Mon. Expect the abundance of drier air and diffluent flow aloft
to inhibit this development, so will continue with a dry forecast
throughout Monday afternoon.

Tuesday through Saturday: Minimal changes for the extended periods
from prior forecasts. Ensembles continue to prog a high confidence
and minimal spread in the 500mb high-amplitude ridge building over
Western Canada through Thursday. This will maintain a quasi-
northwest flow setup for the Upper Midwest and Great Lakes regions.
Operational solutions continue to agree, with the surface ridge
remaining an influence on the Great Lakes region through at least
Wed ngt, before beginning to drift east Thursday. This will allow a
steady increase in chances for showers/thunderstorms in the final
few periods of the extended. Temperatures Tue/Wed will mainly be in
the low/mid 70s, then steadily return to the upper 70s and lower 80s
by the end of the week.

Beachler

&&

.AVIATION...
For the 18Z TAFs...

A cold front is currently shifting over the eastern terminals.
This cold front will likely help focus thunderstorm development over
the next couple hours as it shifts east-southeastward into east
central Illinois and northwestern Indiana. It appears the threat of
storms at all terminal sites will remain low, with the better focus
expected to remain south of interstate 80. However, these
thunderstorms may impact southerly departure routes from the
airports this afternoon. Otherwise, expect mainly VFR conditions
this afternoon after a brief period of lower CIGs and primarily  a
west-northwest wind.

KJB

&&

.MARINE...
300 AM CDT

A small craft advisory may be needed Monday night into Tuesday due
to strong winds and building waves.

Strong high pressure is centered over the east coast and deep low
is pressure moving into northern Ontario, with a trailing cold
front extending south across the western Great Lakes to the south
high plains. As the cold front and associated sfc trough
approaches the lake and the high remains nearly stationary, south
to southwest winds over the lake have increased to 15-25 kt. As
the front pushes across the lake today, winds will shift to more
westerly, initially arnd 15-25 kt, but diminishing a bit through
the day as weak high pressure builds in behind the front. A
secondary surge of colder air will push down the lake Monday night
while strong high pressure builds into the northern plains. Winds
will turn northerly and increase to 15-25 kt Monday night and
remain northerly through Tuesday. The long fetch of brisk north
winds should set up small craft advisory conditions for the south
end of the lake. As high pressure builds across the lake Tuesday
night through Wednesday night, winds will become relatively light
with variable direction.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

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000
FXUS63 KLOT 261728
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1228 PM CDT SUN JUN 26 2016

.UPDATE...

1101 AM CDT

UPDATED THE FORECAST THIS MORNING TO LOWER POPS, ESPECIALLY OVER THE
NORTHERN HALF OF THE AREA THIS AFTERNOON. A LINE OF LIGHT WEAKENING
SHOWERS IS HEADING TOWARDS THE CHICAGO METRO, BUT NO MORE THAN A
QUICK LIGHT SHOWER IS EXPECTED WITH THIS ACTIVITY. AN OUTFLOW
BOUNDARY FROM SOME EARLY THUNDERSTORMS OVER NORTHWESTERN INDIANA,
HAS PUSHED OVER MY FAR SOUTHEAST, OVER PORTIONS OF BENTON COUNTY. A
FEW SHOWERS AND STORMS DEVELOPED ALONG THIS BOUNDARY, BUT HAVE
ALREADY MOVED EAST OF THE AREA OVER THE COUPLE HOURS.
MEANWHILE, THE SURFACE COLD FRONT ITSELF APPEARS TO NOW BE MOVING
TOWARDS THE FAR WESTERN PORTIONS OF THE CHICAGO METRO AREA. GIVEN
THAT CONDITIONS OVER THE SOUTHEASTERN Quadrant OF MY CWA HAVE
CLEARED, AND ARE WARMING THROUGH THE 80S WITH DEW POINTS INTO THE
LOW 70S, EXPECT THAT SOME ADDITIONAL STORMS WILL DEVELOP BY EARLY
THIS AFTERNOON. ITS EVEN POSSIBLE THAT THE CURRENT LINE OF LIGHT
SHOWERS COULD BEGIN TO BUILD INTO STORMS AS THEY MOVE FARTHER EAST
INTO THE BETTER INSTABILITY AXIS OVER EAST CENTRAL ILLINOIS INTO
NORTHWESTERN INDIANA.

IT CURRENTLY APPEARS THE FAVORED AREAS FOR THUNDERSTORMS THIS
AFTERNOON WILL BE MAINLY SOUTH OF INTERSTATE 80 AND EAST OF
INTERSTATE 55, WITH THE BEST CHANCES OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA. THESE STORMS WILL BE Capable OF PRODUCING
ISOLATED MARGINALLY SEVERE WIND GUSTS TO 60 MPH, AND VERY HEAVY
RAINFALL. WITH PWATS UP AROUND 2 INCHES THESE STORMS COULD DROP A
QUICK 1 TO 2 INCHES OVER THE AREAS THEY IMPACT.  AS SUCH, THERE IS A
LOW THREAT FOR SOME MINOR Localized FLOODING. THE DECENT MOVEMENT TO
THE STORMS SHOULD LIMIT THE THREAT OF SIGNIFICANT FLASH FLOODING.

KJB

&&

.SHORT TERM...
239 AM CDT

Through tonight...

Robust shortwave over Manitoba Canada continues to drift east
towards Ontario, with a frontal boundary stretching south through
Wisconsin and bending southwest through Missouri. Along and ahead of
this boundary considerable atmospheric moisture is present, with Td`s
mainly in the lower 70s across much of Eastern Iowa/Western Illinois
stretching north into Southern Wisconsin. The light southerly flow
this morning will hold the PWATs around 2", but with some mixing
progged for midday/afternoon, it is possible Td`s may come down
slightly or into the upper 60s to around 70 degrees. Additionally
within the warm/moist channel, thunderstorms continue to feed
northeast across Eastern Iowa into West Central Wisconsin. Skies
continue to be mostly clear early this morning over Northeast IL;
however, upon daybreak clouds will begin to thicken from west to
east.

Low level convergence will remain minimal today, as the better
dynamics remain displaced well north of Illinois. Instability
coupled with a weak lobe of vorticity drifting east later this
morning should allow thunderstorms to develop, although challenges
remain with placement and timing. Most operational guidance members
continue to point towards areas along and east of Pontiac to Gary
line with the highest probs from 17z through 22z, so have adjusted
POPs accordingly to reflect this. Meanwhile west of this area
chances diminish due to the timing of the vort lobe and instability
development. Depending on the timing of convective development,
given the abundance of low-level moisture and minimal shear, storms
will likely be slow-moving and could easily produce heavy downpours.
This may translate to heavy rain producing storms, and localized
flooding. Temperatures today are progged to be very warm/humid;
however, given the thick cloud cover progged to arrive by late
morning through the afternoon, this may keep sfc temps from
returning to the 90s in many areas. Heat indices will range from 92-
99.

Upon frontal passage flow will turn westerly as skies begin to thin
due to the growing influence from an approaching surface ridge over
Central Canada. This will keep the overnight period dry, but the
lack of cooler air aloft will still produce lows in the mid/upr 60s
to around 70 closer to Lake Michigan.

Beachler

&&

.LONG TERM...
239 AM CDT

Monday through Saturday...

Warm air aloft will linger one more day with skies remaining
mostly sunny for much of the day. Td`s will be falling into the
upper 50s/low 60s due to increased mixing Monday. The result of
drier air and full sun with warm air aloft, should allow the surface
to quickly warm through the 80s and approach 90-92 in a few areas by
early afternoon. Some of the hi-res guidance members pivot a mid-lvl
wave southeast across Iowa late Mon afternoon, and could push some
clouds and a very minimal chance of precip into the Southern CWA aft
20z Mon. Expect the abundance of drier air and diffluent flow aloft
to inhibit this development, so will continue with a dry forecast
throughout Monday afternoon.

Tuesday through Saturday: Minimal changes for the extended periods
from prior forecasts. Ensembles continue to prog a high confidence
and minimal spread in the 500mb high-amplitude ridge building over
Western Canada through Thursday. This will maintain a quasi-
northwest flow setup for the Upper Midwest and Great Lakes regions.
Operational solutions continue to agree, with the surface ridge
remaining an influence on the Great Lakes region through at least
Wed ngt, before beginning to drift east Thursday. This will allow a
steady increase in chances for showers/thunderstorms in the final
few periods of the extended. Temperatures Tue/Wed will mainly be in
the low/mid 70s, then steadily return to the upper 70s and lower 80s
by the end of the week.

Beachler

&&

.AVIATION...
For the 18Z TAFs...

A cold front is currently shifting over the eastern terminals.
This cold front will likely help focus thunderstorm development over
the next couple hours as it shifts east-southeastward into east
central Illinois and northwestern Indiana. It appears the threat of
storms at all terminal sites will remain low, with the better focus
expected to remain south of interstate 80. However, these
thunderstorms may impact southerly departure routes from the
airports this afternoon. Otherwise, expect mainly VFR conditions
this afternoon after a brief period of lower CIGs and primarily  a
west-northwest wind.

KJB

&&

.MARINE...
300 AM CDT

A small craft advisory may be needed Monday night into Tuesday due
to strong winds and building waves.

Strong high pressure is centered over the east coast and deep low
is pressure moving into northern Ontario, with a trailing cold
front extending south across the western Great Lakes to the south
high plains. As the cold front and associated sfc trough
approaches the lake and the high remains nearly stationary, south
to southwest winds over the lake have increased to 15-25 kt. As
the front pushes across the lake today, winds will shift to more
westerly, initially arnd 15-25 kt, but diminishing a bit through
the day as weak high pressure builds in behind the front. A
secondary surge of colder air will push down the lake Monday night
while strong high pressure builds into the northern plains. Winds
will turn northerly and increase to 15-25 kt Monday night and
remain northerly through Tuesday. The long fetch of brisk north
winds should set up small craft advisory conditions for the south
end of the lake. As high pressure builds across the lake Tuesday
night through Wednesday night, winds will become relatively light
with variable direction.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




000
FXUS63 KLOT 261601
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1101 AM CDT SUN JUN 26 2016

.UPDATE...
1101 AM CDT

UPDATED THE FORECAST THIS MORNING TO LOWER POPS, ESPECIALLY OVER THE
NORTHERN HALF OF THE AREA THIS AFTERNOON. A LINE OF LIGHT WEAKENING
SHOWERS IS HEADING TOWARDS THE CHICAGO METRO, BUT NO MORE THAN A
QUICK LIGHT SHOWER IS EXPECTED WITH THIS ACTIVITY. AN OUTFLOW
BOUNDARY FROM SOME EARLY THUNDERSTORMS OVER NORTHWESTERN INDIANA,
HAS PUSHED OVER MY FAR SOUTHEAST, OVER PORTIONS OF BENTON COUNTY. A
FEW SHOWERS AND STORMS DEVELOPED ALONG THIS BOUNDARY, BUT HAVE
ALREADY MOVED EAST OF THE AREA OVER THE COUPLE HOURS.
MEANWHILE, THE SURFACE COLD FRONT ITSELF APPEARS TO NOW BE MOVING
TOWARDS THE FAR WESTERN PORTIONS OF THE CHICAGO METRO AREA. GIVEN
THAT CONDITIONS OVER THE SOUTHEASTERN Quadrant OF MY CWA HAVE
CLEARED, AND ARE WARMING THROUGH THE 80S WITH DEW POINTS INTO THE
LOW 70S, EXPECT THAT SOME ADDITIONAL STORMS WILL DEVELOP BY EARLY
THIS AFTERNOON. ITS EVEN POSSIBLE THAT THE CURRENT LINE OF LIGHT
SHOWERS COULD BEGIN TO BUILD INTO STORMS AS THEY MOVE FARTHER EAST
INTO THE BETTER INSTABILITY AXIS OVER EAST CENTRAL ILLINOIS INTO
NORTHWESTERN INDIANA.

IT CURRENTLY APPEARS THE FAVORED AREAS FOR THUNDERSTORMS THIS
AFTERNOON WILL BE MAINLY SOUTH OF INTERSTATE 80 AND EAST OF
INTERSTATE 55, WITH THE BEST CHANCES OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA. THESE STORMS WILL BE Capable OF PRODUCING
ISOLATED MARGINALLY SEVERE WIND GUSTS TO 60 MPH, AND VERY HEAVY
RAINFALL. WITH PWATS UP AROUND 2 INCHES THESE STORMS COULD DROP A
QUICK 1 TO 2 INCHES OVER THE AREAS THEY IMPACT.  AS SUCH, THERE IS A
LOW THREAT FOR SOME MINOR Localized FLOODING. THE DECENT MOVEMENT TO
THE STORMS SHOULD LIMIT THE THREAT OF SIGNIFICANT FLASH FLOODING.

KJB

&&

.SHORT TERM...
239 AM CDT

Through tonight...

Robust shortwave over Manitoba Canada continues to drift east
towards Ontario, with a frontal boundary stretching south through
Wisconsin and bending southwest through Missouri. Along and ahead of
this boundary considerable atmospheric moisture is present, with Td`s
mainly in the lower 70s across much of Eastern Iowa/Western Illinois
stretching north into Southern Wisconsin. The light southerly flow
this morning will hold the PWATs around 2", but with some mixing
progged for midday/afternoon, it is possible Td`s may come down
slightly or into the upper 60s to around 70 degrees. Additionally
within the warm/moist channel, thunderstorms continue to feed
northeast across Eastern Iowa into West Central Wisconsin. Skies
continue to be mostly clear early this morning over Northeast IL;
however, upon daybreak clouds will begin to thicken from west to
east.

Low level convergence will remain minimal today, as the better
dynamics remain displaced well north of Illinois. Instability
coupled with a weak lobe of vorticity drifting east later this
morning should allow thunderstorms to develop, although challenges
remain with placement and timing. Most operational guidance members
continue to point towards areas along and east of Pontiac to Gary
line with the highest probs from 17z through 22z, so have adjusted
POPs accordingly to reflect this. Meanwhile west of this area
chances diminish due to the timing of the vort lobe and instability
development. Depending on the timing of convective development,
given the abundance of low-level moisture and minimal shear, storms
will likely be slow-moving and could easily produce heavy downpours.
This may translate to heavy rain producing storms, and localized
flooding. Temperatures today are progged to be very warm/humid;
however, given the thick cloud cover progged to arrive by late
morning through the afternoon, this may keep sfc temps from
returning to the 90s in many areas. Heat indices will range from 92-
99.

Upon frontal passage flow will turn westerly as skies begin to thin
due to the growing influence from an approaching surface ridge over
Central Canada. This will keep the overnight period dry, but the
lack of cooler air aloft will still produce lows in the mid/upr 60s
to around 70 closer to Lake Michigan.

Beachler

&&

.LONG TERM...
239 AM CDT

Monday through Saturday...

Warm air aloft will linger one more day with skies remaining
mostly sunny for much of the day. Td`s will be falling into the
upper 50s/low 60s due to increased mixing Monday. The result of
drier air and full sun with warm air aloft, should allow the surface
to quickly warm through the 80s and approach 90-92 in a few areas by
early afternoon. Some of the hi-res guidance members pivot a mid-lvl
wave southeast across Iowa late Mon afternoon, and could push some
clouds and a very minimal chance of precip into the Southern CWA aft
20z Mon. Expect the abundance of drier air and diffluent flow aloft
to inhibit this development, so will continue with a dry forecast
throughout Monday afternoon.

Tuesday through Saturday: Minimal changes for the extended periods
from prior forecasts. Ensembles continue to prog a high confidence
and minimal spread in the 500mb high-amplitude ridge building over
Western Canada through Thursday. This will maintain a quasi-
northwest flow setup for the Upper Midwest and Great Lakes regions.
Operational solutions continue to agree, with the surface ridge
remaining an influence on the Great Lakes region through at least
Wed ngt, before beginning to drift east Thursday. This will allow a
steady increase in chances for showers/thunderstorms in the final
few periods of the extended. Temperatures Tue/Wed will mainly be in
the low/mid 70s, then steadily return to the upper 70s and lower 80s
by the end of the week.

Beachler

&&

.AVIATION...
For the 12Z TAFs...

Main forecast concern this period remain the potential for
thunderstorms.

Latest radar and satellite imagery indicating that the convective
activity associated with band pcpn over nwrn IL is weakening with
diminished lighting activity. However, sct shra are trying to
develop out ahead of the main pcpn area coincident with the pre-
frontal trough that had been the focus for some pcpn overnight.
The short range, high res guidance continues to struggle with this
system and confidence remains low with respect to ts. Based on the
latest trends of shra trying to develop have gone with a VCSH at
the Chicago area terminals for a few hours this morning. Also,
given the potential that TS this afternoon may either develop on
top of the Chicago area terminals or to the southeast, have backed
off to VCTS. The area remains very warm and humid and the frontal
forcing will come at a diurnally favorable time, so can`t rule out
the TS chances.

There is relatively high confidence that the cold front should
push east of the terminals through the afternoon, early afternoon
for RFD and late afternoon for the Chicago area terminals.
Following the passage of the cold front, winds should veer from
swly to wly or wnwly and cloud cover should diminish to skc or sct
ci.

&&

.MARINE...
300 AM CDT

A small craft advisory may be needed Monday night into Tuesday due
to strong winds and building waves.

Strong high pressure is centered over the east coast and deep low
is pressure moving into northern Ontario, with a trailing cold
front extending south across the western Great Lakes to the south
high plains. As the cold front and associated sfc trough
approaches the lake and the high remains nearly stationary, south
to southwest winds over the lake have increased to 15-25 kt. As
the front pushes across the lake today, winds will shift to more
westerly, initially arnd 15-25 kt, but diminishing a bit through
the day as weak high pressure builds in behind the front. A
secondary surge of colder air will push down the lake Monday night
while strong high pressure builds into the northern plains. Winds
will turn northerly and increase to 15-25 kt Monday night and
remain northerly through Tuesday. The long fetch of brisk north
winds should set up small craft advisory conditions for the south
end of the lake. As high pressure builds across the lake Tuesday
night through Wednesday night, winds will become relatively light
with variable direction.

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO




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