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Current Conditions

A message from COD Meteorology

Current Local Radar

Temperature
71°F
Feels Like:
71°F
Dew Point	Humidity
65°F	81%

Partly Cloudy

Wind Strength
Light	Moderate	Strong
West-southwest at 5 mph

Local Graphical Forecast (Updated: 06/27/19 6:15 am)

Thursday (6/27)
Day	Night

	40%
High	Low
91	71

Friday (6/28)
Day	Night

40%	30%
High	Low
91	71

Saturday (6/29)
Day	Night

30%	20%
High	Low
91	70

Sunday (6/30)
Day	Night

20%
High	Low
91	71

Monday (7/1)
Day	Night


High	Low
89	70

Tuesday (7/2)
Day	Night


High	Low
87	68

Wednesday (7/3)
Day	Night


High	Low
85

Detailed Text Forecast (Updated: 06/27/19 6:15 am)

Thursday: Mostly sunny, with a high near 91. Heat index values as high as 95. South wind 5 to 10 mph.

Thursday Night: A 40 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 71. South southwest wind 5 to 10 mph.

Friday: A 40 percent chance of showers and thunderstorms, mainly before 8am. Partly sunny, with a high near 91. Heat index values as high as 97. South southwest wind 5 to 15 mph.

Friday Night: A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 71. Southwest wind 5 to 10 mph, with gusts as high as 15 mph.

Saturday: A 30 percent chance of showers and thunderstorms, mainly before 8am. Mostly sunny, with a high near 91. Southwest wind around 5 mph, with gusts as high as 10 mph.

Saturday Night: A slight chance of showers and thunderstorms before 8pm, then a slight chance of showers and thunderstorms after 2am. Partly cloudy, with a low around 70. Chance of precipitation is 20%.

Sunday: A 20 percent chance of showers and thunderstorms before 8am. Mostly sunny, with a high near 91.

Sunday Night: Partly cloudy, with a low around 71.

Monday: Mostly sunny, with a high near 89.

Monday Night: A slight chance of showers and thunderstorms after 8pm. Partly cloudy, with a low around 70.

Tuesday: A chance of showers and thunderstorms. Mostly sunny, with a high near 87.

Tuesday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 68.

Wednesday: A chance of showers and thunderstorms. Partly sunny, with a high near 85.

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SPC Convective Outlook Day 1

See Product Description

064
ACUS01 KWNS 270535
SWODY1
SPC AC 270534

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 AM CDT Thu Jun 27 2019

Valid 271200Z - 281200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER A PORTION
OF CENTRAL AND NORTHERN MONTANA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
MINNESOTA INTO THE SOUTHERN GREAT LAKES...

...SUMMARY...
Scattered thunderstorms capable of very large hail, intense wind
gusts and perhaps a couple of tornadoes will be possible across
portions of west-central into northeastern Montana Thursday
afternoon and night. Other severe storms with damaging wind will be
possible from southern Minnesota into a portion of the Great Lakes.

...Synopsis...

The synoptic upper pattern will remain characterized by a cutoff
upper low over the northwest states and a low amplitude ridge over
the northern Plains. The upper low will drift only very slowly east
during the period. A well-defined MCV associated with storms ongoing
over the central Plains early this morning will continue through the
upper ridge and into the Great Lakes region. At the surface a
quasi-stationary front will reside from the southern Great Lakes
westward into the northern High Plains. A cold front will move
slowly east through the northern Rockies, reaching eastern MT toward
the end of this period.

...Montana through western ND...

Easterly near-surface winds will persist over the northern Plains
north of the stationary front resulting in westward advection of
boundary layer moisture with dewpoints in the 50s F expected across
central MT and near 60 F in the eastern part of the state. With
steep lapse rates already in place, MLCAPE should climb to around
1500 J/kg as the surface layer warms during the day. Another in a
series of vorticity maxima will rotate through the upper low
circulation and into the northern Rockies during the time of peak
destabilization, and storms should redevelop over the higher terrain
and spread northeast into central and northeast MT. A mid-upper jet
along the southeastern periphery of the upper low will contribute to
40-50 kt effective bulk shear supportive of supercell storms as the
initial mode. Very large hail and damaging wind will be the main
threats. Veering low-level wind profiles with height will contribute
to sufficient 0-2 km storm relative helicity for low-level
mesocyclones, and a few tornadoes will be possible especially toward
early evening north of the front across central and northern MT
where LCLs should be lower. Storms may eventually congeal into an
MCS and spread east, reaching western ND overnight with a continued
threat for damaging wind.

...Southern Minnesota into the Great Lakes...

An organized MCS ongoing over western SD will reach southern MN
between 12-15Z today and might pose an ongoing threat for damaging
wind. A well-defined MCV is associated with this MCS. The boundary
layer will become moderately to strongly unstable downstream along
and south of a warm front from southern MN into southern WI. Storms
may redevelop or ongoing storms may intensify as the atmosphere
destabilizes. Activity may reorganize as a forward propagating MCS
and continue east through the southern Great Lakes, generally in
vicinity of the warm front. Damaging wind will be the main threat.
Given potential for an organized wind event, an upgrade to enhanced
might be required for a portion of this region once uncertainties
regarding details of the convective and mesoscale evolution have
been mitigated.

..Dial/Cook.. 06/27/2019

$$

The "Convective Outlooks" issued by SPC can be thought of as a detailed discussion of the Severe Thunderstorm threat and it's associated risks nationwide. Risk levels range from Marginal to Slight, Enhanced, Moderate, and High and are issued based on the likelihood of 3 major severe weather threats; the risk of tornadoes, damaging winds, and hail. These discussions are often heavily laced meteorological terminology that may be difficult to understand without a background in the field. However understanding these discussions shouldn't be thought of as necessary. Instead, should DuPage county fall under one of these threat levels for severe weather, the response should be to have a heightened level of awareness about the deveoloping weather. Keep an eye on the "Watch County Notification" for any active severe weather watches issued for DuPage county; the "Hazardous Weather Outlook" and "Severe Weather Statement" can also be helpful in explaining the developing risk; additionally, watch for "Active Weather Warnings" and keep an eye on our "Regional Satellite and Radar" products which can be viewed with active watches/warnings or lightning activity.

Hazardous Weather Outlook

See Product Description

094
FLUS43 KLOT 270954
HWOLOT

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
454 AM CDT Thu Jun 27 2019

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
281000-
Winnebago-Boone-McHenry-Lake-Ogle-Lee-De Kalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Kankakee-Livingston-Iroquois-Ford-
Porter-Newton-Jasper-Benton-
454 AM CDT Thu Jun 27 2019 /554 AM EDT Thu Jun 27 2019/

This Hazardous Weather Outlook is for portions of North Central
Illinois...Northeast Illinois and Northwest Indiana.

.DAY ONE...Today and Tonight.

Weather hazards expected...

Elevated Thunderstorm Risk...with an associated:
Limited hail risk...up to quarter size.
Elevated damaging wind risk...up to 60 mph.
Limited Flooding Risk.
Limited Excessive heat Risk.

DISCUSSION...

Isolated thunderstorms are possible this afternoon along a lake
breeze in northeast Illinois and northwest Indiana. Confidence is
low for this development.

A line of thunderstorms is expected to form across the upper
midwest this afternoon and move south into far northern Illinois
this evening. There remains low confidence regarding how strong
this activity will be and far south into Illinois it will move.
Strong to severe thunderstorms are possible during this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday...
Limited Severe Thunderstorm Risk.
Limited Excessive Heat Risk.
Saturday through Tuesday...
Limited Thunderstorm Risk.
Limited Excessive Heat Risk.
Wednesday...
Limited Thunderstorm Risk.

DISCUSSION:

There will be periodic chances for thunderstorms but confidence
is low for specific timing and location. If thunderstorms do
develop...they may become strong to severe and produce locally
heavy rain.

A very warm and humid airmass is expected to remain in place
through the middle of next week with high temperatures in the
upper 80s to lower 90s and afternoon heat index values in the
middle to upper 90s.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed this evening.

GENERAL STORM MOTION OF THE DAY:

Moving toward though southeast at 20 to 30 mph.

$$

LMZ740>745-281000-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
454 AM CDT Thu Jun 27 2019

This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.

.DAY ONE...Today and Tonight.

Weather hazards expected...

Limited Thunderstorm Risk...with an associated:
Limited hail risk...up to quarter size.
Limited thunderstorm wind gust risk...up to 60 mph.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday...
Limited Severe Thunderstorm Risk.
Saturday through Wednesday...
Limited Thunderstorm Risk.

$$

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The "Hazardous Weather Outlook" contains information regarding any and all weather expected to occur within the region that could be hazardous to travel, life or property. This is one of our most highly recommended products to check on a daily basis, and it some cases multiple times per day should significant weather be expected to affect DuPage county.

SPC Convective Outlook Day 2

See Product Description

936
ACUS02 KWNS 270557
SWODY2
SPC AC 270556

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Thu Jun 27 2019

Valid 281200Z - 291200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
CENTRAL AND NORTHEAST MT INTO NORTHWEST ND...

...SUMMARY...
Widely scattered severe storms are expected across parts of central
to northeast Montana into western North Dakota on Friday. Large hail
and damaging wind gusts will be possible with these storms.

...Montana into the Dakotas...

A lobe of the Pacific Northwest upper low will eject northeast into
Alberta on Friday, leaving a somewhat weaker/broader trough across
the Pacific Coast. Strong southwesterly 500 mb winds of 50-70 kt
will continue to stream across much of Montana, while easterly
low-level flow maintains mid 50s to low 60s dewpoints as far west as
central MT. Convection is likely to be ongoing at the beginning of
the period and could initially be strong to severe in the vicinity
of northeast MT/northwest ND, but is expected to decay rather
quickly during the morning. Strong heating and a continued stream of
moisture into the area beneath the upper ridge centered over the
Dakotas should result in airmass recovery from morning convection,
and 1000-3000 J/kg MLCAPE is forecast by most guidance by afternoon.
While the shear and instability parameter space will be favorable
for severe storms capable of large hail and damaging wind gusts,
some uncertainty regarding coverage exists as the upper level ridge
builds over the northern Plains and some warming occurs over eastern
MT. With the upper low ejecting northeast, upper forcing for ascent
and continued moist advection across the region should be sufficient
for storms to develop during the afternoon over higher terrain of
southwest/central MT. A low-level jet will modestly increase during
the evening as a weak surface low strengthens across WY, and a
Pacific cold front shifts eastward across MT overnight. This should
support upscale growth into one or more bands of eastward
progressing convection, posing a threat for damaging wind and hail.
The greatest threat during the afternoon and evening will likely
remain across central into northeast MT where capping will not be as
strong as further east.

...Mid-MO Valley to Great Lakes Vicinity...

Severe threat further east remains quite uncertain and will mainly
be driven by mesoscale features dependent in part on ongoing
convection at the beginning of the period. Guidance continues to
vary in where morning convective systems may be ongoing, but
somewhere from IA into WI/MI appears likely as a shortwave impulse
is expected to be located over the upper Great Lakes during the
morning. A belt of 30-40 kt midlevel west/northwesterly flow will
spread across the upper Great Lakes toward NY/PA by the end of the
period. Mid 60s to low 70s F surface dewpoints will be maintained on
south/southwesterly boundary-layer winds and strong heating ahead of
a southward sagging cold front/composite outflow will result in
strong instability and weak capping. Storms are likely to develop in
the vicinity of the surface boundary and near any remnant MCVs and
outflow boundaries from previous convection. Effective shear appears
somewhat marginal, in the 25-35 kt range, likely limiting discrete
cells to some degree. Storm clusters will still be able to take
advantage of large CAPE and steep lapse rates, in addition to high
PWs to produce large hail and damaging gusts. Given uncertainty in
where exactly the greatest severe threat may develop, Marginal
severe probs will be maintained for now.

...MAXIMUM RISK BY HAZARD...
Tornado: 2% - Marginal
Wind: 15% - Slight
Hail: 15% - Slight

..Leitman.. 06/27/2019

$$

The "Convective Outlooks" issued by SPC can be thought of as a detailed discussion of the Severe Thunderstorm threat and it's associated risks nationwide. Risk levels range from Marginal to Slight, Enhanced, Moderate, and High and are issued based on the likelihood of 3 major severe weather threats; the risk of tornadoes, damaging winds, and hail. These discussions are often heavily laced meteorological terminology that may be difficult to understand without a background in the field. However understanding these discussions shouldn't be thought of as necessary. Instead, should DuPage county fall under one of these threat levels for severe weather, the response should be to have a heightened level of awareness about the deveoloping weather. Keep an eye on the "Watch County Notification" for any active severe weather watches issued for DuPage county; the "Hazardous Weather Outlook" and "Severe Weather Statement" can also be helpful in explaining the developing risk; additionally, watch for "Active Weather Warnings" and keep an eye on our "Regional Satellite and Radar" products which can be viewed with active watches/warnings or lightning activity.

SPC Convective Outlook Day 3

See Product Description

279
ACUS03 KWNS 270732
SWODY3
SPC AC 270731

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0231 AM CDT Thu Jun 27 2019

Valid 291200Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
NORTHERN ND INTO NORTHWEST MN...

...SUMMARY...
Severe thunderstorms will be possible across parts of North Dakota
into Minnesota on Saturday. Large hail and damaging winds will be
the main concern.

...North Dakota into the Upper Midwest...

A shortwave trough will shift eastward across the Canadian Prairie
Provinces on Saturday. This will suppress the upper trough over the
northern Plains as it pivots eastward toward the Great Lakes by
Sunday morning. Associated height falls will bring a band of
enhanced west/southwest midlevel flow across parts of ND into MN
while cooling temperatures aloft spread steepening lapse rates
eastward across the region. A cold front near the MT/ND border will
progress east/southeast through the period across the Dakotas and
become a focus for thunderstorm development during the afternoon and
into the overnight hours. Exact evolution of the threat is a bit
unclear as strongest upper forcing for ascent will remain north of
the region, but impressive shear and extreme instability will
support intense convection. Large hail and damaging winds will be
possible with any storms that develop. At least some tornado
potential appears possible as backed low level flow will be present
ahead of the cold front, and at least some orthogonal component of
midlevel flow to the cold front will exit, resulting in at least
isolated potential for discrete storms. However, midlevel capping at
least through late afternoon may temper the tornado threat as
convection could grow upscale during the evening and shift southeast
along the instability gradient into central MN/western WI.

...Eastern OH into PA and the Mid-Atlantic Vicinity...

Convection may be ongoing Friday morning across portions of the
lower Great Lakes as a deepening shortwave trough and attendant cold
front pivot southeast across the northeastern U.S. by Sunday
morning. Ahead of the front, west/southwesterly low-level flow will
maintain 60s F dewpoints. Ensuing height falls will bring
strengthening northwesterly flow and cooling temperatures aloft
across the region. As strong heating occurs, 1000-2000 J/kg MLCAPE
appears plausible. Line segments and thunderstorm clusters capable
of hail and strong gusts will be possible, though timing of the cold
front and impacts from prior day's convection will preclude higher
severe probs at this time.

..Leitman.. 06/27/2019

$$

The "Convective Outlooks" issued by SPC can be thought of as a detailed discussion of the Severe Thunderstorm threat and it's associated risks nationwide. Risk levels range from Marginal to Slight, Enhanced, Moderate, and High and are issued based on the likelihood of 3 major severe weather threats; the risk of tornadoes, damaging winds, and hail. These discussions are often heavily laced meteorological terminology that may be difficult to understand without a background in the field. However understanding these discussions shouldn't be thought of as necessary. Instead, should DuPage county fall under one of these threat levels for severe weather, the response should be to have a heightened level of awareness about the deveoloping weather. Keep an eye on the "Watch County Notification" for any active severe weather watches issued for DuPage county; the "Hazardous Weather Outlook" and "Severe Weather Statement" can also be helpful in explaining the developing risk; additionally, watch for "Active Weather Warnings" and keep an eye on our "Regional Satellite and Radar" products which can be viewed with active watches/warnings or lightning activity.