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Current Conditions

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Current Local Radar

Temperature
72°F
Feels Like:
72°F
Dew Point	Humidity
67°F	85%

Fair

Wind Strength
Light	Moderate	Strong
Southwest at 5 mph

Local Graphical Forecast (Updated: 06/27/19 7:15 am)

Thursday (6/27)
Day	Night

	30%
High	Low
91	71

Friday (6/28)
Day	Night

20%	30%
High	Low
91	71

Saturday (6/29)
Day	Night

20%	20%
High	Low
91	70

Sunday (6/30)
Day	Night


High	Low
91	71

Monday (7/1)
Day	Night


High	Low
90	70

Tuesday (7/2)
Day	Night


High	Low
87	68

Wednesday (7/3)
Day	Night


High	Low
86

Detailed Text Forecast (Updated: 06/27/19 7:15 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 30 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 71. South southwest wind 5 to 10 mph.

Friday: A 20 percent chance of showers and thunderstorms. 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 1am. Mostly cloudy, with a low around 71. Southwest wind 5 to 10 mph.

Saturday: A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91. Southwest wind around 5 mph, with gusts as high as 10 mph.

Saturday Night: A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 70.

Sunday: Mostly sunny, with a high near 91.

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

Monday: Mostly sunny, with a high near 90.

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

Tuesday: A chance of showers and thunderstorms. Partly 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 86.

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SPC Convective Outlook Day 1

See Product Description

635
ACUS01 KWNS 271253
SWODY1
SPC AC 271252

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0752 AM CDT Thu Jun 27 2019

Valid 271300Z - 281200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
CENTRAL/NORTHERN MONTANA AND PARTS OF THE UPPER MISSISSIPPI VALLEY
REGION...

...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 this afternoon
and evening. Other severe storms with damaging wind will be
possible from parts of Minnesota eastward to Lake Michigan.

...Synopsis...
The upper-air pattern this period will continue to feature a
slow-moving synoptic cyclone over the pacific Northwest, and an
amplifying ridge downstream over the Great Plains. A shortwave
trough -- including a very well-defined MCV now evident in
composited radar animations over southern ND -- will move east of
the mean ridge across MN today, reaching the eastern Lake Superior/
eastern Upper MI/northern Lower MI region by 12Z. Another, older
MCV-related shortwave trough -- now apparent in midlevel moisture-
channel imagery over the Mid-South and lowest Ohio Valley -- will be
cut of from the prevailing westerlies for several days starting
today, as it drifts southward to southwestward.

At the surface, the 11Z national chart showed a wavy warm front
across portions of OH, northern IN, northern IL, northeastern IA,
southwestern/west-central MN, intercepted there by an MCS moving
eastward out of SD. The warm front is expected to move northward
through the day across much of WI, Lake Michigan and parts of Lower
MI before being overtaken by the convection. By 00Z, an outflow-
reinforced cold front will extend from southeastern MN or WI across
the central/western SD/NE border area and northeastern WY, arching
west-northwestward as a combined warm front/dryline over south-
central/southeastern MT, into an area of low pressure over south-
central MT. That low-pressure area is expected to move slowly
eastward across central/southern MT through the period, while a
trailing low-level cold front shifts slowly eastward across eastern
ID, eastern NV and western WY.

...MT/ND...
Thunderstorms should develop this afternoon over higher terrain from
southwest of BTM through the GTF area and northeastward toward HVR,
increasing in coverage and intensity as they move into a favorably
moist/unstable air mass. The greatest concentration of convection
and of severe potential still appears to be over the "Enhanced" risk
area, and little change has been made to the previous lines over
this region.

A pronounced, isallobarically forced/maintained easterly component
of boundary-layer winds near the surface is expected north of the
area of surface low pressure. This will contribute to enhanced
low-level storm-relative flow, as well as advection/transport of
supportive moisture into the regime, and favorable deep shear/SRH.
Time series of forecast soundings reasonably depict steady
enlargement/elongation of the preconvective 0-3-km hodographs from
late afternoon through early evening from central to northeastern
MT, amidst 35-50 kt effective-shear magnitudes. This process will
be conterminous with a lowering of LCL related to continued theta-e
advection, and to the early stages of diabatic surface cooling.

As long as the mode remains favorable (i.e., discrete to semi-
discrete supercells, not clustered into a forward-propagational cold
pool already), a slight risk may exist for tornadoes, in addition to
the large/damaging hail and severe gusts attendant to supercells in
such an environment. Before the evening cooling, and lingering
above the shallow near-surface stable layer afterward, will be a
deep layer of well-mixed air with nearly dry-adiabatic lapse rates
favorable for severe gusts. Some consolidation of convection into a
wind-producing, forward-propagating complex is possible over
northern MT this evening.

...Upper Mississippi Valley/Midwest...
An ongoing complex of strong-severe thunderstorms, southeast of the
ND MCV, is expected to produce sporadic severe wind/hail in the near
term as it moves eastward across MN astride the low-level warm-
frontal zone. This activity may organize further through the
remainder of the morning and into the afternoon, as it encounters a
low-level air mass that will be gaining buoyancy. Increasing
inflow-layer CAPE should result from a combination of warm
advection, moist advection, and diabatic surface heating along and
south of the warm front. Associated damaging-wind potential appears
to be relatively maximized from southeastern MN into central WI,
where the greatest juxtaposition of lift and instability should
overlap near the warm front and immediately ahead of the MCS. For
near-term details on this system, refer to SPC severe thunderstorm
watch 452 and accompanying mesoscale discussions.

...Mid-South/Delta region...
Scattered to locally numerous thunderstorms in clusters are expected
to occur episodically, in the zone of enhanced low/midlevel ascent
corresponding to the southern semicircle of the MCV. The most
intense cells will be capable of unloading deeply water-loaded
columns as strong-severe downbursts. Cold pools and related outflow
boundaries may effectively shunt the convective area southward in an
expanding arc, as the foregoing/preconvective boundary layer
diabatically destabilizes through the afternoon. Vertical wind
profiles and shear generally will be weak, indicating storm-scale/
boundary processes will be the primary foci for additional
initiation, and the main influences on storm intensity. Lingering
coolness in midlevels (i.e., -10 to-12 deg C 500-mb temperatures)
will overlie rich low-level theta-e with surface dew points commonly
in the low-mid 70s F. This will yield seasonally steep low/middle-
level lapse rates for the area, and MLCAPE 2500-3500 J/kg in support
of sporadically strong-severe multicells.

...Southern High Plains...
Widely scattered to scattered thunderstorms should occur for a few
hours this afternoon into early evening, offering a short-lived
threat for severe gusts. Activity should form atop an intensely
heated and well-mixed boundary layer characterized by nearly
dry-adiabatic lapse rates and high DCAPE. MLCAPE will range from
less than 500 J/kg in the western fringe to around 1500 J/kg east,
commensurate with the eastward increase in moisture through the
dryline. However, MLCINH also will strengthen substantially
eastward from the dryline, keeping the convective/severe threat from
spreading much into the moist sector. Weak deep-layer flow/shear
also will limit storm organization to multicell/pulse in nature.

..Edwards/Jewell.. 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.