Excessive Heat in Wisconsin, July 2 to 6, 2012

Name: Excessive Heat in Wisconsin, July 2 to 6, 2012
Start: 2012-07-02T10:00
End: 2012-07-06T19:00
Location: Wisconsin

July 2 to 6, 2012 · NWS MKX · 20 events in 20 counties and zones

Where it happened

Every event with a place to put it; 20 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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Wind
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The toll

Deaths: 9
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 20

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS MKX wrote it up.

A hot air mass settled over southern Wisconsin to start the month of July, bringing 100-degree heat to many locations for multiple days between July 2nd and July 6th. While humidity levels were relatively low considering the temperatures, maximum heat indices still climbed to between 100 and 115 during the hot spell. Milwaukee and Madison each recorded two of the top-ten hottest days on record on July 4th and July 5th. Direct heat-related deaths included: a middle-aged man in Dane County, a middle-aged women in the city of Milwaukee and a middle-aged man in the city of Milwaukee. Additionally, indirectly-related heat fatalities occurred in Rock County and in Walworth County in which heat was a secondary cause of death. Based on news reports hundreds of people received medical treatment at hospitals or clinics due to heat-related illnesses, however, the exact number is unknown. These treated people were considered injured and a broad estimate of 300 was assigned to south-central and southeast Wisconsin.

The counties surrounding Dane had 4 days of 100 degrees or higher, while counties toward Lake Michigan had 2 or 3 days. The cites of Janesville, Kenosha, Middleton, Sullivan, and Paddock Lake topped out at 106 degrees, which was Wisconsin's highest temperature for the 2012 summer season. Numerous new daily record highs were set as well as record high minimums. The long duration of this excessive heat period makes this probably one of the four most dangerous heat waves to strike southern Wisconsin in recorded history.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Milwaukee, WI wrote its last area forecast discussion before the first event at Jul 2, 2:30 AM CST, 7 hours 30 minutes earlier.

Area forecast discussion, Jul 2, 2:30 AM CST, 7 hours 30 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
330 AM CDT MON JUL 2 2012

.TODAY AND TONIGHT...FORECAST CONFIDENCE IS LOW TO MEDIUM.

HRRR DEVELOPS AN MCS ALONG THE WARM FRONT THIS MORNING OVER WEST
CENTRAL WI AND DROPS IT SOUTHEAST THRU CWA ALONG WARM FRONT...IN
LINE WITH 00Z NAM AND 00Z ECMWF. HIRES WRF-ARW DOES SOMETHING
SIMILAR...WITH PCPN ALONG FRONT BEING ENHANCED IN THE EAST BY
ADDITIONAL LOW-LEVEL FORCING FROM INTERACTION WITH LAKE BREEZE
BOUNDARY.

CLOUD TOPS ARE COOLING ON IR IMAGERY OVER SE MN INTO ERN IOWA IN
REGION OF 850MB THERMAL AND MOISTURE ADVECTION...WITH LIFT
ENHANCED BY DCVA AHEAD OF WEAK SHORT WAVE CURRENTLY OVER SW MN ON
WATER VAPOR LOOPS.

LIMITING FACTORS ARE CAP THAT HAS TO BE OVERCOME...AND LACK OF
SHEAR TO SUPPORT UPDRAFTS IN OVERALL WEAK FLOW...WHICH HAPPENED
YESTERDAY EVENING WITH SHORT-LIVED CELLS IN MINNESOTA AROUND AND
NORTH OF THE TWIN CITIES. CONVECTIVE PARAMETRIZATION SCHEMES HAVE
BEEN VERY SENSITIVE OF LATE AND FOR THE MOST PART HAVE BEEN TOO
BROAD-BRUSHED WITH PRECIPITATION.

STILL...GIVEN ACTIVITY ALONG THE FRONT THE PAST FEW DAYS THERE IS
STILL SUPPORT TO KEEP A CHANCE FOR STORMS TO FIRE ALONG FRONT
TODAY. HOWEVER...THIS IS A LOW CONFIDENCE FORECAST AND A GOOD CASE
OF ONLY HAVING 100 POPS IN THE ISOLATED AREAS WHERE THE
STORM/STORMS DO DEVELOP AND ZERO POPS EVERYWHERE ELSE SINCE ANY
CONVECTION IS EXPECTED TO BE SPOTTY...CLOSER TO WHAT THE REGIONAL
GEM IS DEPICTING.

WILL TAKE CONVECTION OUT OF MOST OF THE CWA THIS EVENING...BUT
LEAVE A BUFFER OF SLIGHT CHANCES IN THE FAR NE BETWEEN 00Z AND 06Z
TUE TO ACCOUNT FOR POSSIBLE SLOWER PASSAGE OF FRONT TO THE NORTH.

FORECAST SOUNDINGS SHOW POTENTIAL FOR DEEP MIXING AGAIN TODAY WITH
DEW POINTS MIXING OUT INTO THE LOWER 60S...THOUGH SLIGHTLY HIGHER
WITH POOLING ALONG FRONT. 925MB TEMPS SUPPORT MID 90S
INLAND...WITH ONSHORE FLOW LIMITING HIGHS TO THE MID TO UPPER 80S
LAKESIDE. CONVECTION AND CLOUDS COULD TEMPER READINGS. HEAT INDEX
VALUES MAX OUT AT 95 TO 97 IN THE SOUTHWEST AND LOWER ELSEWHERE SO
NO HEAT ADVISORY FOR TODAY AT THIS TIME. NEXT SHIFT WILL HAVE
MONITOR IF CONVECTION DOES NOT FORM...AND TEMPS AND/OR DEW POINTS
GO HIGHER.

WITH LIGHT BUT PERSISTENT SOUTHWEST FLOW...EXPECT LOWS AROUND 06Z
TUESDAY...THEN READINGS STEADY OUT OR SLOWLY RISE.

.SHORT TERM...TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.

UPPER LEVEL RIDGE WILL SHIFT FROM THE NORTHERN PLAINS TO THE
WESTERN GREAT LAKES REGION DURING THIS TIME. BREEZY SOUTHWEST
WINDS DEVELOP ACROSS THE FORECAST AREA ON TUESDAY...AS PRESSURE
GRADIENT INCREASES WITHIN WARM SECTOR AIRMASS. AREA FORECAST
SOUNDINGS FROM NAM SHOWING DEEP MIXING FROM THE SURFACE UP TO
AROUND 750MB...WHICH WILL ALLOW FOR GUSTS IN THE 20 TO 25 MPH
RANGE.

925MB TEMPERATURES OF 30 TO 32 DEGREES CELSIUS ON THE NAM SUGGEST
HIGHS IN THE UPPER 90S TO AROUND 100 ACROSS THE ENTIRE AREA. DEW
POINTS SHOULD MIX DOWN INTO AT LEAST THE MID 60S FAHRENHEIT DURING
THE AFTERNOON...POSSIBLY LOWER. THIS WILL BRING HEAT INDEX VALUES
OF 100 TO 105 ACROSS THE AREA. THUS...A HEAT ADVISORY WILL LIKELY
NEED TO BE ISSUED LATER TODAY FOR TUESDAY.

NAM BRINGS COLD FRONT SOUTHEAST INTO THE AREA DURING THE LATE
AFTERNOON HOURS TUESDAY...THEN SOUTHEAST THROUGH THE REST OF THE
AREA TUESDAY EVENING...WITH HIGH PRESSURE FOR INDEPENDENCE DAY
INTO WEDNESDAY NIGHT. GFS/ECMWF/CANADIAN SHOWING FRONT NOT MOVING
INTO THE AREA UNTIL LATE TUESDAY NIGHT INTO WEDNESDAY...THEN HAS
LIGHT QPF ACROSS PORTIONS OF THE AREA WEDNESDAY.

NAM HAS MODEST LOW LEVEL FRONTOGENESIS RESPONSE WITH THE FRONTAL
PASSAGE LATE TUESDAY AND TUESDAY NIGHT...WITH A PASSING VORTICITY
MAXIMUM. GFS IS WEAKER WITH THE FRONTOGENESIS RESPONSE IN THIS
LAYER THAN THE NAM. IN ADDITION...THE OTHER MODELS DELAY THE
VORTICITY MAXIMUM PASSAGE UNTIL WEDNESDAY. NAM MEAN LAYER CAPES
IMPRESSIVE WITH DEEP MIXING AND LITTLE CAP LATE TUESDAY...BUT NOT
SURE IF ENOUGH LIFT WILL TAP INTO THIS INSTABILITY.

LEANING TOWARD THE DRIER LOOK OF THE NAM...GIVEN THE DRY PATTERN
WE HAVE BEEN IN...BUT WILL LEAN TOWARD THE TIMING OF THE OTHER
MODELS. KEPT TUESDAY DRY...AND HAVE SLIGHT CHANCES FOR THUNDER
TUESDAY NIGHT IN THE NORTHEAST HALF OF THE AREA...LINGERING IN THE
FAR SOUTHEAST COUNTIES ON INDEPENDENCE DAY. THIS PERIOD COULD VERY
WELL BE DRY.

HIGHS INDEPENDENCE DAY WILL REMAIN VERY WARM AWAY FROM LAKE
MICHIGAN. EXPECTED DEW POINTS IN THE UPPER 60S SHOULD BRING HEAT
INDEX VALUES NEAR OR JUST ABOVE 100 DEGREES ACROSS SOUTH CENTRAL
INTO PORTIONS OF SOUTHEAST WISCONSIN AWAY FROM THE LAKE. ANOTHER
HEAT ADVISORY MAY BE NEEDED ON INDEPENDENCE DAY IN THESE AREAS.

.LONG TERM...THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS
MEDIUM.

UPPER LEVEL ANTICYCLONE OVER EASTERN KANSAS AND WESTERN MISSOURI
WILL GENERALLY LINGER THROUGH THIS PERIOD. RIDGE AXIS OVER THE
REGION THURSDAY WILL SHIFT EAST BY FRIDAY...WITH ANOTHER RIDGE
AXIS BUILDING IN THE NORTHERN PLAINS ON SATURDAY. AREA GETS INTO
MORE NORTHWESTERLY FLOW OVER THE WEEKEND. CONTINUE TO FAVOR THE
DRIER LOOK OF THE ECMWF FOR THURSDAY THROUGH THURSDAY NIGHT...WITH
THE FRONTAL BOUNDARY REMAINING NORTH OF THE AREA.

THIS SHOULD ALLOW TEMPERATURES TO BECOME VERY WARM ONCE
AGAIN...WITH 925MB TEMPERATURES SUPPORTING LOWER TO MID 90S. DEW
POINTS IN THE 60S MAY LEAD TO HEAT INDEX VALUES ONCE AGAIN NEAR
CRITERIA FOR AN ADVISORY.

COLD FRONT FINALLY DROPS SOUTH THROUGH THE AREA SATURDAY ON
ECMWF...WITH NORTHEAST WINDS PERHAPS BRINGING COOLER AND MORE
SEASONABLE TEMPERATURES BY SUNDAY. GFS QUICKER WITH THIS FRONTAL
PASSAGE...SO USED CONSENSUS POPS AND TEMPERATURES FOR THE WEEKEND.

&&

.AVIATION/12Z TAFS/...

EXCEPT FOR PATCHY GROUND FOG REDUCING VSBYS AT TIMES...EXPECT VFR
CONDITIONS THROUGH THE FORECAST PERIOD. EASTERN SITES WILL HAVE A
SLIGHTLY BETTER CHANCE TO SEE THUNDER BUT CONVECTION CHANCES AT
ANY ONE TAF SITE ARE TOO LOW TO PUT IN FORECAST. IF A SITE GETS
CONVECTION...WILL SEE LOWER MVFR CIGS/VSBYS.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...WOOD

Hazardous weather outlook, Jul 2, 10:00 AM CST, 0 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1100 AM CDT MON JUL 2 2012

WIZ046-047-051-052-056>060-062>072-030930-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
1100 AM CDT MON JUL 2 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL
WISCONSIN...SOUTH CENTRAL WISCONSIN AND SOUTHEAST WISCONSIN.

.DAY ONE...REST OF TODAY AND TONIGHT

HEAT INDEX VALUES WILL RANGE FROM 95 TO 100 TODAY...WITH LOWER
VALUES NEAR LAKE MICHIGAN. A HEAT ADVISORY IS IN EFFECT THROUGH
FRIDAY DUE TO THE PROLONGED HEAT EVENT FOR SOUTH CENTRAL AND
SOUTHEAST WISCONSIN...EXCEPT FOR THE LAKESHORE COUNTIES.

THERE IS A SMALL CHANCE FOR A THUNDERSTORM OR TWO TO DEVELOP THIS
AFTERNOON THROUGH EARLY EVENING AS A WARM FRONT LIFTS THROUGH THE
REGION. IF THUNDERSTORMS DEVELOP...THERE IS A SLIGHT RISK FOR SEVERE
WEATHER NORTHEAST OF A WISCONSIN DELLS TO RACINE LINE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

HEAT INDEX VALUES WILL RANGE FROM 95 TO 105 FOR MUCH OF THE WEEK
INLAND FROM LAKE MICHIGAN. THE HOTTEST DAY WILL BE TUESDAY WHEN AIR
TEMPERATURES ARE FORECAST TO BE AROUND 100 INCLUDING LOCATIONS NEAR
LAKE MICHIGAN. A HEAT ADVISORY IS IN EFFECT FOR THE WHOLE AREA ON
TUESDAY...AND FOR INLAND COUNTIES THROUGH FRIDAY EVENING.

A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE REGION TUESDAY NIGHT
AND WEDNESDAY BRINGING SMALL CHANCES OF THUNDERSTORMS. ANOTHER FRONT
WILL BRING SMALL CHANCES OF THUNDERSTORMS FOR FRIDAY NIGHT INTO
THE WEEKEND.

A COMBINATION OF HOT TEMPERATURES...BREEZY SOUTHWEST WINDS AND THE
PERSISTENT DRY CONDITIONS WILL LEAD TO ELEVATED FIRE CONDITIONS
TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EARLY EVENING.

LMZ643>646-030930-
SHEBOYGAN TO PORT WASHINGTON WI-
PORT WASHINGTON TO NORTH POINT LIGHT WI-
NORTH POINT LIGHT TO WIND POINT WI-
WIND POINT WI TO WINTHROP HARBOR IL-
1100 AM CDT MON JUL 2 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...REST OF TODAY AND TONIGHT

THERE IS A SMALL CHANCE FOR A THUNDERSTORM OR TWO TO DEVELOP THIS
AFTERNOON THROUGH EARLY EVENING AS A WARM FRONT LIFTS THROUGH THE
REGION. IF THUNDERSTORMS DEVELOP...THERE IS A SLIGHT RISK FOR SEVERE
WEATHER NORTH OF WIND POINT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SOUTHWEST WIND GUSTS WILL APPROACH SMALL CRAFT CRITERIA TUESDAY.

A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE REGION TUESDAY NIGHT
AND WEDNESDAY BRINGING SMALL CHANCES OF THUNDERSTORMS. ANOTHER
FRONT WILL BRING SMALL CHANCES OF THUNDERSTORMS FOR FRIDAY NIGHT
INTO THE WEEKEND.

MRC
WWW.WEATHER.GOV/MKX

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

20 excessive heat. Local standard time, as filed.

Excessive Heat, Marquette

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Marquette forecast zone
Reported by: COOP Observer
Coordinates: 43.820, -89.399 (the zone’s center; the record gives no point)

Excessive Heat, Green Lake

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Green Lake forecast zone
Reported by: COOP Observer
Coordinates: 43.800, -89.045 (the zone’s center; the record gives no point)

Excessive Heat, Sauk

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Sauk forecast zone
Reported by: AWOS
Coordinates: 43.427, -89.948 (the zone’s center; the record gives no point)

Excessive Heat, Columbia

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Columbia forecast zone
Deaths: 2 direct, 0 indirect
Reported by: COOP Observer
Coordinates: 43.467, -89.334 (the zone’s center; the record gives no point)

Excessive Heat, Iowa

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Iowa forecast zone
Reported by: AWOS
Coordinates: 43.001, -90.135 (the zone’s center; the record gives no point)

Excessive Heat, Dane

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Dane forecast zone
Deaths: 1 direct, 0 indirect
Reported by: ASOS
Coordinates: 43.067, -89.418 (the zone’s center; the record gives no point)

Excessive Heat, Lafayette

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Lafayette forecast zone
Reported by: COOP Observer
Coordinates: 42.661, -90.132 (the zone’s center; the record gives no point)

Excessive Heat, Green

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Green forecast zone
Reported by: AWOS
Coordinates: 42.680, -89.602 (the zone’s center; the record gives no point)

Excessive Heat, Rock

When: July 2, 10:00 AM CST to July 6, 7:00 PM CST
Where: Rock forecast zone
Deaths: 0 direct, 3 indirect
Reported by: AWOS
Coordinates: 42.671, -89.072 (the zone’s center; the record gives no point)

Excessive Heat, Fond du Lac

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Fond du Lac forecast zone
Reported by: ASOS
Coordinates: 43.754, -88.488 (the zone’s center; the record gives no point)

Excessive Heat, Sheboygan

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Sheboygan forecast zone
Reported by: ASOS
Coordinates: 43.756, -87.800 (the zone’s center; the record gives no point)

Excessive Heat, Dodge

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Dodge forecast zone
Reported by: AWOS
Coordinates: 43.416, -88.707 (the zone’s center; the record gives no point)

Excessive Heat, Washington

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Washington forecast zone
Reported by: AWOS
Coordinates: 43.369, -88.231 (the zone’s center; the record gives no point)

Excessive Heat, Ozaukee

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Ozaukee forecast zone
Reported by: COOP Observer
Coordinates: 43.403, -87.891 (the zone’s center; the record gives no point)

Excessive Heat, Jefferson

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Jefferson forecast zone
Reported by: AWOS
Coordinates: 43.021, -88.776 (the zone’s center; the record gives no point)

Excessive Heat, Waukesha

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Waukesha forecast zone
Reported by: AWOS
Coordinates: 43.018, -88.304 (the zone’s center; the record gives no point)

Excessive Heat, Milwaukee

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Milwaukee forecast zone
Deaths: 2 direct, 0 indirect
Reported by: ASOS
Coordinates: 43.022, -87.929 (the zone’s center; the record gives no point)

Excessive Heat, Walworth

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Walworth forecast zone
Deaths: 0 direct, 1 indirect
Reported by: COOP Observer
Coordinates: 42.669, -88.542 (the zone’s center; the record gives no point)

Excessive Heat, Racine

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Racine forecast zone
Reported by: ASOS
Coordinates: 42.730, -87.812 (the zone’s center; the record gives no point)

Excessive Heat, Kenosha

When: July 3, 11:00 AM CST to July 6, 3:00 PM CST
Where: Kenosha forecast zone
Reported by: ASOS
Coordinates: 42.573, -87.840 (the zone’s center; the record gives no point)

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Excessive Heat, Columbia	2012-07-06		Male	Permanent Home	Direct
Excessive Heat, Columbia	2012-07-07		Female	Permanent Home	Direct
Excessive Heat, Dane	2012-07-06	37	Male	Permanent Home	Direct
Excessive Heat, Rock	2012-07-05	83	Female	Permanent Home	Indirect
Excessive Heat, Rock	2012-07-08		Male	Permanent Home	Indirect
Excessive Heat, Rock	2012-07-10		Male	Permanent Home	Indirect
Excessive Heat, Milwaukee	2012-07-05	49	Female	Permanent Home	Direct
Excessive Heat, Milwaukee	2012-07-06	42	Male	Permanent Home	Direct
Excessive Heat, Walworth	2012-07-05		Male	Other	Indirect

What these are

Excessive Heat: Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Wisconsin in 2012 Every state in 2012 This day in weather history Warnings in Wisconsin, July 2012

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 404556, 404557, 404558, 404559, 404560, 404561, 404562, 404563, 404564, 404565, 404566, 404567, 404568, 404569, 404570, 404571, 404572, 404573, 404574, 404575.