Winter Storm in Wisconsin, April 11, 2007

Name: Winter Storm in Wisconsin, April 11, 2007
Start: 2007-04-11T02:00
End: 2007-04-11T17:00
Location: Wisconsin

April 11, 2007 · NWS MKX · 19 events in 19 counties and zones

Where it happened

Every event with a place to put it; 19 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 1
Injuries: 0
Property damage: $190,000
Crop damage: None recorded
Events: 19

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 strong winter storm affected much of south-central and southeast Wisconsin on April 11th. Although heavy, wet snow accumulated to 3 to 8 inches, east-northeast winds gusting to around 30 to 42 knots (35 to 48 mph) created near-blizzard conditions (visibility of 1/4 to 1/2 mile for a couple hours) in open areas when convective bands of snow moved through. The maximum wind gust of 42 knots (48 mph) was measured at on the Kenosha city lakeshore. Some rain, freezing rain, and sleet were mixed in with the snow. With temperatures hovering around the freezing mark, some snowmelt occurred while it was snowing. The combination of ice accumulating on power lines, snow accumulations on trees and tree branches, and the gusty winds resulted in scattered power outages. About 10,000 customer lost electrical power in south-central Wisconsin and about 44,000 lost power in the southeastern counties. Newspaper articles indicated that there were numerous vehicle accidents due to slippery roads and poor visibilities. Many schools were closed. Milwaukee Mitchell Field (Milwaukee Co.) and Madison Truax Field (Dane Co.) both set new daily snowfall records of 7.0 and 5.3 inches, respectively. The old records were 3.2 and 3.8 inches, respectively; set back in 1997. Numerous airplane flights were delayed by up to 3 hour or more, or were cancelled at the Milwaukee and Madison airports. Other maximum county snowfall amounts, either measured or estimated, include 8 inches in southeast Marquette County, 8 inches in northcentral Columbia County, 8 inches in Hales Corner (Milwaukee Co.), 8 inches in Union Grove (Racine Co.), 8 inches in Delevan (Walworth Co.), 7 inches in Reedsburg (Sauk Co.), 7 inches in southwest Green Lake County, 7 inches in extreme northcentral Kenosha County, 7 inches in southeast Waukesha County, 6.9 inches in Mt. Horeb (Dane Co.), 6.5 inches in Clinton (Rock Co.), 6.5 inches in eastern Iowa County, 6.4 inches in Arygle (Lafayette Co.), 6.2 inches in Cedarburg (Ozaukee Co.) 6 inches in northwest Green County, 6 inches in western Dodge County, 6 inches in Jackson (Washington Co.), 6 inches in far northwest Jefferson County, and 5.5 to 6 inches in far northeast Fond du Lac County and far northwest Sheboygan Counties. On the low side, only 3 to 4 inches accumulated in a swath from Janesville to Watertown to Fond du Lac. At the start of the storm, a 17-year old boy died from the secondary effects (indirectly-related) of hypothermia/exposure near Busseyville in southwestern Jefferson County. He was found dead in a marshy location on Koshkonong Creek.

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 Apr 10, 7:45 PM CST, 6 hours 15 minutes earlier.

Area forecast discussion, Apr 10, 7:45 PM CST, 6 hours 15 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
845 PM CDT TUE APR 10 2007

NO BIG SURPRISES SHOWING UP THUS FAR...SO ANTICIPATE LITTLE CHANGE
TO THE FORECAST THIS EVENING.  KDVN SOUNDING DID COME IN MUCH DRIER
THAN THE 18Z NAM FOR 00Z WED. WHILE THE OBSERVED SOUNDING AT GREEN BAY
WAS PRETTY CLOSE. WE NEED SOME EVAPORATIVE COOLING TO BRING THESE
TEMPS DOWN IN ORDER TO SUPPORT THE HEAVY SNOWFALL.  DWPNTS ACROSS
THE CWA STILL HOLDING IN THE LOWER TO MID 20S ACRSS THE WRN CWA...IN
THE UPPER 20S IN THE EAST DUE TO THE MARINE INFLUENCE FROM LAKE
MICHIGAN. AIR TEMPS IN THE EAST IN THE MID TO UPPER 30S WHILE STILL
IN THE LOWER TO MID 40S ACROSS THE WEST.  THE EVAPORATIVE AND
DYNAMIC COOLING WILL BE EFFECTIVE AND EXPECT TEMPS TO BE COLD ENOUGH
DURING THE PRODUCTIVE PERIOD OF THIS STORM.

WATER VAPOR IMPRESSIVE WITH H7 WAA AND THETA-E ADVECTION ACROSS MN
AND IA SHOWING UP NICELY. PROFILER OVR SRN MO SHOWS H8 WNDS BLOWING
ABOUT 55KTS.  GULF IS TAPPED EFFICIENTLY.

ANY UPDATES TO THE FORECAST THIS EVENING WILL BE TO INITIAL
TIMING...WILL NOT BE ADJUSTING ANY SNOWFALL ACCUMULATIONS.

SNOWFALL TOTALS WILL BE A DIFFICULT ISSUE. SOIL TEMPS HOLDING AT
AROUND 40 DEGREES. THERE WILL BE SOME MELTING AT THE BOTTOM LAYER OF
THE SNOWPACK AS THE SNOW PILES UP.  A SLUSHY LAYER WILL LIKELY
DEVELOP...CAUSING THE SNOW DEPTH TO DIMINISH AS TIME GOES ON.
TYPICAL FOR THIS TIME OF YEAR...THOUGH.

DAVIS

---- PREVIOUS DISCUSSION BELOW ----

.SHORT TERM...
TONIGHT THROUGH WEDNESDAY NIGHT-
SURFACE LOW NOW ORGANIZING OVER TEXAS PANHANDLE WITH 4-5 MB 3 HOUR
FALLS. THIS LOW SHOULD MOVE ACROSS OKLAHOMA AND GRADUALLY ABSORB
NORTHERN LOW OVER NEBRASKA/KANSAS. THE SYSTEM SHOULD DEEPEN LATE
TONIGHT AND WEDNESDAY AS IT MOVES ACROSS MO-IL-IN. LOW THEN HOOKS
A BIT WEDNESDAY NIGHT AND NAM ACTUALLY TUCKS IT BACK OVER SOUTHERN
LAKE MICHIGAN FOR A WHILE THOUGH MOST GUIDANCE TAKES IT INTO LOWER
MICHIGAN.

OBVIOUSLY THIS IS A VERY FAVORABLE TRACK FOR HEAVY SNOW FOR
SOUTHERN WISCONSIN. MODELS CONTINUE TO TREND A TAD COLDER WITH 850
MB TEMPS HOLDING IN FAVORABLE -3 TO -5 C RANGE MOST OF THE EVENT
NOW. STRONG 850 TO 700 MB WARM ADVECTION SHOWN ESPECIALLY VERY
LATE TONIGHT INTO WEDNESDAY...WITH CLASSIC 50 TO 60 KNOT EASTERLY
850 MB JET TYPICAL OF BIG SNOWSTORMS RIGHT OVER SOUTHERN WISCONSIN
BY 18Z WEDNESDAY. GFS HAS STRONGEST FRONTOGENESIS IN 800 TO 600 MB
LAYER AROUND 00Z THURSDAY...SO WENT WITH WARNING UNTIL 03Z
SOUTHWEST AND 06Z NORTHWEST PART OF CWA.

TOTAL QPF RANGES FROM 0.75 TO 1 ON GFS TO 1 TO 1.75 ON NAM.
LOCAL 4 KM AND 20 KM WRF ARW RUNS ARE BETWEEN THE GFS AND NAM SO
WENT WITH 0.90 TO 1.30 QPF FROM NORTH TO SOUTH ACROSS CWA.

LOOKING OVER COBB AND ROEBBER TECHNIQUES...WENT WITH 11 TO 1
RATIO NORTHWEST...10 TO 1 RATIO CENTRAL...AND 8 TO 1 RATIO EAST OF
THE KETTLE MORAINE RIDGE ALONG THE LAKE MICHIGAN SHORELINE. THIS
YIELDS 8 TO 10 INCHES OF SNOW MOST AREAS AND ABOUT A FOOT ALONG
THE KETTLE MORAINE RIDGE FROM WESTERN SHEBOYGAN COUNTY TO
NORTHWEST WALWORTH COUNTY. NAM AND LOCAL WRF MODELS INDICATE
ENHANCED CONVERGENCE AND QPF IN THIS AREA.

PRECIPITATION WILL BE SLOW TO DEVELOP THIS EVENING AS LOW LEVEL
DRY AIR MUST BE MOISTENED FROM PRECIPITATING DECK ABOVE. GIVEN MID
40S TEMPERATURES THIS AFTERNOON SOME OF THE PRECIPITATION WILL
START AS RAIN OR MELTING WET SNOW BEFORE CHANGING OVER TO ALL SNOW
AFTER MIDNIGHT. THE PRECIPITATION MAY TAKE UNTIL ALMOST MORNING TO
REACH THE SHEBOYGAN AREA.

A LITTLE MORE CYCLOGENESIS INDICATED THAN EARLIER RUNS WITH THIS
EVENT SO WINDS WILL BE STRONGER AND WENT WITH A WINTER STORM
WARNING RATHER THAN HEAVY SNOW WARNING. GIVEN THE WET NATURE OF
THE SNOW THE BLOWING AND DRIFTING MAY NOT BE AS SIGNIFICANT AS
SOME WINTER STORMS.

THURSDAY AND FRIDAY -
RIDGE SHOULD BUILD IN BETWEEN SYSTEMS AND ALLOW FOR DRY WEATHER
THOUGH READINGS DURING THE DAY COULD BE 5 TO 10 DEGREES BELOW
NORMAL. DID NOT FULLY ACCOUNT FOR SNOW COVER EFFECTS AND THIS MAY
NEED TO BE ADJUSTED DOWNWARD IF WE GET CLEARING AT NIGHT.

.LONG TERM...
SATURDAY-
12Z GFSENSEMBLES AND 12Z OPERATIONAL GFS CONTINUED SOUTHWARD
TREND...00Z AND 12Z ECMWF ARE SOUTH. THUS RATHER THAN HAVING A
RAIN EVENT WITH MIX NORTH IT MAY END UP BEING EITHER ALL SNOW OR
THE NORTHERN EDGE OF PRECIPITATION SHIELD. CUT TEMPERATURES QUITE
A BIT...INTRODUCED MORE SNOW...AND TOOK OUT THUNDER. ALSO QPF IS
MUCH LOWER.

SUNDAY AND MONDAY-
ANOTHER BREAK AS HIGH PRESSURE BUILDS IN.

MONDAY NIGHT INTO TUESDAY-
06Z AND 12Z GFS SHOWS WEAK FRONT MOVING THROUGH WITH A SLIGHT
CHANCE OF SHOWERS.  NOT A BIG DEAL.

CRAVEN

&&

.AVIATION...
DRY INFLUENCE OF DEPARTING HIGH HAVING A SAY ON ADVANCE
OF THICKER CLOUDS/PCPN. NEVERTHELESS 88-D SHOWING MALF RETURNS FROM
SE MN INTO SW WI WITH STG H7 WAA. MAINLY VFC CIGS ACRS ERN IA AND
ERN MN. WITH MAINLY ERN COMPONENT OF LOW LEVEL WIND FIELD TNGT
WOULDNT BE SURPRISED IF SLOWER ONSET OF MVFR/IFR CIGS PLAYED OUT BY
GFS MOS ENDS UP BEING RIGHT. WILL LEAN IN THAT DIRECTION FOR NOW.
WILL USE LOCAL WRF MODEL AS A GUIDE TO BRING IN QPF TOWARDS AND
AFTER MIDNIGHT...WHICH HELP MOISTEN UP THE LOWER LEVELS LEADING TO
THE LOWER CIGS. STRONGEST LIFT EXPECTED DURG THE DAY ON WEDNESDAY SO
HAVE IFR CIGS/VSBYS THRU AT LEAST 18Z WITH MOST LIKELY A
CONTINUATION OF THESE TRENDS AND PERHAPS INTO THE LIFR RANGE AFTER
18Z.

10

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 1 AM TO 10 PM CDT WEDNESDAY FOR WIZ056-
057-062>064-067>070.

WINTER STORM WARNING FROM 4 AM WEDNESDAY TO 1 AM CDT THURSDAY
FOR WIZ046-047-051-052-058>060-065-066-071-072.

&&

CRAVEN/02 - LONG TERM
COLLAR/10 - AVIATION

Hazardous weather outlook, Apr 10, 2:40 PM CST, 11 hours 20 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
340 PM CDT TUE APR 10 2007

WIZ046-047-051-052-056>060-062>072-111100-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
340 PM CDT TUE APR 10 2007

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

.DAY ONE...TONIGHT

A WINTER STORM WARNING IS IN EFFECT FOR ALL OF SOUTHERN WISCONSIN
FOR LATER TONIGHT. PLEASE REFER TO THE URGENT WINTER WEATHER MESSAGE
FOR ALL OF THE DETAILED INFORMATION ON THIS STORM SITUATION.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A WINTER STORM IS IN EFFECT FOR ALL OF SOUTHERN WISCONSIN WEDNESDAY
INTO WEDNESDAY EVENING. AGAIN...PLEASE REFER TO THE URGENT WINTER
WEATHER MESSAGE FOR MORE INFORMATION.

SNOW OR RAIN IS EXPECTED FRIDAY NIGHT INTO SATURDAY. THE
PRECIPITATION TOTALS FROM THIS INITIAL SYSTEM...COMBINED WITH THIS
NEXT STORM SYSTEM MAY CAUSE MORE RIVER LEVELS TO RISE TO...OR ABOVE
FLOOD STAGE.

.SPOTTER INFORMATION STATEMENT...

SNOW REPORTS TONIGHT INTO WEDNESDAY NIGHT WOULD BE APPRECIATED.

LMZ643>646-665-111100-
SHEBOYGAN TO PORT WASHINGTON-
PORT WASHINGTON TO NORTH POINT LIGHTHOUSE-
NORTH POINT LIGHTHOUSE TO WIND POINT-
WIND POINT TO WINTHROP HARBOR ILLINOIS-
WISCONSIN ADJACENT OPEN WATERS OF LAKE MICHIGAN TO MID LAKE-
340 PM CDT TUE APR 10 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...TONIGHT

A SMALL CRAFT ADVISORY IS IN EFFECT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH THURSDAY AFTERNOON. A
GALE WARNING MAY BE REQUIRED FOR WEDNESDAY.

CONDITIONS MAY REACH SMALL CRAFT ADVISORY CRITERIA FRIDAY NIGHT
THROUGH SUNDAY.

COLLAR
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

19 winter storm. Local standard time, as filed.

Winter Storm, Marquette

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Marquette forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.820, -89.399 (the zone’s center; the record gives no point)

Winter Storm, Green Lake

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Green Lake forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.800, -89.045 (the zone’s center; the record gives no point)

Winter Storm, Fond du Lac

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Fond du Lac forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.754, -88.488 (the zone’s center; the record gives no point)

Winter Storm, Sheboygan

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Sheboygan forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.756, -87.800 (the zone’s center; the record gives no point)

Winter Storm, Sauk

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Sauk forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.427, -89.948 (the zone’s center; the record gives no point)

Winter Storm, Columbia

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Columbia forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.467, -89.334 (the zone’s center; the record gives no point)

Winter Storm, Dodge

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Dodge forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.416, -88.707 (the zone’s center; the record gives no point)

Winter Storm, Ozaukee

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Ozaukee forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.403, -87.891 (the zone’s center; the record gives no point)

Winter Storm, Iowa

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Iowa forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.001, -90.135 (the zone’s center; the record gives no point)

Winter Storm, Dane

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Dane forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.067, -89.418 (the zone’s center; the record gives no point)

Winter Storm, Jefferson

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Jefferson forecast zone
Deaths: 0 direct, 1 indirect
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.021, -88.776 (the zone’s center; the record gives no point)

Winter Storm, Waukesha

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Waukesha forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.018, -88.304 (the zone’s center; the record gives no point)

Winter Storm, Milwaukee

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Milwaukee forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 43.022, -87.929 (the zone’s center; the record gives no point)

Winter Storm, Lafayette

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Lafayette forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 42.661, -90.132 (the zone’s center; the record gives no point)

Winter Storm, Green

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Green forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 42.680, -89.602 (the zone’s center; the record gives no point)

Winter Storm, Rock

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Rock forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 42.671, -89.072 (the zone’s center; the record gives no point)

Winter Storm, Walworth

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Walworth forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 42.669, -88.542 (the zone’s center; the record gives no point)

Winter Storm, Racine

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Racine forecast zone
Property damage: $10,000
Reported by: COOP Observer
Coordinates: 42.730, -87.812 (the zone’s center; the record gives no point)

Winter Storm, Kenosha

When: April 11, 2:00 AM CST to 5:00 PM CST
Where: Kenosha forecast zone
Property damage: $10,000
Reported by: COOP Observer
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
Winter Storm, Jefferson	2007-04-11	17	Male	Outside/Open Areas	Indirect

What these are

Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.

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

The same day elsewhere

Every storm in Wisconsin in 2007 Every state in 2007 This day in weather history Warnings in Wisconsin, April 2007

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: 29425, 29426, 29427, 29428, 29429, 29430, 29431, 29432, 29433, 29434, 29435, 29436, 29437, 29438, 29439, 29440, 29441, 29442, 29443.