Parts of southeast Wisconsin lay within the warm sector of a mid-latitude cyclone for much of the day with persistent southerly winds blowing ahead of a cold front draped from western Iowa through the Texas panhandle.  As the front pushed across southwest Wisconsin, moderate CAPE and strong shear were present and two lines of thunderstorms developed, with the second of these lines producing three weak tornadoes. One inch diameter hail was also reported in association with the second line of thunderstorms.

Tornado in GREEN LAKE, WISCONSIN
From 30-APR-10 18:19:00 to 30-APR-10 18:20:00 (CST-6)
Location: KINGSTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

This Green Lake County tornado segment was the 2nd of a 3-segment tornado that initially started in Marquette County.  This Green Lake County segment started about 1 mile north of where the Fox River enters Green Lake County, and moved northeast.  A survey of this segment was not possible due to swamp conditions along the path. However, ths tornado was seen by people near Princeton in Green .  It is assumed that there was minor vegetative damage along this 2nd segment.  The average path width in this 2nd segment was estimated at 30 yards. The damage indicator used to rate this segment was: DI 27 (TH), DOD 3, 75-80 mph.  This tornado exited Green Lake County over the far northwest corner of Pukaway Lake and re-entered Marquette County and eventually dissipated near Fern Dr. and 22nd Ln at 1824 CST.  Refer to the two Marquette County segments for other details.

Tornado in MARQUETTE, WISCONSIN
From 30-APR-10 18:20:00 to 30-APR-10 18:24:00 (CST-6)
Location: MONTELLO
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This Marquette County tornado segment was the 3rd of a 3-segment tornado that initially started in Marquette County at 1815 CST and then crossed Green Lake County and re-entered Marquette County.  It re-entered just southwest of the intersection of CTH C and 20th Ct. and moved northeast.  Several trees had broken branches or were partially uprooted.  It ended near Fern Dr. and 22nd Ln at 1824 CST.  The average path width in this 3rd segment was estimated at 30 yards.  The damage indicator used to rate this segment was: DI 27 (TH), DOD 3, 75-80 mph.  Refer to the associated Green Lake County and  Marquette County segments for other details.

Tornado in MARQUETTE, WISCONSIN
From 30-APR-10 18:15:00 to 30-APR-10 18:17:00 (CST-6)
Location: GLENOAK
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado segment is the 1st of a 2-segment, weak, tornado that spun up about 4 miles southeast of Glen Oak in Marquette County.  It moved northeast into Green Lake County where it eventually dissipated on the north shore of Pukaway Lake.  Specifically, it spun up about 1/2 mile southeast of the intersection of CTY B and 16th Rd. and exited Marquette County roughly 2 miles to the northeast in the middle of the Grand River.  Several trees were damaged or partially uprooted.  There was no other structural damage.  The average path width was 35 yards.  The EF0 rating was based on DI 27 (TH), and DOD 2, 65-70 mph, after a NWS survey.  The responsible thunderstorm was the sourthern of two parallel-moving storms with weak circulations, each moving northeast.    Refer to the second segment that continue into Green Lake County.

Tornado in MARQUETTE, WISCONSIN
From 30-APR-10 18:15:00 to 30-APR-10 18:19:00 (CST-6)
Location: GLENOAK
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This weak tornado had 3 segments - Marquette County, Green Lake County, and a final path back in Marquette County.  The first segment, described here, spun up southeast of Glen Oak near the intersection of Hwy 22 and 16th Ct., and moved northeast.  Several trees had broken branches or were parrtially uprooted.  The damage indicator used to rate this segment was: DI 27 (TH), DOD 3, 75-80 mph.  This tornado exited Marquette County and went into Green Lake County, about a mile north of where the Fox River exits Marquette County.  The average path width was 30 yards.  The responsible thunderstorm was the northern of two parallel-moving thunderstorms with embedded  circulations.  Refer to the Green Lake County segment extension and the final segment that occurred in Marquette County.  This tornado ultimately ended at 1824 CST in Marquette County.

Hail in GREEN LAKE, WISCONSIN
From 30-APR-10 18:00:00 to 30-APR-10 18:00:00 (CST-6)
Location: GREEN LAKE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Tornado in GREEN LAKE, WISCONSIN
From 30-APR-10 18:00:00 to 30-APR-10 18:02:00 (CST-6)
Location: BERLIN
Tornado F-scale: EF1
Property damage: 130.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A weak tornado spun up southeast of Berlin near the intersection of CTH AA and Forest Ridge Rd.  The tornado moved northeast and disappated near the intersection of CTH V and White Ridge Rd. The average path width was 60 yards.  A damage survey noted seven high tension wood power poles were snapped.  A few trees were uprooted including one that fell on and damaged a car.  There was minor roof damage to a barn.  Several small barrels were thrown over 100 yards into a nearby field.  A portable toilet was moved about 50 feet.  Near the end of the track, a TV antenna was snapped and there was damage to the facia of a home.  A small shed was destroyed and a couch that was outdoors was thrown about 75 feet.  The Green Lake County Emergency Manager estimated property damage at $30,000.  Additionally, it is estimated that the power-pole and line replacement cost was about $100,000.

Tornado in GREEN LAKE, WISCONSIN
From 30-APR-10 18:17:00 to 30-APR-10 18:23:00 (CST-6)
Location: DALTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This tornado segment in Green Lake County was the 2nd of a 2-segment tornado that stared in Marquette County at 1815 CST.  It entered Green Lake County about 6 miles northwest of Dalton at the mid-point of the wide part of the Grand River and continued to move northeast.  It crossed Pukaway Lake and came ashore just east of the corner of Marquette County near a boat launch site.  A few trees had broken branches or were partially uprooted.  The average path width was 35 yards.  The EF0 rating was based on DI 27 (TH), and DOD 2, 65-70 mph, after a NWS survey. The responsible thunderstorm was the sourthern of two parallel moving storms with embedded circulations.  The northern storm also produced a weak tornado.