More Heavy Rains Over Minnesota:
September 20-21, 2007

rainfall map

Summary

Heavy rains fell once again across central and northern Minnesota on September 20-21, The heavy rain was associated with a warm front that lifted slowly northward across the state. The first main wave of heavy thunderstorms moved from northeast South Dakota into some of the more drought stricken areas of west central Minnesota. One of the drier spots this past summer has been Pope County, and heavy rains fell at Glenwood with 2.83 inches reported by a Soil and Water Conservation District rain gauge volunteer. Roads had to be barricaded for a time in Sauk Centre with water up to a foot deep in spots. Lighting sparked fires in four locations in Strearns County in the early afternoon. These storms then shifted into Pine County by the late afternoon.

Another area of strong to severe thunderstorms developed just west of the Twin Cities and slowly moved to the east dumping heavy rain on the central and northern Twin Cities. Urban street flooding was reported with six inches to a foot of water on University Avenue between Snelling and Rice. A storm sewer geyser was 10 to 25 feet in the air at East River Road and Pillsbury Road in Minneapolis. 2.03 inches of rain fell in North St. Paul, with 1.79 inches at the University of Minnesota St. Paul Campus. The Twin Cities International Airport saw 1.26 inches of rain. An automated tipping bucket measured 1.75 inches of rain from 6pm to 7pm located on Maryland Avenue about 1/2 mile east of Lake Phalen in St. Paul.

There was some damage reported in the Twin Cities, mainly due to the heavy rains. The Twin Cities International Airport shut down for about 30 minutes due to the wind and rain. St. Paul College cancelled classes after water overwhelmed the roof drainage system. A 13 year old boy drowned after being swept over a small concrete dam in runoff-swelled Battle Creek in Battle Creek Park.

Listed below are local storm reports and a public information statement courtesy the National Weather Service.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE DULUTH MN
202 PM CDT FRI SEP 21 2007

...NON-TORNADIC WINDS CAUSED DAMAGE ACROSS SOUTHERN PINE COUNTY AND
IN PINE CITY THURSDAY EVENING...

A DAMAGE SURVEY TEAM FROM THE NATIONAL WEATHER SERVICE IN DULUTH
TRAVELED TO PINE COUNTY THIS MORNING TO INVESTIGATE STORM DAMAGE
THAT OCCURED LATE THURSDAY AFTERNOON.

THE DAMAGE SURVEY TEAM FOUND A BROAD SWATH OF SPROADIC WIND DAMAGE
ACROSS EXTREME SOUTHERN PINE COUNTY.  WIND DAMAGE WAS ALMOST
EXCLUSIVELY CONFINED TO TREES AND BRANCHES. SOME MINOR STRUCTURAL
DAMAGE WAS OBSERVED WHERE TREES OR LARGE BRANCHES WERE BLOWN ON TO
BUILDINGS IN PINE CITY AND ALONG COUNTY ROAD 7 JUST WEST OF PINE
CITY. THERE WAS ALSO SOME MINOR DAMAGE TO FENCES... OUTBUILDINGS AND
TWO DUGOUTS AT THE BASEBALL FIELDS AT PINE CITY HIGH SCHOOL. NO
STRUCTURAL DAMAGE TO ROOFS... HOMES OR BUILDINGS WAS NOTED THAT WAS
CAUSED DIRECTLY BY STRONG WINDS.

THE DAMAGE PATH RANGED BETWEEN 2 AND 4 MILES WIDE AND BEGAN AT THE
WESTERN COUNTY BORDER... BETWEEN GRASSTON AND HENRIETTE... AND
EXTENDED EASTWARD ALONG AND 1 TO 2 MILES NORTH AND SOUTH OF PINE
COUNTY ROAD 7 TO POKEGAMA LAKE AND PINE CITY. SOME SPOTTY DAMAGE TO
TREES WAS ALSO NOTED UP TO 2 MILES EAST OF PINE CITY ALONG NORTHERN
ROAD AND COUNTY ROAD 8. THUS... THE TOTAL LENGTH OF THE DAMAGE PATH
WAS ABOUT 9 TO 10 MILES LONG AND 2 TO 4 MILES WIDE.

SEVERAL CHARACTERISTICS OF THE DAMAGE PATH INDICATE NON-TORNADIC OR
"STRAIGHT LINE" WINDS.  WHEN COMPARING THE DAMAGE PATH WIDTH TO ITS
LENGTH... A TORNADO TYPICALLY LEAVES A DAMAGE PATH FROM ONLY A FEW
HUNDRED YARDS TO A MILE WIDE AND IS MANY MILES LONG. THE DAMAGE PATH
WIDTH OBSERVED IN PINE COUNTY WAS TOO WIDE WHEN COMPARED TO THE PATH
LENGTH TO BE ASSOCIATED WITH A TORNADO. IN ADDITION... DAMAGED
TREES... BRANCHES AND DEBRIS WERE ALL BLOWN DOWN TOWARD THE EAST...
SOUTHEAST OR SOUTH... AND ALSO EXHIBITED A DIVERGENT OR "FANNING
OUT" PATTERN... WHICH IS A CLASSIC CHARACTERISTIC OF NON-TORNADIC
DOWNBURST WINDS.

EVEN THOUGH THE DAMAGE WAS NOT CAUSED BY A TORNADO... THIS IS STILL
A VERY INTERESTING EVENT FROM A METEOROLOGICAL PERSPECTIVE.
TYPICALLY... WINDS STRONG ENOUGH TO CAUSE DAMAGE ARE NOT ABLE TO
PENETRATE TO THE GROUND WHEN THE NEAR SURFACE LAYER OF AIR IS AS
COLD AND STABLE AS IT WAS YESTERDAY IN PINE COUNTY DURING THE TIME
OF THE STORM. SURFACE TEMPERATURES BETWEEN 3 AND 4 PM YESTERDAY WERE
ONLY IN THE LOWER 50S ACROSS SOUTHERN PINE COUNTY.

WE HOPE TO HAVE A MORE COMPLETE DAMAGE REPORT... INCLUDING PICTURES
AND MAPS... POSTED ON OUR WEBSITE WITH THE NEXT DAY OR TWO AT
WEATHER.GOV/DULUTH.

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
856 PM CDT THU SEP 20 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0822 AM     HAIL             BURR                    44.72N 96.28W
09/20/2007  M1.00 INCH       YELLOW MEDICINE    MN   FIRE DEPT/RESCUE

0855 AM     HAIL             DAWSON                  44.93N 96.05W
09/20/2007  M2.00 INCH       LAC QUI PARLE      MN   TRAINED SPOTTER

0920 AM     TSTM WND DMG     1 NE WATSON             45.02N 95.79W
09/20/2007                   CHIPPEWA           MN   CO-OP OBSERVER

            LARGE TREE DOWN.

1042 AM     FLASH FLOOD      SAUK CENTRE             45.74N 94.96W
09/20/2007                   STEARNS            MN   TRAINED SPOTTER

            ROADS ARE GETTING BARRICADED AROUND TOWN...DUE TO
            FLOODING.

1042 AM     FLASH FLOOD      SAUK CENTRE             45.74N 94.96W
09/20/2007                   STEARNS            MN   TRAINED SPOTTER

            ROADS ARE GETTING BARRICADED AROUND TOWN...DUE TO
            FLOODING.

1042 AM     FLASH FLOOD      SAUK CENTRE             45.74N 94.96W
09/20/2007                   STEARNS            MN   LAW ENFORCEMENT

            ROADS ARE GETTIING BARRICADED AROUND TOWN...DUE TO
            FLOODING.

1042 AM     TSTM WND DMG     BENSON                  45.32N 95.61W
09/20/2007                   SWIFT              MN   LAW ENFORCEMENT

            TWO TREES DOWN IN TOWN. ONE BLOCKING A STREET.

1125 AM     HAIL             4 S BELGRADE            45.39N 95.00W
09/20/2007  E0.88 INCH       KANDIYOHI          MN   LAW ENFORCEMENT

            RELAYED VIA HAM RADIO.

1135 AM     HAIL             BROOTEN                 45.50N 95.12W
09/20/2007  E0.88 INCH       STEARNS            MN   LAW ENFORCEMENT

            RELAYED VIA HAM RADIO.

1202 PM     HAIL             MELROSE                 45.68N 94.81W
09/20/2007  M0.75 INCH       STEARNS            MN   AMATEUR RADIO

            MEASURED 0.8 INCH DIAMETER.

1258 PM     HAIL             STARBUCK                45.61N 95.53W
09/20/2007  E1.00 INCH       POPE               MN   LAW ENFORCEMENT

0257 PM     TSTM WND DMG     ST STEPHEN              45.70N 94.28W
09/20/2007                   STEARNS            MN   AMATEUR RADIO

            PARTIAL BARN ROOF BLOWN OFF.

0257 PM     TSTM WND DMG     ST STEPHEN              45.70N 94.28W
09/20/2007                   STEARNS            MN   AMATEUR RADIO

            20 INCH TREE DOWN.

0259 PM     TSTM WND DMG     SARTELL                 45.62N 94.21W
09/20/2007                   STEARNS            MN   AMATEUR RADIO

            MULTIPLE ONE AND A HALF TO TWO FOOT TREES DOWN.

0304 PM     TSTM WND DMG     SARTELL                 45.62N 94.21W
09/20/2007                   STEARNS            MN   AMATEUR RADIO

            TIN OF MEDICAL BUILDING ROOF BLOWN OFF.

0410 PM     TSTM WND DMG     ISANTI                  45.49N 93.25W
09/20/2007                   ISANTI             MN   PUBLIC

            20 INCH DIAMETER TREE DOWN ACROSS ROAD.

0410 PM     FLASH FLOOD      2 N SAUK CENTRE         45.77N 94.96W
09/20/2007                   STEARNS            MN   TRAINED SPOTTER

            4.85 INCHES RAIN SINCE 1000 AM. SPOTTER REPORTS ONE FOOT
            DEEP IN TOWN AT RAILROAD CROSSING.

0415 PM     TSTM WND DMG     2 S MORA                45.85N 93.29W
09/20/2007                   KANABEC            MN   TRAINED SPOTTER

            LARGE PINE TREES DOWN.

0415 PM     TSTM WND DMG     MORA                    45.88N 93.29W
09/20/2007                   KANABEC            MN   TRAINED SPOTTER

            HIGH WINDS. MANY TREES DOWN IN CITY. 18 INCHS IN
            DIAMETER. MINOR STRUCTURAL DAMAGE TO SOME HOMES.

0418 PM     TSTM WND DMG     LITCHFIELD              45.12N 94.53W
09/20/2007                   MEEKER             MN   AMATEUR RADIO

            TREES SHREADED.

0423 PM     TSTM WND DMG     LITCHFIELD              45.12N 94.53W
09/20/2007                   MEEKER             MN   AMATEUR RADIO

            22 INCH DIAMETER TREES DOWN.

0425 PM     HAIL             LITCHFIELD              45.12N 94.53W
09/20/2007  E0.88 INCH       MEEKER             MN   TRAINED SPOTTER

0430 PM     TSTM WND DMG     LITCHFIELD              45.12N 94.53W
09/20/2007                   MEEKER             MN   AMATEUR RADIO

            TREE DOWN ON MOBILE HOME NORTH SIDE OF LITCHFIELD.

0433 PM     HAIL             LITCHFIELD              45.12N 94.53W
09/20/2007  E1.75 INCH       MEEKER             MN   AMATEUR RADIO

0454 PM     HAIL             COKATO                  45.08N 94.19W
09/20/2007  E0.75 INCH       WRIGHT             MN   AMATEUR RADIO

0505 PM     HAIL             WAVERLY                 45.07N 93.97W
09/20/2007  E1.75 INCH       WRIGHT             MN   TRAINED SPOTTER

0505 PM     HAIL             MONTROSE                45.07N 93.91W
09/20/2007  E0.75 INCH       WRIGHT             MN   TRAINED SPOTTER

0508 PM     FLASH FLOOD      BLOOMINGTON             44.83N 93.32W
09/20/2007                   HENNEPIN           MN   TRAINED SPOTTER

            6 TO 12 INCHES OF WATER ACROSS ROADWAY...83 ST SOUTH AND
            PENN AVE.

0510 PM     HAIL             2 N MONTROSE            45.10N 93.91W
09/20/2007  E1.75 INCH       WRIGHT             MN   TRAINED SPOTTER

0512 PM     HAIL             2 SW BUFFALO            45.16N 93.90W
09/20/2007  E1.00 INCH       WRIGHT             MN   TRAINED SPOTTER

0515 PM     HAIL             BUFFALO                 45.18N 93.87W
09/20/2007  E1.00 INCH       WRIGHT             MN   TRAINED SPOTTER

0517 PM     HAIL             DELANO                  45.04N 93.79W
09/20/2007  E0.88 INCH       WRIGHT             MN   TRAINED SPOTTER

0520 PM     HAIL             PLYMOUTH                45.02N 93.46W
09/20/2007  E0.88 INCH       HENNEPIN           MN   TRAINED SPOTTER

0520 PM     HAIL             WATERTOWN               44.96N 93.85W
09/20/2007  E1.75 INCH       CARVER             MN   PUBLIC

0522 PM     HAIL             MAPLE PLAIN             45.01N 93.66W
09/20/2007  E0.88 INCH       HENNEPIN           MN   AMATEUR RADIO

0523 PM     HAIL             BUFFALO                 45.18N 93.87W
09/20/2007  E1.00 INCH       WRIGHT             MN   TRAINED SPOTTER

0527 PM     HAIL             LORETTO                 45.06N 93.64W
09/20/2007  E0.75 INCH       HENNEPIN           MN   TRAINED SPOTTER

0527 PM     HAIL             HANOVER                 45.16N 93.66W
09/20/2007  E0.75 INCH       HENNEPIN           MN   TRAINED SPOTTER

0534 PM     TSTM WND DMG     WATERTOWN               44.96N 93.85W
09/20/2007                   CARVER             MN   AMATEUR RADIO

            TREES DOWN...JUST NORTH OF TOWN. 4-6 INCH BRANCHES DOWN
            IN TOWN.

0538 PM     HAIL             PLYMOUTH                45.02N 93.46W
09/20/2007  E0.88 INCH       HENNEPIN           MN   TRAINED SPOTTER

0550 PM     TSTM WND DMG     GOLDEN VALLEY           44.99N 93.36W
09/20/2007                   HENNEPIN           MN   NWS EMPLOYEE

            TREES DOWN...POWER OUT.

0550 PM     HAIL             NEW HOPE                45.04N 93.39W
09/20/2007  E0.75 INCH       HENNEPIN           MN   CO-OP OBSERVER

0550 PM     HAIL             GOLDEN VALLEY           44.99N 93.36W
09/20/2007  E1.00 INCH       HENNEPIN           MN   NWS EMPLOYEE

0602 PM     FUNNEL CLOUD     NEWPORT                 44.87N 93.00W
09/20/2007                   WASHINGTON         MN   LAW ENFORCEMENT

            NEAR WAKOTA BRIDGE.

0602 PM     HAIL             NEW BRIGHTON            45.07N 93.20W
09/20/2007  E0.75 INCH       RAMSEY             MN   TRAINED SPOTTER

0614 PM     HAIL             MINNEAPOLIS             44.96N 93.27W
09/20/2007  E0.88 INCH       HENNEPIN           MN   TRAINED SPOTTER

            I-35W AND 35TH STREET SOUTH.

0614 PM     FUNNEL CLOUD     INVER GROVE HEIGHTS     44.83N 93.06W
09/20/2007                   DAKOTA             MN   TRAINED SPOTTER

            AT SOUTHVIEW BLVD AND HWY 52.

0618 PM     FUNNEL CLOUD     EAGAN                   44.82N 93.16W
09/20/2007                   DAKOTA             MN   LAW ENFORCEMENT

            NEAR I-35E AND YANKEE DOODLE RD.

0620 PM     HAIL             BROOKLYN PARK           45.11N 93.35W
09/20/2007  E0.75 INCH       HENNEPIN           MN   TRAINED SPOTTER

0620 PM     HAIL             2 S ST MICHAEL          45.18N 93.66W
09/20/2007  E0.75 INCH       WRIGHT             MN   AMATEUR RADIO

0625 PM     FUNNEL CLOUD     INVER GROVE HEIGHTS     44.83N 93.06W
09/20/2007                   DAKOTA             MN   AMATEUR RADIO

            AT HWYS 13 AND 52

0625 PM     HAIL             BLAINE                  45.17N 93.21W
09/20/2007  E0.75 INCH       ANOKA              MN   TRAINED SPOTTER

0626 PM     HAIL             ROGERS                  45.19N 93.55W
09/20/2007  E0.88 INCH       HENNEPIN           MN   AMATEUR RADIO

            INTERSECTION 494 AND 101.

0628 PM     HAIL             2 NW ROGERS             45.21N 93.58W
09/20/2007  E0.88 INCH       HENNEPIN           MN   TRAINED SPOTTER

            ALONG I94.

0632 PM     FLASH FLOOD      ST PAUL                 44.95N 93.10W
09/20/2007                   RAMSEY             MN   TRAINED SPOTTER

            6 TO 12 INCHES WATER ON UNIVERSITY AVE BETWEEN SNELLING
            AND RICE.

0634 PM     FUNNEL CLOUD     HASTINGS                44.73N 92.85W
09/20/2007                   DAKOTA             MN   AMATEUR RADIO

            AT INTERSECTION OF 61 AND 10.

0635 PM     TSTM WND DMG     WOODBURY                44.91N 92.92W
09/20/2007                   WASHINGTON         MN   AMATEUR RADIO

            LATE REPORT RECEIVED AT 715 PM. 25 FOOT SPRUCE TREE DOWN.
            10 INCH LIMBS DOWN. STREET SIGNS DOWN.

0637 PM     FLASH FLOOD      RICHFIELD               44.88N 93.28W
09/20/2007                   HENNEPIN           MN   TRAINED SPOTTER

            66TH AND PORTLAND S...2 FEET OF STANDING WATER AT
            INTERSECTION...2 STALLED CARS.

0637 PM     FLASH FLOOD      MINNEAPOLIS             44.96N 93.27W
09/20/2007                   HENNEPIN           MN   TRAINED SPOTTER

            STORM SEWER GEYSER AT E RIVER RD AND PILLSBURY RD 10 TO
            25 FEET.

0640 PM     HAIL             ANOKA                   45.21N 93.39W
09/20/2007  E1.00 INCH       ANOKA              MN   TRAINED SPOTTER

0642 PM     HAIL             ST PAUL                 44.95N 93.10W
09/20/2007  E0.75 INCH       RAMSEY             MN   AMATEUR RADIO

0645 PM     HAIL             BECKER                  45.37N 93.87W
09/20/2007  E1.00 INCH       SHERBURNE          MN   TRAINED SPOTTER

0648 PM     FUNNEL CLOUD     RIVER FALLS             44.86N 92.62W
09/20/2007                   PIERCE             WI   LAW ENFORCEMENT

0700 PM     HAIL             COON RAPIDS             45.17N 93.31W
09/20/2007  E0.88 INCH       ANOKA              MN   TRAINED SPOTTER

            HWY 10 AND MAIN STREET

0703 PM     HAIL             COON RAPIDS             45.17N 93.31W
09/20/2007  E1.00 INCH       ANOKA              MN   TRAINED SPOTTER

0711 PM     HAIL             BLAINE                  45.17N 93.21W
09/20/2007  E1.00 INCH       ANOKA              MN   AMATEUR RADIO

0717 PM     FUNNEL CLOUD     3 NW ELLSWORTH          44.77N 92.52W
09/20/2007                   PIERCE             WI   TRAINED SPOTTER

0725 PM     HAIL             2 W COKATO              45.08N 94.23W
09/20/2007  E0.75 INCH       WRIGHT             MN   TRAINED SPOTTER


PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
642 PM CDT THU SEP 20 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     TSTM WND DMG     5 SSW PINE CITY         45.76N 93.01W
09/20/2007                   PINE               MN   TRAINED SPOTTER

            SEVERAL 18 INCH TREES UPROOTED
For more information contact: climate@umn.edu