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 Stearns 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 canceled 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