Record Low Pressure Hits Minnesota October 26-27, 2010

An extremely strong low-pressure system on October 26-27 set sea-level pressure pressure records in Minnesota and produced widespread damaging winds associated with the storm's powerful and massive circulation.

The storm system began as an area of low pressure emerged from the Bighorn Mountains in eastern Wyoming on October 25th. The system was already quite strong at that time, and the ingredients aloft were nearly perfect for a period of rapid intensification. By evening of the 26th, the storm had hooked northward towards the Minnesota/Canada border and had already broken Minnesota record for lowest sea-level pressure. For a period of over 36 hours, from the 26th into the 27th, strong winds raged across a huge swath of central North America, as the storm's circulation sprawled across a large portion of the continent.

High Wind Warnings were posted from southeast Montana to Ohio, with Blizzard Warnings over a much of North Dakota. The strongest wind gust reported in Minnesota was 65 mph at both Georgeville in Stearns County, and Mehurin Township in Lac Qui Parle County.

This is one of the strongest non-tropical storms on record for lowest minimum pressure in the United States. The lowest pressure found, after adjusting for the true mean sea level pressure, was 28.21 inches (955.2 millibars) at 5:13 pm at Bigfork in Itasca County. This shatters the old Minnesota lowest pressure record of 28.43 inches (962.7 millibars) that was set in the November 10, 1998 storm at both Austin and Albert Lea.

To illustrate how strong of a storm this is, 28.21 inches is equivalent to a Category 3 Hurricane. The lowest pressure for the storm that sank the Edmund Fitzgerald on November 10, 1975 was 28.95 inches. Even with the Armistice Day storm, the lowest pressure recorded was 28.55 inches. Of course, pressure is only one measure of a storm's intensity.

During the evening hours of October 26, snow became mixed with the rain over northern Minnesota, by daybreak on October 27, a white blanket of snow covered parts of northern Minnesota. The heaviest snow total found so far was near Twig in St. Louis County with 9 inches. The Duluth National Weather Service Office measured 7.4 inches. Heavy rains also fell with this storm. with 3 to 5.5 inches reported in portions of northeastern Minnesota.

The Duluth and Chanhassen offices of the National Weather Service compiled summaries of this historic weather system.

Listed below are Public Information Statements and Storm Summaries from the National Weather Service. More details can be found here for the October 26-27 storm.

STORM SUMMARY NUMBER 7 FOR MIDWEST HIGH WIND EVENT
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD  
1000 AM CDT WED OCT 27 2010
 
...RECORD BREAKING LOW PRESSURE SYSTEM BEGINS TO WEAKEN AS IT
MOVES INTO ONTARIO CANADA...
 
BLIZZARD WARNINGS...WINTER STORM WARNINGS....AND WINTER WEATHER
ADVISORIES ARE IN EFFECT ACROSS MUCH OF NORTH DAKOTA...NORTHERN
MINNESOTA...EXTREME NORTHWESTERN WISCONSIN...AND NORTHEASTERN
MONTANA.
 
HIGH WIND WATCHES...WARNINGS AND WIND ADVISORIES REMAIN IN EFFECT
FOR AN EXTENSIVE AREA ACROSS MUCH OF THE NORTHERN PLAINS INTO
PARTS OF THE CENTRAL PLAINS...THE MIDWEST...UPPER GREAT
LAKES...AND THE NORTHERN OHIO VALLEY. STORM WARNINGS ARE IN EFFECT
FOR PORTIONS OF THE WATERS OF THE GREAT LAKES.
 
FOR A DETAILED GRAPHICAL DEPICTION OF THE LATEST
WATCHES...WARNINGS AND ADVISORIES...PLEASE SEE WWW.WEATHER.GOV

AT 900 AM CDT...A STRONG LOW PRESSURE SYSTEM WITH A CENTRAL
PRESSURE OF 969 MB...28.61 INCHES...WAS LOCATED OVER SOUTHERN
ONTARIO...NEAR PICKLE LAKE. NATIONAL WEATHER SERVICE RADARS AND
SURFACE OBSERVATIONS INDICATED AREAS OF LIGHT TO OCCASIONALLY
MODERATE RAIN AND SNOW ACROSS PORTIONS OF THE NORTHERN PLAINS AND
MIDWEST. WINDS WERE GENERALLY 20 TO 30 MPH SUSTAINED...WITH GUSTS
AS HIGH AS 40 TO 50 MPH...PARTICULARLY ACROSS THE DAKOTAS.

...SELECTED STORM TOTAL SNOWFALL IN INCHES FROM 1200 PM CDT MON
OCT 25 THROUGH 800 AM CDT WED OCT 27...

...MINNESOTA...
DULUTH                                7.4                     
TWO HARBORS 7 NW                      7.1                     
CLOQUET 4 WNW                         5.0                     
TWIG 5 SE                             5.0                     
HEWITT 0.3 ENE                        4.0                     
UNDERWOOD 7.6 NNW                     4.0                     

...NORTH DAKOTA...
HARVEY                                8.0                     
GRENORA                               6.0                     
MINOT                                 4.0                     
WILLISTON                             3.1                     
BISMARCK 5 NW                         2.5                     
KILLDEER 0.6 WNW                      2.5                     
LINTON 5 WNW                          2.5                     

...SELECTED PEAK WIND GUSTS IN MILES PER HOUR EARLIER IN THE
EVENT...

...IOWA...
BOONE AIRPORT 4 ESE                     58                     
ORANGE CITY                             58                     
SPENCER                                 58                     
WAUKON                                  51                     
ESTHERVILLE AIRPORT                     50                     
IONIA 2 N                               49                     
CHARLES CITY 3 E                        45                     

...ILLINOIS...
MACKINAW 1 NE                           70                     
DUPAGE AIRPORT                          61                     
FAIRVIEW                                60                     
LAWRENCEVILLE AIRPORT                   60                     
OSKALOOSA                               60                     
JACKSONVILLE                            58                     
OLNEY                                   57                     
FLORA 1 E                               56                     
PETERSBURG 8 E                          55                     

...INDIANA...
GREENFIELD                              77                     
SW MONROEVILLE                          75                     
MOORESVILLE 2 NW                        70                     
TERRE HAUTE                             70                     
ODON                                    68                     
SHERIDAN                                68                     
NORMAL 1 N                              67                     
COLUMBIA CITY                           65                     
ANDERSON 5 N                            63                     
INDIANAPOLIS                            61                     

...MICHIGAN...
POINT AUX BARQUES 3 W                   71                     
FREDA                                   69                     
GRAND MARAIS                            68                     
DAVISON                                 65                     
SOUTH HAVEN 1 W                         64                     
ESCANABA                                58                     
MUSKEGON 4 W                            58                     
PLOVER                                  58                     
FAIRPORT                                56                     
CADILLAC                                54                     

...MINNESOTA...
GEORGEVILLE                             65                     
MEHURIN                                 65                     
HANLEY FALLS                            63                     
LAKE BENTON                             62                     
MORRIS                                  62                     
SAUK CENTRE                             62                     
ALEXANDRIA                              61                     
LANGHEI                                 61                     
GLENWOOD                                60                     
MINNEAPOLIS                             60                     
ST. CLOUD                               50                     

...MONTANA...
COMERTOWN 6 S                           60                     

...NORTH DAKOTA...
FARGO/HECTOR FIELD                      64                     
BISMARCK                                61                     
HETTINGER                               61                     
MANDAN 4 S                              60                     
JAMESTOWN                               59                     
ADAMS                                   58                     
GARRISON                                58                     
DICKINSON                               56                     
MINOT                                   54                     
WILLISTON                               47                     
LINTON                                  46                     

...NEBRASKA...
ONEILL                                  55                     
GRAND ISLAND                            54                     
OGALLALA                                54                     
VALENTINE                               54                     
BROKEN BOW                              51                     
ORD                                     47                     
HASTINGS                                45                     

...SOUTH DAKOTA...
UNION CENTER                            70                     
SISSETON                                64                     
ABERDEEN                                62                     
CASTLEWOOD                              62                     
FAITH                                   62                     
RAPID CITY/ELLSWORTH AFB                62                     
BUFFALO 1 N                             61                     
DRAPER 4 NNE                            61                     
MOBRIDGE 1 ENE                          61                     
PHILIP 3 E                              61                     
OACOMA                                  60                     
PIERRE MUNI ARPT                        60                     

...WISCONSIN...
SHERWOOD                                76                     
ALGOMA                                  68                     
ALGOMA CITY MARINA                      68                     
KENOSHA MUNI ARPT                       68                     
SHIOCTON 4 W                            59                     
PLOVER                                  58                     
BELLEVUE                                57                     
EYOTA RWIS 2 SE                         56                     
VIROQUA AWOS                            56                     
GREENVILLE                              55                     
LA CROSSE 3 E                           50                     


THE SURFACE LOW IS EXPECTED TO STEADILY WEAKEN TODAY AS IT
CONTINUES TO MOVE EAST-NORTHEASTWARD INTO CANADA. BLIZZARD OR NEAR
BLIZZARD CONDITIONS ARE POSSIBLE WITHIN THE WARNED AREA TODAY.
CONDITIONS SHOULD IMPROVE ACROSS THE REGION BY THIS EVENING AS THE
PRESSURE GRADIENT DECREASES CAUSING THE WINDS TO RELAX. LIGHT RAIN
AND SNOW SHOWERS WILL CONTINUE TO BE POSSIBLE ACROSS THE REGION
THROUGH EARLY THURSDAY MORNING HOWEVER.

THE NEXT STORM SUMMARY WILL BE ISSUED BY THE HYDROMETEOROLOGICAL
PREDICTION CENTER AT 400 PM CDT. PLEASE REFER TO YOUR LOCAL
NATIONAL WEATHER SERVICE OFFICE FOR ADDITIONAL INFORMATION ON THIS
EVENT.



PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE DULUTH MN
845 AM CDT WED OCT 27 2010

...LOW PRESSURE RECORDS BROKEN ON OCTOBER 26 2010...

THIS IS A PRELIMINARY STATEMENT ON THESE PRESSURE RECORDS. HERE IS
WHAT WE KNOW SO FAR ABOUT THE LOW PRESSURE RECORDS SET ON OCTOBER
26TH:

AN UNUSUALLY INTENSE LOW AFFECTED THE STATE OF MINNESOTA. AT 513 PM
CDT...THE AUTOMATED WEATHER OBSERVING SYSTEM AT BIGFORK MINNESOTA
RECORDED A 954.96 MILLIBAR /28.20 INCHES/ PRESSURE. THIS BREAKS THE
ALL TIME MINNESOTA STATE RECORD FOR THE LOWEST OBSERVED PRESSURE.

THE PREVIOUS RECORD WAS 962.6 MB SET ON NOVEMBER 10 1998 AT ALBERT
LEA AND AUSTIN IN SOUTHERN MINNESOTA. THE RECORD WAS INITIALLY
BROKEN SHORTLY AFTER 10 AM AS THE LOW PASSED BY AITKIN MINNESOTA.
HOWEVER...THE LOW CONTINUED TO INTENSIFY INTO THE AFTERNOON.

.DULUTH...THE LOW PRESSURE RECORD AT DULUTH WAS SET AT 1113 AM
WITH A PRESSURE OF 960.72 MILLIBARS /28.37 INCHES/. THE PREVIOUS
RECORD WAS 964.3 MILLIBARS WHICH OCCURRED ON NOVEMBER 10 1998.

.INTERNATIONAL FALLS...THE LOW PRESSURE RECORD AT INTERNATIONAL
FALLS WAS SET AT 345 PM WITH A PRESSURE OF 955.98 MILLIBARS /28.23
INCHES/. THE PREVIOUS RECORD WAS 971.9 MILLIBARS ON OCTOBER 10 1949.

.WISCONSIN...THE LOW PRESSURE RECORD FOR THE STATE OF WISCONSIN WAS
SET IN SUPERIOR AT 1115 AM WITH A PRESSURE OF 961.06 MILLIBARS
/28.38 INCHES/. THE PREVIOUS RECORD WAS 963.4 MILLIBARS WHICH
OCCURRED AT GREEN BAY ON APRIL 3 1982.

...LOWEST BAROMETRIC PRESSURE RECORD SET IN LA CROSSE WI...

AT 553 AM ON OCTOBER 26TH...THE BAROMETRIC PRESSURE FELL TO
971.4 MILLIBARS /28.685 INCHES OF MERCURY/. THIS JUST BARELY BEAT
THE PREVIOUS RECORD OF 971.6 MILLIBARS /28.691 INCHES OF MERCURY/
ON NOVEMBER 10 1998.  THE TABLE BELOW CONTAINS THE FIVE LOWEST
BAROMETRIC PRESSURES AT LA CROSSE WI SINCE 1933.

              LOWEST BAROMETRIC PRESSURE READINGS
                       AT LA CROSSE WI
                       1933 TO PRESENT

                           SEA LEVEL
            SEA LEVEL      PRESSURE
            PRESSURE       IN INCHES
  RANK    IN MILLIBARS     OF MERCURY     DATE      TIME
  ----    ------------     ----------     ----      ----
    1        971.4          28.685     10/26/2010  553 AM
    2        971.6          28.691     11/10/1998  150 PM
    3        971.9          28.700     04/03/1982  900 AM
    4        973.6          28.750     11/11/1940  700 PM +
    5        973.8          28.756     01/11/1975  500 AM

   + ARMISTICE DAY STORM

...THIRD LOWEST BAROMETRIC PRESSURE IN ROCHESTER MN...

AT 654 AM ON OCTOBER 26TH...THE BAROMETRIC PRESSURE FELL TO
972.9 MILLIBARS /28.73 INCHES OF MERCURY/ AT ROCHESTER INTERNATIONAL
AIRPORT. THIS WAS THIRD LOWEST BAROMETRIC PRESSURE. THE LOWEST
PRESSURE AT ROCHESTER WAS 964.8 MILLIBARS /28.49 INCHES OF MERCURY/
ON NOVEMBER 10 1998.  THE TABLE BELOW CONTAINS THE FIVE LOWEST
BAROMETRIC PRESSURES AT ROCHESTER MN SINCE 1948.

              LOWEST BAROMETRIC PRESSURE READINGS
                       AT ROCHESTER MN
                       1948 TO PRESENT

                           SEA LEVEL
            SEA LEVEL      PRESSURE
            PRESSURE       IN INCHES
  RANK    IN MILLIBARS     OF MERCURY     DATE
  ----    ------------     ----------     ----
    1        964.8          28.49      11/10/1998
    2        971.1          28.67      01/11/1975
    3        972.9          28.73      10/26/2010
    4        974.9          28.79      03/27/1950
    5        975.7          28.81      04/03/1982


PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
800 PM CDT TUE OCT 26 2010

...PUBLIC INFORMATION STATEMENT...

...SUMMARY OF THE PEAK WIND GUSTS IN SOUTHERN MINNESOTA
AND WEST CENTRAL WISCONSIN ON TUESDAY...

LOCATION               PEAK GUST           TIME OF PEAK GUST
------------------------------------------------------------
...AUTOMTED ASOS AND AWOS SITES...

APPLETON                63 MPH                   5:14 PM TUE
MORRIS                  62 MPH                   5:12 PM TUE
ALEXANDRIA              61 MPH                   5:27 PM TUE
GLENWOOD                60 MPH                   3:34 PM TUE
OLIVIA                  60 MPH                   4:53 PM TUE
MINNEAPOLIS             60 MPH                   7:04 PM TUE
CANBY                   60 MPH                   6:34 PM TUE
BENSON                  59 MPH                   2:33 PM TUE
GRANITE FALLS           59 MPH                   3:33 PM TUE
ST. JAMES               59 MPH                   2:55 PM TUE
REDWOOD FALLS           57 MPH                   2:53 PM TUE
MARSHALL                57 MPH                   2:15 PM TUE
NEW ULM                 56 MPH                   2:55 PM TUE
REWOOD FALLS            55 MPH                   4:16 PM TUE
PAYNESVILLE             53 MPH                   3:53 PM TUE
WILLMAR                 53 MPH                   2:56 PM TUE
MONTEVIDEO              52 MPH                   2:34 PM TUE
ST. CLOUD               50 MPH                   3:53 PM TUE
HUTCHINSON              49 MPH                   2:52 PM TUE
MANKATO                 47 MPH                   2:35 PM TUE
OWATONNA                47 MPH                   2:54 PM TUE
GLENCOE                 47 MPH                   6:53 PM TUE
ST. PAUL                44 MPH                   3:53 PM TUE
EAU CLAIRE              44 MPH                   2:56 PM TUE
FLYING CLOUD AIRPORT    44 MPH                   3:53 PM TUE
LAKEVILLE               42 MPH                   4:14 PM TUE
MENOMONIE               41 MPH                   2:36 PM TUE


...AUTOMATED MESONET DATA...

MEHURIN                 65 MPH                   4:23 PM TUE
GEORGEVILLE             65 MPH                   6:01 PM TUE
HANLEY FALLS            63 MPH                   2:10 PM TUE
SAUK CENTER             62 MPH                   4:03 PM TUE
LANGHEI                 61 MPH                   2:16 PM TUE
GEORGEVILLE             59 MPH                   4:11 PM TUE
LESTER PRAIRIE          55 MPH                   3:54 PM TUE
BELLE PLAINE            52 MPH                   3:47 PM TUE