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Archive for June, 2012

On June 19th and 20th, northeast Minnesota and northwest Wisconsin were hit by large rain storm that caused extensive flooding and property damage. This is the second post in a series where I explore geospatial data and products to visualize precipitation patterns and flooding associated with the storm.

River Levels – Advanced Hydrologic Preduction Service, National Weather Service
AHPS maintains a water tab on the National Weather Service website that includes river observations and forecasts. The image below shows river gage levels for over 5,000 locations across the U.S. for June 27, 2012. You can see the legacy of the Duluth Solstice storm, as well as Tropical Storm Debby in Florida.


The following two images show river observations and the two-day forecast for June 27 covering the area served by the Duluth NWS office. Flood conditions remain on the St. Louis and upper Mississippi Rivers.

This links to the hydrograph for the gage on the St. Louis River at Scanlon, Minnesota. The first hydrograph image below for June 21 shows the rapid increase of over 11 feet in the river level in less than one day. The second image from June 27 shows the slow decline in river level from major to moderate flood stage.

National Water Information System – U.S. Geological Survey
The National Water Information System (NWIS) provides similar stream information as AHPS, but with more ability to explore observations for different time periods. The image below shows a national view of daily streamflow for June 27.

This link provides a custom query to show gage height, discharge, and precipitation for the station on the St. Louis River at Scanlon from June 14 to 27, 2012

Lake Superior Streams Data Viewer – Natural Resources Research Institute, University of Minnesota-Duluth
As part of the Lakes Superior Streams project to enhance public understanding of human impacts on aquatic ecosystems, NRRI developed interactive data visualization tools to animate and simplify the presentation of complex, real-time stream data. Sensors were placed in several Duluth trout streams. The Solstice flood destroyed these sensors, with the exception of one at the mouth of the estuary in the Duluth Shipping Canal. This story by Minnesota Public Radio describes what happened to the sensors, while the image of flow in Amity Creek below provides a graphical perspective.

The data viewer for the Duluth Shipping Canal (http://www.lakesuperiorstreams.org/streams/data/Java/stLoRvr.html) shows water movement into and out of the St. Louis River Estuary. The 7-day plot below is centered on the storm event. The blue background shows water movement from Lake Superior into the estuary, while brown shows water movement out of the estuary and into the lake. Before the storm, the alternating shades of light blue and brown show the “seiche” effect of water movement between the lake and estuary. After the storm, the dark brown pattern shows more consistent high movement of water out of the estuary.

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On June 19th and 20th, northeast Minnesota and northwest Wisconsin were hit by large rain storm that caused extensive flooding and property damage.  This post is the first in a series where I explore geospatial data and products to visualize precipitation patterns associated with the storm, as well as the resulting impacts.

NEXRAD Composites – Iowa Environmental Mesonet

I find the Iowa Environmental Mesonet (IEM) a useful source of information to visualize precipitation events.  The Current and Historical IEM NEXRAD Composite Loop allows users to create an animated loop of NEXRAD base reflectivity with up to 100 frames with an interval as short as five minutes from an archive that dates back to 1995.

The first animation of the Duluth Solstice storm is at the scale of the continental United States with 100 frames at 60 minute intervals that runs from June 17, 2012 at 12:00 PM CDT to June 21, 2012 at 12:00 PM CDT.

The second animation is at the scale of the northern Minnesota with 100 frames at 10 minute intervals that runs from June 19, 2012 7:00 PM CDT to June 20, 2012 11:30 AM CDT.

Weather and Climate Toolkit – National Climatic Data Center
The National Climatic Data Center (NCDC) in Asheville, North Carolina maintains an archive of NEXRAD products.  Here I used NCDCs Weather and Climate Toolkit to examine the storm total precipitation for the Solstice Flood.  The precipitation event started on June 19, 2012 at 05:41 GMT and ended on June 21, 2012 at 12:14 GMT with a maximum rainfall of 7.4 inches.  The conversion from Greenwich Mean Time to Central Daylight Time is – 5 hours (i.e. if the ending time is 12:14 GMT, then it would be 07:14 AM CDT).  The toolkit allows creation of animations of NEXRAD products, as well as export of shapefiles and Google Earth KMZ files.

Advanced Hydrologic Prediction Service – National Weather Service

The Advanced Hydrologic Prediction Service (AHPS) provides information products to improve flood warnings and water resource forecasts. The Water page of the National Weather Service features several AHPS products including river observations, forecasts and precipitation.

The image below shows single day observed precipitation for June 20, 2012.  Note that 12:00 GMT is the start and end time of a standard hydrologic day used by AHPS in river modeling.  This runs from 07:00 AM CDT on June 20 to 07:00 AM on the following day.

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