This visible satellite image shows a couple of important aspects about this afternoon’s weather. First, the clouds that remained over eastern Minnesota and western Wisconsin which kept temperatures from climbing into the lower 90s. Second, the clearing in western Minnesota that has allowed sunshine and high dew points to produce heat index values about 100; including 106 at 3PM in Canby.
In the previous blog you’ll note the Storm Prediction Center’s rather high probability of tornado potential in western Minnesota. There is a boundary from the differential heating due to the cloud-free area and the persistent cloud cover. This is displayed nicely in the graphic of the dew points, temperatures and pressure field as generated from 3PM surface observations.
Temperature contours are in red, dew point highlighted by colored background and pressure field in black. Basic meteorology suggests the inflow of winds from the south and southeast, along with the advancing low pressure, high dew points and afternoon heating will result in thunderstorm development in eastern South Dakota and western Minnesota.
We’ll watch how this unfolds in the later afternoon and early evening hours.
Meanwhile, Pete Boulay of the State Climate Office shared this tid-bit after probing the dew points recorded this summer at the Twin Cities International Airport. So far this summer as of 3pm August 1, there have been 98 hours of dew point temperatures of 75 degrees or higher. This breaks the old record of 78 hours that was set back on 2001.
Some branches were blown down along with power lines as the storms swept through east central Minnesota between 1230PM and 230PM this afternoon. Here’s a link to the storm reports out of the Chanhassen NWS Office.
Heavy rain also was reported with over two inches at Hutchison and an inch and a half at Target Field near downtown Minneapolis from late morning to mid afternoon.
Stay abreast of potentially dangerous weather conditions developing as we go into the evening hours.