A Dry September Leads to a Dry October

by Angela Schilling, Meteorologist
October 01, 2011 8:07 PM


For some, a dry September is well welcomed, and for others they’re itching for some rain.  Especially across the east, 2011 proved to be one of the driest Septembers on record.  In Sioux Falls, the rain bucket has remained dry for the last several weeks.  September 20th was the last time we saw rain in the Sioux Empire, picking up a measly three hundredths of an inch.  Temperatures have also been running a good 5 to 10 degrees above normal for this time of year.  Highs on Saturday were in the 80's along the Missouri River with 70's along the I-29 corridor. 

August also proved to be drier than normal, and as a result several places set records for the driest August/September combined.   The images below show the rainfall amounts as well as the averages for the month of September.  The farther you head east, the drier the rain bucket remains with many records being broken across Iowa and western Minnesota.  Interesting to note, in Sioux Falls the rainfall total for  August-September is lower than the monthly average for September alone.  As we head into the month of October, the dry spell looks to continue, with more records to be shattered. 





We’ll have to watch temperatures especially on Monday and Tuesday as highs are expected to reach the 80’s along the I-29 corridor and come close to 90 west of the James…a good ten to twenty degrees above average for this time of year.  A prime example of returned flow, a ridge of high pressure at the surface will continue to scoot off to the east over the next couple of days, allowing our winds to come out of the south.  Winds will also be breezy throughout the week, at a good 15 to 25 miles per hour during the day...and 10 to 20mph overnight.  Windy conditions are common in a  highly amplified pattern.




Over the last couple of weeks the culprit for the mild weather in the Northern Plains has been a cut off low positioned over the Great Lakes.  As of now, the cut off low is making it’s way along the eastern seaboard, which creates an amplified pattern, with a trough in the west, and a ridge in the central portion of the United States.  Looks like the upper level ridge will stick around for quite some time, before it starts to break down by the later half of the week.  As of now the ridge is situated over western South Dakota but will continue to slide eastward as the week progresses.