SNOW IN SEPTEMBER!...

September 17, 2019

None of us was around to appreciate the event but it's a documented fact that snow whitened parts of Iowa September 16th, 1881. Being an Iowa boy (63 years here), I thought I knew everything about the states unique weather but this little baby managed to slip in under my rug. Here's a nice little account of that day 138 years ago from the NWS in Des Moines.

 

Snow in September?

September 16, 2019 by NWS Des Moines

 

Believe it or not, there have been at least nine years in which snow has been recorded in Iowa in the month of September, most recently in 1995, as detailed in Table 1 at the end of this document. The most remarkable of these events is the very early snowfall of September 16, 1881, which was amazing not only for its earliness in the season but also for the extent and amount of snowfall. The track of the surface low pressure center associated with this storm system is illustrated in Figure 1, a reprint of the original “War Department Weather Map” from September of 1881. At the time weather observations and reports were filed by the U.S. Army Signal Service, the progenitor of the modern National Weather Service. In the report of the Chief Signal Officer for that month, the development of the low pressure center is detailed as follows:

 

“This storm, which pursued a very anomalous track, was first evident in Texas, where on the 14th it moved in a track nearly due east. At the midnight observation, while the storm center was near New Orleans, a barometric depression extended from the Gulf of Mexico to the Lake Superior region. At the same time [an area of high pressure] prevailed with fair weather in New England. These conditions were unfavorable to an eastern progress of the storm, and on the 15th the depression moved in a northerly course to Lake Michigan. On the 16th, with diminishing energy, the storm center moved into Iowa and Minnesota, and on the 17th into Manitoba. The track on the 16th and 17th is very remarkable, and probably for a storm of such energy will have no parallel in the history of the Signal Service.”

On September 14, as the low moved across the Gulf of Mexico, fair weather prevailed across most of Iowa until a cold front moved through late in the day. At Des Moines the high temperature was 80 degrees but then the official observer wrote that, “Low stratus clouds moved rapidly from north and northwest during the afternoon and evening.” On the 15th, as the low pressure center moved northward toward Chicago, it pulled down unseasonably cool air behind the front into Iowa and spread a cold rain across much of the upper Midwest. At Des Moines the temperature fell through the day, with a high of 58 degrees measured early in the morning. The observer noted, “Cloudy and threatening weather prevailed during the day, low stratus clouds moved from the north.

 

”By the morning of September 16, the low pressure center was moving slowly westward into southern Minnesota and northern Iowa, pushing cold air even further southward into the central U.S. Frost was noted as far south as Arkansas and Texas and at Fort Gibson, Oklahoma ice formed on standing water. Across eastern Nebraska, southern Minnesota, and about the northwestern two thirds of Iowa the colder air allowed rain to mix with or change entirely over to snow at times, mostly in the morning. At Des Moines the high temperature for the day was only 46 degrees and the observer recorded that, “Few flakes of snow was observed.” Further north and west the snow was heavier, in some areas melting as it fell but in others managing to accumulate for a short time. At Algona an estimated 4 inches of snow fell in the morning, breaking some tree branches, but all melted by noon. The snow was observed as “quite heavy” at Creston, while “several inches” were noted between Des Moines and Atlantic and 4-6 inches were estimated on the Rock Island Railroad between Stuart and Avoca.

 

This stands as one of only two occasions in which fairly widespread, measurable snow has fallen in Iowa in the month of September, the other being on September 25, 1942. In that storm most of the state received snow with amounts ranging up to 4 inches at Allison, Forest City, Mason City, and Millerton with scattered tree and utility line damage noted across the state. 

 

Table 1: Years in which snow has been recorded in Iowa in September.


1881 – widespread measurable snowfall on the 16th (see above)
1895 – “first snowflakes” noted at Madrid on the 28th
1912 – “few flakes” observed at Storm Lake and Marshalltown on the 17th and 18th
1938 – flurries reported at Orleans and Maquoketa on the 18th and 19th
1939 – traces of light snow and sleet across northern IA, 0.1” at Sheldon and 0.2” at Sibley, on the 29th and 30th
1942 – widespread measurable snowfall on the 25th (see above)
1961 – light snow across northwestern half of IA on the 30th, a few measurable amounts ranging up to 3.0” at Swea City
1985 – a few flakes at Des Moines on the 24th, widespread wintry mix with 0.5” at Audubon and Storm Lake on the    29th and 30th
1995 – a few flakes and ice pellets mixed with rain across northern IA on the 22nd

 

Above blog post by Jim Lee

 

On the topic of winter, my guy Steve Gottschalk in Lowden, Iowa sent this regarding woolly worms and some other folklore he uses to make his winter forecasts...

 

Terry, thought I would update on the woolly bears. I have 14 reports now and 12 of them are saying a cold winter. I have killed a record number of crickets in my apartment. Almost triple my old record. Spiders are trying to come in big time. This is a hopeful sign of a hard winter.

Taking this a step further, a cold pattern is shown developing over Canada by the last week of September. This is the projected jet stream flow September 25th. 

Look at the cold air that configuration delivers to our friends north of the border. These are the day 10-15 temperature departures. Now that's a healthy reservoir of cold air if it develops as shown.

Highs September 29th are holding in the teens and 20s in central and northern Canada.

The GFS has some lows down around freezing in northern Wisconsin and the UP of Michigan. Still no frost or freeze indicated in my area.

However, with all that cold air up north, the snow pack rapidly builds. This is the snow that's projected to fall by October 1st on the GFS.

The EURO weeklies out Monday evening depict this for snowfall between now and November 1st.

If the snow in Canada comes as shown by November 1st, that greatly increases the chances for cold to deepen and expand over the great white north. This would set the table for what I believe has the potential to be a healthy winter here in the Midwest. I'll be watching the trends closely the next 2-3 weeks. 

 

Meantime, enjoy what's left of summer. And summery it will feel with highs the rest of the week generally in the low to mid 80s across the central Midwest. Roll weather...TS

Share on Facebook
Share on Twitter
Please reload

ARCHIVED POSTS
Please reload

RECENT POSTS
Please reload

© 2019 Terry Swails