Clouds of the Day - Middle Level Clouds - Wednesday, 18 October 2023
/This morning featured middle level clouds as a storm system centered in Minnesota move to the northeast dragging a cold front across the area. Clouds early in the day were Altocumulus floccus. The name comes from the Latin word floccus for its resemblance to tufts of wool. It indicates a thin layer of unstable air. The Altostratus dominated the mid morning to early afternoon sky. The flat layer cloud indicates there is weak upward motion creating these clouds. We did receive a few sprinkles of rain from the Altostratus.
Altocumulus floccus
Altostratus
Altostratus
Altostratus
The satellite image below reveals more about the clouds. At ground level all that could be seen was a mostly flat cloud layer. The satellite image shows the instability present with cellular clouds along the back northwest edge of the cloud band and over Kansas. That band is ahead of a cold front crossing Iowa.
The entire storm shape on the satellite image looks like a comma. The head of the comma is in the colder air aloft that is circulating counter clockwise around over South Dakota. The comma tail is the curved cloud band from Minnesota through Wisconsin and northwest Illinois, Iowa and on to northwest Missouri and Kansas. The comma head is rotating counterclockwise and the tail is moving east and northeast with individual clouds moving to the northeast.
GOES 16 11:51 a.m. October 18, 2023 Visible Satellite Image
Surface Map 11:00 a.m. Wednesday, 18 October 2023 plotted by Digital Atmosphere available at weathergraphics.com
The streamlines on the chart below show the wind direction at the surface associated with the storm. The surface low center is over northern Minnesota. The upper level low center is to the southwest over eastern South Dakota as shown on the satellite image.
Surface Streamlines, 11:00 a.m. Wednesday 18 October 2023, Plotted by Digital Atmosphere, www.weathergraphcis.com