Clouds of the Day - May 5, 2020

It’s been raining steadily this morning. So far, between 1:30 a.m. and 11:00 a.m. the rain gauge has measured .36 inches of rain which is a rainfall rate of .04 inches per hour. Check the rain gauge meteograph below.

The cloud type this morning is nimbostratus. Nimbostratus is one of ten principal cloud types. It is gray, or sometimes darker, because of its thickness and falling precipitation. It is classified as a middle cloud because it forms in the mid-levels, usually as altostratus, and thickens and lowers. Falling rain (or snow) gradually saturates the lower levels, lowering the cloud base into the lower levels. Nimbostratus looks the same as stratus but stratus does not have precipitation, except possibly drizzle.

Note: Look at yesterday’s blog. The day started with sunshine but altostratus spread overhead during the day. The altostratus was running ahead of today’s storm system and was the forerunner of today’s nimbostratus and rain.

Nimbostratus

Nimbostratus

Meteograph of rainfall. This chart ends at 11:40 a.m. with .41 inches of rain. Light rain continues.

Compare today’s (5th) solar profile with yesterday’s (4th) and the day before (3rd). Look at the cloud photos for each day below. The photos each day are displayed in chronological order. The 3rd recorded sudden large variations in solar energy due to rapidly changing cloud cover. The 4th began sunny but quickly clouded over with altostratus. Variations in the cloud thickness are plainly visible in the profile. Today began with light rain and thick nimbostratus which is evident on the very low amount of solar energy getting to the ground.

The radar image below shows where rain is falling over central Iowa, including the Waterloo and Cedar Falls area, as of 11:55 this morning. The entire area is shifting eastward and time-lapse shows slow rotation centered in the rain area southeast of Storm Lake in northwest Iowa. The rain is light but steady where it is falling. The radar image is from Radarscope software available here: https://www.radarscope.app/.

The rain gauge data below was added this May 5th post on May 6th. It shows the complete rainfall traces for total rainfall (blue) and rainfall rate per hour (magenta). The first measurable rain (blue line) was at 1:30 a.m. on May 5th with the last measured rain at 9:20 p.m. The rainfall rate (magenta) is indicated across the bottom of the graph with most reports at .06” per hour up to .12” per hour. The sudden drop in the accumulated rainfall is at Midnight when the gauge starts a new day at zero.