Wednesday, July 06, 2022

Feast to Famine: Ohio Rainfall Since June 1st. Any Relief?

Remember the active spring we had?  Seems like it was years ago.

Most of northern Ohio had between 1/2" and 2"+ rainfall above normal during the first half of June. The driest areas were eastern Geauga, Lake and most of Ashtabula counties.  

June 1-15 Rainfall vs Normal

Since the wetter stretch of weather in early June, rainfall has been sparse. Most of the area was running 1-2" below average since June 15th. This was in our long range forecast issued back on June 18th. Rainfall map is below.

June 15-30 Rainfall vs Normal

However since the start of July, the pattern has reverted back to a spring one albeit briefly. Storm track has brought rain/storms in from the West-Northwest. Below is the July 1-6 rainfall vs normal.  

Let's break down the actual rainfall amounts over 3 day periods. I circled the regions where rainfall is between 0.75" and 1.25"

Now July 4 through early July 6th. Circled regions show rainfall between 0.75" and 1.5" and 2-3". Notice the extremely dry conditions across Lake, portions of Geauga and Ashtabula counties. 

The soil moisture has dropped significantly across the Ohio Valley since mid June.  Recent rainfall will help.  Duration of rain is key. Since these storms have moved fast, much of rain runs off instead of being absorbed into the ground.

Long range forecast shows rain this week. Beyond Saturday July 9, rainfall remains well below normal through July 19th!


Tuesday, July 05, 2022

Are Summers Becoming More Consistently Humid/Less Breaks?

The plots below are the average dew point for each day from June 1 to September 30 since 1972 for Cleveland. I color coded each dew point range for easy reference.

Dark Blue: 30-49°

Light Blue:  50-59°

Light Green:  60-69°

Dark Green:  70-80°

First image is the month of June. Reading left to right for day one through 30. Horizontal black line separates each decade. I notice more breaks from high humidity days in the 1970s and 1980s. More consistently high humidity in the mid/late 1990s into the early 2000s. Recently, lower humidity days seem more frequent in the first half of the month

Second image is July. Over the last 10-15 years the frequency of "lower humidity" days (light blue) seems less than previous decades.

Third image is August

Fourth image is September:

Let's only display the days with dewpoints UNDER 60.  Basically more comfortable days. Now we can see the frequency of delightful days for each summer month/day.  Some quick observations:

* Breaks in the humid days in June look to be more frequent in the 1970s/80s and early 2000s
* Breaks in humid days in July more frequent in the 1970s, early 80s and early 2000s.
* Breaks in humid days in August more frequent in the 1970s.
* Breaks in humid days in early September more frequent in 1970s and 1980s