Rainfall 2021 vs 2002: April 1 to May 5

Rainfall this spring has overall been above normal.  Using NOAA MRMS radar data from the Iowa Mesonet Site here is a county by county breakdown of total rainfall over this 35 day period comparing this year to last year

Legend for each graphic below (2" to 7")

Mansfield, Ashland, Wayne, Holmes Counties

Lake, Ashtabula Counties

Cuyahoga County

Erie County

Geauga County

Huron County

Lorain, Medina Counties

Summit, Portage Counties

Stark County

Tuscarawas County

Where Does This Summer's Rainfall & Humidity Rank?

No big surprise here.  Even after an almost 2 week rainfall break in late July/early August, this summer still ranks 2nd all-time through August 19!

The individual rainfall events have been significant. Here is the number of 1/2" inch rainfall days.

28 of the 80 total days have had at least 0.1" rainfall. That is far and away the most of any summer.

The volume of rain water that's fallen across northern Ohio this summer is DOUBLE last summer!

For comparison, 6.6 trillion gallons of roughly 5% the volume of Lake Erie!

Our original summer outlook highlighted ABOVE NORMAL rainfall with an active July which has worked out very well.  We were hoping for near storm days and more dry breaks which would have allowed for more 90 degree days.  My initial call was for 10-15 days above 90. We went with slightly above to account for drier periods. As of this August 20th we stand at only 6. 

Number of severe thunderstorm warnings still running BELOW AVERAGE.

Continental upper level pattern has matchup pretty well with our initial outlook. 500mB heights vs normal in the images below show every 15 days starting June1st. Notice the frequent LOW in the central US and high pressure ridges flanking it.

How about the humidity.  Where does this summer rank?  2021 ranks 5th since 1948. Interesting summer of 2018 was more humid overall as was the summer 2010. The most humid summer was 1995

The extreme humidity has come in spurts.  We measure extreme humidity period in hours above a certain level. So far this summer's extreme humidity is lagging behind last year. In fact EVERY summer in the last 5 years has featured MORE EXTREME humidity than summer 2021.  See image below.

Updated Rainfall vs Normal Since Early May

The first two weeks of May ended up above normal with the exception of Lake, Ashtabula and portions of Geauga counties. Rainfall averaged more than 1" above normal for 60% of the area.

Between May 15 and 31st conditions dried out significantly. More than 1" below normal during the second half of May for most areas.

The first week of June the frequency of more hyper-local rainfall has gone up.  Deficits are still widespread as of this writing (June 7).

This week, the Sonoran High (western ridge) and the Bermuda High sandwiched the central US low which has stalled allowing for disturbances to rotate around the low and into the Ohio Valley producing frequent afternoon/evening slow moving storms. Animation is from Monday through Thursday.

Dewpoints reached 70 for the first time this year.

Noon dew points, Tuesday June 8

Afternoon storms Monday, June 7 were heavy in spots. Around 60-70% coverage (1/4" or more) with15% of the area (1" or more) most of which centered in portions of Lake, Portage and southern Stark, northern Tuscarawas counties.

Total system rainfall forecast (not counting local storms) through Friday June 11.

Labor Day Heavy Rainfall in Ohio. Summer heat to snow out west

 Stalled front between 6am and mid afternoon created training of storms across most of northern Ohio.

Radar loop from 5am to 7pm Labor Day

More than 90% of northern Ohio received 1" or more (green or yellow colors) above

I calculated that more than 80 BILLION of gallons of rain fell over a 12 county area between 6am and 6pm. 

Labor Day's rainfall ranks 3rd all-time at Hopkins? 

Here is the top 30 rainiest days. I boxed in red the events that occurred in September.

Today's rain is exactly 24 years after the remains of Hurricane Fran passed over eastern Ohio setting our single day rainfall record of 4.59"

I dug up some of the NWS Cleveland forecast messages from the Iows Mesonet Database (check it out. It's a great resource) issued from that day in 1996:

8:30am message from NWS Cleveland on 9/7/1996

10:40am NWS message from NWS Cleveland on 9/7/1996

All of this here in Ohio doesn't compare to the dramatic changes parts of Colorado will go through weatherwise over the next 24 hours. Mid 90s to ower 30s with accumulating snow!

Per "Maxar_Weather" on Twitter: "...Years in which Denver recorded both a 100° high and measurable snow. The shortest time in between was 25 days in 1962, with 100°+ on 8/14 and snow measured on 9/8. Denver reached 101° on Saturday and is expected to record measurable snow three days later--Tuesday."

Updated Rainfall vs Normal

Rainfall vs normal last 60 days across Ohio Valley and Midwest

Rainfall vs normal last 14 days

Ohio Valley rainfall last 72 hours (June 15 morning thru June 18 morning)

Updated rainfall numbers at NWS Cleveland (Hopkins Airport)