Winter 2022-23 Recap - Part I - Temperatures

This is a recap I should have posted months ago.  As we are on the eve of the FOX 8 Winter Outlook for winter 2023-24, now is a great time for a detailed recap of last winter--or the lack of winter.  Below will be numerous charts bar graphs highlighting various metric we use in describing the overall winter.  Most of these revolve around temperatures and snow. I like to give historical and spatial perspective with each metric.  So what you will see are bar graphs (for Cleveland, Ohio - December through February unless otherwise noted) and maps (for some) highlighting some of the metrics versus normal. 

Overall temperatures for northern Ohio (Cleveland) were well above normal last winter

Winter 2022-23 was the 3rd warmest on record!

Winter temperatures were well above normal for most of the Great Lakes, mid-west and Ohio Valley

Overall winter temperature ranks were top 10 from Texas, the entire gulf coast and up the eastern seaboard

68 of the 89 possible days had high temperatures above normal!

Number of days with high temperatures UNDER 30 (Lowest since 1997-98. Second lowest since 1871)

Number of days with high temperatures at/above 40 (Third highest and most since 1931-32)

Number of days with high temperatures at/above 50

Number of days with low temperatures at/under 20

This animation shows the temperatures across the US starting November 1 through February for each 15 days period.  Red indicates above normal.  Blue is below normal.  Notice how variable the temperatures were in November and December vs January and February. 

Temperatures around Christmas week 2022 were bitterly cold across much of the middle of the US. Many thought the cold in mid/late December was an indication of a colder January.

The temperature pattern flipped bigtime in January!

January max and min temperatures across the US (map courtesy Brian Brettschneider)

December temperatures vs normal

Final January and February temperatures vs normal

Final winter temperatures - Dec through Feb versus normal

Why The Abnormally Dry September? How Does This Year Rank?

We just finished one of the driest Septembers on record in northern Ohio. 

Comparing August to September shows how the pattern flipped to a drier one starting in late August.

It wasn't just across Ohio, much of the Ohio Valley, mid-west and dep south (exception is east coast) saw below normal rainfall in September.

The comparisons are stark when comparing the percentage of normal for the mid-west/Great Lakes versus August. Blue/green are regions above normal. Brown/tan/white colors are below normal. 

What changed in late August/September?

Upper level pattern was stalled in August. Frequent fronts and rainfall.

AUGUST 1-15

Pattern started changing in late August. High pressure began to build across the upper mid-west and across western Canada.

AUGUST 16-31

By September, the pattern settled into this configuration. High pressure over Canada and across the SW US.  Low pressure across the Gulf of Alaska and a weak low across the mid Atlantic (tropically driven)

You'd figure some of the moisture from the east coast/mid-Atlantic low would influence our weather across Ohio and the Great Lakes given the overall flow around the ridge over Canada.  Yet the relative humidity, degree of rising air (Lifted Index) and the zonal winds were well below average. 

Overall relative humidity:

Rising air (Lifted Index)

Zonal Winds

Jet stream across North America was especially strong from Indonesia east across the dateline into Mexico and the deep south. Northern branch was also very strong off of eastern Asia, across the Bering Sea and into the eastern Pacific.  Very weak jet across the northern half of the US/Canada. This kept the strong low pressure outside the northern US/Great Lakes.

Dry conditions contributed to above normal temps in the upper mid-west with near normal temps across Ohio.

This is not a precursor of the winter ahead.  More on a few of the drivers of winter 2023-24 in the weeks ahead.

Historic August Rainfall/Severe Weather Recap

The clean up continues after the second round of heavy rain/severe storms across northern Ohio.

17 school districts closed due to damage and power outages:

Here is the COMPLETE radar loop from August 23 at noon through early August 25 before sunrise. Warnings, watches and lightning are included for northern Ohio.

I separated the 2 day rain event into 3 separate radar loops starting at 9pm August 24 through August 25 at 3am:

August 23 - 12:30PM through August 24 - 5AM

August 24 - 5AM through August 24 9AM

August - 9PM through August 25 - 5AM

Historic rainfall over 48 hours with two separate large clusters of rain/storms:

Another vantage point shows the heaviest rain from southern Michigan through Ohio and western PA.

Since August 1, most of northern Ohio has received 200-400% of normal rainfall:

Severe storm warnings were widespread. Most of northern Ohio was under a severe thunderstorm warning at some point between August 23 and early August 25.

4 tornado warnings. 12 tornadoes. COMPLETE NWS RECAP

The EF-1 that occurred on the east side of Cleveland was the first tornado that occurred within the Cleveland city limits since July 12, 1992 per NWS Cleveland. That tornado occurred near Hopkins Airport.

Here are ALL of the tornadoes from 1950 to 2022 in Cuyahoga County

Why did this heavy rain occur?  What were the factors that lead to this?

The huge ridge of heat in the central US has been a fixture for at least a week. 

Where high pressure resides, low pressure has to follow either down or up stream. Disturbances rode up and over the ridge and down through the Great Lakes.  

Great lakes radar loop from Wednesday through Friday: The excessive heat watches/warnings are shown in red.

Couple this with the high humidity (dewpoints above 75) and you have the recipe for heavy rainfall.

Interestingly, the historic Derecho in 1969 on the 4th of July produced MORE rainfall!

Here are the final rainfall numbers between August 23-25 using the same perspective as the 1969 map above (for comparison)

Oh and almost 75,000 lightning strokes over the 48 hour period across Ohio!