Tag: excessive rainfall

At the risk of going overboard on the Summer of 2023, I have another set of charts you may want to look at.

I through it would be fun and informative to see the frequency for hot days across our Nation.

Here I have the frequency for highs in the 90s across the CONUS (Continental United States), the longest streak across the CONUS, the frequency of lows of 70 or more and I few more NCEI charts to show how hot of a summer this was both nationally and regionally. I also have a few precipitation maps so you can see that the great frequency for hot weather was were it rained less, relative to normal for that area.

I have added 2 slides to this presentation ( 8 and 9). These two slides show that what one uses for the “normal”, greatly impacts what the departure from normal looks like. I used 1991 to 2020, the official NWS normal period for the image on the top left, then 1895 to 2000 for the image on the top right, not the area of below normal is significantly less. That is because the period 1991 to 2020 was warmer than the 1895 to 2000 period. On the bottom left the mean is 1895 to 2020, that has no below normal areas. This seems questionable to me since the ranked normal’s on the next slide look a lot like the 1895 to 2000 on slide 8. I added this because I was getting some questions on this matter. I hope this helps.

Here is my forecast for this coming week, plus a look at the current fall foliage report. The short story is warm and dry this week of the Great Lakes and northern New England. Wet along most of the East Coast and over the western CONUS. It will be cool and wet over the western CONUS.

I am expecting warm and dry weather this week over Michigan but warm and wet over the east coat, and cool and wet over the west coast.

Fall Foliage Map

Here is my updated version of the summer of 2023 climate. I have added some details on Southwest Michigan including the severe weather events this summer. I have also added slides on the large scale pattern, that is our transition from La Nina this past winter to El Nino this summer. This lead to persistent blocking over North America, which is why there were persistent heat over the south and wet weather over the eastern 1/3 of the CONUS.

This was a summer that featured persistent weather patterns over most of North America and lead to one of the most active Canadian wildfire seasons on record. It also lead the the 15th warmest summer on record (back to 1895) over the CONUS.

GRR August 24th Event Link

DTX August 24th Event Link

DTX August 24th Event Flooding Link

DTX EVENT SUMMARYhttps://www.weather.gov/dtx/severeweather07202023
DTX EVENT SUMMARY

It appears cool weather will prevail over the eastern Continental United States (CONUS) for the next 3 weeks. It should be drier than normal over the Great Lakes but wetter than normal over the East Coast and Western Plains.

Expect the next 3 weeks to be cooler than normal over most of the eastern United States. It will be dry over the Great Lakes but very wet over the eastern seaboard.

Severe Storms, on Thursday night (8-24-23) cause power outages, flooding and an EF1 tornado over Lower Michigan. This shows some preliminary reports from the storm last night.

It was a HOT JULY over most of the CONTINENTAL UNITED STATES but that was not the case for the Upper Midwest and Great Lakes.

As promised I have posted the national images of July 2023. The short story is it was the 7th warmest and 45th wettest for the CONUS. In Michigan it was the 58th warmest and 5th wettest on record.

Heavy Rain was forecast for yesterday afternoon into mid morning today. The slides below show the what actually happened.

We forecast heavy rain between I-94 and I-96 and that is exactly what did happen. The heaviest rainfall report showed 4.50 inches in Middleville, most of that area had between 1″ and 3″ of rain from the event.

Heavy Rainfall is expected over most of Lower Michigan from Monday Afternoon into Tuesday Morning

Heavy Rain is expected over most of the southern half of Lower Michigan between 2 pm Monday and 8 am Tuesday morning.

An unusually strong storm system for this time of year is expected to track east across Lower Michigan from Monday into Tuesday morning. This will be an occluded system, with the track of the surface low near I-94. It is typical for the heaviest precipitation to be within 100 miles of track of the surface low, but on the north it’s track. This system as a closed upper low with it and a coupled jet with it. The precipitable water reaches above 1.5 inches Monday afternoon over the southern 1/3 of Lower Michigan as this system tracks through the area. There is also good model continuity with this system so it gives me confidence that the heavy rainfall will happen. Just exactly were is questionable but I would have to believe between I-94 and Route 10, between Monday afternoon and Tuesday morning a large part of that area should see more than an inch of rainfall.

I had my all time record one hour Rainfall rate Saturday Morning, at my Grandville Weather Station.

Exceptional rainfall occurred during the early morning hours at Grandville between 1 am and 2 am. This storm broke my all time 5 minute rainfall rate record and 1 hour rainfall rate record.

With Grandville Weather Data at my house having records back to the fall of 1995, the 2.95″ of rain that was recorded in both my 4″ rain gauge and my Davis Weather Station (nice that they agreed) , is my all time record rainfall in one hour. The previous record was 2.30″ during a thunderstorm during the evening of July 17 2oo6 between 9:45 pm and 10:45 pm. The 0.50″ in 5 minutes is also a new record for 5 minute rainfall, exceeding the 0.41″ on June 18th 2021.

The pictures above are from our home, looking north out of what is my son John’s bedroom window. The time posted on the pictures are EST, so you have have to add one hour to get the correct time for these images.

Heavy Rain and Risk for Severe Storms Today

The Storm Prediction Center has put most of the southern 1/3 of Lower Michigan an enhanced risk for severe storms today (mostly late morning into mid afternoon). Locally heavy rainfall is expected too.

Most of the rainfall today will be from late morning into mid afternoon.

My experience in forecasting over the past 46 years tell me that for Southwest Michigan convection during the spring and summer months, warm fronts, stationary fronts and surface waves bring this area the most rainfall. Cold fronts bring us the least (typically). This event is warm front with a surface wave that develops into a surface low. This tells me most area should see meaningful rainfall today.