It Just May Snow Here Yet!
Month: December 2023
Revisiting This December being One of the Warmest on Record for Most of the Western Great Lakes and Northern Plains and a Brief Look at the 2nd Least Percent Snow Cover on Record for December over the Continental United States (CONUS)
I have had quiet a few question on if we will have White Christmas this year. This post will try to answer that.
The short story is if you live in the central or eastern CONUS it is very unlikely you’ll have snow on the ground Christmas morning.
I have updated this to show the percent snow cover and ENSO state for each of the 10 years. At the end I have 2 tables that show the years with the ENSO index numbers and the snow cover for that Christmas. The bottom table sorts the percent snow cover from highest to lowest to see if there is a correlation between the ENSO state and the percent snow cover on Christmas day.
| Area Covered By Snow: | 53% |
| Area Covered By Snow: | 26.6% |
| Area Covered By Snow: | 26.5% |
| Area Covered By Snow: | 28.1% |
2019 was ENSO neutral with the ONI index at +0.7 while the MEI index was 0.1.
| Area Covered By Snow: | 24.6% |
| Area Covered By Snow: | 49.0% |
| Area Covered By Snow: | 44.1% |
24.6%
2016 was a strong El Niño, the ONI index was +2.5 while the MEI index was +1.9. The ONI at 2.5 was an all time record for the ONI index.
| Area Covered By Snow: | 37.2% |
| Area Covered By Snow: | 35.5% |
| Area Covered By Snow: | 41.7% |
Below is a table showing the percent snow cover on Christmas
Below is a table showing the percent snow cover on Christmas Day in chronological order.
Below is a table showing ENSO numbers and the percent snow cover on Christmas day for that year sorted from the highest percent snow cover to the lowest. There does not seem to be a significant correlation to the ENSO state and the percent snow cover on Christmas Day.
This is an updated version of my Winter Forecast
My actual forecast remains unchanged. I mostly updated the ENSO slides and added monthly model forecasts from the ECMWF and the CFSv2.
CPC’s forecast for this winter has not changed significantly in the past few months.
The QBO should allow for more arctic air to reach the CONUS once we get into January and February.
I am thinking snowfall will generally be below normal over Michigan, however sections of the East Coast, from North Carolina to Maine could have well above normal snowfall since El Nino’s favor Nor-Easters (Coastal Storms). When we get into a cooler pattern in January, I’d expect to see some heavy snow events along the east coast. See slide 48 for details.
It is looking like December 2023 will end up being in the top 5 warmest Decembers on record across Michigan. This will likely be true not only in Michigan but across most of the northern CONUS.
So far, as of the 16th, December is averaging 6 to 8 degrees above normal across Southern Lower Michigan. Flint is warmest with +7.8, while while Grand Rapids is the least with +5.5. Most other climate sites are between 6 and 7 degrees warmer than normal through the 16th in Michigan. Over northern Michigan Alpena has the least positive departure with +4.1 while Gaylord is +5.9 and Traverse City is +5.1. We are expecting two cold days (Monday and Tuesday) but the rest of December is expected to well above normal. Thus, December 2023 is likely to be in the top 5 warmest on record over most of Lower Michigan.
I thought it would be fun to look at our Fall of 2023 climate and now close what happened came to what would typically happen during an El Niño Fall.
In our string of nationally much warmer than normal seasons, the fall of 2023 was 124th out of 129 falls for warmer than normal. This puts this fall warmer than 96% of all falls since 1895! No area of the CONUS had a below normal temperatures (bottom 1/3 coldest) this fall.
Here is a quick look at November.
For the most part, November was not was warm, relative to normal as October was, in fact the eastern half of the CONUS was cooler than normal in November, as were parts of the Pacific Northwest. It was an extremely dry month over most of the CONUS, ranking 111th dries out of 128 years (91%). Only the Gulf Coast and Florida were wetter than normal. Snowfall was mostly below normal but a snow storm brought heavy snow from Kansas to near Chicago around the 25th resulted in up to a foot of snow in that area, bringing them above normal snowfall for November.
It looks like our warmer than normal temperatures will persist over the western CONUS but over the eastern half of the CONUS, largely based on the MJO, with some ensemble model support colder and snowier weather will follow the last 2 weeks of December. Over the Southeast it will just be cool and wet.
themarinocast 