Winter Outlook 2008-2009 Update-Jan 2009

January 22, 2009:

This is the updated Winter Outlook 2008-2009. Before we go into the upcoming months, we will first look at the last two months and what has happened and why.

November in a nutshell was a book of three tales. The beginning started off very warm with highs in the 70’s. This seemed like it was going to set up for the perfect yearly early November severe weather outbreak, however a strong ridge bringing the warmer temperatures gradually fell apart. Instead of one or two strong systems we had four systems come through the period of two weeks. Mid-month was the tale of the cold, frigid arctic air. Temperatures barely made it into the upper 40’s for 7 days. The last third (tale) was average temperature-wise giving us a reprieve from the cold. Overall, for the month Athens ended up with an average temperature of 42° F that is -2.9 F below normal.

We had only two days with .25 or more rain fall and the wettest period of the month occurred the 13th through the 15th when (.28+.07+.56)” of rain fell. This was the strongest system of the month that dropped average highs drastically and brought the first snowfall to Athens on the overnight of the 17th/morning of the 18th. Total rainfall for Athens in the month of November was 2.04”, that’s -1.21” below normal.

Click here for daily statistics on November.

December was an active, wild, roller-coaster for the southeast Ohio area. Here is the maximum, minimum, and average temperature per day throughout the month for Athens:


Strong low pressure systems were the normal thing every 7 days. These lows moved along a “conveyor belt” that set up just to our northwest for most of the month. Southeast Ohio would be under the influence of a warm front for a day or two. The associated cold front would sweep through the next day giving us a drastic drop in temperatures.

Here is the pattern for the United States in the month of December:


To sum the month up, the average temperature for December in Athens was 36° F. That is actually 0.4° F warmer than the monthly normal average. Parkersburg, West Virginia’s average temperature was 34.8° F, that’s -0.8° F below normal, so for the southeast Ohio area it was about as average for December as you can get. A few extremes occurred throughout the month including a record set on the 27th of 72° F, and the near record cold of 5° F on the 22nd. Also because of the active weather pattern, there was more than average precipitation that fell for all of Ohio including Athens. For the month of December, Athens received 3.44” of precipitation which was .23” above normal.

Click here for daily statistics on December

Now looking ahead into the next two upcoming months, will winter persist with the frigid cold or will it give in to spring warmth early? First, let’s look at what has happen synoptically and globally the last few months and see why things have been what they are with the tele-connections.

This has been a very cold start to 2009. Looking at this month so far, the temperature has been 4.1° F below normal at 27 ° F. This was thanks to a strong trough in place over the eastern US and a ridge over the western US.

The western states have seen near record high temperatures for the entire month and mostly above normal temperatures. These represent the south/southwesterly wind flow that will bring warmer temperatures from the tropics thanks to a strong high pressure within a trough. This warmth has gotten as far north as southern Canada and the upper Rockies. The eastern states have a north/northwesterly flow that ushers in colder air from Canada to as far south as Florida. Also weak low pressure systems, one after the other (known as Alberta Clippers), have been the norm.

At the current moment, January 22nd, the trough is beginning to retreat back up to the north instead of digging down into the Gulf States. The trough is deteriorating slightly too giving into a low pressure system in southern California. These both are symbolic of the jet stream taking a more west-to-east orientation. This will change the weather drastically for many in the United States.

Current pattern:


That is in the process to changing to this pattern:

The pattern is a La Nina currently and has developed in the last month. Sea surface temperatures have dropped a degree Celsius in many of the Nino areas including the Nino 3.4 sector, the sector that affects our weather the most. This would explain the past ridge/trough pattern we were in. Recently, however the sea surface temperatures (SST’s) have risen a quarter to a half of a degree Celsius. This has caused a weakening in the strong trough to the west helping aid the change of patterns to an amplified west to east pattern.

Here is the mean ensemble forecast of the standard SST within the Nino 3.4 sector along with the past few months:



From the chart above the forecast is for the SST to stay around what it is now, in a slight La Nina, for the next month. Then it is predicted to gradually start going back up as the seasons change. This years La Nina (around -1° K) is much less amplified that last years was at this time (around -1.75° F). This is why it hasn’t gotten nearly as warm as last years January was with an average temperature of 33° F, that’s 6° F higher than this year thus far, and about 2° F above normal. Using this CFS (NCEP (National Center for Environmental Prediction) Climate Forecast System/Model) forecast of the SST’s and the past years with the same conditions, they can make this North American map of chances that there will be temperatures above/below normal:


And precipitation above/below normal:


So when all this information boils down into simple text and results I decided that:

The rest of January: warmer than the earlier 2/3 but will cool off the last few days. Dry, with only light precipitation.

February: Cold spell early, warming late and overall average temperature for the month. Two or three mid-month snowstorms as the pattern shifts warmer, and more southerly.

March: Warm, although a mid-month cold period. Start off very wet and dry out by the end of the month.



Christopher Redmond
cr898005@ohio.edu