Oct 26, 2011

Autumn Has Taken Hold

The cool and crisp feeling of Autumn is finally being felt here at OSNW3. It took a while. We have yet to dip below the freezing mark, however. Fairly soon though we will be adding the 2011 date to the Winter History page.

(**First Freeze took place on Oct-28)

The later it comes, the better in my opinion. Only because recent climate trends show more snow falls in winter when the first cold blast takes place a couple weeks later than average. The average first freeze in Oshkosh is Oct 12 (1981-2010). This year has more climatological posibility since it is another La Nina year. A comparison for Oshkosh winters during La Nina is below.

"For the second winter in a row, La Niña will influence weather patterns across the country, but as usual, it’s not the only climate factor at play. The ‘wild card’ is the lesser-known and less predictable Arctic Oscillation that could produce dramatic short-term swings in temperatures this winter." Read more here.

With that said, when it comes to predicting the weather my confidence lies with Lezak's Recurring Cycle theory. No matter the ENSO condition, following the LRC allows one to make accurate long range forecasts. This being my sophomore year following the LRC I plan to take a bold step and create a winter/spring forecast for Oshkosh. It will include snowfall amounts, temperature trends, and event specific time frames all based on the LRC. I plan to publish something around Thanksgiving. For more information on the LRC please click here. For a forecast now, and tomorrow and the coming weekend, check out the OSNW3 Weather Brief below.

(OSNW3 Weather Brief)
(OSNW3 October Observations)

(OSNW3 October 2011 Summary)
(click on graph for the month summary data - it will open a new tab/window)

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Oshkosh La Nina Comparison (Updated 2011)
What does La Nina mean for Northeast Wisconsin and Oshkosh specifically? I did some digging and documented the results for Oshkosh. Results are below.

Oshkosh Climate Stats
Since the winter of 1949-50, Oshkosh:

* In La Niña winters: averages 49.0" of snow
* In all other winters: averages 38.6" of snow
* Overall: averages 43.8" of snow



On the bottom graph, you can see a running total trend for snowfall for the winter months since 1949-50 in Oshkosh. Through December, snowfall in La Niña months tends to be pretty close to overall averages. However, from January through March is when the snowfall tends to be above normal.

If you consider a winter snowfall within 7 inches of the mean to be "average", then only 4 of the 20 La Niña winters saw below average snowfall, with 5 average, and 12 above average. When the Oceanic Nino Index (ONI, sea-surface temperature anomalies in the Nino 3.4 Region) has been -1.0C or lower - indicating a moderate or strong La Niña - half of those winters saw 49 inches or more of snow in Oshkosh.

The last 5 winters have seen above average snowfall in Oshkosh (DJF - 25.3" 1981-2010). The winter of 2005-2006 saw 32.0 inches of snow. Oshkosh ended below 30 inches for winters of 2002 through 2005 when the totals were 23.0, 27.2, 26.2 inches respectively. Data set located here.

I then compared the meteorological winter, Dec-Jan-Feb, eliminating the transition months of Oct, Nov, Mar, and Apr from above. I found that the strongest seasons of the ONI index were not always big snow producers. That is especially true when the index is strong coming into October. It tends to deepen some throughout the winter but Oshkosh lacks the big snow totals. Average snowfall when a Jul-Sep index is -1 or deeper is 28.0", only two plus inches above the average Oshkosh winter.

(Oshkosh La Nina Winter)

More Met Winter Info:
Meteorological Winter Total Snowfall List
Meteorological Winter Total Snowfall Graphs

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Predictions for OSNW3's Winter
Winter is just around the corner and each season predictions are made for the first 1" snowfall, the first "actual" day of Winter, and the total snowfall for the season at OSNW3. Below is how it breaks down.

Predict the:
First 1" snowfall at OSNW3. (submit by Oct-31)
First "actual" day of Winter at OSNW3. (submit by Oct-31)
Seasonal snowfall at OSNW3. (submit by Dec-1)

Climate data and info to help you choose.
Lezak's Recurring Cycle Theory @ OSNW3
OSNW3 Winter Firsts and Lasts:
OSNW3 Winter definitions of "actual"

Current Predictions:
joshherman - October 23, 2011 at 10:20:18 pm
Dec 9 - First 1" snowfall at OSNW3
Dec 17 - First "actual" day of Winter at OSNW3

DoubleJ - October 25, 2011 at 12:23:23 pm
Nov 28 - First 1" Snowfall
Dec 12 - First Actual Winter Day

In past years all three guesses were to be submitted by Oct-31, however this year I felt the seasonal snowfall should be delayed until Dec-1 so participants could utilize the LRC and potentially have a basis for the final guess. Please feel free to make a prediction. The more the merrier!

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Front Of House
Slowly buy surely we are losing the leaves. I have failed to capture a photo of the FOH and TAS since Oct-15. I will grab one soon and update because things look different now than they did 10+ days ago. I did measure some hail on Oct-25 at 12:25pm in Neenah, WI. 3/4" almost! Largest I've ever personally measured. Was only able to capture the event with my phone and I have yet to transfer the video but it was coming down hard for a couple minutes semi-covering the pavement before it almost instantly melted.

(FOH - Oct 15, 2011)

(FOH - Oct 29, 2011)

(TAS - Oct 15, 2011)

(TAS - Oct 29, 2011)