Jan 2, 2012

Oshkosh Winter Prediction - Cycle 1 Performance Review

How is the winter forecast based on the LRC performing as we begin a new cycle? I will admit my thinking in November was that long term climatology would prevail and not become the preventing factor in snow production as it has been thus far. The much advertised 'split flow jet' and 'bottled up AO' are the culprits in busting my snowy predictions this cycle. As for temperatures, however, the prediction of a warmer than average winter is steadfast. Overall the middle of the atmosphere keeps on the cycling and we can look forward to the 2011-12 LRC feature patterns again and again. Below are some numbers to quantify the first cycle forecast performance.

Days with Measurable Snow (0.1" or greater)
Cycle 1 = 13 days (Nov-16 thru Jan-2)
- Actual
- 5 days with 0.1" or greater snowfall.
- 14 days with Trace or greater snowfall.
- 38% accuracy

Total Snow Accumulation
Cycle 1 = 16 inches of snow (Nov-16 thru Jan-2)
- Actual
- 2.4 inches of snow
- 2.18 inches of precipitation. A 10:1 snow to water ratio would have equaled 21 inches of snow had it all been snow.
- 15% accuracy

The data trend leads me to believe that there will be enough warm spells to compensate for the majority of cold air events within each cycle leading to Above Average temperatures for the winter. The numbers tell me 1 to 3 degrees above average each cycle. Don't get me wrong, there will be some cold stretches this winter, there is no doubt about it, but with warm-ups scattered about may make the overall winter not seem so harsh temperature wise.
- Actual
- Daily Maximum temperatures are currently 4.5 degrees above the (81-10) 30 year average.

What should we expect in Cycle 2? The trends show a mild start to January with a cool down by the end of the month. February should continue with what we saw in much of December but hopefully this time around most of the precipitation will fall as snow. The most recent snowfall and wind event (Jan 1-2) should recur sometime around Feb-17. Sticking with the original forecast made back in November for this cycle, we should expect about 12 days with measurable snowfall accumulating around 17 inches. Temperatures should stay above average for the cycle once again. For an idea of when the precipitation may occur see the OSNW3 LRC Calendar 2011-12 and follow the blue highlighted dates. Remember to give or take a day, or two!

(500mb Forecast Trend For Green Bay)

(Temperature Forecast Trend For Oshkosh)

If there are any questions or thoughts on my research and analysis of the LRC or how I presented the material just let me know in the comments section of the blog. Thanks for reading!