The PDO refers to the configuration of temperatures across the mid-lattitude Pacific Ocean as opposed to the ENSO which refers to the equatorial Pacific. The QBO refers to the oscillation of the equatorial zonal wind in the stratosphere and is measured as an westerly or easterly index with westerly having a positive index and easterly negative. Once again, a strong trough is located in the Southern Plains, as shown by the deep negative height anomalies centered over Texas. Beginning with the ECMWF model, with this forecast going out to 10 days, we see a deep trough pushing into the Southern Plains, neutrally-tilted, as the isobars pushing due south show. The SPC doesn’t issue specific risk areas for more than two days in advance, they only put out outlines. It’s not solely the presence of the moderate risk that makes this rare, it’s the fact that this moderate risk area was put out two days in advance.

I can’t put my finger on it, but I believe that the event ended up being a High Risk severe weather event. Its associations and relationships are known and a ENSO event is easily quantifiable. The results are interesting in a study that involved looking at strong ENSO events (strong La Nina’s or strong El Nino’s) and snowfall and temperatures across northern New England. Snowfall in winters featuring significant ENSO events was a bit suprising. The ENSO conversation is typically the easiest part of the preseason discussion. Making sure your image is composed correctly is a vital part of photography. The current situation we are in (top left image) includes low pressure in the West and high pressure in the East. In the above code, the .predictMultipleImages() function will return an array which contains a dictionary per image. Model guidance indicates the storm system will continue to churn in the Southern Plains, with the previously mentioned warm front now becoming stationary and draping itself over much of the slight risk area. Snow cover area however often proves to be an important thermal feedback especially when trying to predict the sign of temperature.

The average snow cover area for the northern hemisphere during this period is 25.3. The period ending this November 30th will come in just at or slightly over that number. Expected thunderstorm development will be along this frontal boundary and associated slight risk area. Closer analysis of the slight risk area reveals the risk to be on the low end, meaning this will not be a widespread severe weather event in terms of severity. Slight risk of severe weather extends from Texas through Oklahoma and into Missouri. Just like with the PDO, 10 years ago, there has been work and increased discussion over the last several years regarding the Quasi-Biennial Oscillation and its relationship to the behavior of weather patterns in the northern hemisphere winter. It would be healthy to maintain a bit of cynicism regarding the results since the sample size which spanned 60 years and 21 qualifying winters is rather small. Still it is fair to suggest that the winter forecast made in 2007-2008 was a bit too pessimistic.

Secondly, it did provide a bit of inspiration for some preseason research. Further research demonstrated that the resistance can be inherited by offspring of gene-altered sows. Preseason forecasts can be a mess to evaluate in hindsight for their inexactitudes, inaccuracies and unquantifiable subjectivities. While all long range forecasts come with a high risk for an incorrect forecast, any trend in any set of models is usually a sign that the trending factor has a higher potential of verifying. For one, it is another in an invariable string of reminders of how inaccurate these forecasts can be. It is very inexact and can change over the course of the season. It is the middle of November and the weather has been excruciatingly mild so it must be time to kick off the seventh season of Single Chair Weather Blogging. 3750 which is comparatively cheap when you consider what the National Weather Service pays for their equipment.