A Few Thoughts About This La Nina

At this time, we DO NOT have a La Nina at present. However, the Pacific waters are experiencing La Nina conditions that may lead to a La Nina. One must remember that a La Nina is not considered an official La Nina until sea surface temperature anomalies of -0.5 or less are registered for 5 consecutive 3-month periods within the Nino 3.4 region

Year	DJF	JFM	FMA	MAM	AMJ	MJJ	JJA	JAS	ASO	SON	OND	NDJ
2010	1.7	1.5	1.2	0.8	0.3	-0.2	-0.6	-1.0	-1.3	-1.4	-1.4	-1.4
2011	-1.3	-1.2	-0.9	-0.6	-0.2	0.0	0.0	-0.2

Many of the models are nearly split on how the La Nina conditions will progress the rest of the year into next year. The official ensemble mean predicts La Nina conditions to strengthen and continue into the Northern Hemisphere spring 2012.

The La Nina conditions are expected to peak in January or February of 2012 before easing somewhat by May. Forecast anomalies appear to suggest a stronger La Nina for winter 2011/2012 than the previous winter.

Part of my upcoming winter forecast contends that the predicted La Nina will not be as strong as last winter. This is a good reason why I wait and gather all available data before issuing my official winter weather forecast.

I've seen some of the winter forecasts put out there so far. While I admire their input about how the cog of winter's machine will affect regions of the United States, there's just too many variables that have not been considered because those variables simply have not been measured yet.

The closer we get to the month of December, the more reliable the forecast should prove to be. Even at that, statistically, one will not 'nail' the overall forecast.

For those who will rely on whether La Nina will affect the overall pattern for the United States, remember that blocking patterns and cutoff lows could become the main driving force once again for the upcoming winter. Jet stream patterns could prove erratic at times. Remember, also, weather is global. What happens in other countries could affect our weather here. Simply put, looks like another interesting winter of extremes.

In my final segment about working on the winter forecast, I'll be looking at favored locations to look at for weather to become quite interesting in our part of the world. Also, La Nina will have its own input, which will add to the drama. Stay tuned....

MS