Saturday, January 3, 2009

NOAM Temperature Departures - December '08

A notably...nay brutally...cold December was heralded for the eastern CONUS by many well-known LR wx forecasters as meteorological winter approached.

Offered for your consideration...a cumulative temperature departure animation for NOAM here.

Northeastern CONUS temperatures never did observe negative anomalies...nor did the mid-Atlantic region except for a brief period centered around the 8th. The negative anomaly centroid was over the SE for much of the month before retrograding into the upper Plains.

End-of-month snapshot of precipitation departures.



Note main storm track running NE through MO - IL - MI and secondary axis from MS - TN - WV continuing into New England.

The primary storm track is at odds with the statistical correlation between 'NAO - precipitation.' The map below indicates when NAO is positive the storm track runs from MO - IL - MI...as observed during December. Problem is...the daily average NAO for December was -0.281.



The ten-year NAO precipitation correlation time period was selected b/c it excludes the +PDO / +ENSO years that dominated the late 80s and early 90s. The correlation coefficient must be at least +/- 0.6 to be statistically significant.

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