Is the little girl to blame for the wacky weather? Hopefully that little burst at least gave our Fort Drum soldiers a little taste of home.
La Nina which from what I have read so far means “Little Girl” in Spanish and it seems that we are seeing the little girl cast her spells in many parts of the world. Sully who is a visitor to the Golden Snowball website has been giving us some great informative information about what could be going on right now weather wise. From what Sully says and trust me when I say I could be mis-interpreting it because it’s pretty technical stuff, is that come the end of this month it will be an official La Nina and most likely a labeled as a pretty strong La Nina or at the very least a moderate one. I’m not going to go rant on about it because I’m still a little clueless (go figure huh) and I’m still Reading up on it. From what I have read it happens because of the water temperatures get colder in the 3.4 region, I think. One thing I did read is that the waters around Australia were colder than normal which may be playing a little havoc as to what normally occurs during a La Nina. Hopefully Sully will stop by when he is feeling a little better and clear up anything I have wrong. Most likely all of it 🙂 Below are some of Sully’s responses that he posted at GSB and once again a big thanks Sully for the great information and Sully has a great informative weather blog at http://www.wunderground.com/blog/sullivanweather/ 🙂
Part of a Conversation about the Warm Weather and La Nina (Little Girl);
SULLY: To have two consecutive years of all-time record breaking warmth is quite unusual. Then again, when one has such a powerhouse Pacific storm system flooding the country with mild Pacific air on the heels of a record breaking area of high pressure (a few records for highest atmospheric pressure were broken over the southeast last week) the return flow of air between these two very large strong synoptic features will most certainly be able to tap the sub-tropics/tropics. The Pacific system’s source air also came from near 30°N, which is the top of the ‘horseshoe’ of warmer than normal SST’s that typically exists during La Nina winters. If you notice many of the all-time record highs across the Northeast for January occurred in 1950 (Strong La Nina) and 1967 (cold neutral – ONI -0.4 close to the 5 month consecutive -0.5 or lower to meet La Nina criteria as the next 3 months dipped into weak La Nina conditions -0.5,-0.6,-0.5). Those years also had major severe weather outbreaks very similar to those experienced over the previous two days.With that being said La Nina is also known for its wild temperature fluctuations and this will show itself later this month as a rather significant arctic outbreak should push its way over from Siberia. There’s already indications of this arctic air becoming displaced as there’s ridging beginning to develop, and more importantly, retrograde over eastern Asia/western Pacific. Usually when this event begins to take place arctic air is about 7-10 days away for the western hemisphere. AO/NAO variables at that time will determine how far south this arctic air will push. Current ensemble means have neutral conditions in the day 7-14 period which would have this airmass evac over the Canadian Martimes/northern New England, but this is still one to two weeks away and much can change between now and then. As it is the AO has been wildly variable for the last 6 months so I doubt a neutral AO will prevail over that entire time frame so somewhere over the northern tier of the US will get clipped by this airmass.
1/8/08 4:45 PM
Patrick said…
Sully, thanks for the great detailed explanation as to what’s going on. WeatherT from the forum also mentioned something about some pretty cold air getting ready to most likely over take the NE. Out of curiosity is the current La Nina considered weak or strong???
Sully said…
Patrick, The current La Nina is actually considered ‘moderate’. The CPC rates La Nina on the ONI index which is a measure of the nino 3.4 region anomalies averaged over a 3 month period. In order to qualify for La Nina anomalies of -0.5 or greater must be met for the 3 month averaged period for a timespan of 5 consecutive months. Technically by this definition, we have yet to attain ‘La Nina’ (this will change at the end of January which will be the 5th consecutive month these conditions will be met). The rankings are as follows:
Weak: -0.5 to -1.0
Moderate: -1.0 to -1.5
Strong: >-1.5
The latest 3 month averaged value for Oct-Nov-Dec was -1.2.—–With that being said, as far as I’m concerned we’ve reached strong La Nina conditions. The SOI has recently skyrocketed, indicating strong La Nina and the pattern over the US all winter has exhibited classic La Nina, overcoming other climatic variables.
More La Nina Information at:
http://www.enn.com/climate/article/24177
http://www.elnino.noaa.gov/lanina_new_faq.html
http://www.cpc.ncep.noaa.gov/products/predictions/90day/fxus05.html
patrick – so at the risk of sounding like a broken record, with a strong la nina, is the pronosis for a warm last couple of months of winter?
sean