La Nina

[Brandon Brown]

I've read that the La Nina this year is going to stay through the spring. Does anyone know what effects the La Nina will have in the plains this spring? Does it make for a more active storm season, or does it do the opposite and make for a quiet, storm free spring?

Thanks in advance guys/gals...
Brandon

 

[Gene Moore]

My thoughts on a typical La Nina spring include some research and my personal experience. For me La Nina is the least productive for tornadoes, although I've had some very spectacular chase days in La Nina years.

- More drylines - hot and dry SW US - stronger cap firing late or east
- Less chase days and opportunities on the classic plains and high plains
- Tornadoes more common near and east of the Mississippi and eastern US
- More night tornadoes over plains (some research to support this but not conclusive) result of stronger cap
- Cold season tornado events and outbreaks (already seen this recently)
- Big Outbreak - some of the biggest outbreaks have occurred during La Nina springs. If this big day occurs and you miss it you may miss much of the season. Examples: 1974 April 3/4 Midwest US - 1974 June 8th Oklahoma. 1999 May 3rd.

Generally my La Nina years are the leanest for tornadoes unless I nail the outbreak. Outside of those years my worst chase years have been La Nina springs such as 1988, 2000.

Some helpful links for La Nina:
http://ggweather.com/enso/years.htm
Specifically 1998:
http://www.pmel.noaa.gov/tao/elnino/la-nina-pacific.html
These maps I think show typical La Nina better::
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/lanina/prank/mamninapr.gif
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/lanina/trank/mamninatr.gif
From this page:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/lanina/index.html
Another link in plain language:
http://www.stormfax.com/elnino.htm

Also see Stormtrack for La Nina discussions... there was one in 06.