As I warned back when temperatures were in the 80s, don't get used to them because there was more chill to come and the early warmth was not a sign of an early summer. Indeed, the southern groundhog lied to us and the chill returned often and with a vengence, including a light freeze in the Georgia Mountains and several frosts elsewhere in Georgia and adjacent states.

Looking ahead, it looks like our thermometer roller-coaster will continue another 2 weeks, at least. Typical of the La Nina temperature contrast clashes, the national tornado threat is elevated as mentioned in previous posts, as the stronger than normal jet stream provides increased wind shear for rotation in storm cells.

Research published in AMS/NWA Journals shows this is particularly true for tornado swarms and/or stronger-- longer track tornadoes in the regions of the Midwest, Ohio and Tennesee River Valleys and the Mid-Mississippi River Valley and Delta. This is primarily, but not exclusively, just North and West of Atlanta.

Looking back the last La Nina year was 2008 which saw 1,689 tornadoes across the country during that year, ranking second place out of the last 59 years! The previous La Nina occurred in 2000 which ranked 19th out of the past 59 years with 1,075 tornadoes. 1999 was also a La Nina year with 1,342 tornadoes, coming in at fifth place out of 59. These years were all part of my analog package for the long-range outlook for spring, summer and hurricane season.

It is too early for a summer forecast, but I will post some maps here for the general trends on temperature departures from average over the next 60-150 days.

See the slide show for national trend maps. Click on the maps to see more with larger graphics.

 
Jet stream and thermometer go up and down Photo: accu weather graphic

Slideshow: Long-term temperature trend forecast