See home paage update on this outbreak of severe weather, reminisecnt of the Palm Sunday outbreak in April 1965, at the end of a La Nina that would become an El Nino. We ARE LIKELY TO SEE WELL OVER THE NUMBER OF STORMS THAT WE SAW THAT OUTBREAK BUT THEY WILL BE SIMILAER IN STRENGTH AND DAMAGE AND IN SOME OF THE SAME AREAS.

Earlier this week, severe weather including powerful tornadoes accompanied a storm that brought snow to the north. A total of 48 tornados were reported on the 28th and 29th of February.

The year is off to an active start. Note the active April and May in the strong La Nina of 2011 and the active May in the La Nina of 2008. 2009 and 20o10 were quieter as El Nino came on.

This afternoon another low in Illinois should fire off severe weather in the warm sector.

You can see the edge of the warm tropical air pushing north this morning with showers on the leading edge.

SPC has an outlook for severe weather for today (through tonight with now a HIGH risk of severe weather (tornadoes, hail, damaging winds).

The probability of tornadoes is greatest over the Ohio and Tennessee Valley into the north central Gulf States.

Climatology shows the peak back over the plains.

However, in La Nina years it is further east.

Cook and Schaefer, 2008, showed that historically in the cool season  (winter and early spring) during the neutral phase, tornado outbreaks typically occurred from central Oklahoma and Kansas eastward through the Carolinas. During cold phases, tornado outbreaks have typically occurred in a zone stretching from southeastern Texas northeastward into Illinois, Indiana, and Michigan. During anomalously warm phases activity was mainly limited to the Gulf Coast states, including central Florida.

For srping, significant differences as a function of ENSO phase were found in both the number of tornadoes and the number of strong and violent tornadoes for the Mideastern States, and for F2 and greater tornadoes over the entire contiguous United States. In these cases, more tornadoes appear to occur during La Nina months.

Tom Grazulis of the tornado project identified the top ten states for various tornado statistics. Those states under the gun today are in yellow.