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Tornadoes Close To Record Low Level

August 1, 2013

By Paul Homewood

 

 

torgraph

torngraph

http://www.spc.noaa.gov/wcm/#data

 

Provisional tornado numbers up to the 30th July are one of the lowest on record, according to NOAA’s Storm Prediction Centre.

 

The figures are based on LSR’s, or Local Storm Reports. It usually takes about three months for tornadoes to be confirmed and graded, with some LSR’s discarded as either duplications or found not to be tornadoes.

The top chart uses percentiles, based on 1954-2012, so giving a longer historical perspective. As many smaller tornadoes were not even reported in earlier decades, the SPC adjust earlier years up to compensate.

Last year’s tornado numbers were also extremely low, which is interesting given the contrast in US temperatures between last year and this. The two GISS maps below show the Spring temperature anomalies for each year.

The SPC themselves admit they don’t understand how tornadoes form, but an important ingredient is the collision of cold, dry air and warm moist air. In 2012, most of the country, and certainly tornado alley, was consistently warm. This year, it has been consistently cold, even down to the gulf. By and large, the conditions needed for the collision of warm and cold air have not existed.

 

nmaps

nmaps3

http://data.giss.nasa.gov/cgi-bin/gistemp/nmaps.cgi?year_last=2013&month_last=6&sat=4&sst=3&type=anoms&mean_gen=0303&year1=2013&year2=2013&base1=1981&base2=2010&radius=1200&pol=reg

 

Now contrast the last two years with 2011, when tornadoes were near to record highs. The difference is very obvious.

 

nmaps1

 

 

 

Most tornadoes occur between April and July, so, fingers crossed, tornado numbers will remain at a very low level for the rest of the year.

 

tornadoes_bymonth

 

http://www1.ncdc.noaa.gov/pub/data/cmb/images/tornado/clim/tornadoes_bymonth.png

3 Comments
  1. John F. Hultquist permalink
    August 1, 2013 5:01 pm

    And if the next 6 weeks looks like Mar-Apr-May of 2011 all bets are off.

    I notice for the Atlantic Ocean, the NHC still reports “No tropical cyclones at this time” – ??

    Here in central Washington State the folks have more immediate concerns. The nearest fire to us (Colockum Tarps Fire; 104 square miles) has dropped a bit of ash on us but is now headed in another direction.
    http://www.komonews.com/news/local/More-evacuations-ordered-as-wildfires-surge-217811021.html

  2. Brian H permalink
    August 1, 2013 11:44 pm

    The game “Twister” is no competition for the twists on twisters twitted by the CAGW Believers.

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