I routinely monitor weather in a broad band from the Gulf of Mexico to Northern Ontario. On Monday a variety of severe weather warnings were posted from south to north throughout this vast area. These included tornado warnings from Texas to Kansas and flood warnings from Memphis to Northern Ontario.
The Newcastle-Moore tornado in Oklahoma on May 20, 2013 has been featured in the media quite a bit and unfortunately, a few more fatalities may still be discovered as the search through the rubble continues. This tornado has been upgraded to EF-5 after assessment of the damage, which suggests wind speeds well in excess of 200 miles/hour (300 kilometers/hour). Although the Moore tornado caused fewer fatalities than the tornado on May 21, 2011 that devastated Joplin, Missouri it is likely to rival this event for total damage. The Joplin tornado caused $2.8 billion in damage.
Last Monday was the final day of the long weekend in Canada. Fireworks are often the custom on “Victoria Day” but in Thunder Bay Ontario most remained indoors as heavy rains and rising flood-waters dampened any thoughts of celebration. Ironically it was nearly the anniversary of the major flood event that happened last year. The total rain amounts were very similar: 4 to 5 inches (100 to 125 millimeters), but the timing and the origin of rain were quite different. The rain fell in less than four hours in May 2012 in contrast to falling over four days this year. There was still damage but it will be probably be measured in tens of thousands dollars, rather than the approximately $100 million in 2012.
A question in Thunder Bay was – were the events on Monday in Oklahoma and Northern Ontario connected? Fortunately they were not, but happened close enough. The prolonged precipitation this year was due to a slow-moving low that moved from west to east, and was not the tail end of the storms over “tornado alley”. Some moist airflow from the Gulf did reach Minnesota on Tuesday but did not combine with the more northerly system.
United States has the highest incidence of tornadoes in the world, with a yearly average of 1,253 every year (National Climatic Data Center). Surprisingly Canada is No. 2 with only about 100 per year.
Until next week,
Graham
