For most people living in the midwest or southeast this March, it certainly felt like an above-average month when it comes to severe weather. Typically, severe weather can be broken up into two seasons: spring and fall. We have bad storms all year, but the peaks tend to be around early in the spring, with another peak early in the fall. This March certainly lived up to its climatological record of having a spike in severe weather, compared to January and February, as well as compared to other Marches.
The month was active, but was it above-average? Jump the squiggle.
The short answer is yes, March 2011 was slightly above average in terms of total severe weather reports, tornado reports, wind reports, and hail reports. But just slightly.
Here's a table of all reports from 2001 to 2011, including a 10 year averages from 2001-2010. I'll refer back to this table from time to time, which is why I'm including it here at the top of the diary instead of somewhere else.
Total Reports
Total reports is a combination of confirmed tornadoes, wind damage, and reports of large hail (>1.00"). There were 1651 reports of severe weather for the month, occurring over 24 days. The biggest outbreaks were on 3-23 (with 409 reports), 3-26 (with 198 reports), and 3-27 (with 183 reports). The 10 year average is 1372.5, and 2011 clocked in with 1651 reports.
Here's a map from the SPC showing all the reports, with each red dot indicating the touchdown point of a tornado, each green dot indicating a report of large hail, and each blue dot indicating a report of damaging winds. Click the map to go to the SPC's severe weather summary page.
Tornado Reports
There were 115 confirmed tornadoes for the month, which is above the 10 year average by about 30 or so twisters. That may not seem like a lot, but if your house got hit, it's significant. I can't find EF ratings for all 115 tornadoes that touched down, partially because the SPC doesn't release such information until the end of the year. However, there was an
EF3 in Tennessee, as well as an
EF2 tornado that touched down just a few miles down the street from me.
Most of the tornadoes were concentrated in the southeast this spring, but not wholly confined to this part of the country. There were a couple of tornadoes out in California, as well as in other states from Iowa to Virginia and everywhere in between.
Hail Reports
Hail reports for the month were just barely above average, coming in at 878 reports ranging anywhere from baseball to quarter in size. The main concentration was in the southeast up through the Ohio Valley, as most of the storms in these areas were individual cells instead of in lines, which helped greatly in hail production.
Wind Reports
Wind reports for the month were above average, thanks to the amount of squall lines that developed in the lower southeast and across the mid-Atlantic region. There were a total of 658 reports, coming in about 200 above the 10 year average. The reports are mostly what you would expect -- roof damage, windows taken out, barns blown down, trees on power lines, and incredible wind gusts (a few days ago there was a 100MPH wind recorded at the Plaquimines Parish Gov't Office in Louisiana).
March won't necessarily be a harbinger of things to come, as weather patterns can vary wildly from one month to the next, so we'll have to wait and see what April brings. On Monday and Tuesday of this week, there's a good chance for severe weather across the midwest and southeast, so the month will have at least a head start in catching up and adding to the year's totals.
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