Friday May 24, 2013
Are you ready for "Swarmageddon 2013??
In case you haven't heard, the Magicicada brood II--the 17-year cicadas located in eastern North America--is due to emerge this spring/summer. For many, it's an annoyance of an event characterized by a sea of insects on lawns, in trees, and in the air, and by the choir of chirping that can be heard nearly 24/7. (At 7 kHz, this chirping, which is a mating call of the Magicicada, is one of the loudest sounds known to be produced by insects).
Here's where weather and climate ties in to their appearance: the cicada nymphs will emerge from the ground when the soil at 8" down holds steady at a temperature of 64°F (17.8°C) or higher. Soil readings in my area just rose above that mark as of last week, so something tells me I may be seeing orange and black in the very near future. Have you seen (or heard) any cicadas in your area? Share your sightings and cicada stories in the comments below.
Also, be sure to check out the National Public Radio (NPR) Radiolab Cicada Tracker where you can track and report cicada sightings along the Eastern U.S. If it's strictly soil temps you're after, visit the NOAA NCDC Climate Reference Network observations page.
Image credit: USDA Agricultural Research Service
Thursday May 23, 2013
Unsettled weather patterns over the past two weeks have led to several recent tornado outbreaks: 23 tornadoes in Texas, Oklahoma, Louisiana, and Alabama (May 15-17), including an EF4 in Granbury, TX; and 49 confirmed tornadoes across the Midwest and lower Plains regions (May 18-22), including the Newcastle/Moore, OK tornado. But prior to May, tornado activity was so quiet, the U.S. was said to be experiencing a "tornado drought." Between May 2012 - April 2013, only 197 EF1 or stronger tornadoes occurred--an all-time record minimum for any 12-month period dating back to the 1950s. The combined death toll from these storms was also at a record low--seven.
Even states like Iowa, which is normally a poster child for tornadoes, managed to pass by the most active part of tornado season unscathed. On May 19, 2013, the first tornado touched down in the state (near Slater, IA) since May 24 of last year! This 359-day streak without a tornado was the longest tornado-free period in Iowa state history. The cool spring and the ongoing Midwest drought played a large part in the reduced storminess. (Thunderstorms need heat and moisture to form.)
Tuesday May 21, 2013
Yesterday afternoon around 3pm Central, a violent tornado touched down near Newcastle, OK, about 20 miles south of Oklahoma City. The massive, mile-wide tornado traveled northeast for nearly 20 miles and remained on the ground for approximately 40 minutes. Included in its path were two schools--Plaza Towers and Briarwood Elementary--as well as the city's hospital, Moore Medical Center, all of which were destroyed.
Damage survey teams are currently conducting surveys of the Newcastle, Moore, and south Oklahoma City areas. As of this afternoon, their findings confirm the tornado's rating as a strong EF5 (200+ mph (322+ km/h) winds). In fact, scientists estimate that the amount of energy released during the storm's life span was several times that of the power of the Hiroshima bomb.
It's looking more and more likely that Monday's tornado may make weather history as the third deadliest tornado in the Oklahoma City area, and possibly one of the top 5 most damaging tornadoes in U.S. history. The last time a tornado of this magnitude tore through the Moore community was on May 3, 1999. That storm, which also rated an EF5, caused 36 fatalities. The current death toll stands at 24.
For the latest updates on the Newcastle/Moore tornado and the ongoing May 18-21, 2013 tornado outbreak, follow this link to the NWS Norman, Oklahoma WFO page.
Friday May 17, 2013
At the start of the week, temperatures across Minnesota, Wisconsin, and Iowa soared into the triple digits. For many cities, including Omaha, NE (which hit 101°F) and Minneapolis, MN (which hit 98°F), it was the earliest in the year they've ever experienced such high temperatures. The hottest temperature of all--108°F--occurred in Tekamah, NE, with Sioux City, IA coming in a close second at 106°F.
Not even 2 weeks ago, many of these same cities were 50-70°F colder and blanketed by 1-12+ inches of snow, thanks to a very rare May winter storm. The May 1-3 snowstorm set all-time snow records for the month of May, including for the cities of:
- Rochester, MN--it received 7" of snow (previous record 2" on May 4-5, 1944);
- Sioux Falls, SD--it received 1.5" of snow (previous record 0.1" on May 1, 1967) ;
- Omaha, NE--it received 3.1" of snow (previous record 2" on May 9, 1945);
- and Osage, IA--it received 13" of snow. This is also the most snowfall to occur anywhere in the state of Iowa during the month of May.
Topeka, KS, Kansas City, MO, and Des Moines, IA received 1 inch, 2.5 inches, and 6.9 inches of snowfall, respectively. Only once before (May 3, 1907) have these three cities experienced a May snowstorm. (That storm's snow totals were 3.2" at Topeka, 1.7" at Kansas City, and 1.2" at Des Moines.)
Back-to-back extreme and opposing events like these have led to the phrase "weather whiplash" being tossed around in recent weather news, but what exactly does it mean?