Living With Risk
"I enjoy Minnesota summers. Both weeks!" the parable goes.
How could we have a 7 month boating season in 2012, only to be tracking late May frosts & jackets one year later? A new level of erratic.
18" snow in April - icy lakes in May. No, Minnesota is not for the squeamish. But those cold fronts we love to complain about inoculate us to a large degree from the worst tornadoes and ocean-roaming weather beasts: hurricanes can't touch us.
Texas, Alabama, North Carolina: roughly 4 times more billion dollar weather disasters since 1980 than Minnesota, says NOAA. In spite of our many weather faults we have no active earthquake faults. California is lovely, when tectonic plates aren't shifting. As long as that super-volcano in Yellowstone behaves itself we'll be just fine.
Today: more clouds, low to mid 60s, but the heaviest T-storms rumble over far southern Minnesota. Not great but at least it won't snow. A warm front limps north tomorrow, sparking scattered T-storms for Memorial Day, but no all-day rains.
A stormy pattern is in place all week; 80s by midweek with sufficient moisture & wind shear for a few severe storms. No storms with names though. "Andrea" may form near Florida within 2 weeks.
Even Greener Lawns. Remember the drought? We may go from drought to spotty flash flooding this week as a series of warm fronts surge northward, each one initiating convection (thunderstorms). There's even a potential for an MCS, a meso-convective system: swarms of heavy/severe thunderstorms that tend to blow up late at night, capable of minor wind damage and flooding rains. Talk about a weather turnaround. NOAA's QPF product prints out some 3-5" amounts over Iowa and southeastern South Dakota, the best chance of heavy rain over far southern and western Minnesota.
A Noisy Warm Frontal Passage? Much of today should be dry (slight shower chance), but the approach of warmer, more humid air may set off strong T-storms from Sunday night into Memorial Day, in fact scattered showers and T-storms will linger right through the end of the week. Note that the higher-res 4 km. NAM prints out nearly 2" of rain from late tonight into midday Monday. Graphic: Iowa State.
Major Holiday = Blue Blobs. What happened to the green blobs? Now they're blue, and that means scattered showers and T-storms tonight and Memorial Day, but no steady, all-day rains are expected. We break out into a warm, sticky, thundery airmass by Tuesday and Wednesday with highs reaching the 80s. Finally. 84 NAM outlook: NOAA.
Image credit above: "Cut-off centers of low pressure loitered near California and the U.S. South early this week, with the polar jet stream in a summerlike position across northern Canada. Shown here are upper-level winds as of 8:00 a.m. EDT on May 6." (Image courtesy NOAA/NCEP Model Analysis & Guidance.)
12.13 inches at Grand Meadow, 9.16 inches at Spring Valley, 9.03 inches at Austin, and 8.63 inches at Rochester. The all-time maximum rainfall for the month of May in Minnesota is 15.79 inches at St Francis (Anoka County) in 2012. If Grand Meadow (Mower County) has a wet last week of May, they may threaten that state record this month. For southeastern Minnesota counties May of 2013 already ranks as the 5th wettest May in history, averaging nearly 7 inches of rainfall. This number is likely to increase over the next week before the month concludes next Friday..."
Photo credit above: "In Moore, Okla., there have been dramatic examples of survivors who lived through the killer tornado because the home or other building they were in had a safe room or fortified basement." Jocelyn Augustino/FEMA
Photo credit above: "A handout photo of a tornado in Newcastle, Okla., before it reached Moore, about 10 miles away, on May 20, 2013. With authorities saying they have likely recovered all the bodies to be found beneath the rubble left by the Category 5 tornado, the focus turned to the long and expensive path of recovering from one of the most catastrophic storms in Oklahoma's history." (Nick Rutledge via The New York Times).
1. Meteorologists aren’t any good at forecasting these storms.
How does 99.3 percent sound? In 2011, 553 people lost their lives in tornadoes. For all but four of those victims (99.3 percent), both a tornado watch and a tornado warning were in effect before the storm arrived. Modern tornado warnings are Nobel Prize-worthy endeavors that combine weather science, social science and technology. As recently as 1990, people in the path of a tornado were lucky to get five minutes’ warning. Now, thanks to advances in radar, computer simulations and research on how tornadoes develop, the average “lead time” is 12 minutes — and more than 15 minutes for major tornadoes. The city of Moore had a stunning 36 minutes of warning..."
Photo credit above: "Lightning in the sky over debris from the tornado that devastated Moore, Okla., Thursday, May 23, 2013." (AP Photo/Tulsa World, Mike Simons)
Predicting hurricane track & intensity is as much art as science; knowing which models to trust, and when. My meteorology professors at Penn State would cringe to hear me say this, but intuition and past history can play as big a role as model trends. Predicting hurricane potential 3-4 months from now is equivalent to forecasting what financial markets will be doing in late summer. Good luck with that. But there are factors that lead me to believe that this will be another above average year for tropical storms and hurricanes in the Atlantic basin, with as many as 2-3 hurricanes hitting the U.S. coastline by October. Here's the logic behind that prediction:
* Hurricane Cycle. There is a natural 25-40 year cycle for hurricanes - we entered the busy/active part of that cycle in the mid-90s, so this is a significant factor.
* Warm SST's. Sea surface temperatures are warmer than average, to the tune of 1F. That may not sound like much, but hurricanes get their strength from warm ocean water, and every 1F. of warmth increases hurricane potential by 5-10%
* No El Nino To Save Us. El Nino warming phases in the equatorial Pacific tend to increase winds over the tropics; more wind shear shreds developing tropical storms, reducing the threat of hurricane development in the Atlantic and Gulf of Mexico. Right now we are in an ENSO-neutral state, meaning no El Nino or La Nina in the Pacific.
* Feeling Lucky? The last major (category 3 or stronger) hurricane to strike the USA was Wilma in 2005. The intervening 7 year stretch with no category 3+ hurricane is the longest on record for the USA. Last October we saw what a category 1 storm, Sandy, coming at high tide and a full moon can do. Jet stream winds are more erratic this year, more sweeping north/south dips and bulges to prevailing steering winds aloft, which increases the potential for tropical systems to penetrate unusually far north.
* it's important to remember that, overall, climate change doesn't seem to be triggering more hurricanes in the Atlantic, but since 1970 the number of category 3 or stronger hurricanes has roughly doubled; it may be having a causal effect on hurricane intensity. Scientists believe this may be linked to consistently warmer sea surface temperatures. 90% of all warming is going into the oceans, and that has implications for tropical development.
Three climate factors that strongly control Atlantic hurricane activity are expected to come together to produce an active or extremely active 2013 hurricane season. These are:
- A continuation of the atmospheric climate pattern, which
includes a strong west African monsoon, that is responsible for the
ongoing era of high activity for Atlantic hurricanes that began in
- Warmer-than-average water temperatures in the tropical Atlantic Ocean and Caribbean Sea; and
- El Niño is not expected to develop and suppress hurricane formation..."
Sequester Cuts Wildfire Prevention, Sets Up Bigger Blazes. Grist has another story that caught my eye - here's a portion: "...Last year saw the third-worst wildfire season in five decades; the Southern California fire that threatened thousands of homes earlier this month looks to be only the first flash of what the National Oceanic and Atmospheric Administration announced last week will be an above-average season for much of the Southwest. But the sequester took a 7.5 percent bite out of the Forest Service’s budget, nearly half of which is spent fighting wildfires. That means there will be 500 fewer pairs of boots on the ground and 200,000 fewer acres treated to prevent fires; the agency’s next proposed budget cuts preventative spending by a further 24 percent..." (photo: DNR).
Weather Service To Add Major Might To Computing Power. With any luck I won't to rely on the European ECMWF model quite so much in the years ahead. Kitsap Sun has the story - here's an excerpt: "...After coming under fire for falling behind the capabilities of other nations, the National Weather Service (NWS) is setting out to make an unprecedented increase in its computing power over the next several years, the agency announced this week. The computing boost will triple a key measure of the agency's main weather model, and could yield major improvements to its weather forecasting and warnings capabilities. The program is made possible by recent funding from Congress contained in the Hurricane Sandy relief legislation, which was signed into law in January. The NWS plans to use $25 million of the $48 million provided to it in the Sandy supplemental bill, along with funds that are called for in President Obama’s fiscal year 2014 budget proposal, to bring about “unprecedented” computing upgrades — going from an operational computing capacity of 213 peak teraflops at the end of the current fiscal year, to 1,950 peak teraflops by the end of fiscal year 2015, according to NWS Director Louis Uccellini..."
Image credit above: "
Photo credit: "
Photo credit: Politico, AP.
Photo credit above: Brad Birkholz.
Photo credit above: "Wild Fire via Flick CC."
Photo credit above: "
Photo credit above: "No one can say with any assurance what the dollar value of damages would be from the highly uncertain climate changes that might accompany a planet earth that is steadily warming.: PBS NewsHour.
* Trenberth's article at The Conversation, with additional graphics and imagery, is here.