Category: Thunderstorm


2016-05-12
Meteorological Spring began March 1st and with it comes a heightened emphasis on severe weather safety and preparation. 2016 has seen an increased number of tornadoes and other severe weather events over the past few years. Is that a predictor of spring weather? One answer is…it only takes one.

It only takes one tornado or severe storm to change lives forever. It only takes one to cause millions of dollars of damage. It only takes one to impact the economy of a community. It only takes one to destroy infrastructure, schools, churches, parks, public buildings, etc.

Photo by Author

Photo by Rick Atterberry

As we remind ourselves of safety precautions, we recognize that being prepared can impact survivability reducing deaths and injuries. Damage to property can be mitigated by employing proper construction techniques.

Many states observe Severe Weather Preparedness Weeks in the spring. The National Oceanic and Atmospheric Administration’s (NOAA) Weather Ready Nation efforts consolidate information on best practices.

Beyond that information, now is a good time to review threats that are specific to a given location. Is the area prone to flooding, especially flash floods? Are outdoor sports venues equipped with lightning detectors? Are evacuation and sheltering policies in place?

FEMA

FEMA

Another important piece of information is local protocols for operation of outdoor warning sirens. In general, these sirens are NOT necessarily intended to be heard inside homes and businesses. Some communities sound an all clear. In others, a second activation of the sirens means the threat is continuing for an additional period of time. Some locations employ sirens for flash flooding, nuclear power plant issues, tsunamis and other threats. Be aware of local policies. Always have an alternate way of receiving severe weather information…the All-Hazards Weather Radio System, warning apps, web-based warning systems.

Personal preparedness is everyone’s responsibility. Review shelter areas at home and at work. Create appropriate “Go Kits” for each location plus vehicles. Devise a communications plan to aid in reunification of families and co-workers. Be aware of those in the neighborhood or workplace with special needs who may need your assistance. And, always, be extra vigilant when severe weather is a possibility. A community can only be as prepared as its residents.

Being Prepared is Part of Who You Are

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Preparedness Begins at Home


Julyderecho

July 13, 2015 derecho radar image from NOAA.

Early this week, on July 13, a possible derecho, or at least what the National Weather Service is currently calling “a Derecho-like event,” raced across the middle of the country. It began in Minnesota and swept mostly southward through Wisconsin, Illinois, parts of Indiana and into Kentucky.

The Weather Service describes a derecho as “a widespread, long-lived storm. Derechos are associated with bands of rapidly moving showers or thunderstorms variously known as bow echoes, squall lines or quasi-linear convective systems.”

The “bow echo” refers to the characteristic appearance of a linear storm on weather radar when that storm bows out due to high wind. Storms represented by bow echoes are not always derechos unless they last for a long time which is rarely the case. In fact, large derechos are relatively unusual. Generally there are only one or two a year in most of the country.

The Weather Service has an extensive derecho page.

Weather Underground

Weather Underground

Derechos can be extremely damaging. By definition a derecho must travel 240 miles and include wind gusts of at least 58mph along much of its length and several gusts of over 75mph. Many are much stronger. A derecho that crossed Illinois from northwest to southeast in the late 1990’s included winds measured at over 100mph at the Clinton nuclear power plant and caused extensive damage to a marina at the associated cooling lake.

Effects can be long lasting. On July 4th and 5th in 1999 a derecho crossed the Boundary Waters Canoe area in northern Minnesota/southern Ontario. It devastated a forest there. Wildfires in more recent years have been fueled by the debris from that storm.

Because of their length and the intensity of the straight line winds, derechos can be an extremely costly event. Casualties are rare, but do occur, usually caused by falling trees or other debris and occasionally by watercraft caught by the rapidly moving storms.


We’ll keep things short this week as your author needs to hit the road for visits to our Chicago-area Extension offices.

In some parts of the country, this is Lightning Safety Awareness Week.  The following passage is from the Peoria Journal Star on Monday, June 22, 2015:  … the motorcyclists were traveling side-by-side when lightning hit a taxi van and then the motorcyclists. The driver of the van was injured, but survived, after going into a ditch, but the motorcyclists, who were burnt and suffered heart attacks, died at the scene.  This freak accident occurred in Decatur, Illinois and points to just how unpredictable and dangerous lightning can be.

berryd4

–Douglas Berry via NOAA

Severe storms are forecast in a large part of the Great Lakes region and points east early in the week, so I’d like to share a National Weather Service link that tells you just about everything you need to know about lightning safety.


It’s often said in areas of drought in the southern U.S. that it takes a tropical storm to reverse the situation. This year, as we know, the Texas-Oklahoma drought was fairly well broken by a lingering storm system over Memorial Day weekend which resulted in more than 30 deaths.

BILL_qpfNow comes what is left of Tropical Storm Bill, already as of this morning, reduced to a tropical depression. Some parts of Texas into Arkansas may see 2 to 5-inches of rain in the next day. While these rain totals don’t match some from the Memorial Day storms, they are excessive and flash flooding is a possibility.

As the remnants of Bill move slowly to the northeast across the next several days the heaviest rain will eventually spread into southern Illinois and on to Indiana by late Friday night into Saturday. Here’s the latest hydrological forecast discussion.

In fact, the remnants of Bill will interact with a stalled frontal system which has caused periodic heavy rain for more than a week as it waffled up and down across Illinois and nearby states.flood map Flood warnings have been issued for several rivers in Illinois and extend into portions of the Mississippi River bordering the state. Flooding in Illinois ranges from major to minor and areas of heaviest precipitation have varied daily.

On Monday, tornado warning sirens sounded in downtown Chicago, a relatively rare occurrence. A funnel cloud was observed east of Midway Airport and another near Millenium Park which is just east of Michigan Avenue in the heart of the city. No touchdowns were reported, but some photos taken at the time show an unmistakable wall cloud.

http://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpfpfd

http://videowall.accuweather.com/detail/videos/trending-now/video/4299689121001/watch:-huge-wall-cloud-moves-over-chicago?autoStart=true


From time to time on Weather Wednesday we will step away from purely meteorological topics to address preparedness. This week we’ll discuss one of the most basic preparedness items, a personal or family Go Kit.

A Go Kit should be assembled and customized according to individual needs following some general guidelines from FEMA. Be sure to look under the tabs for additional suggested items.

AP_fairdale_tornado_14_sk_150410_16x9_1600Let’s look at some of the items which should be included:

Water, one gallon per person per day for three days for drinking and sanitation. For long term storage the crystal clear containers hold up better, but water and food stocks should be rotated out regularly.

Food, a three day supply of non-perishable food. If using canned food, be sure to include a can opener. Specialty meals designed for use by campers are also a good option. Check preparation instructions to be sure you have all of the necessary equipment.

Battery powered, hand cranked and/or solar powered radio capable of receiving NOAA All-Hazards Weather Radio and standard broadcast. Carry extra batteries.

Flashlight and extra batteries. Batteries will generally last considerably longer in LED flashlights.

Washington, DC, July 22, 2008 -- A Red Cross "ready to go" preparedness kit showing the bag and it's contents. Red Cross photograph

Red Cross via FEMA

First aid kit. A good basic kit will suffice unless special needs are involved.

Whistle to signal for help. A small air horn is also a good addition, but you can’t beat a whistle for convenience. It takes less volume of air to blow a whistle than to yell which can be important if one is trapped by debris. A whistle or horn also has a better chance of being heard over heavy equipment.

Dust mask.

Plastic sheet and tape if asked to shelter in place.

Local maps. Remember, familiar landmarks may be destroyed in some disasters.

Cell phone with chargers, inverters, solar power, charging packs, etc. Note, avoid using accessories such as the built in flashlight which tend to run down the battery rapidly.

Prescription medications and glasses. Setting aside medication can be problematic so work with your physician and pharmacist to see what can be done.

Cash and change. If the power is out or communications lines down, ATMs will be out of service.

Copies of insurance papers, account numbers, etc. Do keep these in a special place in the kit so you can keep track of them.

Infant formula, diapers, pet food, etc if applicable. Include a leash for your pet and count their water needs as well.

Change of clothes. Err on the side of warmth and waterproof items.

A couple of items recent experience has shown to be very valuable. Sturdy shoes or boots. Sandals and flip flops are not at all useful when walking through debris. If you have identified a shelter area in your home, you might want to keep the spare shoes/boots there.

Bicycle helmets or hard hats may also be useful if easily accessible to your shelter area.

Remember a Go kit should be able to do just that, pick up and go, should the need arise. It is important to temperate the desire to plan for all contingencies with the practical need to perhaps carry the kit for some distance. Kits are also available from retailers, but make sure to customize to your needs.


KHOU via USA Today

KHOU via USA Today

What caused the recent devastating and deadly flooding in Texas, Oklahoma and other states? One thought, advanced by Accuweather and others, is that the developing El Nino played a role. As we’ve written before, an El Nino is warmer than expected waters in the Pacific Ocean. El Nino events result in a split jet stream and it the southern stream likely contributed to the flooding in the South. Typically, heavier than normal rains occur in Spring, Autumn and Winter of El Nino years in a swath from California into the Mid-South.

EPA

EPA

Historically, even weak and/or developing El Ninos can cause the extreme precipitation witnessed in May. California largely missed out although the area around San Diego picked up record rainfall. In past El Nino events California received most of its precipitation during winter months. It remains to be seen if the current event will last that long.

In the meantime drought conditions have been greatly lessened in Texas, at least in the short term. Of course that came with a terrible price…dozens of deaths and hundreds of millions of dollars in damage. The toll continues to rise and many rivers remain in flood.
EDEN Flood Resources:

Agriculture

Flood insurance

Misc collected resources

eXtension Flood Page


It’s been an eventful week on the weather front, so let’s highlight a few points.

KSFY_damage_van_kb_150511_16x9_992

-Damage near Van, TX — KSFY

What started out as a very quiet first quarter of the year as regards the number of tornadoes has become much more active since mid-April. There have been several widespread, damaging and deadly outbreaks, especially over the last ten days or so.

The organization U.S. Tornadoes has begun to compile a rolling list of the highest incidence of tornadoes in 2015. One can see that May is headed toward reversing the early year trend of below normal activity.

storm-thumb-051015In addition, the storms over the past weekend (May 9 and 10) included extremely high rainfall rates in some areas which led to flash flooding and necessitated swift water rescues. Some of the rescues were broadcast live by television stations in Dallas and retransmitted to the entire country via The Weather Channel.

2015-05-09_10-snowfall

— NWS

And if that wasn’t enough, a late season snowstorm on the same weekend buried parts of the Rocky Mountains into the Dakotas. The heavy, wet snow damaged buildings and had to be shoveled out of Coors Field before the Colorado Rockies could host their Sunday afternoon game against the Los Angeles Dodgers.

tropical-storm-anaAnd to top it all off, Tropical Storm Ana, brought gusty winds and copious amounts of rain to the Southeast.


On this Tax Day edition of Weather Wednesday, we’ll revisit last week’s tornado outbreak in Illinois. Statewide, 11 tornadoes have been confirmed in the April 9th event. The earliest, which caused very little damage, was reported just northwest of Peoria in the afternoon hours. By early evening, strong thunderstorms were crossing far northern Illinois and eventually spawned the first EF-4 tornadoes ever reported in DeKalb and Ogle Counties (records kept since 1950) and the strongest tornado in the National Weather Service Chicago Office County Warning Area since an EF-5 devastated Plainfield, in the southwest suburbs, in 1990.

AP_fairdale_tornado_14_sk_150410_16x9_1600

AP

Two people were killed in the unincorporated town of Fairdale where nearly every structure, more than 70 in all counting outbuildings, was either damaged or destroyed. 22 injuries were reported in the outbreak. The tornadoes eventually approached the far western suburbs of Chicago but missed three population centers near their path. Damage was widely scattered in a multi-county area.

PBrooksPhotography_Ashton

PBrooks Photography

This outbreak was well forecast and there is general agreement there was plenty of warning. The Storm Prediction Center (SPC), as it did with the EF-3 and 4 tornadoes in Illinois on November 17, 2013, mentioned possibly tornadic storms at least four days in advance.

The National Weather Service Chicago Office updated their summary of the tornadoes just this morning. This is one of the most complete such documents I’ve ever read and includes some of the few satellite images of a tornado’s path I’ve ever seen. Read it all the way to the bottom and you’ll see the SPC guidance in the week leading up to the storms.

LarissaSebree_HillcrestIL

Wedge tornado and wall cloud near Hillcrest, Illinois. Larissa Sebree via NOAA.

A couple of these tornadoes were extremely well documented via video (note:  Strong language toward end) and live streaming and some of the visuals of the rotating wall clouds were just about textbook. The low sun angle contributed how well the tornadoes were captured.

There was also a significant side issue involving a motorist by the name of Sam Smith who was shooting video. That footage was widely shown on television and the driver was taken to task for getting too close to the storm, even if accidentally.  (There are now licensing issues with the video so we won’t link to it here.  However, it is widely available on You Tube.)

There were a couple of takeaways from his experience which are good reminders to all of us who may encounter storms. First, if a funnel cloud or tornado does not appear to be moving, it is either headed straight for the observer or dead away from the observer. To be safe, get out of that area immediately by driving at right angles to the storm. Second, this motorist backed up to take shelter in his vehicle under a bridge. Although many people have done that and survived, experts say that is a bad idea because wind speed may actually be amplified as it is compressed into that confined space.  There have been fatalities of people under overpasses.


There’s been much talk in recent weeks of a more detailed method of describing the potential for severe weather now being employed by the Storm Prediction Center in its Convective Outlooks. The SPC worked with National Weather Service offices, communications experts and consumers of its products to expand its long time use of the “Slight, Moderate and High” risk categories to “Marginal, Slight, Enhanced, Moderate and High.”

In addition, the chart below describes what the storms might look like under each newly-defined category and what the main threats would be.

Understanding Categories
The Storm Prediction Center has many products that can be used by broadcast meteorologists, emergency managers and the general public to look as far as 8 days ahead. These tools are especially valuable for planning purposes and should never supplant your detailed local forecast.

The Mesoscale Discussions are particularly helpful on days when severe weather is expected. The discussions are issued on an “as needed” basis as storm threats develop. Other tools are updated as often as four times a day. If you’ve never visited the site at spc.noaa.gov, now would be a good time to familiarize yourself with the offerings.