Sunday, August 3, 2008

6/11/08 Little Sioux-Moorhead, Iowa tornado path revisited - solving a "mystery"

The Little Sioux campground EF3 tornado was one of the more publicized tornadoes in 2008 because of 4 boy scouts killed when it destroyed a bunk house where they had been drilled to take shelter (see my earlier post in June). Near the end of the 14 mile track (see first map shown above), this tornado struck storm chasers Kelly Martinson (also known as Kory Hartman) and Kenny Allen as it crossed Highway 183 a couple miles southwest of Moorhead, Iowa, yielding the most impressive up-close example I've ever seen of what it is like to encounter a rain-wrapped tornado. Contrary to some speculation by other chasers online, Kelly and Kenny did not intend to get that close, as the tornado was embedded in rain and the Omaha radar went down near the time of their encounter, making it difficult to judge where the tornado was as they waited for the mesocyclone to approach from the southwest. Also above are images of the same rain-wrapped supercell near Moorhead (observed by storm chasers from Iowa State), and later northwest of Dunlap (from the viewpoint of Shawna and myself).

The ground survey by NWS Omaha the day after the tornado suggested that the tornado did not cross highway 183 southwest of Moorhead, but Kelly and Kenny's video and their personal survey information indicated that it did (see the second map above, a Google maps closeup of the path end showing the discrepancy between the 2 survey tracks). To solve this mystery, Shawna and I revisited the area southwest of Moorhead on a trip to Iowa about a month after the tornado. Using a reference copy of Kelly and Kenny's video provided by Doug Kiesling (see video grab insets on second map above), Shawna and I located where the tornado crossed the highway (see third map above, my own survey of the tail end of the tornado track). From fence damage just west of highway 183 and south of 314th street (see photo above), it was clear that the most intense part of the tornado (50-100 yards wide) did indeed cross the highway where Kelly and Kenny's map indicated. We also found the two broken road signs that are seen being snapped off in Kelly and Kenny's video. Without the video the day after the tornado, it would have been easy to miss this damage, as the fence is located below and some distance west of highway 183 in a treeless area, and the broken signs were hidden in tall grass. Tree damage along and north of 314th street (what was shown as the center of the tornado path in the official survey) appears to have been a result of the north edge of the broader tornado circulation, or possibly inflow winds coming into the tornado from the north or northeast (see my close up map above). This example goes to show that surveying damage is difficult, and not always an exact science, particularly in rural areas.

Also, important to note: The intensity of the low-to-the-ground fence damage lined up with highway 183 strongly suggests that, had Kelly and Kenny been located another 50 yards southwest on highway 183, their vehicle would most likely have been rolled off the highway down a steep embankment, possibly resulting in injuries (the swirling condensation marking the most intense part of the tornado can be seen passing just south of their vehicle on the video). So, they are very lucky... as is the occupant of another vehicle (tail lights seen on the video) a few hundred yards farther down the highway (the most intense part of the tornado passed between the two vehicles). This is a graphic illustration of how dangerous it is to chase high-precipitation supercells with rain-wrapped tornadoes, as well as the potential problems of relying entirely on radar information when you can't see very well.

- Jon Davies 8/3/08


kevin0 said...

Hi, this is kevin From Alaska And I really interested on this weather book that introduces the weather and the situations of the weather .

iowa drug rehab

Anonymous said...

WoW shares many wow gold of its features with previously launched games. Essentially, you battle with wow gold cheap monsters and traverse the countryside, by yourself or as a buy cheap wow gold team, find challenging tasks, and go on to higher aoc gold levels as you gain skill and experience. In the course of your journey, you will be gaining new powers that are increased as your skill rating goes up. All the same, in terms of its features and quality, that is a ture stroy for this.WoW is far ahead of all other games of the genre the wow power leveling game undoubtedly is in a league of its own and cheapest wow gold playing it is another experience altogether.

Even though WoW is a Cheap Wow Gold rather complicated game, the controls and interface are done in warhammer gold such a way that you don't feel the complexity. A good feature of the game is that it buy wow items does not put off people with lengthy manuals. The instructions bygamer cannot be simpler and the pop up tips can help you start playing the game World Of Warcraft Gold immediately. If on the other hand, you need a detailed manual, the instructions are there for you to access. Buy wow gold in this site,good for you, BUY WOW GOLD.

Anonymous said...

I can get twelve sky Gold cheaply,
Yesterday i want to buy 12sky goldfor my brother.
i hope him like it. i will buy twelvesky Gold for him
as birthday present. i like the 12Sky Silver Coins very much.
I usually buy 12 sky gold and keep it in my store.
I can get FFXI Gil cheaply.
Yesterday i bought FFXI goldfor my brother.
i hope him like it. i will give Final Fantasy XI gold to him
as birthday present. i like the cheap Final Fantasy XI Gold very much.
I usually buy FFXI Gil and keep it in my store.

Anonymous said...

Weekends to peopleig2tmean that they can have a two-day wowgold4europe good rest. For example, people gameusdcan go out to enjoy themselves or get meinwowgoldtogether with relatives and friends to talk with each storeingameother or watch interesting video tapes with the speebiewhole family.
Everyone spends agamegoldweekends in his ownmmoflyway. Within two days,some people can relax themselves by listening to music, reading novels,or watchingogeworld films. Others perhaps are more active by playing basketball,wimming ormmorpgvipdancing. Different people have different gamesavorrelaxations.
I often spend weekends withoggsalemy family or my friends. Sometimes my parents take me on a visit to their old friends. Sometimesgamersell I go to the library to study or borrow some books tommovirtexgain much knowledge. I also go to see various exhibition to broadenrpg tradermy vision. An excursion to seashore or mountain resorts is my favorite way of spending weekends. Weekends are always enjoyable for me.
igxe swagvaultoforu wowgold-usaignmax wowgoldlivebrogame thsaleGoldRockU

Anonymous said...

You know ,I have some kal geons, and my friend also has some
kal gold, do you kouw they have the same meaning, Both of them can be called
kal online geons,I just want to buy some
kal online gold, because there are many
kalonline Geons.
You know ,I have some Tales Of Pirates gold, and my friend also has some
Tales Of Pirates money, do you kouw they have the same meaning, I just want to
buy Tales Of Pirates Gold, because there are many
cheap Tales Of Pirates gold

Anonymous said...

I did not know how to get strong, someone told me that you must have last chaos gold. He gave me some lastchaos gold, he said that I could buy last chaos gold, but I did not have money, then I played it all my spare time. From then on, I got some lastchaos money, if I did not continue to play it, I can sell cheap lastchaos gold to anyone who want.
I did not know how to get strong, someone told me that you must have last chaos gold. He gave me some lastchaos gold, he said that I could buy last chaos gold, but I did not have money, then I played it all my spare time. From then on, I got some lastchaos money, if I did not continue to play it, I can sell cheap lastchaos gold to anyone who want.

Anonymous said...

rappelz rupees of Rappelz Online Game has more functions and this Rappelz Game is a very good free game. This rappelz gold of score could go down A LOT if they choose to mess up the classes even more. I would have rated it much cheap rappelz rupees better when it was epic3. If yes, then the first step to buy rupees when you play Rappelz is for you. Play rappelz and feel the power and might of rappelz money. See you in game!
rohan crone has many ways for us to use. When you start the Rohan Online game, your character will be level 1. I remembered that when I started playing this Rohan game with some little cheap rohan money. My friends all told me that the best way to spend rohan online gold is a good way. But I could not like spending my own rohan online crone. If you do not like upgrading level step by step, you can cost rohan gold to help your character to reach level high.

Anonymous said...

Do you know the Archlord gold, in the game you need the
Archlord money. it can help you increase your level. My friends always asked me how to
buy Archlord gold, and I do not know he spend how much money to buy the
archlord online Gold, when I see him in order to play the game and search which the place can buy the
cheap Archlord gold. I am happy with him.
Do you know the cabal alz , in the game you need the
cabal gold. it can help you increase your level. My friends always asked me how to
buy cabal alz, and I do not know he spend how much money to buy the
cabal money, when I see him in order to play the game and search which the place can buy the
cabal online alz. I am happy with him.

Anonymous said...

As a new player , you may need some game guides or information to enhance yourself.
aoc gold is one of the hardest theme for every class at the beginning . You must have a good way to manage your conan gold.If yor are a lucky guy ,you can earn so many age of conan gold by yourself . But if you are a not , I just find a nice way to get cheap aoc gold. If you need , you can buy aoc money at our website . Go to the related page and check the detailed information . Once you have any question , you can connect our customer service at any time .

Making requiem gold is the old question : Honestly there is no fast way to make lots of requiem lant . Sadly enough a lot of the people that all of a sudden come to with millions of requiem money almost overnight probably duped . Although there are a lot of ways to make lots of cheap requiem lant here I will tell you all of the ways that I know and what I do to buyrequiem online gold.

Anonymous said...

The twelve sky Gold should be a timely evolution of the world. Please step up efforts to investigate all types of 12sky gold can be set up in the game. 12Sky Silver Coins to add more rudimentary fashion. The twelvesky Gold can help you combat equipment of the production. Use the 12 sky gold may change the door to door battle for offensive and defensive resident.
For the wakfu kamas, I believe everyone is familiar with the game. For the wakfu gold, I want to say a few points. You must be able to attract firepower with buy wakfu kamas. Originally playing specter in the wakfu money is a stimulating live. Important point is that wakfu kama when CT can hear breathing PS.

Anonymous said...

black mold exposureblack mold symptoms of exposurewrought iron garden gatesiron garden gates find them herefine thin hair hairstylessearch hair styles for fine thin hairnight vision binocularsbuy night vision binocularslipitor reactionslipitor allergic reactionsluxury beach resort in the philippines

afordable beach resorts in the philippineshomeopathy for big with great mineral makeup bargainsmineral makeup wholesalersprodam iphone Apple prodam iphone prahacect iphone manualmanual for P 168 iphonefero 52 binocularsnight vision Fero 52 binocularsThe best night vision binoculars here

night vision binoculars bargainsfree photo albums computer programsfree software to make photo albumsfree tax formsprintable tax forms for free craftmatic air bedcraftmatic air bed adjustable info hereboyd air bedboyd night air bed lowest price

Anonymous said...

new houston house houston house txstains removal dyestains removal clothesstains removalteeth whiteningteeth whiteningbright teeth

jennifer grey nosejennifer nose jobscalebrities nose jobsWomen with Big NosesWomen hairstylesBig Nose Women, hairstyles

Anonymous said...

dessicant air dryerpediatric asthmaasthma specialistasthma children specialistcarpet cleaning dallas txcarpet cleaners dallascarpet cleaning dallas

vero beach vacationvero beach vacationsbeach vacation homes veroms beach vacationsms beach vacationms beach condosmaui beach vacationmaui beach vacationsmaui beach clubbeach vacationsyour beach vacationscheap beach vacations

bob hairstylebob haircutsbob layeredpob hairstylebobbedclassic bobCare for Curly HairTips for Curly Haircurly hair12r 22.5 best pricetires truck bustires 12r 22.5

washington new housenew house houstonnew house san antonionew house ventura

Anonymous said...

find air beds in wisconsinbest air beds in wisconsincloud air beds

best cloud inflatable air bedssealy air beds portableportables air bedsrv luggage racksaluminum made rv luggage racksair bed raisedbest form raised air bedsbed air informercialsbest informercials bed airmattress sized air beds

bestair bed mattress antique doorknobsantique doorknob identification tipsdvd player troubleshootingtroubleshooting with the dvd playerflat panel television lcd vs plasmaflat panel lcd television versus plasma pic the bestadjustable bed air foam The best bed air foam

hoof prints antique equestrian printsantique hoof prints equestrian printsBuy air bedadjustablebuy the best adjustable air bedsair beds canadian storesCanadian stores for air beds

migraine causemigraine treatments floridaflorida headache clinicdrying dessicantair drying dessicant

samfar143 said...

Great job ! Your webpage has provided me all the particulars I expected .
Irving Locksmith
Locksmith In Bayonne NJ
Locksmith Cupertino CA
Locksmith Palo Alto CA
Palo Alto locksmith
Locksmith Palo Alto
Locksmith Palo Alto
hialeah locksmith
irvine locksmiths
irvine locksmiths
hialeah locksmith
hialeah locksmith
mesquite locksmith
hialeah locksmith
mesquite locksmith
locksmith plano texas
Aventura FL locksmith
miami locksmiths
pembroke pines fl locksmith
locksmith plano texas
locksmith plano texas
Aventura FL locksmith
miami locksmiths
miami locksmiths

luck said...

uggs clearance The hottest new boot this fall is the ugg boots for sale , available in kids, toddlers and mom sizes!The Kid's Retro Cargo is also available in sizes for women and children.Please protect yourself from Uggs Outlet fraudulent online sellers by educating yourself about Fake-UGGs!In the U.S., about 100 million new cars a month were sold, including Ford and General Motors Corporation provides most of the two best-selling car in the luxury car brand, Audi and BMW sales are leading the way ugg boots

Robear P said...

Locksmith Near me will fulfill all your Commercial, Car, and Residential Locksmith needs in Plano, TX. You can rely upon Locksmith Plano TX when you face any lock issue.