afischer
EF4
KFYR-TV out of Bismarck has several photos of the gorgeous, slow-moving tornado produced by the tail-end cell near Napolean ND. http://www.kfyrtv.com/sky_spies.asp
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8/26/07 DISC: ND
- Thread starter afischer
- Start date
Sam Sagnella
EF5
A brief compilation of some misc information about the Northwood tornado.
Grand Forks Herald: News Site
Damage to one of the town's biggest emloyers, AgVise Laboratories,
a major soil and plant-testing company.
CEO of AgVise: "business totalled".
Grand Forks Herald: "One killed in Northwood tornado, extensive damage"
City of Northwood (seems like such a nice place
): town website
WFO FGF: "Additional Information on Sunday Evening Tornadoes"
Grand Forks Herald: News Site
Damage to one of the town's biggest emloyers, AgVise Laboratories,
a major soil and plant-testing company.
CEO of AgVise: "business totalled".
Grand Forks Herald: "One killed in Northwood tornado, extensive damage"
City of Northwood (seems like such a nice place
): town website
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Rob Satkus
EF2
The tornado sure was a nice one, but some of those structure shots of the storm are spectacular...especially the one by Rich Dunn
RS
Brian Stertz
EF5
Damage photos from GF Herald in Northwood look more consistent with high end EF-2 damage...unless there was more isolated areas showing structural EF-3 damage. I am curious as to what others think.
Justin Turcotte
EF5
My chase didn't go as planned after punching the core of the Northwood storm. After getting out of the forward flank I parked just west of the U.S. 18 and ND 15 intersection at 8:20 and sat until 8:30. I took a few pics of a funnel west/southwest of Northwood but without radar data thought the danger was passing to the north of Northwood. My last pic of the funnel was at 8:27 and then I bailed as I really had no clue what was happening in the fading daylight. I drove east through Northwood sometime between 8:32 and 8:38 little knowing a violent tornado was on my azz. Sure as hell glad I didn't make a quick stop for coffee as I've been known to do in the past. I was about 10 miles east of there when I heard about a potential tornado strike. The storm had two hook appendages and it appears the Northwood tornado came from the second one after the first was absorbed into the storm or overran by the second appendage. I'll have to check some velocity data to see exactly what part of the storm I saw the funnel develop. In any case I wouldn't be suprised if there was an earlier tornado in the vicinity of Northwood as well based on look of the radar and what I was seeing in the clouds around 8:30.
Radar image at 8:30, about the time I leave my spot just west of Northwood. My estimated position at the time indicated by the white arrow. The Petersburg storm is labelled A. After departing that storm I punched the core of the Northwood storm only to end up in a hook appendage of the storm. This is one reason why punching a core isn't the best idea if you do not have radar in the chase vehicle or a real good nowcaster. I had neither. The thumbnail image of the funnel was taken at 8:27. I don't know if the funnel I photographed was from the mesocyclone that produced the Northwood tornado or was from a decaying one. Some archived velocity images may shed some light.
More pics and discussion from the day on my site: (link fixed)
http://www.plainschase.com/secondary/2007/storm08262007.htm
Radar image at 8:30, about the time I leave my spot just west of Northwood. My estimated position at the time indicated by the white arrow. The Petersburg storm is labelled A. After departing that storm I punched the core of the Northwood storm only to end up in a hook appendage of the storm. This is one reason why punching a core isn't the best idea if you do not have radar in the chase vehicle or a real good nowcaster. I had neither. The thumbnail image of the funnel was taken at 8:27. I don't know if the funnel I photographed was from the mesocyclone that produced the Northwood tornado or was from a decaying one. Some archived velocity images may shed some light.
More pics and discussion from the day on my site: (link fixed)
http://www.plainschase.com/secondary/2007/storm08262007.htm
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Jeff Snyder
EF5
Justin mentioned this, but I figured I'd post a snippet of the official damage assessment:
In addition, as noted in that PNS: "Unfortunately, this is also the first tornado related death in the NWS Grand Forks area of responsibility since the Fargo tornado of June 1957."
--> http://www.crh.noaa.gov/crnews/display_story.php?wfo=fgf&storyid=9922&source=0FGF Damage Assessment said:
In addition, as noted in that PNS: "Unfortunately, this is also the first tornado related death in the NWS Grand Forks area of responsibility since the Fargo tornado of June 1957."
Aaron Kennedy
EF5
I sent my observations to the NWS and Brad Bremer at FGF replied with:
"[FONT=PrimaSans BT,Verdana,sans-serif]We did decide on a low end EF4
maximum rating on the northeast side of town. The lofting of projectiles
was quite impressive. We found a 8200 gallon (aluminum) fuel storage
tank (which must have weighed at least a ton) about 2 miles east of
Northwood deposited in a corn field. The farmer said it must have come
from town as he knew of nobody between there and town who had something
like that."[/FONT]
"[FONT=PrimaSans BT,Verdana,sans-serif]We did decide on a low end EF4
maximum rating on the northeast side of town. The lofting of projectiles
was quite impressive. We found a 8200 gallon (aluminum) fuel storage
tank (which must have weighed at least a ton) about 2 miles east of
Northwood deposited in a corn field. The farmer said it must have come
from town as he knew of nobody between there and town who had something
like that."[/FONT]
I haven't seen any damage pictures above a 2/3... Anyone know if a QRT was called in? My guess with the verdict coming this quickly would be no, and that's unfortunate.
-John
-John
Dustin Wilcox
EF5
I was really hoping that the Tornado had missed the town just to the North, that storm really got its act together right over the Northwood area, I watched it on radar and could see it putting down a nice RFD to the West of town then saw the couplet tucked up in there as it neared the town, when I first heard the reports of damage from Northwood I was hoping it was just RFD damage as according to radar the couplet was just barely North of the towns center and its not a very big town. Here is a pretty sweet radar image I saved during the event, it’s BV on the lowest tilt, and the storm was pretty close the radar as well. You can see it had pretty good inflow winds as well as a well developed RFD.
Tony Lyza
EF3
According to an FGF met on another board, QRT members were contacted, but told them that they could do the survey by themselves.
http://www.easternuswx.com/bb/index.php?s=&showtopic=140768&view=findpost&p=2086222
Having seen the pictures and read the report, low-EF4 looks and sounds like a good judgement. The damage to those large facilities was quite impressive. In addition, one of the reasons cited for EF4, the carrying of large objects over large distances, has precedent. The Valley Mills, TX, tornado of 1973 was rated F5 by civil wind engineers (I believe Texas Tech but I'm not quite certain of that) based off of the carrying of a one ton pickup truck through the air for about a mile. This has been accepted by Grazulis. In addition, the precedent for violent tornado ratings from corn damage was set by Fujita in the Plainfield tornado of 1990. In that tornado, Fujita rated the damage F5 based completely on the scouring of a mature corn field to the point that only 1" stubble remained. I do not know the extent of the corn damage at Northfield, but it sounds as though it approached this level. Maybe someone could clarify further.
So, though perhaps we don't have true traditional indicators of EF4 damage, everything that has been indicated so far out of FGF and posted here indicate that the EF4 rating, though not reached by typical methodology, in all high likelihood holds a good bit of water.
This bugs me a lot. How big of a town, or what proximity to Norman does a tornado need to hit to warrant a QRT?
Reference point 3: http://www.flame.org/~cdoswell/EFscale_rant.html
-John
Chad Cowan
EF5
I'm surprised nobody has mentioned the radar presentation of the Northwood storm while it was further west. In the radar loop that Sam posted above you can almost see what I am referring to. With convection to the north and south, the main storm did not have a hook appendage, the entire storm was the hook. It maintained this structure for a few scans before gobbling up the convection to the south and focusing its broad area of rotation into the Northwood tornado. I would appreciate if someone could post radar and/or velocity data from this.
Aaron Kennedy
EF5
http://people.aero.und.edu/~kennedya/2007/CHASE-082607/radar/
Actually, what sort of looks like is a gigantic hook is two seperate storms. The primary storm first produced a funnel quite a bit earlier. As we approached the storm (red dot), another hook formed as the storm was ingesting the cell to the south. At ~127-130Z or so, this produced a funnel that went ~1/2 to the ground about 10W of Northwood. Once the S most storm was ingested, the LL mesocyclone intensified substantially and another hook echo formed as the Northwood tornado formed.
Actually, what sort of looks like is a gigantic hook is two seperate storms. The primary storm first produced a funnel quite a bit earlier. As we approached the storm (red dot), another hook formed as the storm was ingesting the cell to the south. At ~127-130Z or so, this produced a funnel that went ~1/2 to the ground about 10W of Northwood. Once the S most storm was ingested, the LL mesocyclone intensified substantially and another hook echo formed as the Northwood tornado formed.
Chad Cowan
EF5
Does anyone have smoothed images from ~0z-1z?
