Northern Plains Severe Weather - June 23

[CrazyC83]

After the F4 tornado last night in Elie, Manitoba, the conditions are even worse today - could see a tornado outbreak, and some of it may get into northern North Dakota.

The SPC map is correct but deceptive as it is a conditional probability (should the storms develop farther south than expected).

[WindRunner]

F4? That's pretty impressive, but I guess this is their time of year up there. I just wish we had some good radar feeds from Canada to watch these storms on . . . no doubt they are just as impressive as their more southern sisters.

[HurricaneBill]

What was the last F4 tornado in Canada?

Besides this one, I mean.

[CrazyC83]

1987 in Edmonton. (That one, which killed 27, might have been F5 although officially listed as F4)

At least five tornadoes reported so far according to The Weather Network (Canada's equivalent of The Weather Channel). It seems to be staying north of the border although the SPC might want to put up a Tornado Watch for the northern fringes (although the SLGT is correct for that area).

If the SPC went up into Canada, there would likely be a MDT in much of southern Manitoba for tonight. They do mention a derecho might form into the Boundary Waters region (we've heard that before!)

[CrazyC83]

F4? That's pretty impressive, but I guess this is their time of year up there. I just wish we had some good radar feeds from Canada to watch these storms on . . . no doubt they are just as impressive as their more southern sisters.

Can the GRLevelX systems reach those storms?

[WindRunner]

Level 3 is getting to the one tonight . . . since Level 2 is out the window with one of the available sites being an AFB and the other has data from 1967 in the queue - the FTM mentions "level II degradations until 18z 6/25." It's no fair, I want to see AE on these storms

Oh well, Level 3 does reach . . . KMBX or KMVX will be the two tonight. Right now I can see three tornadoes, one of which is confirmed to be on the ground and just went through a town . . . should be interesting in the morning . . .

[MiamiensisWx]

I have noticed some strong couplets associated with the cells over southern Manitoba, Canada. The cell north of Bottineau is a beast. An intense tornado is likely on the ground. It appears to be cycling per the latest images. In addition, the adjacent cell appears to be exhibiting rotation to the northwest. Helicity values are strong, and the sfc flow is enhancing these sfc-based storms. Since the radar site (Minot AFB in ND) is far from the cells, it is impressive that their presentation is well defined.

[CrazyC83]

That reminds me of Greensburg. Hopefully it isn't headed for a town!

[WindRunner]

For reference, the storm near its worst, shortly before moving through a town (around 3k people if I remember correctly):



Currently (02:23Z):



You can see the first storm fell apart/rainwrapped in the center, while the two storms (one NE, one behind and following it) are slowly intensifying.

EDIT: I don't know what's up with that bottom image, looks like the graphics card botched the save. You can still see the cells, however. Cell on the left appears likely to drop the next funnel, while the center storm still has the SW of a tornado, though not much support in the L3 SRV (ha - big surprise!) . . .

[CrazyC83]

That town I believe is Killarney (population 2,300). Boissevain (1,400), Deloraine (1,000), Melita (1,100) and Souris (1,600) are other towns in the area.

There are definitely more supercells firing up. CAPE is like 8000 J/KG up there. The SPC did call it right thinking the cap would hold south of the border.

[CrazyC83]

New storm with doppler-indicated 80 mph gusts (but no tornado yet) headed towards Winnipeg (the big city in the area - population 720,000).

http://twister.sbs.ohio-state.edu/text/ ... WCN11.CWWG

[CrazyC83]

New SPC watch:

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 446
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT SAT JUN 23 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

NORTHWEST MINNESOTA
NORTHEAST NORTH DAKOTA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 925 PM
UNTIL 500 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 65 MILES WEST NORTHWEST OF
DEVILS LAKE NORTH DAKOTA TO 75 MILES EAST NORTHEAST OF BEMIDJI
MINNESOTA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

DISCUSSION...CLUSTER OF SUPERCELLS WITH A HISTORY OF TORNADOES OVER
SWRN MB ARE EXPECTED TO CONTINUE SEWD OVERNIGHT INTO PORTIONS OF
NERN ND AND NWRN MN. COMBINATION OF MLCAPES OF 1500-2500 J/KG AND
MODERATELY STRONG LOW AND DEEP-LAYER SHEAR ALONG AND S OF WARM
FRONT/OUTFLOW BOUNDARY SHOULD MAINTAIN STORM INTENSITY WITH A THREAT
OF A FEW TORNADOES IN ADDITION TO LARGE HAIL AND DAMAGING WINDS.
ACTIVITY MAY GROW UPSCALE INTO AN MCS EARLY SUNDAY MORNING WITH A
CONTINUED THREAT OF DAMAGING WINDS AND LARGE HAIL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 29025.


...MEAD/HALES


SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 446
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT SAT JUN 23 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

NORTHWEST MINNESOTA
NORTHEAST NORTH DAKOTA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 925 PM
UNTIL 500 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 65 MILES WEST NORTHWEST OF
DEVILS LAKE NORTH DAKOTA TO 75 MILES EAST NORTHEAST OF BEMIDJI
MINNESOTA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

DISCUSSION...CLUSTER OF SUPERCELLS WITH A HISTORY OF TORNADOES OVER
SWRN MB ARE EXPECTED TO CONTINUE SEWD OVERNIGHT INTO PORTIONS OF
NERN ND AND NWRN MN. COMBINATION OF MLCAPES OF 1500-2500 J/KG AND
MODERATELY STRONG LOW AND DEEP-LAYER SHEAR ALONG AND S OF WARM
FRONT/OUTFLOW BOUNDARY SHOULD MAINTAIN STORM INTENSITY WITH A THREAT
OF A FEW TORNADOES IN ADDITION TO LARGE HAIL AND DAMAGING WINDS.
ACTIVITY MAY GROW UPSCALE INTO AN MCS EARLY SUNDAY MORNING WITH A
CONTINUED THREAT OF DAMAGING WINDS AND LARGE HAIL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 29025.


...MEAD/HALES


Note: Click for Watch Status Reports.

WOUS64 KWNS 240221
WOU6

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH OUTLINE UPDATE FOR WT 446
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT SAT JUN 23 2007

TORNADO WATCH 446 IS IN EFFECT UNTIL 500 AM CDT FOR THE
FOLLOWING LOCATIONS

MNC007-029-061-069-071-077-087-089-107-113-119-125-135-241000-
/O.NEW.KWNS.TO.A.0446.070624T0225Z-070624T1000Z/

MN
. MINNESOTA COUNTIES INCLUDED ARE

BELTRAMI CLEARWATER ITASCA
KITTSON KOOCHICHING LAKE OF THE WOODS
MAHNOMEN MARSHALL NORMAN
PENNINGTON POLK RED LAKE
ROSEAU


NDC005-019-027-035-039-063-067-069-071-079-091-095-097-099-
241000-
/O.NEW.KWNS.TO.A.0446.070624T0225Z-070624T1000Z/

ND
. NORTH DAKOTA COUNTIES INCLUDED ARE

BENSON CAVALIER EDDY
GRAND FORKS GRIGGS NELSON
PEMBINA PIERCE RAMSEY
ROLETTE STEELE TOWNER
TRAILL WALSH


ATTN...WFO...FGF...BIS...DLH...





Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is depicted by the shaded areas.

SAW6
WW 446 TORNADO MN ND 240225Z - 241000Z
AXIS..55 STATUTE MILES NORTH AND SOUTH OF LINE..
65WNW DVL/DEVILS LAKE ND/ - 75ENE BJI/BEMIDJI MN/
..AVIATION COORDS.. 50NM N/S /44ENE MOT - 39S INL/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 29025.

LAT...LON 49270023 48729343 47139343 47680023

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU6.


Watch 446 Status Report Message has not been issued yet.

[WindRunner]

That town I believe is Killarney (population 2,300). Boissevain (1,400), Deloraine (1,000), Melita (1,100) and Souris (1,600) are other towns in the area.

There are definitely more supercells firing up. CAPE is like 8000 J/KG up there. The SPC did call it right thinking the cap would hold south of the border.

No, it was some town with a V. The hook encircled the town's dot for a scan . . . hence I had to go look it up so I could worry even more


BTW, Tornado Watch 446 out for NE ND/N MN . . . stretches a good bit further east than you would expect as well, but I guess that allows for some long-tracking . . .

[CrazyC83]

Yeah, they are supposed to continue into the night. May form an MCS/derecho overnight along the international border.

That town might have been Virden. That is located just east of the Saskatchewan line and about 50 miles west of Brandon.

Brandon is the largest city in western Manitoba (population 45,000).

[WindRunner]

Yes! It was Virden . . . thank you very much . . .

That western cell is dropping out a nice hook . . . SRV isn't putting out an impressive signature, but that's probably just Level III again . . .

FYI - regardless of the tornadoes, each of these storms has been fluctuating between an estimated 1.5" to 2.5" hail size over the past couple of hours . . . so should be some good hail regardless. Also, VILD's have been ranging from 4-6 (so far), so should be good wind gusts as well . . . definately looks like a possible transition to linear later tonight like you said, Crazy.

[CrazyC83]

Yep, I think it will transition so that a good MCS will go through SE MB/N MN overnight. It is already starting to transition, as there are no tornado warnings at the moment but the southernmost cell I think could still put down a tornado easily as the radar shows. Although I doubt it would be as big as it could have been earlier.

I guess EC (Canada's NWS) does not have access to these systems.

[CrazyC83]

Winnipeg Airport just reported 67 mph wind gusts.

[WindRunner]

Yep, I think it will transition so that a good MCS will go through SE MB/N MN overnight. It is already starting to transition, as there are no tornado warnings at the moment but the southernmost cell I think could still put down a tornado easily as the radar shows. Although I doubt it would be as big as it could have been earlier.

I guess EC (Canada's NWS) does not have access to these systems.

What systems? They have their own radar, and it isn't like the NWS radar is hard to get, if that's what you're talking about . . .

I just think that EC wait for an amazing radar presentation or reports from the ground before warning . . . i.e. a radar-based warning is at least an F2, and anything weaker only gets a warning if reported. I know this isn't always true, but I remember them operating similar to that during last summer in southern Ontario . . .

[CrazyC83]

Yep, I think it will transition so that a good MCS will go through SE MB/N MN overnight. It is already starting to transition, as there are no tornado warnings at the moment but the southernmost cell I think could still put down a tornado easily as the radar shows. Although I doubt it would be as big as it could have been earlier.

I guess EC (Canada's NWS) does not have access to these systems.

What systems? They have their own radar, and it isn't like the NWS radar is hard to get, if that's what you're talking about . . .

I just think that EC wait for an amazing radar presentation or reports from the ground before warning . . . i.e. a radar-based warning is at least an F2, and anything weaker only gets a warning if reported. I know this isn't always true, but I remember them operating similar to that during last summer in southern Ontario . . .

I mean they may not have access to the GRLevelX that we have...they do have a tendancy to wait a lot for issuing warnings at times, but they do seem to be more liberal in issuing warnings in the Prairies than in Ontario. Some NWS offices do things differently as well.

[CrazyC83]

I have to wonder what would have happened if the cap unexpectedly broke farther south...