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View Full Version : Jun.4/10 - Severe thunderstorms / tornado warning


Derecho
06-04-2010, 11:54 AM
Well, this threat came out of no where, it seems.

For southern Ontario from the SPC:
30% chance of damaging winds
15% chance of hail
5% chance of a tornado

TSTMS SHOULD FORM IN AREA OF SFC HEATING AHEAD OF CLOUD SHIELD FROM
CNTRL IL INTO IND/OH THIS AFTN. STORMS ALSO MAY FORM A BIT FARTHER
N IN ZONE OF CONFLUENT 850 MB FLOW OVER SRN LWR MI.
A FEW SUPERCELLS COULD OCCUR...ESPECIALLY OVER SRN MI/NRN IND AND
NRN OH. THESE COULD YIELD DMGG WIND AND A TORNADO. BUT
INCREASINGLY UNIDIRECTIONAL FLOW WITH TIME SUGGESTS THAT ACTIVITY
WILL TRANSITION TO BROKEN LINE SEGMENTS...WITH EMBEDDED SMALL BOWS
YIELDING DMGG WIND. THE STORMS MAY SPREAD AS FAR E AS THE LWR GRT
LKS BY EVE...WITH GRADUAL WEAKENING EXPECTED THEREAFTER.

DarkSky
06-04-2010, 12:11 PM
Only slight risk for today: http://www.spc.noaa.gov/products/outlook/dy1.gif

.. and EC has forecast (for St. Catharine at least) of only partial clouds today with a high of 23C.

Hopefully daytime heating will bring something in the afternoon, but I'm not too excited about today (yet) :)

Derecho
06-04-2010, 12:18 PM
Only slight risk for today: http://www.spc.noaa.gov/products/outlook/dy1.gif

.. and EC has forecast (for St. Catharine at least) of only partial clouds today with a high of 23C.

Hopefully daytime heating will bring something in the afternoon, but I'm not too excited about today (yet) :)

After overlaying the 5% TOR onto a map of S ON counties, judging by the curve of the 2% over western NY, looks like the 5% extends to almost Barrie, but stating north of Toronto and south of Owen Sound. Hard to tell, though.

Satelite looks great, tons of clearing: http://www.rap.ucar.edu/weather/satellite/g13.2010155.1445_smDTW_vis.jpg

Aww, I just remembered I work at 5pm. Dang it!

Derecho
06-04-2010, 01:48 PM
SPC has kept the 5% tornado probs for S ON at 1630z. HRRR shows some thunderstorms crossing SW/SE Ontario starting around 22z around 5pm.

Derecho
06-04-2010, 05:00 PM
The severe thunderstorm risk has been dropped for all but Essex County by the SPC.

Itchy
06-04-2010, 05:36 PM
I swear some of my favourite chase days have been when we are not even in the slight risk. So many times I have noticed when we are in a medium risk zone or 5 % tornado we wind up with a muggy precip washout.
Does SPC take into account lake-breeze effects of the great lakes or is that something that we are more in tune with ?????
At least 2/3 of any really good storm I have chased has been a result from them

davefootball123
06-04-2010, 10:02 PM
Looks like there could be some golfball sized hail in detriot metro aswell as windsor

davefootball123
06-04-2010, 10:17 PM
Storm near windosr is showing a messo on w undeground

davefootball123
06-04-2010, 11:29 PM
Severe storms moving towards the hammer hopefully

davefootball123
06-04-2010, 11:34 PM
At 10:20 PM EDT Doppler radar indicated a line of severe thunderstorms from near Chatham to Wheatley. This line of severe thunderstorms was moving toward the east at 60 km/h, and was capable of producing wind gusts in excess of 90 km/h.

Doppler radar has indicated some weak rotation within this line. While not immediately likely, tornadoes cannot be ruled out with this line of thunderstorms.

xxCanuck
06-05-2010, 12:10 AM
edit----- nvm

davefootball123
06-05-2010, 12:23 AM
Craxy storm through hamilton. Worst so far this year and it was quite bad. Extremley heavy rain 1.5 inches. The lightning was crazy too. I counted 27 strikes in 1 minute. Thunder was booming and i was worried that the lighntning would take out electronics. I had 4 very close lightning strikes no delay between lightning and thunder. 60-80km/h winds. Tornado warning in simco area and svr thunderstorm warning for us. Dark Sky if you dont get that bad i feel bad for you becuase the lightning was sooooo crazy. It was alot like august 9th of last year. There were a few anvil crawlers and all else was fork.

davefootball123
06-05-2010, 12:29 AM
Looks like it is dying out on radar now, Anything for you Derecho

xxCanuck
06-05-2010, 12:35 AM
Very frequent lightning here as well.

benjaminblizzard
06-05-2010, 02:11 AM
I was coming home from a party in Thornhill, ON when I noticed a nice lightning show. No thunder at that time. The lightning is starting to pick up now and getting the first rumbles of thunder (York U).

Itchy
06-05-2010, 07:20 AM
Definately was a weak supercell, it even had a small hook and small velocity couplet right in it!

As it entered Canada
http://farm5.static.flickr.com/4048/4671514464_147c0a6f56_b.jpg

Velocity scan shortly after above image
http://farm5.static.flickr.com/4061/4670888491_91b7ab1566_b.jpg

Derecho
06-05-2010, 01:11 PM
Looks like it is dying out on radar now, Anything for you Derecho

Nope :(

I saw a flash of lightning on the horizon around 2am.

DarkSky
06-05-2010, 01:27 PM
We were under a severe tstorm watch here in St. Kitts, warnings and tornado warnings in other parts of southern Ontario.

Lots of lightning, but not a lot of visible bolts. Almost zero winds as it approached with the lightning. Very heavy rain as it was overhead, with moderate wind.

This storm gave a lengthy entrance with it's threatening lightning and thunder, made a brief appearance dropping it's rain and wind while overhead, then made a quick exit as it went back to calm very quickly after passing.

50,000ft cloud tops were impressive though.

(photo below had to be edited from original, as original had a background basically one bright flash since the bolts were so close) :

http://www.ontariostorms.com/attachment.php?attachmentid=1571&d=1275754879

Derecho
06-05-2010, 05:07 PM
Did anyone get any radar screen caps of the tornado warned storm from last night?

davefootball123
06-05-2010, 05:29 PM
No sorry but i was watching it closley and there was a rotation couplet on the storm for about 10 minutes