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View Full Version : June 2 Threat: Southern Ontario


Derecho
06-01-2010, 11:39 AM
Great write up from the OSPC regarding Wednesday's threat across southern Ontario. According to the SPC, the current thinking is that the bulk of the activity will remain south of a line from Hamilton to Sarnia, but I wouldn't be surprised to see the threat shift a bit northward for tomorrow. Mr. Kuhn at WFO Downsview appears to agree with the SREF about a tornado threat across southwest Ontario.

WEDNESDAY..ATTENTION ONCE AGAIN RETURNS TO SOUTHERN ONTARIO AS A
FRONTAL WAVE APPROACHES FROM THE MIDWESTERN STATES. THE DAY SHOULD START
OFF SUNNY AND WARM WITH INCREASING CLOUDINESS FROM WEST TO EAST. NAM IS
FASTEST BRINGING IN PRECIP INTO SOUTHWESTERN ONTARIO BUT HAVE DELAYED
HIGH POPS OF SHOWERS AND THUNDERSTORMS UNTIL THE AFTERNOON WHICH IS
CONSISTENT WITH THE GEM REGIONAL AND GFS. BOTH NAM AND GEM SHOW A FAIRLY
POTENT SHORTWAVE NEAR SOUTHERN LAKE MICHIGAN BY 12Z WEDNESDAY. THIS
FEATURE IS QUESTIONABLE AS IT IS LIKELY DUE TO CONVECTIVE FEEDBACK
THEREFORE IT MAY BE OVERDONE OR NOT REAL AT ALL.
HOWEVER SOUNDINGS FROM ALL MODELS SHOW SEVERE POTENTIAL IN THE EXTREME
SOUTHWEST WHERE BOTH INSTABILITY AND SHEAR ARE FAVOURABLE.
CAPES OF UP TO 2000 J/KG COMBINED WITH EFFECTIVE BULK SHEAR VALUES OF 30
TO 40 KNOTS WILL RESULT IN A RISK OF DAMAGING WINDS AND LARGE HAIL. DUE
TO HIGH PRECIPITABLE WATER TORRENTIAL DOWNPOURS ARE ALSO POSSIBLE. GIVEN
THAT THE FORECAST STORM RELATIVE HELICITIES MAY EXCEED 150 MS/S2 IN THE
LOWEST KILOMETRE AS WELL 250 M2/S2 IN THE LOWEST THREE KILOMETRES
ACCORDING TO THE LATEST SREF HAVE MENTIONED THE RISK OF A TORNADO IN THE
CONVECTIVE OUTLOOK. ACROSS NORTHERN ONTARIO THERE IS ONLY A SLIGHT
CHANCE OF AN ISOLATED THUNDERSTORM DURING THE AFTERNOON.

DarkSky
06-01-2010, 12:11 PM
Can't wait. It's been a sloooow start this year for any severe activity.

Derecho
06-01-2010, 12:52 PM
According to the NAM STP model run, between 21z and 00z tomorrow afternoon there is the risk of an isolated tornado anywhere from Windsor to KW/Mount Forest to Toronto and all points east,

These links are subject to change when a new model run is out:
http://wxcaster4.com/nam/CONUS_ETA212_ATMOS_STP_33HR.gif
http://wxcaster4.com/nam/CONUS_ETA212_ATMOS_STP_36HR.gif

Derecho
06-01-2010, 01:44 PM
If the low could shift just 100 or 200km northward
http://www.twisterdata.com/data/models/gfs/3/maps/2010/06/01/12/GFS_3_2010060112_F36_RELV_850_MB.png

Derecho
06-01-2010, 03:25 PM
Fantastic! The SPC has shifted the SLGT risk northward to include most of southern Ontario!

:partyhat:

IF CONVECTION/CONVECTIVE OUTFLOW DOES NOT INTERFERE WITH
DESTABILIZATION IN CLOSER PROXIMITY TO THE FRONT ACROSS THE SOUTHERN
GREAT LAKES...FORCING/SHEAR ASSOCIATED WITH THE APPROACHING
SIGNIFICANT UPPER IMPULSE APPEARS MORE THAN SUFFICIENT TO SUPPORT AN
EVOLVING STORM CLUSTER BY LATE MORNING ACROSS SOUTHERN LOWER
MICHIGAN. IF THIS OCCURS...POTENTIAL EXISTS FOR ACTIVITY TO DEVELOP
EASTWARD ACROSS AND TO THE LEE OF THE LOWER GREAT LAKES THROUGH THE
REMAINDER OF THE AFTERNOON AND EVENING...WITH POTENTIAL FOR A SWATH
OF DAMAGING WINDS...AIDED BY 30-50 KT MEAN WIND FIELDS.

davefootball123
06-01-2010, 03:58 PM
Hey guys looks like it could be a good day tomarrow lets keep are finger crossed. One question for derecho , the first post of this thread with the outlook by environment canada mentioning the posibility of a tornado. Were did u get that. I know you can get the convective outlook of their site but it is not nearly as in depth as that. Thanks

Derecho
06-01-2010, 06:11 PM
Best DP's tomorrow are about 60-65F as far north as Barrie/North side of Toronto. Looks like the possible storm line will pass through southern Ontario around 4-6pm. Appears to be very low instability for tomorrow across S ONT according to the latest GFS run. The NAM is not working today, which really sucks!

Argh! So much uncertainty regarding this. I'm going mad.

Derecho
06-02-2010, 07:46 AM
SPC has a 5% tornado probability for Norfolk County. The rest of us are under a 2% tornado prob. Also, only areas along the shores of Erie and Ontario appear to be under the SLGT probs. But, but rest of us are under see text probs! There is still hope.

The front is currently in over central Lower Michigan, should reach Windsor/Sarnia in 2-3 hours. HRRR CRM indicates the line to reach Toronto in two hours????

EDIT: The latest run of HRRR CRM shows the line over central Michigan, not entering southwest ON like it had indicated during its 09z run. Phew.
Also, cloud deck entering southern Ontario, hopefully we can get enough sunlight to support some destabilization of the atmosphere before the clouds block the sun.

Derecho
06-02-2010, 12:27 PM
24C out, DP is 20C. The line is about 70 km away pushing northeast. The line is moving at about 35 kts, so it should be here in two hours(or less).

EDIT: I'm a little disappointed by this 14z HRRR CRM run for 18z. Hmm...

Derecho
06-02-2010, 12:41 PM
EDIT: It's 130pm and the front is moving through. Winds are about 40kmh max, raining and some light thunder.


The 18z run for CRM looks a little sad, but once the line pushes through, CRM is indicating some thunderstorms to pop up behind the line. Looking good:

For 21z and 22z(its 1642z right now).
(I'll delete these images once the storms have passed, I know they come up in the pic feed on the homepage)

DarkSky
06-02-2010, 01:43 PM
Just from the current system moving through: http://www.wunderground.com/radar/radblast.asp?num=6&delay=15&scale=1&noclutter=0&ID=BUF&type=N0R

It looks like I won't see any action until later on this evening. By which time the storms will have started dissipating due to their loss of daytime heating. Hmph.

davefootball123
06-02-2010, 03:19 PM
In hamilton we got about a half inch of rain some lightning and some thunder. I was out on the field at school when it stated to rain.

Derecho
06-02-2010, 03:31 PM
Just from the current system moving through: http://www.wunderground.com/radar/radblast.asp?num=6&delay=15&scale=1&noclutter=0&ID=BUF&type=N0R

It looks like I won't see any action until later on this evening. By which time the storms will have started dissipating due to their loss of daytime heating. Hmph.

Isolated cells developing back in southwest Ontario. HRRR brings them our way in about 2 hrs.

Not impressed with the current temp.

Date: June 2, 2010 Time: 3:30 pm

Temperature (current): 19.9 C
Temperature (24 hour max/min): 25 C /13.6 C
Humidex: 27.2
Precipitation (15 min/1 hr/24 hr): 0 / 0 / 0 mm
Relative Humidity/Dew Point: 100 % / 19.8 C

Derecho
06-02-2010, 04:14 PM
One can always hold out hope on the 18z HRRR CRM run for 21z this afternoon, still waiting for 22z to come out.
http://rapidrefresh.noaa.gov/hrrrconus/displayMap.cgi?keys=hrrr:&runtime=2010060218&plot_type=cref_t3sfc&fcst=03&time_inc=60&num_times=16&model=hrrr&ptitle=HRRR%20Model%20Fields&maxFcstLen=15&domain=t3&adtfn=1&wjet=1

davefootball123
06-02-2010, 04:16 PM
Have you seen the update map buy the storm presiction center. there still saying hamilton east.

Derecho
06-02-2010, 04:23 PM
Have you seen the update map buy the storm presiction center. there still saying hamilton east.

SE Michigan and SW Ontario still under an isolated severe threat, 5% probs for hail/wind.

22z is in
http://rapidrefresh.noaa.gov/hrrrconus/displayMap.cgi?keys=hrrr:&runtime=2010060218&plot_type=cref_t3sfc&fcst=04&time_inc=60&num_times=16&model=hrrr&ptitle=HRRR%20Model%20Fields&maxFcstLen=15&domain=t3&adtfn=1&wjet=1

I'm so desperate

davefootball123
06-02-2010, 04:24 PM
i beleive they have released the 22z. Not sure though i am new to that site

davefootball123
06-02-2010, 04:30 PM
sorry about that derecho i didnt realize you posted that

davefootball123
06-02-2010, 04:34 PM
they have just released the 23z and 00 for thursday

Derecho
06-02-2010, 04:36 PM
sorry about that derecho i didnt realize you posted that

No problem.

Three more intense cells have developed in the southwest: one near Dresden, another near Alvinston, and another near Watford.

Still waiting for a single bolt of lightning to be detected by radar, none yet.

davefootball123
06-02-2010, 04:38 PM
what lightning setection system do you use and off of what website

davefootball123
06-02-2010, 04:39 PM
they have also released all the way up to 06 thursday. watch the loop it is showing them right through the area. whats is the tornado threat for the area. And do you think these storms will be severe. Because the temps are kind of dissapoining but the humuduty is crazy. I also looked at the capes and they are indicating 2000 from kw to western end of lake ontario.

Derecho
06-02-2010, 04:48 PM
what lightning setection system do you use and off of what website

Allisonhouse.com monthly subscription for Gibson Ridge software.

For your question of the severity of storms, hard to say, wish I knew. :D

davefootball123
06-02-2010, 04:50 PM
Haha. I signed up for the OSPC in depth outlooks. Thanks for the PM about it

davefootball123
06-02-2010, 05:00 PM
it poring rain right now and it look like this may be the story of the night. Heavy rain.

benjaminblizzard
06-02-2010, 05:11 PM
it poring rain right now and it look like this may be the story of the night. Heavy rain.

I agree. I'm disappointed.

xxCanuck
06-02-2010, 05:24 PM
Yup, we have heavy rain here right now.

Derecho
06-02-2010, 05:26 PM
OT, but there is a tornado on the ground in the town of Shin Pond, Maine.

Looks like things are gearing up for a possible line of storms this evening to affect Niagara. The current line extends from London to eastern Ohio.

davefootball123
06-02-2010, 05:30 PM
the hrrr models show it into hamilton a little as well

davefootball123
06-02-2010, 06:24 PM
looks like the storm activity has really died. Were getting burst of heavy rain in hamilton but thats about it

Derecho
06-02-2010, 08:57 PM
Hope you got something out of it, DarkSky! It's too bad the line fully developed once it was east of you.

DarkSky
06-03-2010, 11:35 AM
Hope you got something out of it, DarkSky! It's too bad the line fully developed once it was east of you.

Actually that storm could not have split more perfectly in order to avoid us. We just got a bit of rain... :(

Derecho
06-03-2010, 04:52 PM
Actually that storm could not have split more perfectly in order to avoid us. We just got a bit of rain... :(

This place needs a support group to get us through these stormless times.

Hi, my name is Mike, and I'm...

DarkSky
06-03-2010, 08:38 PM
This place needs a support group to get us through these stormless times.

Hi, my name is Mike, and I'm...

Re-runs of Storm Chasers seasons 1 and 2 :) Works for me.

Derecho
06-03-2010, 11:41 PM
Re-runs of Storm Chasers seasons 1 and 2 :) Works for me.

I have all three seasons. The fourth season debuts this fall; so far away.

davefootball123
06-04-2010, 08:58 PM
yaa no kidding