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Smokin Joe
06-25-2010, 09:25 AM
SPC AC 250730

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT FRI JUN 25 2010

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE GREAT LAKES
VICINITY/MIDWEST...

...GREAT LAKES/OH VALLEY TO NORTHEAST STATES...
WHILE THE WESTERLIES OVER THE NORTHERN TIER OF THE CONUS GRADUALLY
AMPLIFY...MULTIPLE EMBEDDED DISTURBANCES AND MODERATELY STRONG FLOW
ALOFT WILL CONTRIBUTE TO A FAVORABLE LARGE SCALE PATTERN FOR SEVERE
TSTMS ACROSS THE GREAT LAKES REGION/ADJACENT MIDWEST ON SUNDAY.
CURRENT THINKING IS THAT AN MCS MAY BE ONGOING SUNDAY MORNING ACROSS
PORTIONS OF THE UPPER MS VALLEY VICINITY. WHILE SUCH UNKNOWN
MESOSCALE DETAILS COMPLICATE THE FORECAST...IT IS PROBABLE THAT THE
WARM SECTOR AIRMASS TO THE SOUTH/EAST OF THE EARLY DAY MCS SHOULD
AGGRESSIVELY DESTABILIZE AHEAD OF THE EASTWARD ADVANCING LAKE MI
VICINITY SURFACE LOW/ASSOCIATED COLD FRONT. PERHAPS A FEW SUPERCELLS
ARE POSSIBLE...BUT MORE LIKELY...MULTICELLULAR CLUSTERS/LINEAR
SEGMENTS WILL EVOLVE SUNDAY AFTERNOON/EARLY EVENING WITHIN LARGELY
UNIDIRECTIONAL WEST-SOUTHWEST FLOW THROUGH THE LOW/MID TROPOSPHERE.
DAMAGING WINDS WILL LIKELY BE THE PRIMARY SEVERE HAZARD.





Well hopefully this one pans out better for southern on.......

davefootball123
06-25-2010, 06:20 PM
Look slike we have been added to sautardays slight risk for storms. Mabye the moderate back in the plains will coem this way

Derecho
06-26-2010, 02:51 AM
New day 2 issued, looking pretty decent for severe weather across the region. Slight Risk expanded, S ON right in the middle.

EDIT: New day one drops all Ontario from the slight risk.

davefootball123
06-26-2010, 10:40 AM
Ya but we still hopefully hace sunday

Storm Chaser
06-26-2010, 12:03 PM
http://w1.spc.woc.noaa.gov/exper/sref/frames.php?run=2010062609

davefootball123
06-26-2010, 01:16 PM
Wow not to bad for tornado ingerduents. Mabye we will be a little more lucky this time around , looks to be sunday afternoon into the evening....GREAT LAKES REGION/OH VALLEY TO NORTHEAST STATES...
ALTHOUGH STRONGEST LOW LEVEL MASS FLUX SHOULD SHIFT EWD FROM THE
UPPER GREAT LAKES/NRN LOWER MI INTO SRN ONTARIO/SWRN QUEBEC BY
SUNDAY AFTERNOON...INCREASING SWLY LOW LEVEL WINDS ACROSS THE OH
VALLEY ALONG SRN EXTENT OF THE LLJ WILL ADVECT MOISTURE NEWD. HIGH
THETAE AIR MASS...PW VALUES /1.5-2 INCHES/...SPREADING NEWD
SPREADING NEWD ACROSS THE WARM SECTOR COMBINED WITH SURFACE HEATING
WILL RESULT IN MODERATE INSTABILITY THROUGHOUT THE SLIGHT RISK AREA.

TSTMS...POTENTIALLY IN THE FORM OF AN MCS...SHOULD BE ONGOING AT 12Z
SUNDAY ACROSS THE WRN GREAT LAKES INTO PARTS OF THE MIDWEST. NEW
TSTMS ARE EXPECTED TO DEVELOP BY SUNDAY AFTERNOON ALONG A
PRE-FRONTAL BOUNDARY/CONVERGENCE ZONE FROM THE MID MS/LOWER OH
VALLEYS INTO LOWER MI AND POTENTIAL WILL EXIST FOR THE MORNING MCS
TO RE-INTENSITY AS IT MOVES EWD INTO A DESTABILIZING AIR MASS. DEEP
LAYER SHEAR SHOULD BE STRONGEST OVER THE GREAT LAKES WHERE
SUPERCELLS WILL BE POSSIBLE...WITH MULTICELLULAR CLUSTERS/LINE
SEGMENTS MORE LIKELY INTO THE OH VALLEY GIVEN WEAKER SHEAR VALUES
WITH SWD EXTENT. ADDITIONAL TSTM DEVELOPMENT IS EXPECTED IN THE
VICINITY OF THE RETREATING WARM FRONT SUNDAY AFTERNOON WITH MODERATE
INSTABILITY AND EFFECTIVE BULK SHEAR SUFFICIENT FOR ORGANIZED
STORMS...INCLUDING A FEW SUPERCELLS.

AMPLE LARGE SCALE ASCENT AND A STRENGTHENING WEST-SOUTHWESTERLY LOW
LEVEL JET...AHEAD OF THE UPSTREAM AMPLIFYING SHORTWAVE TROUGH...
SHOULD CONTRIBUTE TO THE ORGANIZATION/SUSTENANCE OF MULTIPLE
EASTWARD MOVING LINEAR CLUSTERS/POTENTIAL MCS DURING THE EVENING
HOURS...ESPECIALLY ACROSS THE LOWER GREAT LAKES VICINITY. THIS
ACTIVITY MAY ULTIMATELY OUTRUN THE GREATER RESERVOIR OF INSTABILITY
ACROSS THE MIDWEST SUNDAY NIGHT...BUT AT LEAST SPORADIC WIND DAMAGE
MAY BE POSSIBLE LATE SUNDAY NIGHT/EARLY MONDAY AS FAR EAST AS
UPSTATE NY AND WESTERN NEW ENGLAND.

DarkSky
06-26-2010, 03:01 PM
Hopefully any storm activity will occur between now and Wednesday, with clear skies starting Wednesday as I'll be up north for a few days hopefully enjoying some sunshine :D

Smokin Joe
06-26-2010, 05:31 PM
If I'm reading that first paragraph right are they saying that the better chance for severe is looking more like it will be over southern on?

Smokin Joe
06-26-2010, 05:33 PM
Is it better to have the low level mass flux over u in the afternoon? That's what I mean sorry bout the double post

davefootball123
06-26-2010, 05:37 PM
heres what ec has to say
Sunday..Scattered thunderstorms are likely over Southern Ontario.
There is a slight risk that some of these storms may be severe with
heavy downpours large hail and damaging winds being the main threats.
There is also a slight risk of a tornado.

davefootball123
06-26-2010, 05:39 PM
Is it better to have the low level mass flux over u in the afternoon? That's what I mean sorry bout the double post
Mass flux is the occurrence of low-level gusts in the vicinity of deeper cumulus clouds. So i would say yes. Ohh and also sorry for the double post. I am an idiot i didnt read the spc forecast throughley and now i saw they said a few supercells possible

Derecho
06-26-2010, 07:58 PM
The greatest risk of a tornado tomorrow across southern Ontario looks to be between 4pm-11pm according to the SREF.

EDIT: EHI values don't look to be that impressive according the NAM.

davefootball123
06-26-2010, 08:10 PM
yes that was what i was seeing to

Itchy
06-27-2010, 12:03 AM
Any ideas about likely areas for activity for tomorrow ? I'm gong to head out for sure if things looks okay. I had a little twilight chase today and the storm was really weak but had some structure to it and some nice lighting from the fire red sun.

Derecho
06-27-2010, 12:05 AM
Tornado potential is fleeting tomorrow according the SREF/NAM. Potential is still there, but not as strong as indicated in earlier model runs. 5% tornado risk by the SPC could be pushing it with the latest indications, but really, models are nothing compared to a professional forecasters assessment. We'll have to wait and see how the situation develops. Until then, not much else to say.

If the MCS over the Midwest slows down overnight, it could squash our chances for storms tomorrow. Projected placement of the MCS by dawn is remarkably similar to June 23, entering Michigan around 7am, then hopefully clearing southern Ontario destabilizing the atmosphere by 1-3pm. Hopefully clouds will clear and we'll get a decent shot at high temperatures and modest dewpoints after the MCS exists Ontario. But, if the MCS slows down for whatever reason overnight, we'll be doomed with cloud cover during peak daytime heating.

EDIT: Also to chime in with supercell composites tomorrow, SW ON looks to have the greatest potential for tomorrow for isolated supercells, then a lesser risk from around north of Woodstock to around Mount Forest/GTA/Niagara. Further north of that, parameters don't appear to be as conductive, but like I said: tomorrows potential is remarkably similar to June 23, and that day the Simcoe County supercell fired well north of the projected favourable fields, so we'll have to wait and see.

davefootball123
06-27-2010, 12:12 AM
Hopefully some supercells do fire and its not like june 23rd were 1/4 of southern ontario saw severe weather when they were predicting all of souther ontario

Derecho
06-27-2010, 12:22 AM
Hopefully some supercells do fire and its not like june 23rd were 1/4 of southern ontario saw severe weather when they were predicting all of souther ontario

It wasn't a bust or undercast. With the late evening MCS in SW ON and the Midland tornadoes, the forecast verified. Look at regular events in USA, large SLGTs, MDTs, and HIGHs, but not every point actually experiences severe weather. Just isolated areas sometimes extending 100s of miles apart.

The risk outlines do not constitute a total coverage verification forecast. The probabilities of 5%, 15%, 30%, 45%, and 60% only describe that there is X% chance of severe weather verification within the outlined region.

WhenTWN/EC place all of S ON has 80% chance of thunderstorms in every zone forecast, that only means that potential is high for thunderstorm development, but does not guarantee any given area will be impacted. It's a complicated system and the general public don't quite understand what it really means, hence the 'they always say it will rain and it doesn't'. Most of the time it does rain, it just doesn't directly impact said persons area.

davefootball123
06-27-2010, 12:25 AM
Ya i see what you mean derecho sorry. Im still a little P.Oed. And i dont really consider my self as general public because i am pretty noligable in weather especially thunderstorms and tornados. But ya as i said its just the p.oed side talking

Eabie
06-27-2010, 01:00 AM
Ya i see what you mean derecho sorry. Im still a little P.Oed. And i dont really consider my self as general public because i am pretty noligable in weather especially thunderstorms and tornados. But ya as i said its just the p.oed side talking

I know you are *knowledgeable* about weather (more so than me), but on the SPC site it says "probability of severe weather within 25 miles of a point." 25 miles is a fair distance. I think it's debatable whether June 23 was a bust or not -- I tend to think that it was, considering that the moderate risk for Southern Ontario was eventually dropped and the degree of severe weather that was expected did not seem to pan out. But it's always best to keep the probabilities in mind -- even a moderate risk is only 45%. :)

I'm not going to get too excited until I see a storm outside my window, but I'll continue to follow the forecasts and remain hopeful, of course. Regardless of what happens tomorrow, it's still only late June. :) Just important to stay patient, I guess. But let's hope for the best. :P

davefootball123
06-27-2010, 01:05 AM
I totaley agree with you and im never shure until i see a storm and even then im not sure :p but lets be hopefull for tomarrow. Supercells seem like they have a decent chance

Derecho
06-27-2010, 11:52 AM
Greatest severe threat appears to be across southwestern Ontario according the SPC. This is where the SPC expects the best potential for supercellular development. For the rest of us, looks like isolated supercells and one or more MCS's later today. The first MCS is located in southeastern Michigan right now and crossing Lake Michigan. Looks to clear through southern Ontario around at or before 3pm. Hopefully, it will destabilize our atmosphere enough to allow at at least some severe convective development when the second front arrives this evening. The 1230pm SPC Day 1 update will provide the best picture as to what is expected to occur today. Until then, looks like a very modest threat for today.

Eabie
06-27-2010, 11:58 AM
Greatest severe threat appears to be across southwestern Ontario according the SPC. This is where the SPC expects the best potential for supercellular development. For the rest of us, looks like isolated supercells and one or more MCS's later today. The first MCS is located in southeastern Michigan right now and crossing Lake Michigan. Looks to clear through southern Ontario around at or before 3pm. Hopefully, it will destabilize our atmosphere enough to allow at at least some severe convective development when the second front arrives this evening. The 1230pm SPC Day 1 update will provide the best picture as to what is expected to occur today. Until then, looks like a very modest threat for today.

Does that first MCS pose any threat, or will it substantially weaken for sure by the time it gets here? Even a little lightning and thunder will do. I'm starvin' here. :P

Derecho
06-27-2010, 12:09 PM
Does that first MCS pose any threat, or will it substantially weaken for sure by the time it gets here? Even a little lightning and thunder will do. I'm starvin' here. :P

It's fizzling out, maybe some light rain. It's what comes in behind it where we have the best threat.

davefootball123
06-27-2010, 12:22 PM
At this point it looks like the first mcs is almost fizzeled out mabye it wont even have an impact on golden horshoe southwestern ontario area

xxCanuck
06-27-2010, 01:26 PM
Tornado Watch


Windsor - Leamington - Essex County
12:02 PM EDT Sunday 27 June 2010
Tornado watch for
Windsor - Leamington - Essex County issued

Severe thunderstorms with isolated tornadoes possible today.

This is an alert to the potential development of tornadoes and severe thunderstorms with large hail and damaging winds.

Monitor weather conditions..Listen for updated statements. If threatening weather approaches..Take immediate safety precautions.

A hot and humid airmass settling over Southwestern Ontario has made conditions favourable for the development of severe thunderstorms this afternoon. Along with damaging winds and torrential downpours, isolated tornadoes will be possible with these storms.

Derecho
06-27-2010, 01:27 PM
New day 1 is about. I don't want to be disappointed by it, but I am... slightly.

The slight has shifted father south, 2% and 5% tornado probabilites have shifted south, hail threat has shifted south, 15% wind has been shifted south and east, and the 30% wind has been almost dropped for all areas except Lake Erie.

Except for the 15% hail, KW has almost been dropped from the entire slight risk as far as I can tell. But, I know, I know.. it's not always about MBY! Could be a great day today, especially in the SW.

davefootball123
06-27-2010, 01:40 PM
Looks like some nice storms moving to the northeast from widsor chatam area. Very explosive development. One thing is notice how ec issued a tornado watch before nws did. WOW

Eabie
06-27-2010, 02:09 PM
I'll settle even for a non-severe storm. I just want to hear some thunder again. :)

davefootball123
06-27-2010, 02:46 PM
many storms starting to fire with even some supercells aswell. tornado warning for an arbour and some severe t-storm warnings are starting to be issued

Derecho
06-27-2010, 02:56 PM
Backyard Report: clouds are clearing, blue sky fast approaching from the west and southwest, sun shining now. Besides a few wasps, it's a lovely afternoon out! Currently sitting at 25C, DP 23C, humidex 35C. About to check latest meso analysis. Check back to this post for detals.

According to the latest information from the SPC:
MUCAPE is building to 1,000j/kg currently across central southern Ontario, up to almost 2,000j/kg across the southwest.
Supercells composites and tornado parameters are highest across the southwest currently. I expect a modest northeast trend as the day progresses. Well, one can hope, at least :)
Wind shear levels are currently most favourable back in the southwest, but building up this way.

Not too sure what to expect from all of this, surprising there are so many rotating small storms across southeast Lower Michigan currently. Harder to detect on radar, could be some brief tornadoes today in the southwest.

EDIT: A tornado warning has been issued for the city of Detroit now. Look out SW ON.

Derecho
06-27-2010, 03:20 PM
TORNADO WARNING
ISSUED BY ENVIRONMENT CANADA
AT 2:23 PM EDT SUNDAY 27 JUNE 2010.
---------------------------------------------------------------------
TORNADO WARNING FOR:
=NEW= WINDSOR - LEAMINGTON - ESSEX COUNTY.
---------------------------------------------------------------------
==DISCUSSION==
AT 2:15 PM WEATHER RADAR INDICATES A LINE OF SEVERE THUNDERSTORMS
CAPABLE OF PRODUCING TORNADOES SOUTHWEST OF DETROIT MOVING NORTHEAST
AT 60 KM/H REACHING THE WINDSOR AREA NEAR 2:45 PM. THESE STORMS WILL
ALSO BE CAPABLE OF PRODUCING WIND GUSTS TO 100 KM/H, TORRENTIAL
DOWNPOURS AND LARGE HAIL.

Derecho
06-27-2010, 03:49 PM
SEVERE WEATHER BULLETIN
ISSUED BY ENVIRONMENT CANADA
AT 2:48 PM EDT SUNDAY 27 JUNE 2010.
---------------------------------------------------------------------
WATCHES/WARNINGS IN EFFECT FOR SOUTHERN ONTARIO...

TORNADO WATCH FOR:
=NEW= ELGIN
=NEW= LONDON - MIDDLESEX
=NEW= SIMCOE - DELHI - NORFOLK
=NEW= WOODSTOCK - TILLSONBURG - OXFORD COUNTY
=NEW= GODERICH - BLUEWATER - SOUTHERN HURON COUNTY
=NEW= STRATFORD - MITCHELL - SOUTHERN PERTH COUNTY
WINDSOR - ESSEX - CHATHAM-KENT
SARNIA - LAMBTON.

SEVERE THUNDERSTORM WATCH FOR:
=NEW= DUNNVILLE - CALEDONIA - HALDIMAND
=NEW= BRANTFORD - COUNTY OF BRANT
=NEW= NIAGARA
=NEW= CITY OF HAMILTON
=NEW= WINGHAM - BLYTH - NORTHERN HURON COUNTY
=NEW= LISTOWEL - MILVERTON - NORTHERN PERTH COUNTY
=NEW= WATERLOO - WELLINGTON.

davefootball123
06-27-2010, 04:02 PM
Severe thunderstorm warch all the way up hear now. Aswell as tornado watches from woodstock back. tornado warning in windsor. my weather radio didnt go off for the watch hmm strange

Derecho
06-27-2010, 04:18 PM
KDTX shows a possible tornado is on the ground 3km northeast of downtown Cottam in central Essex County. Another possible tornado is located near Lakeshore in north central Essex County!

Extended to Kent County now, funnel reported.
==DISCUSSION==
AT 3:20 PM WEATHER RADAR INDICATES A CLUSTER OF SEVERE THUNDERSTORM
CELLS CAPABLE OF PRODUCING TORNADOES EAST OF WINDSOR MOVING EAST TO
NORTHEAST AT 60 KM/H. A TRAINED SPOTTER HAS REPORTED A ROTATING WALL
CLOUD AND POSSIBLE FUNNEL WITH THE STRONGEST CELL. THESE STORMS ARE
ALSO CAPABLE OF PRODUCING WIND GUSTS TO 100 KM/H, TORRENTIAL
DOWNPOURS AND LARGE HAIL.

Oh geez, the Cottam area rotation is violent now!

JUST WOW! Central Essex County :eek:

davefootball123
06-27-2010, 04:21 PM
That is a very nice couplet on that intense supercell thunderstorm

Raedwulf
06-27-2010, 04:25 PM
Storm in windsor now shows, 47,000ft tops, 71dbz, 4inch hail, 79kg/m VIL
WOW!
EDIT:!! WOW!!! KG/2 JUST WENT OUT TEN MROE!!!! ITS NOW AT 89!!

Derecho
06-27-2010, 04:27 PM
OMG doppler radar shows a strong tornado may be developing 10km north of Leamington, a tornado must be on the ground right now according to NROT this is insane

Raedwulf
06-27-2010, 04:31 PM
South-central O0 65 dBZ 52,000 ft. 92 kg/mē

Chaos
06-27-2010, 06:50 PM
I live in Elgin, we had a Tornado watch from about 2pm until about 15 minutes ago, been downgraded as a severe T storm watch. Waiting, waiting, waiting...

DarkSky
06-27-2010, 07:55 PM
http://img130.imageshack.us/img130/7121/currentbuffalonexradrad.jpg
(http://img130.imageshack.us/img130/7121/currentbuffalonexradrad.jpg)

Derecho
06-28-2010, 02:02 AM
Not too sure what to expect from all of this, surprising there are so many rotating small storms across southeast Lower Michigan currently. Harder to detect on radar, could be some brief tornadoes today in the southwest.

EDIT: A tornado warning has been issued for the city of Detroit now. Look out SW ON.

Horrible news out of St. Clair County, Michigan right across the river from Sarnia.

One of those small hard to detect if they are rotating storms may have produced a brief tornado in a campground, killing one person and injuring at least three. No warning was in effect. Just couldn't be detected by radar. May have briefly occurred in between radar scans.

DETROIT -- The St. Clair County Sheriff's Office said one person died and at least three others were injured at a campground in Clyde Township after another round of severe weather hit the area Sunday.
http://www.clickondetroit.com/weather/24061421/detail.html