8/6-8/8 Severe Weather Threat

[Brewers]

A strong upper level low will drop south out of Canada into the Great Lakes, setting up the chance for multiple days of severe weather across the region. SPC has N WI and S MN already outlined in its day 4 outlook.

[IWXwx]

Setup looks good for some typical summertime-style severe action down here on Wednesday.

[Minnesota Meso]

Concerning Tuesdays sever threat.  I think the GFS has the right idea that the greatest threat will reside over Iowa and points east during the evening. It's going to be very difficult to get much surface cape values up here in MSP.  I suspect the new 3 day outlook will include MSP  based on the Nam, however that doesn't seem realistic to me.  Looking further at the NAM it seems to agree, but it still brings to much cape this far north.  It looks like IA and points east could be rocking.

[harrisale]

Threat looking better for Southern Ontario Wednesday evening with good turning with height along a slow moving cold front.
 
DTX AFD says maginal threat due to early convection and cloud cover but watch for any clearing as there will be plenty of shear.

OVERNIGHT LOWS WILL REMAIN WARM, WELL INTO THE MID/UPPER 60S, ON   
TUESDAY NIGHT AS THE CWA REMAINS WITHIN THE WARM SECTOR OF THE   
DEVELOPING UPSTREAM CYCLONE. HEIGHT FALLS ASSOCIATED WITH THE PARENT   
WAVE, WHICH IS CURRENTLY SEEN DIGGING INTO THE INTERIOR NORTHWEST,   
WILL BE AUGMENTED BY EVENTUAL PHASING WITH A SPEEDY LOWER AMPLITUDE   
WAVE ROTATING INTO ALBERTA THIS AFTERNOON. ONCE THIS OCCURS OVER THE   
UPPER MIDWEST LATE TUESDAY NIGHT INTO EARLY WEDNESDAY, THE CYCLONE   
WILL UNDERGO A STEADY DEEPENING PHASE WITH RENEWED ASCENT ALONG THE   
LEAD EDGE OF THE NEWLY MERGED PV ANOMALY EXPECTED TO BE SUFFICIENT   
TO SUPPORT A ROUND OF SHOWERS AS THE COLD FRONT PUSHES THROUGH THE   
CWA ON WEDNESDAY AFTERNOON. THE FRONT ITSELF WILL NOT PACK MUCH OF A   
PUNCH AS IT TRANSITIONS TOWARD AN INCREASINGLY FLOW-PARALLEL   
ORIENTATION AT THE EXPENSE OF LOW-LEVEL CONVERGENCE AND COLD   
ADVECTION. SIMILAR TO TUESDAY, BREAKS IN THE CLOUD COVER WILL STILL   
WARRANT WATCHING AS LOCALLY HIGHER PATCHES OF INSTABILITY WILL HAVE   
PLENTY OF SHEAR TO WORK WITH, BUT THE OVERALL SEVERE THREAT SHOULD   
BE MINIMAL. WITH 850MB TEMPERATURES ONLY PROGGED TO FALL A FEW   
DEGREES ACROSS SOUTHEAST MICHIGAN BY THURS MORNING, HIGH   
TEMPERATURES SHOULD HAVE NO PROBLEM REBOUNDING INTO THE MID/UPPER   
70S BY THURSDAY AFTERNOON WITH NOTHING MORE THAN AN ADVANCING CIRRUS   
DECK AVAILABLE TO OBSCURE INSOLATION.

KBUF on the other hand mentions the possibility of strong storms. Average it out and you've got yourself a S. Ontario forecast.
 

WEDNESDAY WILL THEN BE WARM AND HUMID AS THE CONTINUED ADVECTION OF   
SUMMERY AIR OUT OF THE OHIO VALLEY WILL PUSH H85 TEMPS TO ARND 16C   
WHILE SFC DEW POINTS WILL CLIMB INTO THE MID AND UPPER 60S F. THIS   
WILL FURTHER DESTABILIZE OUR AIRMASS THAT WILL ACT TO FUEL THE   
PASSING OF ANY SHORTWAVES FOUND AHEAD OF AN APPROACHING FRONTAL   
BOUNDARY. THIS FRONT OVER THE MID WEST WILL BE CHOCK FULL OF   
WAVES...SO IT WILL TAKE ITS TIME MOVING EAST. THE BULK OF THE DAY   
SHOULD BE RAIN FREE THOUGH AS A MID LEVEL CAP WILL ONLY GIVE WAY TO   
UNIMPRESSIVE MID LEVEL LAPSE RATES <6 DEG C/KM IN THE AFTERNOON...   
SO THIS SHOULD KEEP STORMS FROM BECOMING TOO WIDESPREAD. IT IS WORTH   
NOTING THOUGH THAT STORMS THAT DO DEVELOP COULD BE STRONG AS 06-KM   
SHEAR IS FORECAST TO BE IN THE VCNTY OF 35 TO 40 KTS WITH SBCAPES AS   
HIGH AS 1500 J/KG. WILL INCREASE POPS FROM SLGT TO HIGH CHC BY MID   
AFTERNOON. 

[harrisale]

New slight risk for IN, MI, OH and ON:

 

 

 

 

...MID MS THROUGH OH VALLEY AND LOWER GREAT LAKES REGION...

WITH RICH LOW-LEVEL MOISTURE IN PLACE...THE ATMOSPHERE WILL LIKELY
BECOME MODERATELY UNSTABLE OVER PORTIONS OF OH VALLEY AND GREAT
LAKES PRE-FRONTAL WARM SECTOR. PRIMARY UNCERTAINTY THIS PERIOD IS
EXTENT OF AND PLACEMENT OF ONGOING STORMS AT THE BEGINNING OF THE
PERIOD. CURRENT INDICATIONS ARE THAT STORMS INCLUDING AN MCS OR TWO
MAY BE IN PROGRESS FROM PORTIONS OF THE GREAT LAKES INTO THE MS
VALLEY OR POSSIBLY WRN PARTS OF THE OH VALLEY. STORMS WILL LIKELY
REDEVELOP DURING THE DAY IN WARM SECTOR ALONG RESIDUAL OUTFLOW
BOUNDARIES FROM ONGOING STORMS AND ALONG THE COLD FRONT AND SPREAD
SEWD. WHILE WINDS IN THE SFC-700 MB LAYER ARE FORECAST TO BE WEAK
OVER MUCH OF THIS REGION...SUFFICIENT FLOW AOA 600 MB MAY EXIST TO
SUPPORT AT LEAST ORGANIZED MULTICELLS CAPABLE OF MAINLY DAMAGING
WIND AND POSSIBLY SOME HAIL.

[Chinook]

The SPC has a 30% outlook for southern Minnesota today, and now a mesoscale discussion that covers that area.  Not sure if I should post this here or in the Central/Western forum.

[Brewers]

HRRR has been showing a MCS moving out of MN and diving SE across WI.

[A-L-E-K]

pass

[Geos]

NAM Hi-res showing storms firing over IL, WI, IA by mid-evening tonight.

 

[cyclone77]

Expect some Iowa sub-severe sloppy seconds tonight here. 

[hm8]

Lol @ the slight risk shape right now

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[IWXwx]

Central Illinois is about to get swallowed...waca waca waca waca

 

 

 

I'm still hoping to get in on some severe tomorrow afternoon. If it doesn't happen, round up the usual suspects, dews and debris clouds.

[Geos]

HRRR has been showing a MCS moving out of MN and diving SE across WI.

 

So far that looks to be true. Severe t-storm warnings making there way into WI.

[Minnesota Meso]

Concerning Tuesdays sever threat.  I think the GFS has the right idea that the greatest threat will reside over Iowa and points east during the evening. It's going to be very difficult to get much surface cape values up here in MSP.  I suspect the new 3 day outlook will include MSP  based on the Nam, however that doesn't seem realistic to me.  Looking further at the NAM it seems to agree, but it still brings to much cape this far north.  It looks like IA and points east could be rocking.

 

I will take my crow cooked medium please.  Lots of hail reports knocking out back windows of many vehicles.  Both today's storm and the one on June 21st were somewhat of a adventure for me. I live in the TC north metro in the city of Champlin.  Both days I had to drive to southern MN and pick my mother in Austin to get her to her appointments at the Mayo Clinic in Rochester and get back to my house before the storms.  June 21st was convergence of the storm and my truck in the driveway, today I beat it by about 1/2 hour.  As with 95% of the storms that were cold front initiated since 1989, both storms passed to my south, but just barley.

 

Believe it or not, since my area has plenty of sand, I will have to start watering again.

[cyclone77]

lol @ weird pulse type storms over Iowa tonight.  There's been some very weird storm development/crap out evolutions this evening.  Pretty bizarre considering decent bulk shear and instability in place.  You'd think whatever formed would organize a little better, and not have that "pulsey" aspect.  Looks like a non-event for eastern Iowa and northern IL.  Tomorrow's activity skips over and impacts Indiana and points east.

[wisconsinwx]

lol @ weird pulse type storms over Iowa tonight.  There's been some very weird storm development/crap out evolutions this evening.  Pretty bizarre considering decent bulk shear and instability in place.  You'd think whatever formed would organize a little better, and not have that "pulsey" aspect.  Looks like a non-event for eastern Iowa and northern IL.  Tomorrow's activity skips over and impacts Indiana and points east.

 

It's been even more boring here, haven't had any real good storms here since mid June, almost two months of nothing but an occasional brief heavy rain producer (and I mean ten minute downpours at best).

[cyclone77]

It's been even more boring here, haven't had any real good storms here since mid June, almost two months of nothing but an occasional brief heavy rain producer (and I mean ten minute downpours at best).

 

Yeah overall the "derecho season" so far this year has been pretty wimpy.  Can't complain too much here though, as we did get hit pretty good with one of the few good events of the season back in June.  Overall it's been a pretty lackluster ridge-rider season, but I guess it's not done quite yet. 

[Geos]

That cell exiting Iowa, looks like it's pushing some pretty good heights.

 

Maybe we can shake things up with some tropical remnants a little later in the season. Otherwise, yeah it has been boring as far as t-storms go since June.

[wisconsinwx]

Yeah overall the "derecho season" so far this year has been pretty wimpy.  Can't complain too much here though, as we did get hit pretty good with one of the few good events of the season back in June.  Overall it's been a pretty lackluster ridge-rider season, but I guess it's not done quite yet. 

 

Yep, and we can't really say it's typical of coolish summers, as we've had some good summers for t'storm activity and cool weather (2000, 2004, 2008 to an extent, though that one wasn't that cool).

[Migr17]

THE NATIONAL WEATHER SERVICE IN GREEN BAY HAS ISSUED A

* TORNADO WARNING FOR...
NORTHEASTERN MANITOWOC COUNTY IN EAST CENTRAL WISCONSIN...

* UNTIL 130 AM CDT

* AT 104 AM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED 7 MILES WEST OF TWO CREEKS...AND MOVING EAST AT
100 MPH.

HAZARD...TORNADO...SMALL HAIL AND 70 MPH WIND GUSTS.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE TO
ROOFS...WINDOWS AND VEHICLES WILL OCCUR. FLYING DEBRIS
WILL BE DEADLY TO PEOPLE AND ANIMALS. TREE DAMAGE IS
LIKELY.

* LOCATIONS IMPACTED INCLUDE...
TWO CREEKS AND POINT BEACH NUCLEAR PLANT.
 

Wha...

 

Storms might be expanding on the SW edge of the line as well.  And what a healthy line it is...still.

 

And hi everyone.

[Stebo]

THE NATIONAL WEATHER SERVICE IN GREEN BAY HAS ISSUED A

* TORNADO WARNING FOR...

NORTHEASTERN MANITOWOC COUNTY IN EAST CENTRAL WISCONSIN...

* UNTIL 130 AM CDT

* AT 104 AM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A

TORNADO WAS LOCATED 7 MILES WEST OF TWO CREEKS...AND MOVING EAST AT

100 MPH.

HAZARD...TORNADO...SMALL HAIL AND 70 MPH WIND GUSTS.

SOURCE...RADAR INDICATED ROTATION.

IMPACT...MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE TO

ROOFS...WINDOWS AND VEHICLES WILL OCCUR. FLYING DEBRIS

WILL BE DEADLY TO PEOPLE AND ANIMALS. TREE DAMAGE IS

LIKELY.

* LOCATIONS IMPACTED INCLUDE...

TWO CREEKS AND POINT BEACH NUCLEAR PLANT.

 

Wha...

 

Storms might be expanding on the SW edge of the line as well.  And what a healthy line it is...still.

 

And hi everyone.

 

Probably wrong, however the area between Green Bay and Manitowoc had base velocities of 90kt+ at 1500' with the line forward propagating, if there isn't an inversion and those winds made it to the surface there are going to be some high end reports SE of Green Bay. 

[Chicago Storm]

Might have been a few tors between GB and Appleton as that line passed. There were several couplets and a few DP signatures.

[Stebo]

Might have been a few tors between GB and Appleton as that line passed. There were several couplets and a few DP signatures.

 

Yes I was seeing the same thing, right before the line exploded eastward. That area SW of Green Bay probably had a couple touchdowns.

[SmokeEater]

Severe watch just issued for MI, for that MCS.

[Chicago Storm]

1248 AM TSTM WND DMG 2 NW WRIGHTSTOWN 44.35N 88.19W
08/07/2013 BROWN WI LAW ENFORCEMENT

NUMEROUS TREES DOWN AND POSSIBLE INJURIES AT THE APPLE
CREEK CAMPGROUND.

 

[Stebo]

1248 AM TSTM WND DMG 2 NW WRIGHTSTOWN 44.35N 88.19W

08/07/2013 BROWN WI LAW ENFORCEMENT

NUMEROUS TREES DOWN AND POSSIBLE INJURIES AT THE APPLE

CREEK CAMPGROUND.

 

 

Yeah this was my concern when I saw where it was occurring, that part of WI has a lot of campgrounds. The same with the area in Michigan this is moving into.

[hm8]

Current MCS should slide north/dissipate, allowing SEMI to destabilize nicely. Frontal timing looks pretty damn good and shear as well. Biggest caveat is probably the fact that the front will be aligning more parallel to the flow, decreasing convergence.

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[Boogieman]

FWIW Genesee county under SVR warning until 715AM. At 6:30 we had a nice hail core go right over us, dime to penny size, for probably three minutes and gusts around 60MPH. Still plenty of lightning around. My rain gauge is down as I'm power washing the deck, but eyeballing it, I'd guess we got around .30" or so of rain out of that core in addition to the hail... it got pretty noisy.

 

Had I not been listening to skywarn, I'd have not known about the warning as NOAA weather radio went down. I'd been watching the radar, so I figured it was coming anyway. 

 

Line is now entering Oakland county from the northwest.

 

KIH29 back operational as of 7:06.

[A-L-E-K]

pass

good call

[Powerball]

Yeah, I think I'm going to throw in the towel for today right now.

The morning MCS is weakening, and with only marginally impressive dynamics it's going to take an awful lot of daytime heating to destabilize things for another round of convection this afternoon, which seems doubtful to happen right now with all of the convective debris that will be left behind. We play this game plenty of times, and usually the outcome is the same.