Jump to content
  • Member Statistics

    16,987
    Total Members
    7,904
    Most Online
    Dankles
    Newest Member
    Dankles
    Joined

August 9-12, 2021 Severe Threats


Recommended Posts

15 minutes ago, purduewx80 said:

This turned out to be the best way to see where and when things would pop today. Pretty much nailed the timing of things coming into ORD if you just followed that vort.

Very much so. And if not for that wave, today would have turned out much differently.

The RAP did very well handling things.

  • Like 1
Link to comment
Share on other sites

7 minutes ago, Malacka11 said:

Good chase day for naders? Pardon the obnoxious question

Higher sup/tornado risk may be getting into North Woods territory but could be decent in central WI over to Green Bay. Probably a conditional risk closer to us depending on boundaries/destabilization, but at least for now anything local may be in the south-moving QLCS overnight.

  • Like 1
Link to comment
Share on other sites

17 minutes ago, purduewx80 said:

Don't see how tomorrow isn't at least an enhanced risk day. Whatever convection is around through the morning will lay out boundaries ahead of the front and increasing shear dropping south. Even the guidance w/ AM storms destabilizes things quickly behind it.

Definitely looks like the 3rd consecutive ENH worthy looking day in a row, across portions of WI/IA/IL as it looks for now.

Link to comment
Share on other sites

30 minutes ago, purduewx80 said:

Don't see how tomorrow isn't at least an enhanced risk day. Whatever convection is around through the morning will lay out boundaries ahead of the front and increasing shear dropping south. Even the guidance w/ AM storms destabilizes things quickly behind it.

Agreed. Much like today, I don't think anyone can argue against the threat of widespread severe weather again tomorrow, especially as there is finally some respectable mid level flow. That, combined with a thermodynamic environment that is in many ways similar to today (perhaps slightly less extreme) should yield, at the very least, a threat for damaging winds in linear segments. 

The part I'm less confident on is how this evolves in the context of supercells. Effective shear should meet or exceed 40kts which is also a breath of fresh air, but there isn't really a ton of directional shear available as winds should be SSWly, even optimistically. Secondly, shear vectors off the boundary are.... not great at ~45 degrees or so. With both those things in mind, the way I see this working out from a supercell/tornado standpoint is for the modeled MCS on CAMs later tonight to throw a boundary and then chase wherever that boundary intersects with the cold front. I'm not sure there's enough directional shear or a high enough chance for a discrete supercell otherwise. 

 

Should note that the HRRR is again overmixing tomorrows dewpoints into the 60s along the boundaries, while consensus has dews near 80, so it can be tossed.

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

8 hours ago, Scorpion said:

Was on top an observation tower on Lapham Peak and wind was definitely hurricane force at times, I kept getting pushed around and was unable to stand up. 

scorpion getting it

anyways, hard to imagine morning stuff by dvn hampering things too much later

Link to comment
Share on other sites

Things still on track for S WI today.  Look for supercells to unzip NE to SW along the front.  Upscale growth will occur after an hour or two with a MCS diving SE through the Chicagoland area.  Wind still the largest threat but tornado and hail potential increased from yesterday

  • Like 1
Link to comment
Share on other sites

scorpion getting it
anyways, hard to imagine morning stuff by dvn hampering things too much later

Concern should increase as time goes on.

The longer that complex festers down in the IA/IL/MO border area and the longer it takes for it to slide east of say the IL/IN border, the larger the hole in instability/DP/theta-e fields we’re going to see.

That was very close to being an issue last evening actually. The fading complex(s) in MO yesterday ended up sending modified air northward, and our MCS barely outran it. There was a large hole in the same aforementioned fields, with DP’s in S IA/ N MO just south of the MCS having dropped from the upper 70’s/low 80’s to the mid/upper 60’s.


.
Link to comment
Share on other sites

Definitely looks like the 3rd consecutive ENH worthy looking day in a row, across portions of WI/IA/IL as it looks for now.

That was as of then...

As of now, parts of WI and MI look the be the only safe choices to include in an ENH risk. I’d hold off on any portions of IA/IL until a later time, if at all.


.
Link to comment
Share on other sites

24 minutes ago, Chicago Storm said:


Concern should increase as time goes on.

The longer that complex festers down in the IA/IL/MO border area and the longer it takes for it to slide east of say the IL/IN border, the larger the hole in instability/DP/theta-e fields we’re going to see.

Definitely a cold pool developing with it. I wonder if the synoptic fields being stronger today will help trigger a quick recovery behind it. Lapse rates and shear are more impressive today, which could help make up for a potential lack of 75-80 dews. As some mentioned last night, the boundary this sends north towards the front should locally enhance sfc vorticity and the wind field, probably in S WI. 

The 06Z HRDPS is doing well with that cluster this morning and shows a quick recovery during the mid- to late afternoon. 

  • Like 1
Link to comment
Share on other sites

Definitely a cold pool developing with it. I wonder if the synoptic fields being stronger today will help trigger a quick recovery behind it. Lapse rates and shear are more impressive today, which could help make up for a potential lack of 75-80 dews. As some mentioned last night, the boundary this sends north towards the front should locally enhance sfc vorticity and the wind field, probably in S WI. 

The 06Z HRDPS is doing well with that cluster this morning and shows a quick recovery during the mid- to late afternoon. 

Good catch with the HRDPS. That might be the only piece of guidance that has a handle on the situation... And as you mentioned, it has solid recovery and the area gets rolled this evening (in addition to a hit later this morning).

SPC did upgrade into N IL to an ENH. I probably would have hedged safer for now and kept the ENH in WI/MI for now, with the ability to upgrade further for the 1630 SWODY1.


.
  • Like 1
Link to comment
Share on other sites

Nearly full sunshine here for the moment, but that cloud deck from the IL MCS is about to encroach from the south. Based on the way it's expanding, it may be around for a while. If it is indeed developing a cold pool, we'll have to hope it can recover. Monday didn't clear out until well into the afternoon, but if I recall correctly those morning storms didn't create an organized cold pool.

Link to comment
Share on other sites

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 AM CDT
FOR KENDALL...NORTHERN GRUNDY AND SOUTHERN KANE COUNTIES...

At 922 AM CDT, a severe thunderstorm was located near Yorkville,
moving east at 65 mph.

HAZARD...70 mph wind gusts. The damaging winds may last longer than 
         30 minutes! 

Link to comment
Share on other sites

Velo is collapsing right before getting to the LOT radar site, so those 70-110mph wind gusts are just off the surface...barely.

Surface stable layer must still be in place. Needed this activity to roll through a bit later, say around noon, to have had better transport to the surface.

Link to comment
Share on other sites

  • Hoosier changed the title to August 9-12, 2021 Severe Threats

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...