Absolute Vorticity

I agree enhanced is prob a given and if these NAM trends continue then a moderate risk not out of the question.

tron777 wrote: ↑Wed Jun 16, 2021 9:51 am I get to deal with this in St Louis for high temps:

Fri - 101
Sat - 93
Sun - 96

Can't wait to get back here for the cooler air resides.

Bro, one summer my folks, sister, maternal grandmother, and I went to visit the St Louis Zoo and of course the high that day reached around 100 lol!

Hopefully if there's any action for here north of I-70 i.e. late Fri that it'll be before sunset!

Day 2 enhanced risk now for I-70 corridor (Friday). In addition to the damaging wind threat, could also see training cells with flooding rains possible.

My call of an I-70 rider is looking very very good at this time. For those of us to the south, I think we'll see it late Fri night and early Sat morning. The first round though for late Fri afternoon and evening is probably going to miss CVG in my opinion. I won't be here to verify this so someone will have to tell me how this pans out. Also, if we do get 89'ed or hit 90 on Friday at CVG, can someone update the contest thread for me please? Thanks!

61 at CVG, 55 here this morning. Perfect!

SPC Discussion highlighting Central IN and Central OH for the highest odds of damaging winds.

...Midwest/Ohio Valley into the lower Great Lakes...
A strong shortwave trough will move into the upper MS Valley during
the day and across the Great Lakes overnight. Moderate midlevel
winds will exist well ahead of this feature, with up to 50 kt at 500
mb across IL, IN, and OH during the day. At the surface, a front
will stall from NE into IA and lower MI, with a moistening air mass
to the south and 65-70 F dewpoints.

Storms may be ongoing Friday morning from IN into OH and western
NY/PA where warm advection will be maximized. The warm front will
move east across OH during the day and into western PA and NY around
00Z, as strongly veered 850 mb winds of 30-40 kt result in rapid air
mass recovery. Conservative estimates are that 2000-3000 J/kg MUCAPE
will extend from the lower MO Valley into western OH, beneath 40-50
kt west/northwest flow aloft. Any morning outflow across OH and
vicinity could result in enhanced low-level shear and supercell
potential with any storms that can redevelop during the late
afternoon near the warm front.

The most likely corridor for widespread damaging winds appears to be
from central IN into central OH, where there is a greater
probability of strong instability. Most CAM solutions initiate
storms over northern IN and OH after 20Z, with east/southeast storm
motions. Merging cells or an MCS may produce damaging winds,
although a tornado or two is possible with cellular activity that
can remain within the better SRH near the old outflows and/or warm
front.

Soundings near Dayton from the NAM and GFS both are looking quite favorable for a line of damaging wind producing t-storms. A hail risk is also present but wind I think is going to be the most prevalent. Also, cannot rule out an isolated tornado either. GFS is an hour or two faster then the NAM but out I-70 Crew certainly looks to be fair game in that 5-9pm window in my opinion.

EDIT: I am also concerned for training storms for a few hours as well. The front is expected to stall out on Sat and lift back north as a warm front Sun. Then, we get it as a cold front again Mon of next week. Lots to watch out for! I think the tropical system largely misses us to the SE and is more of a problem for the SE US, Gulf Coast and TN Valley region.

I found this posted on another weather board by a meteorologist. I have quoted the below since the Met posted this to explain what you're looking at on the image below.

Here is an overlay of the NAM supercell composite parameter (which is normally overdone with CAPE) with 500mb wind barbs on Friday afternoon. The high supercell composite parameters are a result in excellent placement of CAPE/ SRH/ 0-6km shear. This seems like a very good setup for reasonably fast-moving severe storms for NW Ohio and into pretty much all parts of Ohio, and possibly starting off with severe storms in northern Indiana.

Great Posts this morning Les and no doubt the closer we get the better shot of severe weather. How quickly will the mcs lose it punch overnight and where will the leftover flows be located. I agree about possible training of storms and if you get involved with this rainfall totals can produce some flash flooding. Another thing to watch is usually southwest of the main action later Friday as you can get one of those rogue storms by itself and many times can produce tornado's. With the tropical system still getting its act together plus it looks to be well southeast of us this means it probably will not take any of our fuel.

tpweather wrote: ↑Thu Jun 17, 2021 7:41 am Great Posts this morning Les and no doubt the closer we get the better shot of severe weather. How quickly will the mcs lose it punch overnight and where will the leftover flows be located. I agree about possible training of storms and if you get involved with this rainfall totals can produce some flash flooding. Another thing to watch is usually southwest of the main action later Friday as you can get one of those rogue storms by itself and many times can produce tornado's. With the tropical system still getting its act together plus it looks to be well southeast of us this means it probably will not take any of our fuel.

Agreed Tim... We might be capped for a while down here so that's why I am more interested in round 2 for us with round 1 mainly being an I-70 event to perhaps as far south as the N Cincy burbs. I think this call looks pretty good for now.

StormTalk! https://www.wave3.com/2021/06/17/goode- ... -blog-617/

Differences between NAM and HRRR.

For Cincy area, HRRR wants to bring in multiple chances during the day for strong storms before the main Friday night round. NAM keeps us mostly dry until Friday night.

The 6z HRRR looked quite ominous in the flash flood potential along I-70 later Friday night. Need to watch that as well.

Trevor wrote: ↑Thu Jun 17, 2021 8:42 am Differences between NAM and HRRR.

For Cincy area, HRRR wants to bring in multiple chances during the day for strong storms before the main Friday night round. NAM keeps us mostly dry until Friday night.

I agree with the NAM. I think anything that tries to push in our direction will fade out until late Fri night / early Sat morning. That should be our time frame for CVG Land. I-70 Crew... those areas should see multiple rounds of strong to severe storms and heavy rainfall. Wind and flash flooding are big time hazards to our north for sure.

cloudy72 wrote: ↑Thu Jun 17, 2021 8:45 am The 6z HRRR looked quite ominous in the flash flood potential along I-70 later Friday night. Need to watch that as well.

Strongly agree with this for the I-70 Crew.

12Z HRRR continues to paint an ominous picture Fri late afternoon and evening for the I-70 folks. Storms fire up around 6-8pm range for the I-70 Crew. Those linger for a while. New storms get going in Iowa, ILL and IN and those will be the overnight batch into Sat morning for Round 2 that we're watching. So far the call of I-70 taking the brunt of this looks good with Cincy / CVG Land and everyone else getting round two late Fri night / early Sat morning time frame.

EDIT: Again, Wind and flash flooding are the primary concerns for folks say from the I-275 Loop in Ohio towards the I-70 corridor. Eric, Mike, Dce, JP, Bo, etc. etc. All of you guys are at risk here.

12Z NAM is coming in now singing a similar tune. I don't like the bowing segments showing up at all. To me this set up screams damaging winds in that 55 to 75 mph range in gusts. Of course, we try not to hype on our forum, but the data shows what the data shows and you guys to the north of Cincy, need to be on your guard.

Interesting on the Nam is it has the incoming system further north and east which is possible but if this happens and moves faster then the GOM system has a chance to move further north. Lets see the other models before making any kind of decision but it does make sense it the first system is faster and further north and east.

Looks like the GFS has slowed things up a bit to better match the NAM and HRRR as far as timing goes so that's nice to see. Whatever is left of Claudette (if it gets named) still looks to be a swing and a miss to the SE as it tracks thru the TN Valley.

Day 2 SPC outlook still showing enhanced risk from northern Cincy burbs to I-70 and northward tomorrow. An update has been to add a hatched wind area around the I-70 corridor for potential significant gusts (75mph+).

EU still is poopooing the whole event region wide. Its handling of convective situations has gone down the same path as its recent winter woes

Bgoney wrote: ↑Thu Jun 17, 2021 2:19 pm EU still is poopooing the whole event region wide. Its handling of convective situations has gone down the same path as its recent winter woes

From what I can see, the Euro appears to be on its own island for this entire event. It's got the cool down next week and everything but it's handling of the Fri / Sat t-storm event (as you mentioned) is suspect. I think a NAM / HRRR / GFS type of blend is good since those 3 pretty much are in decent agreement now.

Sticking with my call of I-70 for late Fri / Fri evening then further to the south for Cincy and CVG Land for Sat morning or so with round 2. I truly think this is how it's going to play out. Like the hatched wind area from the SPC mentioning gusts to 75 possible. If the data from the NAM, GFS, and HRRR is correct, that is going to be a nice call.

Wow!! Tomorrow just looks downright NASTY!! Could very be reports tomorrow of blown in garage doors, blown windows, shingles off roofs, downed trees / tree limbs, power lines i.e. etc.

Glad the Redlegs are in San Diego this weekend wx wise.

Currently 81 here in G'ville.

ILN has my area progged for 90 tomorrow, ripe and juicy set up for those boomers.

tron777 wrote: ↑Thu Jun 17, 2021 9:49 am 12Z HRRR continues to paint an ominous picture Fri late afternoon and evening for the I-70 folks. Storms fire up around 6-8pm range for the I-70 Crew. Those linger for a while. New storms get going in Iowa, ILL and IN and those will be the overnight batch into Sat morning for Round 2 that we're watching. So far the call of I-70 taking the brunt of this looks good with Cincy / CVG Land and everyone else getting round two late Fri night / early Sat morning time frame.

EDIT: Again, Wind and flash flooding are the primary concerns for folks say from the I-275 Loop in Ohio towards the I-70 corridor. Eric, Mike, Dce, JP, Bo, etc. etc. All of you guys are at risk here.

Thanks Les. Really have not been paying attention to this at all. Heard on the radio today of this possibility. Knew it would be covered here.