6/19/09 NOW: OH, IN, MI

[Robert Dewey]

6/19/09 NOW: OH, IN, MI, IA, IL

Just had a wind gust up around 50-55MPH as the back edge of this MCS rolled through... low level clouds screaming to the north just off the deck, and enough wind to make small small twigs airborne 50-60 feet AGL.

It wasn't associated with a thunderstorm, so I'm guessing it was post-MCS subsidence or outflow as the MCS collapses.. Hopefully this doesn't interfere with convection later today, or prohibit northward movement of the warm front.

 

[Mike Kovalchick]

Just had a wind gust up around 50-55MPH as the back edge of this MCS rolled through... low level clouds screaming to the north just off the deck, and enough wind to make small small twigs airborne 50-60 feet AGL.

It wasn't associated with a thunderstorm, so I'm guessing it was post-MCS subsidence or outflow as the MCS collapses.. Hopefully this doesn't interfere with convection later today, or prohibit northward movement of the warm front.

I noted something similar of lesser magnitude near Lansing this morning. It was definately a wake low wind event. Nice description of one can be found here:

http://www.srh.noaa.gov/hun/stormsurveys/2009-04-13/index.php

and here: http://en.wikipedia.org/wiki/Wake_low

..."A wake low will often form along the backside of large areas of rain or large complexes of showers and thunderstorms, sometimes known as mesoscale convective complexes (MCS)..."

 

[Chris Hayes]

This big ole MCS blob over Ohio deffinately has me worried. Thankfully, it's only 8 so theres time for it to clear out of here and allow for destabilization to occur if we manage to get into the warm sectore. Latest RUC run progging cape of well over 2000-3000 for much of Ohio this afternoon, with some areas up to 4000. I'm thinking that thats overdone as the latest run of the NAM/WRF is progging CAPE no higher than 3,000. We'll see.

 

[Kevin Bowman]

i would add Iowa and Illinois

Appears to be a supercell in mchenry county il producing very large hail. i dont have my GR on this computer and for some reason storm relative is not working on Wunderground. Base velocity shows a weak rotation in the higher scans. This storm is moving into a extremely heavily populated region on the nw side of the city of Chicago. Roads will likely be jammed with rush hour traffic coming to a end soon.


edit
just tornado warned. strong rotation, moving into heavily populated areas on the nw burbs

 

[mcwell]

Well.... what's the crystal ball saying now for Michigan??? Is it going to get rocking around here or is it headed south or west???

 

[Bill Schintler]

Nowcast: southeast IA

An outflow boundary from earlier storms was aligned along I-80 in central and eastern Iowa, with backed surface flow to the north. This feature was lifting northward at 10 mph. Meanwhile, the synoptic cold front bisected the state from northeast to southwest. Discrete storms have initiated in Tama and Adair counties, ahead of a larger area of convection in western IA.

Strong instability is already in place south of I-80; to the north stability remains limited due to a shield of broken CI and a cold pool from the morning storms. Areas in eastern IA between I-80 and US-30 should rapidly destabilize over the next few hours as mid-70’s dewpoints advect towards the north, beneath moderate mid-level lapse rates of 7-7.5C/km. An enhanced threat of tornadoes will exist along and just north of the aforementioned outflow boundary where backed surface winds increase directional shear along the northern periphery of a 35kt southwesterly LLJ.

-bill
1:20 PM CDT, 06/19/09

 

[Jason Harris]

Indiana seems to be the action right south of MI border. Allen county tornado warning: decent supercell right n. of Huntington moving SE. tornado report earlier in Fulton county.

 

[Jason Harris]

IN: Fountain, Parke, Vermillion Counties. This storm, which has already had a funnel report ("AT 714 EDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO. THIS
TORNADO WAS LOCATED 6 MILES SOUTHWEST OF GESSIE...OR 7 MILES SOUTH OF
DANVILLE...MOVING EAST AT 25 MPH.") is still looking viable and it out ahead of the clusters and lines coming behind. Gessie should be getting it.

*echo tops are up to 65, 000 feet--it would be nice to see some pics of this storm from various distances.
**Looks like now the storm is going to be undercut by the mass behind it. Guess that's it.
***Mesoscale discussion for MI, watch possible, see what might make it over the lake. or around the bend (South Bend, get it? get it?), so to speak.

 

[nickgrillo]

The 4.5km explicit convection WRF didn't handle the current activity currently developing in central/southern very well. Latest RUC mesoanalysis shows strong CINH for surface-based and mixed-layer parcels across southern MI, obviously indicating the current convection is elevated. Onset of nocturnal cooling / boundary layer de-coupling (leading to further increase in convective inhibition and consequently elevating storm inflow layers) would make me believe any convection that develops / moves into in MI tonight wouldn't be capable of producing much more then marginally severe hail and perhaps some locally damaging winds given the strong flow aloft. Even with the strong low-level SRH, the static stability across in central/southern MI would likely inhibit much of a tornado threat (this would include the IN/OH region closest to the MI border).

Well.... what's the crystal ball saying now for Michigan??? Is it going to get rocking around here or is it headed south or west???