3/1: FCST: Monday on Great Lakes

[nickgrillo]

How many of you are gonna be chasing in the upper great lakes region on Monday? It looks like their will be a risk of severe weather from Illinois to Southwest Michigan with the threat being Supercells with tornadoes and damaging winds. What do the rest of you think of this system and are any of you gonna be chasing that far north?

Thanks,

Nick Grillo

 

[Amos Magliocco]

FCST: 3/1/2004 Illinois-Indiana border region

The Day 3 surprised me. I hadn't thought about Monday's potential until a few minutes ago and have been scanning the ETA ever since. My first impressions are that the setup looks as good as anything going on in Texas tomorrow, maybe better since there isn't the extreme forcing to hasten a linear mode. I'm a southern plains chaser by training and after two years in Indiana, I'm still trying to adjusting to the unusual shear profiles associated with these ejecting systems. They don't always look pretty, but they do produce tornadoes occasionally.

Monday is interesting. Low level shear and LCL's would seem to favor some rotating storms ahead of the cold front, likely fast-moving low topped stuff. With 48 hours to work on moisture return, I could buy into the idea that theta-e values are underforecast on the 12Z ETA. CAPE projections are based on the massive rain shield ETA exhibits over the region, which may or may not come true. Again, the pitfalls of indices.

The very cold midlevels are a sure thing and attendant steep lapse rates certainly warrant attention. For the acutely storm-starved like me, it's a no brainer if the 12Z ETA verifies. Right now I'd guess a target about fifty to one hundred miles west of the Illinois-Indiana border. I'd probably stay on the interstate as long as possible to keep pace with things.

I'm off on Monday and it's close to home, so why not? 8)

Amos

 

[Joel Wright]

By Monday there should be plenty of low level moisture available for the system to work with. The slight risk extends all the way north into northern Illinois! The southeast half of Illinois and far southwest Indiana look pretty good at this point. Further north the surface winds will be backed more, but so will the mid and upper level winds as well, so not much of a gain in that respect. If we can get enough sunshine to poke through and add some additional energy, this may end up being a fairly decent early season event. :wink:

 

[Simon Brewer]

You might condsider heading south into Kentucky, because there might be a mess of warm-air advection precip over Indiana throughout the day on Monday. But further south into Kentucky you might get some clearing ahead of the on going squall-line, and there will be a squall-line. If you do get some clearing ahead of the squall-line then look for gravity waves to initiate low-topped supercells ahead of the squall-line.

This setup happens quite often in the spring and fall east of the Mississippi River, especially in the Ohio and Tennessee River Valleys. If some cells can initiate east of the squall-line given the intense 0-1 km helicity values these cells could easily be tornadic! Even the squall-line could be tornadic as it moves into the great low-level shear in the Ohio Valley.

Simon

 

[George Tincher]

I'll pay close attention to Monday, mainly for the reasons mentioned by Simon. I suspect the worst of the weather will remain to my west over the western-most portions of KY and TN, but you just never know. I figure that at the least, I might encounter a night-time MCS if conditions allow it to hold together that long.

 

[Amos Magliocco]

18Z ETA maps

18Z ETA showed continued improvement in moisture return and CAPE values. This is post-precip passage, according to this run. The late afternoon storm development is forecast after the passage of a weak, elevated line of showers early in the morning. Be interesting to see how it really plays out.


http://weather.cod.edu/forecast/ETA/offeta...S_2_dewp_48.gif

http://weather.cod.edu/forecast/ETA/offeta...S_0_cape_48.gif

Amos

 

[Jon Miller]

I may chase Monday depending on what things look like on Sunday.
I'm go for Indiana over to central Illinois (5 hr drive) if the moisture gets here -dew pts mid 50's or preferably higher. Central Illlinois is a tornado prone area. It is very flat prarie like terrain similar to central and eastern Kansas and they seem to get a higher than normal number of tornadic storms than surrounding areas. Situation seems to be somewhat similar to the Nov 10, 2002 Ohio tornados. - Jon Miller

 

[Amos Magliocco]

0Z ETA update

0Z ETA offers little change from prior runs regarding Monday's setup, though it is worth noting that a wise friend of mine took the time to verify initialization and said ETA overestimated Gulf dewpoints as much as 10F. So we'll see. I'm still planning to chase as of now. No specific target yet.

Amos

 

[Dan Cook]

Forecast discussions from both DVN and ILX stations both mention possibility of tornadoes.

Forecast Discussion for Quad Cities CWA
HWO for Quad Cities CWA

Forecast Discussion for Central Illinois

 

[Simon Brewer]

I have classes on Monday and Tuesday, and I will most likely not be attending those on Wednesday (Texas Storm Chase), but I would be up in the Ohio Valley on Monday.

It looks pretty good!
Simon

 

[Joel Wright]

Things definitely look interesting for Monday. This is far from a perfect setup, but it's the FIRST day of March! :shock:

 

[Simon Brewer]

That's right, the 1st Day of March... it's a good omen!!!!

You guys have to go chase to see what occurs!!!

Simon

 

[Robert Dewey]

Nick... I live here in MI as well, in Rochester Hills, or about 15 miles east of DTX. I just got done looking at the forecast models (FEB/29 12Z ETA) for tomorrow, and it looks like the best instability and shear combo will be in extreme southern WI/northern IL into extreme southwest lower MI. By the time any storms make it further east than that, it will be getting dark, and sfc low will actually be weakening, so I wouldn't anticipate much in eastern MI.

What catches my eye as well, is later next week in the Wed-Fri time-frame. Most models - UKMET/ECMWF/GFS - are developing a very strong sfc low across TX. One thing is for sure, this system will have more than enough moisture to work with, and depending on the exact track, we could be looking at 2 inches of rain or 2 feet of snow...But thats Michigan for ya! (by the way, Detroits record 24hr snowfall occured on April 6 1886, with 24.5", so it can snow late - http://www.crh.noaa.gov/dtx/1886-1974.htm).

 

[Joel Wright]

I'm hoping the low holds off on weakening a bit, which would allow it to hang back in Iowa longer. The GFS inicates this, but the ETA fills it in quicker allowing it to propagate eastward more rappidly. I think the GFS is more on track and I look for the low to still be hanging back in central Iowa around mid afternoon. With the dry/warm slot kicking around the base of the low, and with advancing cold air aloft, I think extreme eastern Iowa and northern Illinois could see a nice low topped event. Due to lack of low level moisture, I look for mainly a hail event with some very weak/brief tornadoes where the moisture has pooled the most. Either way I'm very thankful for such an early season event and will enjoy it as much as I can. Especially since it could snow later in the week!! 8)

 

[Ben Cotton]

Ahhh, it feels so good to be writing chase discussions in February. Not that this is very in-depth, but I didn't post my earlier one (sorry, guys).

0Z model runs are out. The Td situation seems to be improving somewhat...although still nothing to jump for joy over. The BUFKIT soundings have improved the low level moisture as a result...and things don't look as bleak now as they did. Hwvr...still xpecting a hail event...but wl not count out tornadoes. Shear looks pretty good...so if some moisture will pool somewhere...brief spin-ups might occur. If nothing else this shud provide a good opportunity to shake the cobwebs out and field test new equipment. The SDS may abate shortly...I await the first rumbles of thunder. How cool would it be to see my first tornado on March 1 of all days?


Ben