se WI/ne IL/nw IN/se MI lake effect snow event

[KeenerWx]

LSX WRF...

http://www.crh.noaa..../wrfdisplay.php

The thing is very transient according to that run. Would slam everyone basically at some point in time, but would not stay over one area long enough to support MAJOR totals.

[weatherguru]

LSX WRF...

http://www.crh.noaa..../wrfdisplay.php

It looks alot better this for NE IL and shows a nice band of heavy LES in Cook for a while. Looks more confined in NE IL

[Hoosier]

LSX WRF...

http://www.crh.noaa.gov/lsx/wrf/wrfdisplay.php

I might be missing it but does it have a total qpf map?

[weatherguru]

The thing is very transient according to that run. Would slam everyone basically at some point in time, but would not stay over one area long enough to support MAJOR totals.

I see what u mean but before that lake band really gets going it still shows a decent period of LES for Cook, County.

[KeenerWx]

Hopefully tomorrow night we can get ahold of MetTech so he can run us something for this event (only, of course if he's willing and not busy).

[Thundersnow12]

I might be missing it but does it have a total qpf map?

No it doesn't which kinda stinks, thats the IWX WRF that has it I believe.

[Hoosier]

No it doesn't which kinda stinks, thats the IWX WRF that has it I believe.

speaking of which

it's the 12z run as of this post but it should automatically update

[weatherguru]

speaking of which

it's the 12z run as of this post but it should automatically update

It looks overdone though.

[Hoosier]

It looks overdone though.

I've noticed the qpf does tend to run high on some hi-res models. Not sure about this one.

[KeenerWx]

I've noticed the qpf does tend to run high on some hi-res models. Not sure about this one.

Not AS bad...

[Hoosier]

Not AS bad...

When's your call coming out?

[weatherguru]

I've noticed the qpf does tend to run high on some hi-res models. Not sure about this one.

That'd be perfect hit for Lake and Ohare and fluff up to 6-10+ if that pans out with sypnotic/les.

Skilling updated his blog and going with least 2.5 and most 6.1 by Sunday.

My thinking right now with the sypnotic snow in NE IL will be 2-4 inches prehaps up to 6 inches if it ends up a bit furthur NE and stronger but that is being a weenie here but with the combined long period of LES snow regardless if it doesent show a prolonged single classic band of LES I think Lake, Cook, eastern Dupage, Will counties will see total of 4-8 inches with locally more mainly right along the lakeshore. Remember ratios will be higher than 10:1 ratio through a good porton of the event so that will help with boost totals ecp any lake enhancement with the sypnotic snow. NW IN could see up to a foot by Monday as a more northerly flow will help with a more stronger and organized band in NW IN.

It will be interesting to see if LOT ends up going with snow advisory for Lake and Cook counties tommorow night or prehaps even lake effect snow warning. I do think advisory type snows is a good bet mainly in eastern Lake, Cook and ecp Will Counties. LES should kick in after mid-night tommorow night and continue through Saturday and possible a good portion of Sunday.

[KeenerWx]

When's your call coming out?

Probably within the next hour or so. I'm going to get off of here so I can focus.

Then I'll come back and post. Everyone will probably be gone by then, though.

[Hoosier]

It will be interesting to see if LOTS ends up going with snow advisory for Lake and Cook counties tommorow night or prehaps even lake effect snow warning. I do think advisory type snows is a good bet mainly in eastern Lake, Cook and ecp Will Counties. LES should kick in after mid-night tommorow night and continue through Saturday and possible a good portion of Sunday.

I agree that advisory lake snows are a good bet in those counties. I'm trying to remember the last time that Cook/Will were under a Lake Effect Snow Watch or Warning and I can't. I know extreme southeastern Cook flirted with warning criteria on 1/20/09 but LOT didn't upgrade.

[Stebo]

Im actually really looking forward to DTX morning discussion...wondering if we may see several inches here.

Josh I am really wondering the same thing, I could easily see Northeastern suburbs up my way and north being Advisory, with lakeshore counties in warning. Really unusual to say the least however.

[TheWeatherPimp]

Probably within the next hour or so. I'm going to get off of here so I can focus.

Then I'll come back and post. Everyone will probably be gone by then, though.

I'll still be up. I'm wide awake So I'll be waiting and if you get to bored, you can run it by me first on aim haha

[Thundersnow12]

I agree that advisory lake snows are a good bet in those counties. I'm trying to remember the last time that Cook/Will were under a Lake Effect Snow Watch or Warning and I can't. I know extreme southeastern Cook flirted with warning criteria on 1/20/09 but LOT didn't upgrade.

I wouldn't be surprised if they shifted the WAA's further northeast given the qpf amounts on the 0z runs of the NAM/GFS

[TimChgo9]

I am figuring 1-3" on the synoptic snow, and lake effect will give me another 1-3" I think.

I could have 4- 6" on the ground by Monday. that would be way cool..

[weatherguru]

I wouldn't be surprised if they shifted the WAA's further northeast given the qpf amounts on the 0z runs of the NAM/GFS

I mentioned that. Typically these type of systems end up furthur north than progged. So 3-6+ from this sypnotic snow and combined lake enhancement as HI-RES is showing would not be surprised but still sticking with 2-4 for NE IL.

[Chicago Storm]

0z...

MKE:

ECMWF: 0.21"

GFS: 0.32"

NAM: 0.28"

GGEM: NA

UGN:

ECMWF: 0.35"

GFS: 0.37"

NAM: 0.39"

GGEM: NA

ORD:

ECMWF: 0.43"

GFS: 0.35"

NAM: 0.52"

GGEM: NA

GYY:

ECMWF: 0.31"

GFS: 0.35"

NAM: 0.53"

GGEM: NA

VPZ:

ECMWF: 0.25"

GFS: 0.27"

NAM: 0.36"

GGEM: NA

DTW:

ECMWF: 0.08"

GFS: 0.08"

NAM: 0.12"

GGEM: NA

[weatherguru]

0z...

MKE:

ECMWF: 0.21"

GFS: 0.32"

NAM: 0.28"

GGEM: NA

UGN:

ECMWF: 0.35"

GFS: 0.37"

NAM: 0.39"

GGEM: NA

ORD:

ECMWF: 0.43"

GFS: 0.35"

NAM: 0.52"

GGEM: NA

GYY:

ECMWF: 0.31"

GFS: 0.35"

NAM: 0.53"

GGEM: NA

VPZ:

ECMWF: 0.25"

GFS: 0.27"

NAM: 0.36"

GGEM: NA

DTW:

ECMWF: 0.08"

GFS: 0.08"

NAM: 0.12"

GGEM: NA

Looks wetter on each run.

[KeenerWx]

Alright, this is going to be short because I don’t want tospend too much time mulling over details at this point. We are still 24+ hours from seeing any lake response whatsoever, and are about 48+ hours away from seeing the significant stuff. Therefore, things WILL change, and there’s not alot of sense in making a huge effort on the first call. With that said, I did look over stuff for quite awhile so this is my best interpretation of events tocome. In about 24 hours, we should have a much greater grasp as to what’s going to happen.

Because it’s nearly impossible to separate the discussion between LE and synoptic in this thread, I will offer a quick call on the synoptic stuff so you can get an idea of what I’m thinking as for total snow.

Generally, 1-2” across NW Indiana, 2-3” in City and it’snorthern/southern burbs, 3-5” generally along/south of Peoria—Pontain—Watseka.

Now, onto the lake effect..

It seems like we should see some sort of lake response around 24 hours from now. SNSH will be moving off the lake into NE Illinois.Weak as they may be, there will still be some moisture coming off the lake.Therefore, minor lake accumulations COULD start Saturday early AM.

What happens after this fact is left for the imagination.There seems to be three solutions lining up at this point.

1) An organized lake band starts to form by late Saturday into Sunday morning, and impacts NW Indiana for 6-12 hours, before moving off into Illinois during Sunday evening, and then moving back into NW Indiana for the rest of the event (Sunday LATE to Monday afternoon).

2) Pretty much the same thing, except lake bandstays in NE Illinois/extreme Western portion of NW Indiana for much longer (12+hours as opposed to 6-12 hours).

3) Lake band remains unorganized until Sunday.

There are more potential scenarios, however, those are theones that are being pushed the most by recent models.

Anyway, what’s for certain…

· 850’s throughout the event will range from about -8 degrees celcius to about -12 degrees celcius. Given that lake temperatures are around 3.5-4.5 degrees celcius, this puts delta T’s at approximately 12-16. Usually the threshold for any modest lake response is 13. Therefore, we will be playing around with sufficient, yet not significant instability throughout the event.

· Inversion heights will likely be between 4500and 7000 ft throughout the event. Usually, for something major, you would want inversion heights AOA 7500 feet. Towards the end of the event, we get close to that, but never seem to go above 7500 feet. (This is based off of WRF interpretations—may be subject to error).

· Peak instability and best dynamics come together between Sunday early AM and Sunday early evening. During this time period, I might expect the band to be ripping out 1-2” per hour in favored locations.

Some things I want to note:

1) I don’t think we’ll see a mesolow formation. Winds at the beginning are light, but I just don’t see enough coming together for a mesolow.

2) Wind speeds during the peak of this thing will range from about 12-18 mph. This is sufficient enough to displace heaviest totals inland. However, I do not expect significant inland penetration.

3) When it comes down to the final event, I really do not believe we will see a HIGHLY transient band. Will it move, yes. However, I do not see it going all over the place like the STL WRF. Something is telling me that we may see some convergence develop on the south side of Lake Michigan which will keep the band parked over parts of NW Indiana for awhile.

4) Parameters do not impress me too much with this event. What does impress me is the duration. That will be a saving grace to make this event significant. I do not expect this band to be ripping for 48hours straight. Instead, I see a modest lake response for about 24-30 hours and a stronger band formation for about 12-18 hours.

Alright, now for my first stab. Here’s the map. (Yes, I realize the lines aren't perfectly smooth. However, this is what I was envisioning when I was playing out the orientation of the band).

Dark Blue: 1-3”

Light Blue: 3-6”

Purple: 6-12”

Pink: 12”+??? (??? Because I’m not fully convinced on the strength of the band. However, current trends for duration and placement suggest that 12”+ is not out of the question for this area).

[KeenerWx]

I guess it wasn't "short", but it's missing a lot of technicalities. I really would like to see some data for significant lake responses in Cook County and the overall synoptic picture during such an event.

Still think mesoscale models might be displacing the band a little too far west. However, I can't discount their persistence.

I guess something you should know about this "first call" is that yes, I do have an overly large 6-12" range, which will not occur as pictured. However, once I reevaluate the situation tomorrow afternoon, i will finer tune the map. Getting too detailed this far out will do nothing but burn you.

[A-L-E-K]

Thanks for your thoughts Keener, LOT seems to favor the LE starting in NE IL moving into NW IN and then pushing back into NE IL on Sunday before dying. And it's hard not to have too large an area of 6-12" at this range, but i'll be shocked if those amounts push that far west if only based on climo.

[A-L-E-K]

I wouldn't be surprised if they shifted the WAA's further northeast given the qpf amounts on the 0z runs of the NAM/GFS

Not happening, dry air is killing the action the further northeast you go, just as it has all season with this setup. Models have time and time again been too agressive pushing precip into the area. Chicago outside far western suburbs sees 1-2" tops synoptic.

LOT will issue headlines for Lake, Lake, Cook and Porter this afternoon. I don't even know if they have lake snow advisories. Warnings are unlikely.

[A-L-E-K]

hi-res nmm pretty wet and still snowing at hr 48, ARW further north (actually shafts NW IN through 48).

0z 4km WRF good for NE IL as well. starting to see some decent hi-res support.

[michsnowfreak]

DTX still being cautious, saying at the very least occasional snow showers will be cwa-wide. However, like stebo said, I can see this potential being a rare lake effect advisory perhaps for at least part of SE MI (likely warning near lakeshore).

[A-L-E-K]

12z NAM looking pretty good in the LES department for NE Illinois.

[weatherguru]

12z NAM looking pretty good in the LES department for NE Illinois.

Yep and looks to last at least 36hrs.I smell advisories or potential warnings late tonight or tommorow morning.

[tornadotony]

Not happening, dry air is killing the action the further northeast you go, just as it has all season with this setup. Models have time and time again been too agressive pushing precip into the area. Chicago outside far western suburbs sees 1-2" tops synoptic.

LOT will issue headlines for Lake, Lake, Cook and Porter this afternoon. I don't even know if they have lake snow advisories. Warnings are unlikely.

I'm thinking the headlines will likely be LES advisories for Lake IL, Porter, and Will, and LES warnings for Cook and Lake IN.

Keener, your map looks good, but I would shift the axis of 12"+ about 3-4mi south given the decent flow. I would also adjust the 6-12" area accordingly along the IL/IN border and across Lake County IN.