March 10-15 Multi Wave Setup

[IWXwx]

1 hour ago, Chicago Storm said:

As Hoosier mentioned...Thermodynamics for the LE setup look good, waters are mild and ice-free, and you have the global models showing substantial LE by western side standards.

Im sure we'll see some crazy high QPF amounts on some of the hi-res guidance when it comes into range.

Definitely one of the best looking lake setups for this side of the lake I can remember.

Is Alek too close to shore to get buried or will that even be an issue?

[Chicago Storm]

Is Alek too close to shore to get buried or will that even be an issue?

Even with near shore temps in the low 40's, it should stay all snow. Only time there may be an issue is Monday during the day, but that's not only a lakeside issue.

[ILSNOW]

chicago prelim snowfall map

http://www.weather.gov/crh/weatherstory?sid=lot#.WMRuKfkrKUk

 

 

URGENT - WINTER WEATHER MESSAGE
National Weather Service Milwaukee/Sullivan WI
245 PM CST Sat Mar 11 2017

...Prolonged period of light to moderate snow expected...

.Snow will spread across southern Wisconsin Sunday evening and not
end until Monday evening over south central Wisconsin. Lake effect
snow will continue the snow into Tuesday for far eastern
Wisconsin. 4 to 9 inches of powdery snow is forecast with the
highest amounts southwest of Madison and over far eastern
Wisconsin due to lake enhanced snow. Modest east to northeast
winds are expected with some blowing and drifting snow to occur.
Motorists can expect snow covered roads and reduced visibilities.

WIZ052-059-060-065-066-071-072-120445-
/O.NEW.KMKX.WW.Y.0010.170313T0300Z-170314T1800Z/
Sheboygan-Washington-Ozaukee-Waukesha-Milwaukee-Racine-Kenosha-
Including the cities of Plymouth, Sheboygan Falls, Howards Grove,
Oostburg, West Bend, Germantown, Hartford, Mequon, Cedarburg,
Grafton, Waukesha, Brookfield, New Berlin, Menomonee Falls,
Muskego, West Allis, Wauwatosa, Greenfield, Franklin, Oak Creek,
South Milwaukee, Cudahy, Racine, and Kenosha
245 PM CST Sat Mar 11 2017

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM SUNDAY TO 1 PM
CDT TUESDAY...

The National Weather Service in Milwaukee/Sullivan has issued a
Winter Weather Advisory for snow...which is in effect from 10 PM
Sunday to 1 PM CDT Tuesday.

* TIMING...Expect snow to develop late Sunday evening and then
  diminish around the middle of the day on Tuesday.

* PRECIPITATION RATES...The heaviest snowfall rates will occur
  between midnight and noon on Monday well inland from Lake
  Michigan...with heavier snowfall rates continuing at times over
  the lake counties into Monday night and Tuesday morning.

* SNOW ACCUMULATIONS...Total snow accumulations of 6 to 8 inches
  are expected with the highest totals in the lake counties. The
  snow will be dry and powdery.

* WINDS / VISIBILITIES...East winds 10 to 15 mph becoming
  northeast 10 to 15 mph for late Monday afternoon and night.
  Gusts up to 20 to 25 mph especially near Lake Michigan. Patchy
  blowing snow and drifting is expected. Look for reduced
  visibilities.

* IMPACTS...Plan on difficult driving conditions...including
  during the morning commute on Monday and Tuesday. East winds 10
  to 15 mph becoming northeast Monday afternoon. Gusts up to 20
  mph with patchy blowing snow and some drifting expected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter weather advisory for snow means periods of snow will
cause primarily travel difficulties. be prepared for snow covered
roads and limited visibilities...and use caution while driving.
The latest road conditions for Wisconsin can be obtained by
calling 5 1 1 or by visiting www.511wi.gov.

[SchaumburgStormer]

URGENT - WINTER WEATHER MESSAGE
National Weather Service Chicago IL
343 PM CST Sat Mar 11 2017

ILZ003>005-008-010>012-019>021-120545-
/O.NEW.KLOT.WW.Y.0003.170313T0300Z-170314T0300Z/
Winnebago-Boone-McHenry-Ogle-Lee-De Kalb-Kane-La Salle-Kendall-
Grundy-
Including the cities of Rockford, Belvidere, Woodstock, Oregon,
Dixon, Dekalb, Aurora, Elgin, Ottawa, Oswego, and Morris
343 PM CST Sat Mar 11 2017

...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM SUNDAY TO 10 PM
CDT MONDAY...

The National Weather Service in Chicago has issued a Winter
Weather Advisory for Snow, which is in effect from 10 PM Sunday
to 10 PM CDT Monday.

* TIMING...Snow will overspread northern Illinois late Sunday
  evening or around midnight and continue through much of the day
  Monday.

* ACCUMULATIONS...3 to 6 inches.

* OTHER IMPACTS...Visibilities will be reduced during heavier
  snowfall. Plan on difficult driving conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of snow
will cause primarily travel difficulties. Be prepared for snow
covered roads and limited visibilities...and use caution while
driving.

&&

$$

[Snowstorms]

1 hour ago, blizzardof96 said:

12z model summary for YYZ/YXU(inches of liquid). My best estimates if station data was not provided.

GFS: 0.6"/0.65"

GEFS: 0.5-0.75"

EPS: 0.5-0.6"

NAM: 0.5"/0.4"

ECMWF: 0.8"/0.7" 

CMC: 0.45"/0.65"

Great analysis. There could be some decent LES enhancement for Oakville-Hamilton area. Winds are not conductive for any LES enhancement for Toronto. However, we'll have to see if we can develop some deformation bands as we get closer. 

 

 

[Hoosier]

LOT going 3-6" for counties near the lake, with additional accumulations beyond the end of the advisory.

[cyclone77]

18z RGEM with a nice corridor of 0.50-0.75" of precip from southwest MN down into northwest IL.  Precip still ongoing as well at the end of the run.  DVN hoisted WS watches for a good chunk of their cwa.

[London snowsquall]

2 hours ago, blizzardof96 said:

12z model summary for YYZ/YXU(inches of liquid). My best estimates if station data was not provided.

GFS: 0.6"/0.65"

GEFS: 0.5-0.75"

EPS: 0.5-0.6"

NAM: 0.5"/0.4"

ECMWF: 0.8"/0.7" 

CMC: 0.45"/0.65"

Thanks for the YXU numbers. 

[homedis]

I have a good feeling about this set up especially here near in N. Chicago suburbs near the lake. I haven't been paying much attention to this system but you all have been a life saver to catch me up lol.

[OHweather]

It looks like we will have partial sampling of our main shortwave for these 0z runs and full sampling for 12z. If there are going to be any last minute significant trends they'd start soon. Also need to watch how the models handle convention over the Gulf or off the southeast coast. 

[Hoosier]

RGEM is wet.

[snowlover2]

56 minutes ago, Hoosier said:

RGEM is wet.

0z GGEM is jucier. IN gets the shaft a bit. 0z GFS was a little better than the 18z.

[cyclone77]

4km NAM incorrectly depicting rain Monday over quite a large area where it will most definitely stay all snow.  Forecast soundings show that only the skin layer has a shot of barely making it above freezing over most of the areas depicted as rain.  For that reason it is likely low-balling snowfall amounts over parts of IL/extreme southern WI/portions of IN.  

The 00z suite held fairly steady for this part of the sub.  Looks like we're pretty locked in for 4-6" of snow.

[HillsdaleMIWeather]

3 minutes ago, cyclone77 said:

4km NAM incorrectly depicting rain Monday over quite a large area where it will most definitely stay all snow.  Forecast soundings show that only the skin layer has a shot of barely making it above freezing over most of the areas depicted as rain.  For that reason it is likely low-balling snowfall amounts over parts of IL/extreme southern WI/portions of IN.  

The 00z suite held fairly steady for this part of the sub.  Looks like we're pretty locked in for 4-6" of snow.

And with lake enhancement someone should likely make a run for 8" plus. 

[Hoosier]

9 minutes ago, cyclone77 said:

4km NAM incorrectly depicting rain Monday over quite a large area where it will most definitely stay all snow.  Forecast soundings show that only the skin layer has a shot of barely making it above freezing over most of the areas depicted as rain.  For that reason it is likely low-balling snowfall amounts over parts of IL/extreme southern WI/portions of IN.  

The 00z suite held fairly steady for this part of the sub.  Looks like we're pretty locked in for 4-6" of snow.

Good catch.  Seems like some sort of error where it thinks the precip type is rain if 2m temps get above a certain level. It looks a bit too aggressive with warming given clouds/precip.  925 mb temps also are around -4c or -5c during the daytime...that'd probably be snow in mid April let alone mid March.  

[Hoosier]

I'm repeating myself but that is an impressive LES signal on the models off of Lake Michigan.  Hard to find much wrong.  In the spirit of not wanting to overlook something, I guess one thing you could point to is some shear in the cloud layer at times, but I don't think it's going to be a huge detrimental effect. 

[Snowstorms]

0z Euro still holds serve (atleast for my region) and shows 8-12" with ratios factored in of (12-15:1, which seems idealistic). This is a contradicting post to what I said in the banter thread. Still loads of time, but hopefully things go well. 

Looks like a model battle. 0z GFS/CMC vs 0Z RGEM/EURO/UKIE/NAM for my region. 0z ECMWF is definitely further West vs 12z. 

Some decent LES enhancement in Chicago as well where Euro had 3-6"+ and around 4-6" for Detroit. 

 

[ILSNOW]

heard euro is a solid hit around here with 7-8 inches and 9 inches by the lake in lake county.

[hawkeye_wx]

That's a strange dry pocket the euro just dropped on eastern Iowa.  I'm assuming what it's doing is keeping the intial heavier surge of snow north, then keeping a second heavier band of snow close to the low as it passes to the south.  I'm hoping it's just a flukey run.

[Chinook]

If you believe the Canadian, with Kuchera snow ratios, (and the Canadian is not always the most accurate model,) this could be one of the most disruptive snow storms of all time with 24-30 for SE Pennsylvania and N. New Jersey.

[cyclone77]

54 minutes ago, hawkeye_wx said:

That's a strange dry pocket the euro just dropped on eastern Iowa.  I'm assuming what it's doing is keeping the intial heavier surge of snow north, then keeping a second heavier band of snow close to the low as it passes to the south.  I'm hoping it's just a flukey run.

Looked like one of those typically dry Euro runs we get sometimes.  Model QPF dropped off over a large region, with the exception of up in parts of southern MN/northern IA.  High-res guidance is still looking pretty solid.  I'd bet the 12z EC comes back in a little wetter than this run.

[michsnowfreak]

DTX going 3-5" here. Unlike most of our snow events this winter, it will be a long duration light snow, however I think March sun angle is irrelevant with the temperatures. Will be like a nice snow globe day probably.

[Ottawa Blizzard]

Looks like snow totals have dropped off significantly for Toronto, at least as per the GFS and NAM.  If those models are right, we'll be lucky to see 2" out of this.

[Powerball]

7 hours ago, Chinook said:

If you believe the Canadian, with Kuchera snow ratios, (and the Canadian is not always the most accurate model,) this could be one of the most disruptive snow storms of all time with 24-30 for SE Pennsylvania and N. New Jersey.

Honestly, can't say I'm not jealous.

 

[ILSNOW]

Chicago NWS  from early morning  on possible lake effect. 12z NAM says no.

 

 

The surface low will move northeast across the Ohio valley tonight
into Tuesday before it eventually gets absorbed a deep nor`easter
low off the Atlantic coast. As this process occurs, cold upper
level low pressure will build southward through the upper Great
Lakes and strong arctic surface high pressure will move into the
Upper midwest. Several important pieces of the puzzle are coming
together to support our first organized lake effect snow event of
the season. This process will allow some very cold air to return
to the region, and will create steep low level lapse rates due to
the relatively "warm" lake. 850 Temp to lake surface temperature
differences are about 15 to 18 C, which is pretty decent. These
steep lapse rates appear to extend over a deep moist low level
layer. Lake induced CAPE values reach in excess of 500 J/KG and
equilibrium levels up to 10000 ft or so are also strongly
indicative of the potential for effective snow producers. With the
strong high to our northwest and a nor`easter low, this is a
favorable synoptic setup for our area for the development of lake
effect snow into Illinois and for the possibility of a convergent
band.

The complicating factor is that these situations are highly
contigent on the development of a stronger single band for the
higher impacts, and this is highly contigent not only on the
development of a low level convergent axis, but how long that axis
lingers in one area. The GFS/GEM depict a strong convergent axis
pointed into northeast Illinois for an extended period of time.
If this were to occur in conjunction with the increasingly
favorable thermodynamic environment, some heavy snow showers would
be expected. The EC does too but is more transient. What
decreases confidence is that the NAM is more progressive with this
convergent axis and does not linger it as long, but has several
transient periods of synoptic/lake enhancement Monday night and
again Tuesday afternoon in Illinois, but has the convergent axis
focused a bit farther east more into southern Cook county
eastward into Indiana. The 6z NAM is not that impressive either.

Confidence and Headlines: We feel confident there will be lake
effect snows regardless of how long they last, but certainly
impacts hazard decisions. These situations are challenging, even
at a shorter distance, but a signal is there for a potentially
significant event if things come together. The lake effect will
also shift into Northwest Indiana where conditions remain
favorable for at least occasional snow showers through the day
Wednesday, possibly significant as well. It is possible we will
need to handle this event with a separate headline. We do taper
the advisory towards Livingston county the earliest once rates
ease and temperatures become marginal, hold onto areas away from
the core Chicago metro through the day, with the highest impacts
on the earlier side. Finally, we have not changed the end time of
the lake adjacent counties yet (late Monday evening) as this will
be the time synoptic snows ease in Indiana, while lake effect
processes begin to ramp up in WI and NE IL. Did not have high
enough confidence to do a lake effect snow/winter storm watch for
lake effect snow in NE IL just yet, though it is conceivable one
could be issued as we get closer. And for Indiana, it as mentioned
earlier significant snows could fall there from lake effect but
the time window is more Tuesday into Wednesday. It is also
possible that the advisory could be extended for a transient but
potent band of snow (note: Milwaukee has their advisory for the
whole event to cover both the synoptic and lake effect). We have
chosen to not run out a long drawn out advisory at this point as
there could be a break, and due to the higher impact potential of
round two.

[Baum]

^

seems odd the NAM is such a negative outlier on the lake effect potential into Chicagoland. Discussion notes NAM's reluctance to show an event. Wonder what gives?

[buckeye]

Looks like a close call here.  I-70 seems to be the dividing line between mix and snow.  12z Nam has come in further south though.

On another note, the DC folks must be biting their nails.... I could see them getting anywhere from a heavily-tainted 2" to 18"...and maybe you only have to walk a block to see the difference... lol.

[buckeye]

9 hours ago, cyclone77 said:

4km NAM incorrectly depicting rain Monday over quite a large area where it will most definitely stay all snow.  Forecast soundings show that only the skin layer has a shot of barely making it above freezing over most of the areas depicted as rain.  For that reason it is likely low-balling snowfall amounts over parts of IL/extreme southern WI/portions of IN.  

The 00z suite held fairly steady for this part of the sub.  Looks like we're pretty locked in for 4-6" of snow.

I noticed this here too.   NAM was showing rain in places where the 700, 850, were all well below normal the entire time.   Surface temps were slightly above freezing but nothing more than a couple of degrees.

Maybe a met can chime in?

[Trent]

I don't think I've pulled out the SREF plumes all season, but they're now up to a mean of 10" for CLE with 7 members over 15" and a 31" outlier total just for laughs . Mean at DTW is just under 8" with that same outlier at 26". ORD with a mean of about 6".

[HighTechEE]

12 minutes ago, buckeye said:

I noticed this here too.   NAM was showing rain in places where the 700, 850, were all well below normal the entire time.   Surface temps were slightly above freezing but nothing more than a couple of degrees.

Maybe a met can chime in?

ILN is calling for almost all rain for KDAY tomorrow into the evening and the 850s never gets above -5C?