Dec 29-Jan 2 potential storm event

[Snownado]

Indy is only at 27 at 1pm and the forecast high is 35. Not sure it will even make it to the 30 today. 

[Hoosier]

18 minutes ago, Hoosier said:

We'll see what the Euro shows shortly.

Don't have the better maps but it looks pretty icy.

[Chicago Storm]

Don't have the better maps but it looks pretty icy.

 

 

 

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[Baum]

those seem like higher amounts. Verbatim. .10 ice/.5 sleet/ and 2-3 " snow FMBY. Winter Storm Worthy. Bring it south, and I'll take the all snow scenario.

[Chicago Storm]

One thing to consider for portions of SE IA and N IL, is that many locations still have ice on trees (etc) from the first storm.

Around here there’s still a solid glaze on trees, and I’d guarantee areas well to the W/SW that picked up 0.25-0.50” of ice definitely have more on the trees.

Could lead to more sig issues overall out that way.


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[Cary67]

20 minutes ago, Chicago Storm said:

 

 

 

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Looks like I'm golden again.lol

[michaelmantis]

Just now, Chicago Storm said:

One thing to consider for portions of SE IA and N IL, is that many locations still have ice on trees (etc) from the first storm.

Around here there’s still a solid glaze on trees, and I’d guarantee areas well to the W/SW that picked up 0.25-0.50” of ice definitely have more on the trees.

Could lead to more sig issues overall out that way.


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I was just looking out the window and thought the same exact thing.

There is still a glaze as well as branches covered in ice. The lack of sun and wind has meant nothing has knocked off.

If temps stay marginal and turns out extreme N IL gets ice and not snow that could get bad pretty quickly. 

[SchaumburgStormer]

2 minutes ago, Chicago Storm said:

One thing to consider for portions of SE IA and N IL, is that many locations still have ice on trees (etc) from the first storm.

Around here there’s still a solid glaze on trees, and I’d guarantee areas well to the W/SW that picked up 0.25-0.50” of ice definitely have more on the trees.

Could lead to more sig issues overall out that way.


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Still probably .2” on many trees out here. Didn’t get warm enough long enough yesterday to lose much 

[McHenrySnow]

1 minute ago, michaelmantis said:

I was just looking out the window and thought the same exact thing.

There is still a glaze as well as branches covered in ice. The lack of sun and wind has meant nothing has knocked off.

If temps stay marginal and turns out extreme N IL gets ice and not snow that could get bad pretty quickly. 

That's interesting because we don't have any ice on the trees around us. 

[michaelmantis]

Just now, McHenrySnow said:

That's interesting because we don't have any ice on the trees around us. 

Not sure where in McHenry county you are but I'm 3 miles south of I90 on Randall Road and every tree has ice on it still, branches (and Christmas lights) totally encapsulated in ice.

This next storm setup looks to be similar to the last one, minor temp differences and precip types/intensity may vary over a relatively short distance. 

[McHenrySnow]

3 minutes ago, michaelmantis said:

Not sure where in McHenry county you are but I'm 3 miles south of I90 on Randall Road and every tree has ice on it still, branches (and Christmas lights) totally encapsulated in ice.

This next storm setup looks to be similar to the last one, minor temp differences and precip types/intensity may vary over a relatively short distance. 

I'm in McHenry. Maybe we were far enough north that we got more sleet than freezing rain so the freezing rain we got melted more easily. Not sure, but there really isn't much out there. 

[Cary67]

No ice or very little on the trees here in Cary either

[IWXwx]

17 hours ago, RCNYILWX said:

Would recommend looking at the 00z HREF page tonight for freezing rain tomorrow night into Friday. They recently added 3 hr and 24 hr FRAM mean ice accumulation to the winter parameters. FRAM (freezing rain accumulation model) is what we use in the NWS for ice accums and it's much more sophisticated than the QPF to ice accums that's available on COD, Pivotal Wx, WeatherBell, etc.

Here's a link to a pdf about the FRAM if you're interested in learning more:
https://www.google.com/url?sa=t&source=web&rct=j&url=https://vlab.ncep.noaa.gov/documents/10157/137122/FRAM_VLAB_Presentation.pdf/50ff7877-c52d-80f4-1413-b294db7710e9&ved=2ahUKEwjUmoSJ8_btAhV6B50JHVLaDZYQFjAAegQIBBAC&usg=AOvVaw2fMu-m4aPPk_bnXxwA6ivl&cshid=1609372449468

Sent from my SM-G965U using Tapatalk
 

Thanks for the link to the HREF page and the link. The pdf does a good job of explaining what and why data is ingested into the model. The output seems more reasonable than the sites mentioned above (at least without paying for the data).

[Hoosier]

9 minutes ago, Chicago Storm said:

One thing to consider for portions of SE IA and N IL, is that many locations still have ice on trees (etc) from the first storm.

Around here there’s still a solid glaze on trees, and I’d guarantee areas well to the W/SW that picked up 0.25-0.50” of ice definitely have more on the trees.

Could lead to more sig issues overall out that way.


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Good point.  Hopefully that is factored in to the NWS advisories/warnings in some way.  In some areas that have leftover ice, getting a quarter inch of ice may be more like getting a half inch, or getting a half inch may be more like getting three quarters, etc. 

[Chicago Storm]

One thing to consider for portions of SE IA and N IL, is that many locations still have ice on trees (etc) from the first storm.

Around here there’s still a solid glaze on trees, and I’d guarantee areas well to the W/SW that picked up 0.25-0.50” of ice definitely have more on the trees.

Could lead to more sig issues overall out that way.


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To prove my point, these pictures below were just taken in Steward IL...




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[DaveNay]

4 minutes ago, Chicago Storm said:

To prove my point, these pictures below were just taken in Steward IL...




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Exactly what my trees look like (due east of Steward on Perry Rd)

[NEILwxbo]

28 minutes ago, Chicago Storm said:

One thing to consider for portions of SE IA and N IL, is that many locations still have ice on trees (etc) from the first storm.

Around here there’s still a solid glaze on trees, and I’d guarantee areas well to the W/SW that picked up 0.25-0.50” of ice definitely have more on the trees.

Could lead to more sig issues overall out that way.


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In DKB there’s a lot of small branches down from the other night, still about 0.25” of ice on just about every surface. If any freezing rain gets that far north could be bad

[kevlon62]

I'm in McHenry. Maybe we were far enough north that we got more sleet than freezing rain so the freezing rain we got melted more easily. Not sure, but there really isn't much out there. 

I think that explains it. About halfway southeast driving down to Crystal Lake yesterday there was a noticeable difference in ice. Like the icicles all along the bottom edge of street signs started showing up, along with noticeable glazing on the trees and shrubs. That icing zone sounds like it tapered off further toward Cary.

Looks like another corridor wild card event tomorrow.

Sent from my SM-N960U using Tapatalk

[WeatherMonger]

ILX late morning AFD update.

 

Quote

.UPDATE...
Issued at 1103 AM CST Thu Dec 31 2020

Looking over much data this morning, there appears to be a favor
towards slightly shifting the track of tonight`s system to the
southeast. This would introduce the highest icing potential
between the IL River Valley and say around I-72. This track would
also include an increase in snowfall across the nw portion of the
CWA from the IL River Valley nw. Rainfall will still persistent
across the se CWA, however the chance for light freezing rain at
the onset is possible. Will continue to monitor models, and
complete the afternoon package with changes to the Winter Storm
Watch/Advisory. Did discuss the potential for Ice Storm product,
however this is not used as much as Winter Storm products

 

[Hoosier]

The backside changeover to snow prospects are getting my attention more.  Depending on how much ice there is and how much melts before the changeover to snow, that could be an added thing to stress the trees as whatever falls on the backside looks to be a wetter snow variety around here.

[Hoosier]

Congrats Alek 

[RCNYILWX]

Congrats Alek 

This might be worst/best case scenario, but was thinking that even for the areas that get more snow and sleet plus some ice, going to be very dense, high water content stuff, so the impacts would be more than those snow amounts would typically entail, along the lines of your thinking.

 

 

 

[sbnwx85]

Good write up from IWX. 

Area Forecast Discussion
National Weather Service Northern Indiana
246 PM EST Thu Dec 31 2020

.SYNOPSIS...
Issued at 246 PM EST Thu Dec 31 2020

Dry conditions tonight will give way to a round of wintry weather
on New Years Day. Precipitation will begin as an icy mix Friday 
morning, changing to all rain from south to north Friday 
afternoon into Friday evening. Roads will likely become very 
slippery for a time until temperatures warm above freezing. Quiet 
weather on Saturday is then followed by a chance for snow Saturday
night into early Sunday. 

&&

.SHORT TERM...(This Evening through Friday Night)
Issued at 246 PM EST Thu Dec 31 2020

Ice accumulations/impacts remain the primary concern on New Years 
Day as a moisture-laden stacked low kicks north to Missouri, then 
opens east-northeast through central IL/IN and northwest OH later 
Friday into Friday night. The main slug of moisture (and organized 
precip shield) tied to leading isentropic ascent and strong 800-600 
mb fgen is expected to lift north into our IN/OH counties btw 12-15z 
Fri, and into MI by 15-17z. At the surface, easterly winds will 
unfortunately maintain temps near to just below freezing as the 
approaching storm system forces a corridor of moist and warm air 
over it. The result will be a wintry mess, with the potential for 
some snow and sleet to mix in initially thanks to wet bulb cooling. 
The best chance for sleet/snow to hang on more than an hour or so is 
across far northern zones as 12z models did come in a farther south 
with the track of the system, and thus slightly cooler warm nose 
temps into lower MI. 

A very quick transition to freezing rain is expected elsewhere as 
the warm layer exceeds 5C over a rather shallow/marginal near sfc 
layer. How quickly the freezing rain transitions to rain and 
potential impacts (ice accretions) remains sensitive to the near 
freezing sfc temps. Confidence is high for at least a 3 hour 
duration of freezing rain, and medium confidence in a 6 hr or 
greater period as sfc temps try to creep up to 33-34. As for ice 
accums, possible limiting factors include warm droplets having 
trouble freezing and heavier rainfall rates. Given these lingering 
uncertainties, opted to hold pretty close to the previous forecast 
on timing and ice accums, generally 0.10-0.25" which lines up nicely 
with the WW.Y. There remains some potential for ice accums to 
overachieve (>0.25; Ice Storm Warning) in mainly ne IN, far nw OH 
and south-central MI if the colder solutions and longer fzra 
duration verify. If these higher end ice accretions verify there 
could be a low threat for isolated power outages as easterly winds
will gust 20-30 mph for a time.

Precipitation should trend more drizzly from south to north 
approximately 21z Fri-02z Sat before the main low pressure system
tracks through with more organized precip Friday night. Some wet 
snow could mix back in Friday night across far nw IN and lower MI 
within the system trowal/deformation axis. Little to no snow 
accumulation is expected, though some additional light icing 
cannot be ruled out Friday night mainly along/north of US 6 as sfc
temps linger near freezing. 

&&

[vortex]

Wind gusts to 30 mph tomorrow with the ice too won’t help matters.  

[purduewx80]

Still a lot of disagreement on the temp profile, but with the TROWAL (trough of warm air aloft) feature and compact upper low moving in, there will be some convective elements to the precip shield. With all of that, there should end up being a narrow band of +SN that pivots nearby later tomorrow evening. 

[MIstorm97]

Temp profile still is questionable here in SE MI. Small differences in the strength and depth of the warm nose will mean the difference between sleet and freezing rain here. Plus the onshore easterly surface flow will keep areas east of the glacial ridge, including the immediate Detroit area, slightly warmer. Areas along and west of the glacial ridge certainly have a greater risk of more significant ice accretion. This is demonstrated well in the 12z HREF mean FRAM accretion, with <0.1" accretion in Detroit, 0.1" imby, and 0.2-0.3" along and west of the glacial ridge. A WWA was just issued by DTX, which at this point is a good call. That pivot band of snow on the backside of this storm looks to pass over here after hitting the Chicago area. Going for an imby call of 0.1" of ice accretion and a couple tenths of sleet for the Friday afternoon/evening period, followed by some rain, and then transitioning back to wintry precip with 1.5" of snow falling. The trailing vort on Sunday looks good for 1-3" of snow as well.

[WeatherMonger]

We're running about 3-5 degrees below forecast highs today. Doesn't look like we'll get above freezing

 

 

[WeatherMonger]

New WPC Ice Accrual map

 

[Natester]

Just now, WeatherMonger said:

New WPC Ice Accrual map

 

Wouldn't be surprised to see substantial power outages in Missouri and Illinois tomorrow, especially with the wind gusts forecast to be at or over 35 mph.

[Hoosier]

12 minutes ago, Angrysummons said:

Temps will warm through the night. Poor job by forecasters, who should realize this. They will bust too low this evening.

Trends overnight are definitely more important than what is happening right now.  I agree with that.  NWS has a low of 26 for Springfield tonight, which will probably end up being relatively close considering it is 27 there now.