SIGNIFICANT overrunning event OV/NE later this week?

[wxguy25]

Looks that way. Details will be sketchy for the next 2-3 days but suffice to say the POTENTIAL exists for a significant overrunning snow/ice event from central IL, IN, OH, PA / NJ /NY, SNE. Sorry Mid Atlantic Mason-Dixon line southward, this looks like mainly a miss for you.

The system over the lakes this afternoon will move northeastward into SE Canada dragging a cold front eastward across NEW England, which will then stall out during the middle of the week. Weak waves will ride eastward along the QS front, each pushing it SOMEWHAT further south on TUE and WED as weak s/w energy breaks away and ejects eastward from the trough over the SW US.

A STRONG arctic high building over South/central Canada in back of the confluence zone over Quebec/Ontario will dive southeastward helping to drive the front further south on WED and THU as the main s/w ejects out of the SW and phases w/ the northern branch over the upper Midwest. But w/ NO block or 50-50 the s/w will be able to push the high off the coast.

An intense thermal gradient will set up from North to south across the front which means that precip enhancement via frontogenesis combined w/ intense WAA overrunning the cold air will result in a heavy icing event where the subfreezing layer is SHALLOW, and warm advection/isentropic snows in places that the cold air is the deepest.

The 12z ETA and GFS differ on how far south the front/cold air advance as the high builds southward. The GFS as usual was further south w/ LESS QPF and the ETA warmer further north w/ MUCH heavier QPF.

The -10 C isotherm at h85 runs right through the northern fringe of the precip shield across S NY into SNE along the MA border w/ NH and VT, indicating that what precip is falling along the northern half of the precip shield is in the form of snow. ETA 1000-850mb thicknesses indicate ZRA/IP making it all the way into the PHL NW suburbs at 84hrs and into NYC. BOS appears to be all snow. The GFS at 84hrs/0z THU would bring ZRA and IP into NRN MD, DE and into the PHL metro area; w/ P-type all snow From the NW PHL suburbs into C NJ and the rest of N NJ/NE PA/NYC/SNE.

http://www.wxguy.storm2k.org/models/CON ... K_84HR.gif
http://www.wxguy.storm2k.org/models/CON ... K_84HR.gif
http://www.wxguy.storm2k.org/models/CON ... H_84HR.gif

[IndianaWxOnline]

Good discussion. Pretty much similar to my thoughts.

[wxguy25]

Good discussion. Pretty much similar to my thoughts.

Thanks. I was just reading your discussions page and checking out the first call map. You noted:

"the GFS forecast model, which I
personally hate, but unfortunately most forecasters use, at least tv and government forecasters, had the low placed in
Northern Michigan on Tuesday Night and Wednesday"

Agreed 100%. I prefer the heavier ETA QPF given the magnitude of the thermal gradient/baroclinicity developing over a short distance either side of the front. that will significantly enhance ascent and result in heavy precip.

[IndianaWxOnline]

So any suggestions wxguy25 for my site or discussion page, or anything that I can improve on.

I try my best for a 17 year old, haha!

[wxguy25]

So any suggestions wxguy25 for my site or discussion page, or anything that I can improve on.

I try my best for a 17 year old, haha!

Actually, I think it is I who should be asking you what to do to improve my site! LOL!! Secondly I would have never guessed that you were only 17. Keep up that level of work and you will make a phenomenal meteorologist, Brandon.

The only thing that I would suggest is adding some graphics to compliment your discussions. Model images…etc…That way your users will be able to visualize what you’re describing to them.

[Chris the Weather Man]

Good Analysis, wxguy25. I agree with you, I would take any snow at this point....... But hey, like you said, The REAL Fun starts after Jan 20th, if we can get the -NAO....... Which I hope we do.....

[IndianaWxOnline]

Thanks! I will work on adding some model graphcis, etc.

[wxguy25]

Good Analysis, wxguy25. I agree with you, I would take any snow at this point....... But hey, like you said, The REAL Fun starts after Jan 20th, if we can get the -NAO....... Which I hope we do.....

IF the 12z GFS is right then your going to get snow and accumulations. the 12z ETA thicknesses are too warm for SN in C NJ but low-level thicknesses are low enough for ZRA/IP mix and alot of Icing.

the 18z ETA was warmer than 12z BUT w/ over 1.00" of QPF north of the NY/PA border into SNE someone is going to get HAMMERED w/ ice and then Significant snow north of that where the cold air is deep enough.

[Chris the Weather Man]

Not to get off topic here, but the Day 7 Euro still looks quite mild... But of course, this was expected (forecasted). But its COLD in Canada....

[wxguy25]

Not to get off topic here, but the Day 7 Euro still looks quite mild... But of course, this was expected (forecasted). But its COLD in Canada....

D7 Euro looks the same and will continue to unless the ridge breaks down near 150 W or NAO turns negative. Also FWIW, the ECMWF was further north/stronger w/ the SLP area D4 (1004mb over W PA) IF this is correct the warm front would likely push well into new england and parts of S NY, E PA, and NJ would get into the warm sector.

[dvdweatherwizard]

So any suggestions wxguy25 for my site or discussion page, or anything that I can improve on.

I try my best for a 17 year old, haha!

Gracious, I wish I could've had a website like that when I was 17 years old! I think you are clearly way ahead of the ballgame. I am a 22 year old graduate student in meteorology and I have NOTHING like that as far as websites are concerned. I would agree with wxguy25 and say if you keep up that level of work as you get older, you will SUCCEED.

[IndianaWxOnline]

Thanks wizard. I appreciate it. I try my best, but it comes easy, as I just love the weather. Last night, I couldn't sleep at all because of the potential ice storm, so all I did was work on my website and look at forecast data.

[dvdweatherwizard]

Thanks wizard. I appreciate it. I try my best, but it comes easy, as I just love the weather. Last night, I couldn't sleep at all because of the potential ice storm, so all I did was work on my website and look at forecast data.

LOL, that is AWESOME! I have endured many sleepless nights myself during times when the weather was exciting or I thought that the weather could get exciting (whether it be snow, ice, thunderstorms, or just plain rain sometimes if it was heavy enough ), and I will probably have sleepless nights like that the rest of my life too. My parents thought I was a nut when I was growing up and doing that, and some of my friends think I'm nutty too, but I think they have finally come to except it.

[IndianaWxOnline]

Wxguy25, what do you think about the farther northwest, warmer run of the new ETA?

[wxguy25]

Wxguy25, what do you think about the farther northwest, warmer run of the new ETA?

Supports the stronger 12z ECMWF w/ the SLP deeper and further NW. at h5 the s/w is stronger, develops a negative tilt so a closed low develops over the lakes region and the SLP deepens more significantly as the h3 jet maximum rounds the base of the trough.

There were NO Mexican RAOBS in for the GFS so I would toss that run.

AN ECMWF/ETA (relative) consensus is deadly reliable, and i would follow that.

[IndianaWxOnline]

After closer inspection upon the new ETA, even though it is indicating a much farther North track, amazingly, it still produces a major ice storm for Indiana, therefore I am feeling very good about my forecast right now.

But real quick, lets talk a little more about the flooding situation. The models are indicating an extreme amount of rain over the next few days, which will mean flooding problems. Here is the new GFS forecast model, total 60 hour rainfall:
http://indianaweatheronline.com/Models/gfs_p60_060m.gif
If that were correct, parts of the Ohio River Valley would see almost 5 inches of rainfall over the next 60 hours, which is definitely possible.

Now onto the Ice Storm. The ETA which is the farthest Northwest model, is still indicating a major ice event in Indiana, so therefore, I am feeling pretty good about my forecast, as the storm could be farther South or North and we would still get a major winter storm. Here are the ETA projections for freezing rain, the light blue is all freezing rainfall:
http://indianaweatheronline.com/Models/ ... ngRain.JPG
http://indianaweatheronline.com/Models/ ... gRain1.JPG

One last point for tonight. The models are NOT picking up on the shallow cold-air, and its simple to realize that when you have NWS offices that went from Sunny and 60 to cold and freezing rain, now to ICE STORM WARNINGS. The models are not handling the shallow cold air well, they are not handling the southern extent of the cold air well, they aren't handling the storm well!

[dvdweatherwizard]

After closer inspection upon the new ETA, even though it is indicating a much farther North track, amazingly, it still produces a major ice storm for Indiana, therefore I am feeling very good about my forecast right now.

But real quick, lets talk a little more about the flooding situation. The models are indicating an extreme amount of rain over the next few days, which will mean flooding problems. Here is the new GFS forecast model, total 60 hour rainfall:
http://indianaweatheronline.com/Models/gfs_p60_060m.gif
If that were correct, parts of the Ohio River Valley would see almost 5 inches of rainfall over the next 60 hours, which is definitely possible.

Now onto the Ice Storm. The ETA which is the farthest Northwest model, is still indicating a major ice event in Indiana, so therefore, I am feeling pretty good about my forecast, as the storm could be farther South or North and we would still get a major winter storm. Here are the ETA projections for freezing rain, the light blue is all freezing rainfall:
http://indianaweatheronline.com/Models/ ... ngRain.JPG
http://indianaweatheronline.com/Models/ ... gRain1.JPG

One last point for tonight. The models are NOT picking up on the shallow cold-air, and its simple to realize that when you have NWS offices that went from Sunny and 60 to cold and freezing rain, now to ICE STORM WARNINGS. The models are not handling the shallow cold air well, they are not handling the southern extent of the cold air well, they aren't handling the storm well!

I would think the mesoscale models (maybe you should dig up some models such as the WRF or MM5 online somewhere and see what they're going for in terms of sfc. temperatures. Unfortunately I don't have any links right off the bat, but I would be curious about that) or models like the ETA would handle the low-level cold air the best, and even then they might be too warm sometimes at the surface like you are pointing out. That's certainly one point in favor of a significant ice storm for somebody in that region.

[IndianaWxOnline]

Here is the ETA 215 freezing rainfall probabilities, I am still looking at some other models:

Tonight:


Tuesday, looks to be pretty ice across parts of Kansas and Missouri


Wednesday in the Ohio Valley:

[ohiostorm]

So it looks like East Central Ohio will be more then likely an all rain event?

[Guest]

So it looks like East Central Ohio will be more then likely an all rain event?

Hard to say it this point imo but it will be close.

For me this is looking great with the potential for 10+ inches of snow. But even here any slight shift could change the outcome.

Right now it looks like a big ice threat from about i70 north to about i80/90 and north of there looks to be all snow from IL east to about Columbus, OH. Further east is tough to call.

Best chance for big snows would be Chicago, Detroit and Quad Cities area of IA/IL.
Big time icing looks to be Indianapolis, Mansfield, over to near NYC just to the nw.