01/31 Possible Winter Storm

I like where the low is located at the mid-upper levels on the GFS but it seems to have the surface Low a bit southeast (which is what the Euro tries to do - to a more dramatic extent). Also GFS is more stingy on moisture than some other models which means the big (8”-plus) totals are more confined and areas away from heaviest snow get more modest amounts.

Two positives and a negative:
Positives: 1.) I’m always told look at the placement of the mid/upper levels to find who will get the best snows and they look to be placed well; 2. rb, who is fantastic with this stuff seems to feel strongly this comes a bit further north which initially looked bad, but not so bad if you compare to the Euro;
Negative: I don’t like that the Euro is kicking this OTS to our south and that the surface on the GFS initially goes that way before getting reeled in, as we’ve missed a lot of action  to our south so far this winter, so that track has been blazed so to speak.

Your difference with GFS and CMC - the former showing a N&W cutoff and latter a widespread Godzilla - is with how they handle the upper level jet.

CMC - neutral trough turning negative. Low pressure tucked into coast as it stays west of the western most point of the jet streak seen over Maine.



GFS - positive tilted trough and an upstream jet streak that is WELL off the east coast. Nowhere close to CMC in terms of upper air structure and low placement.



The Canadian is explosive because of the dynamics aloft. Question is can it be trusted over the GFS and EURO?

I'm starting to see a classic comma head pattern on the 700 mb moisture.  That comes with your bigger storms. The mid level low locations determines where the best CCB forms.

The GFS is dumping very high amounts of snow where the CCB sets up. High order magnitude event. I don't think this is done trending either.

The other thing not mentioned much is the wind. Any pressure gradients will cause at least 35-40 mph winds near the coast. Especially with a slow moving low.

This mornings GFS snow map. These have been all over the place the last couple of days. We should get more of a consensus with tonights runs.

Not a bad look on surface low pressure mean. Trajectory is just inside BM.

6z EURO

Frank_Wx wrote:6z EURO

Well, that's just hideous.

Frank_Wx wrote:6z EURO

ugh well if that's the case I'm go do my plans to CT on Sun mon Tues. Be nice and sunny haha. These models don't have a clue. To buy the cmc over euro would be foolish imo cmc usually overdose things no? And gfs headed toward euro. This may be a swing and a miss for all.

CPcantmeasuresnow wrote:This mornings GFS snow map. These have been all over the place the last couple of days. We should get more of a consensus with tonights runs.

as my mother used to say stop watch twc you will know..in this case on Wed what to expected lol

This is a fascinating case study on how you can give basically the same information to the models and get vastly different outcomes.

The SE press is real. Question is just how far? 12z impor-tan-te

You go south; I'll g north. Sounds like the models are dancing.  It also looks like what snow will be will be heavy in a path to the coast and on either side, not much at all. HeeHaw mentioned the comma; is this something like a bit of a Nor'easter?

dkodgis wrote:You go south; I'll g north. Sounds like the models are dancing.  It also looks like what snow will be will be heavy in a path to the coast and on either side, not much at all. HeeHaw mentioned the comma; is this something like a bit of a Nor'easter?

Yes sir.  Classic Nor easter with the comma.  Here is another link from the weather education archives talking about how and why this happens. Im sure there are folks who have seen us use the acronym , CCB. This discusses those details.  Enjoy the light reading while we wait for the 12z suites initiate.  NAM will be rolling in about 15-20.

https://www.njstrongweatherforum.com/t517-ccb-banding-cold-air-conveyor-belt


Here was the 06z Euro showing this very thing quite nicely.  Just need it to shift 75miles north and 25 miles west...give or take depending on where you live.

The mid-levels of the Euro look good to me. It's just disjointed from the surface. That would consolidate too late for us and get NE. That to me is the difference between it and the other guidance. This may not be resolved until tomorrow quite honestly.

Frank_Wx wrote:6z EURO

This would hurt, but at the same time it would be funny as hell. This would be the all time swing and miss for RB who is pretty spot on most of the time.

I still don't believe anything until tonights runs. I believe the energy involved is just getting sampled on shore today. It's strange that the last two years I've had two one foot storms in December and nothing more than 3 inches from any event in January through April. I was hopeful this could break that pattern. Maybe it will, I think we get a good handle on the late runs tonight.

Actually I don't think the energy gets sampled in the models until 12z tomorrow. Maybe 00z tonight.

CPcantmeasuresnow wrote:

Frank_Wx wrote:6z EURO

This would hurt, but at the same time it would be funny as hell. This would be the all time swing and miss for RB who is pretty spot on most of the time.

I still don't believe anything until tonights runs. I believe the energy involved is just getting sampled on shore today. It's strange that the last two years I've had two one foot storms in December and nothing more than 3 inches from any event in January through April. I was hopeful this could break that pattern. Maybe it will, I think we get a good handle on the late runs tonight.

Here is the NAM's initialization. Energy is all but ashore in the SW. the 12z suites today will likely start to dial in with fine tuning in subsequent runs. We shall see

sroc4 wrote:

CPcantmeasuresnow wrote:

Frank_Wx wrote:6z EURO

This would hurt, but at the same time it would be funny as hell. This would be the all time swing and miss for RB who is pretty spot on most of the time.

I still don't believe anything until tonights runs. I believe the energy involved is just getting sampled on shore today. It's strange that the last two years I've had two one foot storms in December and nothing more than 3 inches from any event in January through April. I was hopeful this could break that pattern. Maybe it will, I think we get a good handle on the late runs tonight.

Here is the NAM's initialization.  Energy is all but ashore in the SW.  the 12z suites today will likely start to dial in with fine tuning in subsequent runs.  We shall see

Yes but per Ray I believe the data they are injected with lags and would not contain, for example, 12z time stamps but possibly 6 hours before that.

CPcantmeasuresnow wrote:

Frank_Wx wrote:6z EURO

This would hurt, but at the same time it would be funny as hell. This would be the all time swing and miss for RB who is pretty spot on most of the time.

I still don't believe anything until tonights runs. I believe the energy involved is just getting sampled on shore today. It's strange that the last two years I've had two one foot storms in December and nothing more than 3 inches from any event in January through April. I was hopeful this could break that pattern. Maybe it will, I think we get a good handle on the late runs tonight.

I am far from being an expert like the model folks here, but this dense cold air was sure to be suppressing this storm somewhat though not like this model has.Hell, I will take the 6 inches at this point being ion the LHV.

Frank I think your right.  Even still looking at satellites at least some of the energy is on the west coast now.

Let's go NAM

Show me the capocollo

sroc4 wrote:Frank I think your right.  Even still looking at satellites at least some of the energy is on the west coast now.  

Oh yea. The initialization itself is accurate. Just think the data being used is a snapshot of 6 or so hours back is all.

So maybe the 00z runs tonight will have it, but I always play conservative and say the next day which would be 12z.

Frank_Wx wrote:

sroc4 wrote:

CPcantmeasuresnow wrote:

Frank_Wx wrote:6z EURO

This would hurt, but at the same time it would be funny as hell. This would be the all time swing and miss for RB who is pretty spot on most of the time.

I still don't believe anything until tonights runs. I believe the energy involved is just getting sampled on shore today. It's strange that the last two years I've had two one foot storms in December and nothing more than 3 inches from any event in January through April. I was hopeful this could break that pattern. Maybe it will, I think we get a good handle on the late runs tonight.

Here is the NAM's initialization.  Energy is all but ashore in the SW.  the 12z suites today will likely start to dial in with fine tuning in subsequent runs.  We shall see

Yes but per Ray I believe the data they are injected with lags and would not contain, for example, 12z time stamps but possibly 6 hours before that.

If that’s the 12z initialization, then everything over the RAOB network in North America should have been sampled and injected in today’s 12z suite. However, I’d contend that the mystery isn’t so much with the energy in the Southwest, but with how the vorticity and associated confluence in Southeastern Canada/New England will behave.

docstox12 wrote:

CPcantmeasuresnow wrote:

Frank_Wx wrote:6z EURO

This would hurt, but at the same time it would be funny as hell. This would be the all time swing and miss for RB who is pretty spot on most of the time.

I still don't believe anything until tonights runs. I believe the energy involved is just getting sampled on shore today. It's strange that the last two years I've had two one foot storms in December and nothing more than 3 inches from any event in January through April. I was hopeful this could break that pattern. Maybe it will, I think we get a good handle on the late runs tonight.

I am far from being an expert like the model folks here, but this dense cold air was sure to be suppressing this storm somewhat though not like this model has.Hell, I will take the 6  inches at this point being ion the LHV.

It's all about the mid level vorticity and jet structure. A stronger short wave combats the confluence and raises heights over the coast. The jet structure will then dictate its exact path and axis of heavier snows.

Frank_Wx wrote:

sroc4 wrote:Frank I think your right.  Even still looking at satellites at least some of the energy is on the west coast now.  

Oh yea. The initialization itself is accurate. Just think the data being used is a snapshot of 6 or so hours back is all.

So maybe the 00z runs tonight will have it, but I always play conservative and say the next day which would be 12z.

So, the times of the model runs, 00z, 06z, etc. are based off of the data cycles. So, for example, this morning’s 12z runs, (which haven’t even been run yet, and it’s already technically 14z) will be based on the 12z data cycle, which includes the upper air sounding data retrieved from the weather balloons launched this morning at ~1030z. They launch them a bit early so that the balloons can run their full course and the data be retrieved, QC’d, and then sent over to DC for archiving/injection into the 12z suite initializations (by 12z). Basically, the models lag the times that they’re labeled by because those labels denote the data cycle that they’re based on, not when the models actually start coming out for us to look at. Does that make sense?