Stumbling into a wintry pattern, weenies confused; still shaken from last winter

[Storm At Sea]

DT is probably going to argue that the H5 low is waaay to far west, but I like what I see tonight. This is the first run of the GFS that has had anything within the 180 HR timeframe to watch. I think it may be time for the weenies to come out of hibernation.

[Guest Pamela]

It goes from being good before truncation to being like **** after. This run doesn't make sense. Onto the ensembles.

Not much a fan of Sherlock Holmes, eh?

[RowanBrandon]

DT liked the run:

"AT 192 hrs the GFS appears to be setting up for a major Esst coast Low... BUT after 192 hrs the 0Z GFS fooks things up..."

[andyhb]

DT liked the run:

"AT 192 hrs the GFS appears to be setting up for a major Esst coast Low... BUT after 192 hrs the 0Z GFS fooks things up..."

Not with the SE ridge the GFS has out in front of this thing at 192.

[MJO812]

Not with the SE ridge the GFS has out in front of this thing at 192.

GFS looked good before truncation. After that, it went to ****.

[RowanBrandon]

What southeast ridge?

[Weathergun]

Not with the SE ridge the GFS has out in front of this thing at 192.

Why though, is there going to be a strong SE ridge, with the PV over Maine to begin with?

[MJO812]

0z GGEM is way further east than the GFS

http://meteocentre.com/models/explorateur.php?lang=en&map=na&run=00&mod=gemglb&stn=PNM&comp=1&run2=00&mod2=gemglb&stn2=PNM&hh2=228&fixhh=1&hh=216

http://meteocentre.com/models/explorateur.php?lang=en&map=na&run=00&mod=gemglb&stn=PNM&comp=1&run2=00&mod2=gemglb&stn2=PNM&hh2=216&fixhh=1&hh=228

[MJO812]

0z gefs develops a secondary off the mid atlantic coast and rides northeastward from there. Different than the op.

http://raleighwx.americanwx.com/models/gfsensemble/00zgfsensemblep12204.gif

http://raleighwx.americanwx.com/models/gfsensemble/00zgfsensemblep12216.gif

[andyhb]

What southeast ridge?

With a trough digging that far south out of the west, the ridge to the east is going to be forced to amplify.

[Storm At Sea]

Um, no SE ridge there, bud.

[isnice]

Why though, is there going to be a strong SE ridge, with the PV over Maine to begin with?

That's not the PV, it's an ULL. Still doesn't make sense though.

[NEG NAO]

Euro Ensembles moved west - its obvious we are not going to have any idea how this is going to pan out until we get into the 4 - 6 day range with all the model mayhem going on

http://raleighwx.americanwx.com/models/ecmwfens/00zecmwfens850mbTSLPUS216.gif

[famartin]

GFS shows a cold weekend . Lows in the mid to upper 20s.

That's not really "cold".

[Sundog]

That's not really "cold".

Its actually normal. We are talking about the second half of December.

[NEG NAO]

lets kick this 6Z GFS ensemble image around - is this possible or impossible - a storm cutting into Michigan with a blocking high in southeast Canada ? ?

http://raleighwx.ame...emblep12204.gif

[MJO812]

That's not really "cold".

Colder than what we are seeing now

[cleetussnow]

lets kick this 6Z GFS ensemble image around - is this possible or impossible - a storm cutting into Michigan with a blocking high in southeast Canada ? ?

http://raleighwx.ame...emblep12204.gif

The high was 1040, now it's 1027, it's coming in weaker with subsequent runs, so yes it can cut.

[MJO812]

The high was 1040, now it's 1027, it's coming in weaker with subsequent runs, so yes it can cut.

If the rex block sets up, this storm will have a hard time cutting. If it doesn't, then it will cut.

[Edge Weather]

I don't believe the high ever was 1040mb on an ensemble image. You are probably thinking of an operational run of the model and it is currently progged to be 1048mb at 192 hrs. and over 1040 the entire time it is driving the low into it. There is a very valid question as to whether this storm can really cut into a high of that magnitude, if it is really there of course.

The high was 1040, now it's 1027, it's coming in weaker with subsequent runs, so yes it can cut.

[IsentropicLift]

I don't believe the high ever was 1040mb on an ensemble image. You are probably thinking of an operational run of the model and it is currently progged to be 1048mb at 192 hrs. and over 1040 the entire time it is driving the low into it. There is a very valid question as to whether this storm can really cut into a high of that magnitude, if it is really there of course.

It would be very unusual to get an ensemble mean showing a 1040 MB high. Mostly because it's a blend of all the various members which don't have a high resolution to begin with and then the mean is a smoothed out average of all of them. Therefore there would have to be quite a few members stronger than 1040 in order to get that high of a pressure on an ensemble mean. It would be very unusual to say the least.

[Isotherm]

lets kick this 6Z GFS ensemble image around - is this possible or impossible - a storm cutting into Michigan with a blocking high in southeast Canada ? ?

http://raleighwx.ame...emblep12204.gif

It's possible at 190 hrs on the GFS. At those ranges, a 1004mb low can defeat a 1040mb high with one slap to the face, blindfolded at that. As we approach the time frame, we'll realize that it may take the 1004mb two, or maybe three slaps to the face, to defeat the 1040mb, leaving us with a slightly chillier rain.

[IsentropicLift]

I would like to add that on the 00z Euro you still have a low slamming into a 1036 MB high over SE Canada and if the run went another frame you might get secondary development.

[cleetussnow]

This could wind up going east of course, but I agree with Isotherm. Not east enough to go coastal redevelopment. Could even go up the spine which would be rare.

[NorEaster27]

I would like to add that on the 00z Euro you still have a low slamming into a 1036 MB high over SE Canada and if the run went another frame you might get secondary development.

looks exactly like the Thursday storm of this week.

[MJO812]

DT

"COMMENTS ABOUT 0Z EURO... STILL WRONG ON THE DEC 26-27 LOW

the 0z EURO in my opinion is still WRONG on how it handle the DEC 25-26 LOW coming out of the Delta. "

[Isotherm]

This could wind up going east of course, but I agree with Isotherm. Not east enough to go coastal redevelopment. Could even go up the spine which would be rare.

That post was mostly not serious. My real thoughts are that this is going to try to make a run for the Lakes at least initially, if the data is to be believed regarding a deepening trough in the Rockies. That will pump heights immediately east of the short wave, causing it to begin turning NW much too early for a widespread east coast snow storm. However, I do believe the modelling is probably underestimating the influence of sfc high pressure in Canada. Additionally, as others have alluded to, we need this Friday's storm to remain near the 50/50 region of SE Canada to hold the confluence across the Northeast. Without any confluence, the Christmas event has an open path to cut directly to the Lakes, with zero energy transfer. I think it's going to attempt a cut, but it should secondary somewhere off to the south and east if the confluence is in place. Secondary/energy transfers can be good for us but it's still way too early to be talking specifics. There's no doubt about the improvements in the EPO region which I and others have discussed in the main board winter thread. The cold air should be in place prior to Christmas; it's a matter of keeping that confluence and 50/50 intact over SE Canada so we can force an energy transfer. The amplitude of the trough depicted out West is a bit scary but is to be expected given the -PNA regime. Often times in -PNA/-NAO winters you see many energy transfers, which not surprisingly tend to screw the southeast and mid atlantic while benefiting New England. Sometimes we can get involved as well.

[IsentropicLift]

That post was mostly not serious. My real thoughts are that this is going to try to make a run for the Lakes at least initially, if the data is to be believed regarding a deepening trough in the Rockies. That will pump heights immediately east of the short wave, causing it to begin turning NW much too early for a widespread east coast snow storm. However, I do believe the modelling is probably underestimating the influence of sfc high pressure in Canada. Additionally, as others have alluded to, we need this Friday's storm to remain near the 50/50 region of SE Canada to hold the confluence across the Northeast. Without any confluence, the Christmas event has an open path to cut directly to the Lakes, with zero energy transfer. I think it's going to attempt a cut, but it should secondary somewhere off to the south and east if the confluence is in place. Secondary/energy transfers can be good for us but it's still way too early to be talking specifics. There's no doubt about the improvements in the EPO region which I and others have discussed in the main board winter thread. The cold air should be in place prior to Christmas; it's a matter of keeping that confluence and 50/50 intact over SE Canada so we can force an energy transfer. The amplitude of the trough depicted out West is a bit scary but is to be expected given the -PNA regime. Often times in -PNA/-NAO winters you see many energy transfers, which not surprisingly tend to screw the southeast and mid atlantic while benefiting New England. Sometimes we can get involved as well.

I just feel that the details will change 1000 times between now and when the shortwaves in question actually come ashore. If you wanted to give one model vs another an edge in terms of forecasting relative pressures on a ten day forecast, then of course you would have to side with the Euro thanks to its higher resolution.

Once the models get a better idea as to the strength of the shortwaves involved, things will begin coming into better perspective. I agree that assuming a miller B type setup is the best we are going to do, then you want a weaker parent low.

The models seem to be locked in in terms of phasing occuring over the mid-west and the low closing off and going negative tilt over Oklahoma. So unless the models are very wrong with this phase, redevelopment is the best and only thing we can really hope for.

[MJO812]

looks exactly like the Thursday storm of this week.

240 hours out

[NEG NAO]

Henry thinks the storm is going to cut into the lakes and forgetabout the coastal - so its Henry Vs. DT and JB - who do you think is going to be correct ?

http://www.accuweather.com/en/weather-blogs/meteomadness/snow-and-severe-wx-maps-for-the-storm/2879425