December Mid-Long Range Discussion

[Deck Pic]

The important thing I take away from this is there's more of a chance that we could get something frozen next week, whereas before we were at an almost nil chance.

chances have doubled in my opinion...from about 3% to around 6%

[stormtracker]

chances have doubled in my opinion...from about 3% to around 6%

Agreed.

[usedtobe]

There's a nice High in the right spot, but the damn storm keeps getting further west and we die a WAA death.

As I was saying yesterday, I think it pretty much is a lock that the low tracks to our west but we still could see some snow, sleet or rain at onset. I see very little chance of the low tracking to our south even with the models showing so much uncertainty.

[usedtobe]

chances have doubled in my opinion...from about 3% to around 6%

maybe as much as 10% but it still a long shot.

[WxUSAF]

Ugh..that whole run is fugly. EPO ridge is weaker in the long range, cutter after cutter...

[Bob Chill]

I think the gfs looks quite a bit the same as the 12z run yesterday. The only inconsistency is how far west it tracks and how strong the storm is. Nothing new or interesting has shown up to force it east enough to do us any good.

12z shows a pretty potent and wrapped up 500 and 850 low pretty early on. In the vincinity of St Louis. We all know how that works out without a 50-50 / confluence. We need something in place to keep the system from gaining latitude in the midwest. I don't think any model run has shown a feature that can do that the last 3 days or so. IMO- there is consistency.

[usedtobe]

I think the gfs looks quite a bit the same as the 12z run yesterday. The only inconsistency is how far west it tracks and how strong the storm is. Nothing new or interesting has shown up to force it east enough to do us any good.

12z shows a pretty potent and wrapped up 500 and 850 low pretty early on. In the vincinity of St Louis. We all know how that works out without a 50-50 / confluence. We need something in place to keep the system from gaining latitude in the midwest. I don't think any model run has shown a feature that can do that the last 3 days or so. IMO- there is consistency.

Bob, I think that is a good point and is the basis for thinking a track to our south is a pipe dream at least for the storm right after Christmas. The good news if there is any is the models are different enough beyond that storm to not put much stock in the this GFS run and it's endless stream of cutters. That certainly is possible if we don't pop a negative epo and the pna stays negative but both those things are not that certain. Last night's longr range GEFS ens mean did show enough ridging over western Canada to think there might be more cold air around after the new year than we've had so far. .

[Bob Chill]

Bob, I think that is a good point and is the basis for thinking a track to our south is a pipe dream at least for the storm right after Christmas. The good news if there is any is the models are different enough beyond that storm to not put much stock in the this GFS run and it's endless stream of cutters. That certainly is possible if we don't pop a negative epo and the pna stays negative but both those things are not that certain. Last night's longr range GEFS ens mean did show enough ridging over western Canada to think there might be more cold air around after the new year than we've had so far. .

Yea, and we're getting to the point of no return now too. This particular storm is most likely resolved in general terms. The things that we need to happen in this case aren't the types of things that magically pop up. But we can still get some CAD and something on the front so no reason to drop it like a hot potato.

I'm not worried about the post 10 day switch on this run. Sure everything can go to heck on us but I read all of Don S's stuff in the main forum. His reasoning is sound and jumping to conclusions right now with the latest GFS about the next 2-3 weeks is as precarious as thinking last nights shift east was a clear trend towards a coastal.

It's interesting to see many more ensemble members jump on board with the PNA. That's really good to see. I posted the ens chart from 12.18 earlier but here's today's and the 18th's side by side. Much better consensus.

Favorable -AO still looks like a solid bet as we close out this year and start the next. Pretty big spread in the ens on how negative the index gets but that's not nearly as important as the fact that all but one member keep it negative throughout the forecast. Good enough for me.

[WinterWxLuvr]

Yea, and we're getting to the point of no return now too. This particular storm is most likely resolved in general terms. The things that we need to happen in this case aren't the types of things that magically pop up. But we can still get some CAD and something on the front so no reason to drop it like a hot potato.

I'm not worried about the post 10 day switch on this run. Sure everything can go to heck on us but I read all of Don S's stuff in the main forum. His reasoning is sound and jumping to conclusions right now with the latest GFS about the next 2-3 weeks is as precarious as thinking last nights shift east was a clear trend towards a coastal.

It's interesting to see many more ensemble members jump on board with the PNA. That's really good to see. I posted the ens chart from 12.18 earlier but here's today's and the 18th's side by side. Much better consensus.

Favorable -AO still looks like a solid bet as we close out this year and start the next. Pretty big spread in the ens on how negative the index gets but that's not nearly as important as the fact that all but one member keep it negative throughout the forecast. Good enough for me.

Very general would be my comment. This is still at 7 days.

Second bolded.....I'd think jumping to a conclusion from the latest model forecasts beyond 2-3 days is precarious. Ensembles are a different story, but if you've been watching, the GFS by five days has been all over the place with the features that are considered important in determining the weather on the ground.

I'm not sold. I guess the tactic to live by is no, it probably won't be snow. That works about 98% of the time.

[H2O]

Yea, and we're getting to the point of no return now too. This particular storm is most likely resolved in general terms. The things that we need to happen in this case aren't the types of things that magically pop up. But we can still get some CAD and something on the front so no reason to drop it like a hot potato.

I'm not worried about the post 10 day switch on this run. Sure everything can go to heck on us but I read all of Don S's stuff in the main forum. His reasoning is sound and jumping to conclusions right now with the latest GFS about the next 2-3 weeks is as precarious as thinking last nights shift east was a clear trend towards a coastal.

It's interesting to see many more ensemble members jump on board with the PNA. That's really good to see. I posted the ens chart from 12.18 earlier but here's today's and the 18th's side by side. Much better consensus.

Favorable -AO still looks like a solid bet as we close out this year and start the next. Pretty big spread in the ens on how negative the index gets but that's not nearly as important as the fact that all but one member keep it negative throughout the forecast. Good enough for me.

Just getting the PNA to relax some might allow the -AO to flex it's muscles more at least to cool things off, which is a start.

[usedtobe]

Bob, there still are more negative members than I like seeing and the spread is really big so we still could be stuck in a carppy pattern or a much better one. The ens mean I think for he pna still is negative.

Porsche, for some reason I couldn't see the right hand side (the east coast) on the figure you posted.

[Porsche]

Bob, there still are more negative members than I like seeing and the spread is really big so we still could be stuck in a carppy pattern or a much better one. The ens mean I think for he pna still is negative.

Porsche, for some reason I couldn't see the right hand side (the east coast) on the figure you posted.

Thanks Wes, let me know if you can see this one. I made it smaller.

[usedtobe]

Thanks Wes, let me know if you can see this one. I made it smaller.

It's a decent example of a banana. The very best cast would be for the pressures in northern Michigan to be higher than the pressure over northern Maine. Still, you can get a feel for the cooler air wedged east of the mountains north of the warm front that runs from near Norfolk southwestward back towards western SC. If we had a colder air mass in place ahead of the storm it certainly would start as some type of winter weather. This airmass is chilly but isn't really arctic air so it's a tougher call.

[Bob Chill]

Bob, there still are more negative members than I like seeing and the spread is really big so we still could be stuck in a carppy pattern or a much better one. The ens mean I think for he pna still is negative.

Just pointing out a trend in guidance towards a more relaxed pna with the majority of members increasing the value vs dropping it. And it's just a #. I've seen a lot of different looks running the pac 500 loops and unfortunately I must admit that none of them have been great. Some good. Some meh. And some that make me want to drop my pc in the bathtub. But with low expectations any pattern that doesn't rule out frozen precip is fine at this point.

[ezweather]

To me, I think this storm will track further east compared to what the GFS will be showing. This storm will be very significant and will impact many folks. Whoever is to the left of where the low tracks, your odds of getting burried with snow is pretty good. The biggest battle will be handling of that block over Eastern Canada. Of course, we have to see how the trough digs over the US next week, where the ridge sets up over the Western US.. Still so many variables with this event. The other key is how the storm late this will track through the Great Lakes this weekend. I believe this is the one that will get this block going.

Another thing when you look at the GFS and it was noted by other pros out there, is the risk of ice, especially in the Middle Atlantic. I can really do with out this nasty element you get during the winter months. Still too early to get into precip types, but another nasty element to this storm next week.

Anyway, definitely more changes ahead, but we definitely can't discount the risk for wintry weather next week. No doubt, this storm will impact many folks next week.

[Porsche]

It's a decent example of a banana. The very best cast would be for the pressures in northern Michigan to be higher than the pressure over northern Maine. Still, you can get a feel for the cooler air wedged east of the mountains north of the warm front that runs from near Norfolk southwestward back towards western SC. If we had a colder air mass in place ahead of the storm it certainly would start as some type of winter weather. This airmass is chilly but isn't really arctic air so it's a tougher call.

Thanks Wes for the reply, makes sense.

[WinterWxLuvr]

The ensemble members would suggest that there are many different scenarios still on the table, with regard to strength, position, and timing.

[usedtobe]

To me, I think this storm will track further east compared to what the GFS will be showing. This storm will be very significant and will impact many folks. Whoever is to the left of where the low tracks, your odds of getting burried with snow is pretty good. The biggest battle will be handling of that block over Eastern Canada. Of course, we have to see how the trough digs over the US next week, where the ridge sets up over the Western US.. Still so many variables with this event. The other key is how the storm late this will track through the Great Lakes this weekend. I believe this is the one that will get this block going.

Another thing when you look at the GFS and it was noted by other pros out there, is the risk of ice, especially in the Middle Atlantic. I can really do with out this nasty element you get during the winter months. Still too early to get into precip types, but another nasty element to this storm next week.

Anyway, definitely more changes ahead, but we definitely can't discount the risk for wintry weather next week. No doubt, this storm will impact many folks next week.

Even if it does, I think the odds are strongly against the primary low tracking south of DC or PHL or redeveloping off the coast south of either. I don't see enough confluence across new england in the ens mean to support that even though there are a few ens ens members with such a track. I don't think the pattern supports it but I guess we'll see.

[Eskimo Joe]

Even if it does, I think the odds are strongly against the primary low tracking south of DC or PHL or redeveloping off the coast south of either. I don't see enough confluence across new england in the ens mean to support that even though there are a few ens ens members with such a track. I don't think the pattern supports it but I guess we'll see.

Slop fest for Baltimore/Frederick/DC?

[MN Transplant]

Trough looks sharper on the Euro. Doesn't look like that helps us at all, but I only have the freebies. 10°C line flies north of us by Thurs morning.

[Bob Chill]

I don't like the free euro panels because I have to speculate too much so I typically don't provide analysis. However, looks like a step backwards in the pac vs 0z. Stays cold in AK though. Yay!

[Ian]

It's pretty ugly. Then again, it might still end up on the coast if enough people imagine it doing so.

[Ian]

It does drop a bit of snow on the front end for the NW burbs verbatim...

[Ian]

Chicago gets walloped. Big area of 12-18" with a 18-24" bullseye to the south of there.

[usedtobe]

It's pretty ugly. Then again, it might still end up on the coast if enough people imagine it doing so.

It's pretty much back to yesterday solution in terms of track and doesn't argue for much frozen or freezing precip.

[Bob Chill]

It's pretty much back to yesterday solution in terms of track and doesn't argue for much frozen or freezing precip.

I though d10 was pretty ugly too. Back to the same ole same ole.

[usedtobe]

Slop fest for Baltimore/Frederick/DC?

Maybe but my guess is they even would be all rain and if they started as freezing rain or snow would rapidly change over to rain.

[Ian]

It's pretty much back to yesterday solution in terms of track and doesn't argue for much frozen or freezing precip.

Yeah.. looking at just the maps I didn't even expect to see any accum around here but there is a little. That shifted west from last night tho... not to mention clown maps are for clowns especially at this range.

[usedtobe]

Yeah.. looking at just the maps I didn't even expect to see any accum around here but there is a little. That shifted west from last night tho... not to mention clown maps are for clowns especially at this range.

I'd like the models to at least show some potential for a little front end action so I could write article on an actual storm rather than playing the two week outlook game.

[WinterWxLuvr]

Anybody concerned about the Euros 7 day forecast, let alone its 10 day forecast should go check out its 7 day forecast 7 days ago.