December Med/Long Range Discussion

[CAPE]

This certainly could work out  with a decent front end thump then flip, but its just a tough pattern.  Best odds are obviously NW of the cities. We have pretty much seen the whole  range of possible outcomes in the guidance now, but with no blocking and a -pna, so much has to go right to get appreciable frozen, esp for the cities and east. 12z Euro yesterday was a best case. What it offered up at 0z is much more likely given the set up.

[Wonderdog]

FWIW, we get some pity light snow on Christmas Eve, at least for now. Need the major models to come around to the CMC. But, the reality of it is that the models are coming around to a typical December in the mid Atlantic, I'm afraid. The battleground area is to our northwest until usually January. Models seem to overestimate the extent of the cold air as we get closer to an event, especially early in the season.

[mdsnowlover]

36 minutes ago, Wonderdog said:

FWIW, we get some pity light snow on Christmas Eve, at least for now. Need the major models to come around to the CMC. But, the reality of it is that the models are coming around to a typical December in the mid Atlantic, I'm afraid. The battleground area is to our northwest until usually January. Models seem to overestimate the extent of the cold air as we get closer to an event, especially early in the season.

gfs had  rain, para light snow ill take the light snow  thank you

[CAPE]

Pattern going forward on the means towards Xmas and beyond features trough over AK and generally higher heights for all of the east. I am ok with a bit above normal temps for the holidays but please not 70 lol. All remains to be seen but the milder look continues to be advertised.

[showmethesnow]

8 minutes ago, Wonderdog said:

FWIW, we get some pity light snow on Christmas Eve, at least for now. Need the major models to come around to the CMC. But, the reality of it is that the models are coming around to a typical December in the mid Atlantic, I'm afraid. The battleground area is to our northwest until usually January. Models seem to overestimate the extent of the cold air as we get closer to an event, especially early in the season.

The last few weeks you could for the most part looked at the extended forecasts on the models  and then shift everything 200-300 miles or even more westward for verification. Problem in my mind has been that the models in the extended keep trying to shift the mean trough eastward but in reality it hasn't occurred. Until we have that happen we are going to be fighting for every flake we get. And now the extended on all 3 models are advertising a fairly substantial warm up in the extended and it is moving up in time. All in all just a typical mid-atlantic winter.

[MN Transplant]

The 06z GFS runs DPs from the negative teens to near 60 in less than two days.

[WinterWxLuvr]

Poor euro.  Getting schooled by the gfs.  

Looks like a small frozen to rain event now. I guess next up is the day 10 event. The gfs has this also to an extent.  

These highs sliding right off the coast are killing us. Just wish one could park itself over the ne.

[Scraff]

I wake up with the only the Canadian up against the world? Meh. Can hope for the theory that every squirrel finds its nut.....or becomes road kill (breakfast in WV).  ;-)

[osfan24]

51 minutes ago, WinterWxLuvr said:

 Poor euro.  Getting schooled by the gfs.  

Looks like a small frozen to rain event now. I guess next up is the day 10 event. The gfs has this also to an extent.  

These highs sliding right off the coast are killing us. Just wish one could park itself over the ne.

Could just be me, but it seems that the GFS is embarrassing the Euro lately. So much for all those predictions of a fast start to winter. Looks like it's going to be a very average December overall for us.

[mdsnowlover]

2 minutes ago, osfan24 said:

Could just me, but it seems that the GFS is embarrassing the Euro lately. So much for all those predictions of a fast start to winter. Looks like it's going to be a very average December overall for us.

that was JB and his winter forecast of cold and snowy dec., the bathtub slosh theory

[Scarlet Pimpernel]

1 hour ago, MN Transplant said:

The 06z GFS runs DPs from the negative teens to near 60 in less than two days.

Wow, from desert-like dryness (but cold) to sweltering humidity!  DPs pushing 60 reminds me of Christmas Eve last year...

 

10 minutes ago, osfan24 said:

Could just be me, but it seems that the GFS is embarrassing the Euro lately. So much for all those predictions of a fast start to winter. Looks like it's going to be a very average December overall for us.

I don't know about "embarrassing the Euro", but the GFS has most definitely improved over the past couple of years.  The Euro is still up there of course, but it's not nearly the same clear-cut winner every time as it was several years back.  When there's a discrepancy in what the two models are showing, you cannot now just assume the Euro has it right.

As for how December has gone and will go, it does appear to be shaping up as fairly "typical" at this point, but we'll see.  I don't know how many "fast start" predictions there were, but I don't believe anyone (on here at least) was pushing for above normal snow in their winter forecasts.  I thought the consensus was near normal temperatures for December.  The average snow in the DC area for December is, what, about 2" I think?  I can see us hitting that, and perhaps exceeding it a bit, this year.  Seems things are highly variable so far this month, wonder if that will be the theme all winter.

[MillvilleWx]

After forecasting at my job for going on 2 years, I've noticed the Euro and GFS are certainly on a more level playing field than in years past. It used to be Euro (The King) in all aspects of numerical output, especially at long leads. The upgrades over the years to the GFS have made it on a more level playing field compared to other guidance. In terms of the 500mb pattern, the Euro still gets my nod as slightly better in terms of verification once we get inside 48-72 hours, but it's not by an egregious margin. 

There is one spot that the Euro does do better in than the GFS and that's tropical. As someone who forecasts out in the Caribbean, the surface reflection aspect of modeling in terms of QPF output and surface pressure analysis and handling of smaller mesoscale features, Euro has everyone by the throat. This is to my knowledge and experience. Could verification say otherwise, sure!! But I'll gladly use Euro for my forecasts in the Caribbean over many other pieces of guidance. Been doing a masterful job. 

[mdsnowlover]

5 minutes ago, MillvilleWx said:

After forecasting at my job for going on 2 years, I've noticed the Euro and GFS are certainly on a more level playing field than in years past. It used to be Euro (The King) in all aspects of numerical output, especially at long leads. The upgrades over the years to the GFS have made it on a more level playing field compared to other guidance. In terms of the 500mb pattern, the Euro still gets my nod as slightly better in terms of verification once we get inside 48-72 hours, but it's not by an egregious margin. 

There is one spot that the Euro does do better in than the GFS and that's tropical. As someone who forecasts out in the Caribbean, the surface reflection aspect of modeling in terms of QPF output and surface pressure analysis and handling of smaller mesoscale features, Euro has everyone by the throat. This is to my knowledge and experience. Could verification say otherwise, sure!! But I'll gladly use Euro for my forecasts in the Caribbean over many other pieces of guidance. Been doing a masterful job. 

it helps to have vastly improved computing equipment and software that has ben upgraded, as you said. I  read in an online article that the NWS is now using cray super computers, instead of IBM version.The computing speed was reported 6x faster.

[Scarlet Pimpernel]

2 minutes ago, MillvilleWx said:

After forecasting at my job for going on 2 years, I've noticed the Euro and GFS are certainly on a more level playing field than in years past. It used to be Euro (The King) in all aspects of numerical output, especially at long leads. The upgrades over the years to the GFS have made it on a more level playing field compared to other guidance. In terms of the 500mb pattern, the Euro still gets my nod as slightly better in terms of verification once we get inside 48-72 hours, but it's not by an egregious margin. 

There is one spot that the Euro does do better in than the GFS and that's tropical. As someone who forecasts out in the Caribbean, the surface reflection aspect of modeling in terms of QPF output and surface pressure analysis and handling of smaller mesoscale features, Euro has everyone by the throat. This is to my knowledge and experience. Could verification say otherwise, sure!! But I'll gladly use Euro for my forecasts in the Caribbean over many other pieces of guidance. Been doing a masterful job. 

Interesting comments on the tropical performance that you've observed...something I did not realize, but I don't normally follow tropical systems nearly as much.

[mdsnowlover]

5 minutes ago, Always in Zugzwang said:

Interesting comments on the tropical performance that you've observed...something I did not realize, but I don't normally follow tropical systems nearly as much.

the path of matthew coming up the coast of florida and se US was correctly predicted by EURO aweek in advance as my sister and her husband live in the landings off ga coast and I warned them on the preceeding friday about adirect hit, and it happened

[psuhoffman]

2 hours ago, Scraff said:

I wake up with the only the Canadian up against the world? Meh. Can hope for the theory that every squirrel finds its nut.....or becomes road kill (breakfast in WV).  ;-)

Couple quick points after glancing over the night runs. Gefs is pretty bad. They lost the strong signal for the system next weekend and mostly support the op. Ggem ens supports their op and most show a significant snow. Gefs still has some support for a storm around the 19-21 on 0z, 6z not so much. Eps hadn't changed much and still has a mean around 3-4"'for next weekend with about half showing something most would be ok with. That number hasn't changed significantly. The mean snow on eps is still around 5" DC 6" bwi and 8" near PA. The other time period eps jumps on is around day 13-15. The heights don't show it on the means but a cluster manages to cut something through the overall ridging that gets some frozen in here. A few simply keep a trough in the east. Gfs has enough hits there also to think that time period is not settled yet despite a pretty awful looking mean h5. 

Non model note. The system this weekend has been trending south the last 24 hours.  I just got a coating this morning and now some guidance says I may get a little tonight before a flip. 24 hours ago even places 50 miles north of me looked all rain. The system midweek also trended south and is now squashed. So something 6 days out still has plenty of time. But we don't want it shifting too far. If 72 hours out we just need a small adjustment I think we will be ok. The cad is likely to trend stronger at the end. But only within reason. If it looks like a low to Chicago with the boundary in upstate ny a late trend won't help. But if it stays close we have a shot. 

[psuhoffman]

Gfs bringing in the system for next weekend way too far north. It's up over central Idaho when at the same time in ggem it's in southern Utah. Huge difference. The high is down south of Chicago on gfs when it's up in Minnesota on ggem. That already says were in trouble later on in the run. We need the high north and west so the low can slide under it instead of shoving straight east because the low is coming tight at it or worse cutting to the nw. 

[stormtracker]

Well, just doing a quick comparison with the CMC (yeah, i know), the GFS won't be great for next weekend.

[stormtracker]

1 minute ago, psuhoffman said:

Gfs bringing in the system for next weekend way too far north. It's up over central Idaho when at the same time in ggem it's in southern Utah. Huge difference. The high is down south of Chicago on gfs when it's up in Minnesota on ggem. That already says were in trouble later on in the run. 

Ninja'd.   What he said.

[HighStakes]

2 minutes ago, psuhoffman said:

Gfs bringing in the system for next weekend way too far north. It's up over central Idaho when at the same time in ggem it's in southern Utah. Huge difference. The high is down south of Chicago on gfs when it's up in Minnesota on ggem. That already says were in trouble later on in the run. 

Strange because the gfs is really drilling the cold in front of the system. has us not getting out of the teens Thurs and fri.

[stormtracker]

Yeah, GFS is just killing us with that low position

[eurojosh]

GFS still has that HP that Bob identified yesterday off OC rather than in NE.

[Ji]

4 minutes ago, stormtracker said:

Yeah, GFS is just killing us with that low position

I said yesterday when the GFS screws us..its usually right despite what euro and cmc show

[MN Transplant]

I know the Euro had it too, but really, how often do we do well in a CAD/retreating high situation when we have a 70kt SW wind at 850?  This isn't '93.

[psuhoffman]

Something I thought when Bob pointed out the suedo 50/50 low on the euro being what we needed yesterday but I didn't want to be a deb.  That is almost always a losing game plan. Those things are just so eratic and transient that needing the strength and location to be spot on from a week out is a problem.  The exception is when the Atlantic blocking is favorable as that promotes a low there. But in a pattern that is progressive I never like needing that. Usually when that does work it's not something we saw from a week out. 

[stormtracker]

2 minutes ago, Ji said:

I said yesterday when the GFS screws us..its usually right despite what euro and cmc show

You right...you right...

Nothing says winter like a 983 low creeping through the lakes.   GFS will probably nail it to perfection.

[showmethesnow]

Looks to be a somewhat better outcome then the 06Z.

[HighStakes]

Still a long way to go with this one although the trend hasn't been great. the storm in late February 2 years ago looked bad a few days out but ended really good for most here. 

[MN Transplant]

12 hours.  Subzero DPs to above freezing.  20 degree line goes from Atlanta to Canada.  Now, GFS DPs are not gospel, but it does indicate how rapidly this all goes downhill.

 

 

[psuhoffman]

9 minutes ago, HighStakes said:

Strange because the gfs is really drilling the cold in front of the system. has us not getting out of the teens Thurs and fri.

Actually it makes sense. It's a see saw effect. the more that trough digs the more the jet buckles behind it. Bigger trough bigger ridge. That brings the storm in further north and the high being south also creates a weakness to its northwest for the low to cut. We would be better off if the whole pattern was flatter and the high ended up over the lakes instead of down at our lat. then the wave would slide east under the cold instead of cutting up to the west of it. It would be a less cold pattern but more stable and better for cold. Some of our coldest temps are followed by rain a couple days later.