Mid to Long Term Discussion 2017

[PackGrad05]

Both the GFS and GEFS have been pretty consistent over the last 3 runs....  HOWEVER, the GEFS remains much colder than the GFS.  I'd lean that way, since ensembles are usually more accurate than the op..  Just interesting that they are both showing that much consistency at this point.

[Poimen]

28 minutes ago, PackGrad05 said:

Both the GFS and GEFS have been pretty consistent over the last 3 runs....  HOWEVER, the GEFS remains much colder than the GFS.  I'd lean that way, since ensembles are usually more accurate than the op..  Just interesting that they are both showing that much consistency at this point.

When the OP GFS is consistently on its own, more often than not it is consistently wrong. Bottom line: consistency is not always a good barometer of the eventual solution. 

[Buddy1987]

6 minutes ago, PackGrad05 said:

Both the GFS and GEFS have been pretty consistent over the last 3 runs....  HOWEVER, the GEFS remains much colder than the GFS.  I'd lean that way, since ensembles are usually more accurate than the op..  Just interesting that they are both showing that much consistency at this point.

And you would have to think that with that strong of an HP to our north funneling in cold air straight out of the St Lawrence Valley that some of the colder solutions will verify. Problem is, IF the OP GFS run were to verify, there would be some hefty and serious amounts of ice accretion. I do think that the CMC and the EURO to an extent have the general correct theme of showing the low cutting under that high pressure and not bulldozing right into it. That would make much more logical sense. 

[packbacker]

Day 8 the GEFS has been wanting to get the SER pumped up with a trough in the Southwest the past few runs.  The EPS/GEPS have been going the other way, less SER.  I think the GEFS has been pretty good at this range so that’s a concern.

They both agree on stronger blocking over the pole though.

 

 

[Orangeburgwx]

Just woke up so I checked the EURO ensembles... just wow

[FLweather]

8 hours ago, WarmNose said:

Textbook 1040 high placement but we rain in the upstate? Toss 

This post made me  Why because it shows no snow for your backyard? High placement or low placement is not text book by any means. Textbook example would be HP over NY PA and Canada with lp well off the coast.  Not lp over land with inverted trough secondary lp south of Cape Cod 

[SnowNiner]

6 hours ago, JoshM said:

I'll take this look 8 days out

 

What I love about that run is the temps.  That's what I like to see in a threat window, temps in the mid to upper 20s.  The problem is when we get the NW trend, we tend to warm it up.  Always riding the razor thin line. 

1 hour ago, packbacker said:

Day 8 the GEFS has been wanting to get the SER pumped up with a trough in the Southwest the past few runs.  The EPS/GEPS have been going the other way, less SER.  I think the GEFS has been pretty good at this range so that’s a concern.

They both agree on stronger blocking over the pole though.

 

 

 

I've noticed that.  It's really beefing up the ridging down south. That's going to really hurt our cold air push. Hopefully the EURO and the EPS is spot on this time.  

[WarmNose]

5 minutes ago, FLweather said:

This post made me  Why because it shows no snow for your backyard? High placement or low placement is not text book by any means. Textbook example would be HP over NY PA and Canada with lp well off the coast.  Not lp over land with inverted trough secondary lp south of Cape Cod 

One would think a 1030'ish HP would need to be in a perfect spot But a 1040!!!? I'd like to think we could be flexible with that one. 

Secondly, I just saw last nights Euro run. Looks money. Ice down to the beaches. NW trend, engage.

[tramadoc]

19 minutes ago, Orangeburgwx said:

Just woke up so I checked the EURO ensembles... just wow

Where did you get/how do you do your soundings? I'm trying to get them for Elizabeth City, NC.

[mackerel_sky]

6z GFS was great! Rain for the 30th storm and our next blockbuster is still right there at hour 360! This pattern is so money!

[BullCityWx]

5 minutes ago, tramadoc said:

Where did you get/how do you do your soundings? I'm trying to get them for Elizabeth City, NC.

weather.us

https://weather.us/forecast/4465088-elizabeth-city/ensemble/euro

[tramadoc]

1 minute ago, Queencitywx said:

weather.us

https://weather.us/forecast/4465088-elizabeth-city/ensemble/euro

Thanks brother. I appreciate it.

[BullCityWx]

Just now, tramadoc said:

Thanks brother. I appreciate it.

no problem. wx.graphics is pretty cool too, kind of a stripped down version of wxbell. 

[tramadoc]

Looks like SE NC does pretty well on the Euro.

[WarmNose]

9 minutes ago, mackerel_sky said:

6z GFS was great! Rain for the 30th storm and our next blockbuster is still right there at hour 360! This pattern is so money!

Not so fast! Euro says the 30th is our redux. I'm all in

[snowlover91]

Everyone should take a look at the CMC ensembles. I found them very good with the early big December snow seen in Western NC.

 

http://meteocentre.com/numerical-weather-prediction/ensemble-forecasting.php?lang=en&map=na&run=00&mod=cmc_geps&stn=PT&stn_type=postagestamp&display=img&hh=180

[BornAgain13]

11 minutes ago, mackerel_sky said:

6z GFS was great! Rain for the 30th storm and our next blockbuster is still right there at hour 360! This pattern is so money!

I hear the sarcasm so loudly lol

[tramadoc]

Euro gives KECG 1" on the mean. A max of 8.1", and a 90th percentile of 3.9"

[BullCityWx]

10 and 15 day snow means on EPS jumped significantly for both Raleigh and Charlotte. 

[tramadoc]

What's the 90th percentile? I get the other stuff. Besides me, I think the only person on this forum in my area is SteveVa and I believe he's in Virginia Beach which is bout an hour north of me.

[SnowNiner]

21 minutes ago, mackerel_sky said:

6z GFS was great! Rain for the 30th storm and our next blockbuster is still right there at hour 360! This pattern is so money!

I'll start looking at the GFS when it starts making sense with its ensembles.  Or better yet, just look at the EPS.  It says the 6z GFS is not crazy.  To me there's a decent signal for a early January storm, with low pressure moving east in the gulf and high pressure pressing down.  High precip and low temps.  I'm just hoping the EPS is right, for both threats! Is that greedy? 

 

[tramadoc]

I think we're the Northeast outliers since everyone else seems to be from the Triangle/Triad/Upstate/Mountains/North Central GA.

[FLweather]

12 minutes ago, snowlover91 said:

Everyone should take a look at the CMC ensembles. I found them very good with the early big December snow seen in Western NC.

 

http://meteocentre.com/numerical-weather-prediction/ensemble-forecasting.php?lang=en&map=na&run=00&mod=cmc_geps&stn=PT&stn_type=postagestamp&display=img&hh=180

Thanks.  Amazing to say but lot of members look like operational Euro.  Euro close but no cigar. Two key pieces I believe how much energy hangs around the sw and  try to under cut the ridge out west.  And energy coming out of the nw.

[FallsLake]

7 minutes ago, SnowNiner said:

I'll start looking at the GFS when it starts making sense with its ensembles.  Or better yet, just look at the EPS.  It says the 6z GFS is not crazy.  To me there's a decent signal for a early January storm, with low pressure moving east in the gulf and high pressure pressing down.  High precip and low temps.  I'm just hoping the EPS is right, for both threats! Is that greedy? 

 

You can definitely see the CAD signal there..

[packbacker]

EPS still ticking the right direction for a potential event.

[Upstate Tiger]

I was just curious how GSP has fared with seasonal snowfall when we have experienced measurable snowfall before Christmas.  Below are the stats.  Not overwhelming odds for above seasonal average snowfall but the 40 year average is 57% of winters experienced above average snowfall.  The seasonal average at GSP is 4.7":

76/77 - 7.0"

81/82 - 12.1"

89/90 - .9"

93/94 - 2.8"

96/97 - 2.4"

2000/2001 - 6.3"

2010/2011 - 8.8"

[Cold Rain]

Still feeling really good about the threat around New Years.  I think it's going to be a big one.

Mack asked about the GFS and ensembles earlier and why the GFS is so bad against, or rather, so different from it's ensembles.  It's not always the case, but at times, and this is one, the ensemble mean looks totally different.  The reason is the chaotic state of the atmosphere.  That's an over simplification, but when you have a pretty stable atmospheric pattern, you generally get more agreement between a model and it's ensembles (and even other model suites), especially through the short and medium ranges.  It's like throwing a stick into a slow moving river and predicting where it will end up at a given time. 

However, when the atmosphere is more chaotic, meaning you have a very active pattern, highly amplified flow, and anomalously strong features (like a mega epo), it's like throwing a stick into a class 5 rapids and trying to predict where it's going to end up.  The Ensembles smooth out the chaos.  In this case, the GFS may end up being correct, but if you look at the ensemble mean, the changes made to the initial conditions of each individual member and then all of them run and blended together, you will see a fairly different picture than the GFS Op.  Plus, given that it looks different than other other models and their ensemble means, you can conclude that the GFS is an outlier and likely erroneously handling certain features within the chaotic flow.

You also can get a sense of the degree of the chaos of the atmosphere by the amount of flip-flopping a model does over a period of time.  We're seeing a lot of that.  What it should tell you is that there are lots of solutions on the table.  That said, the best approach in my opinionis to look at the trends of the ensembles over a period of time (days) and note things like:  How are height fields trending?  Does there continue to be a storm signal?  Are things like the PNA, NAO, EPO trending stronger or weaker with time?  That will help identify whether or not there is a realistic signal for a winter storm (or whatever you're looking for).

Winter storms around here are precarious to begin with.  It's always threading the needle. The best we can do is look for a signal and see if it has merit.  In this case, my analysis is that there is a legitimate signal for a widespread winter storm, and the eye of the needle is wider than it usually is.  So far, that is what I am seeing, and I feel pretty good about it.

[Orangeburgwx]

10 minutes ago, Cold Rain said:

Still feeling really good about the threat around New Years.  I think it's going to be a big one.

Mack asked about the GFS and ensembles earlier and why the GFS is so bad against, or rather, so different from it's ensembles.  It's not always the case, but at times, and this is one, the ensemble mean looks totally different.  The reason is the chaotic state of the atmosphere.  That's an over simplification, but when you have a pretty stable atmospheric pattern, you generally get more agreement between a model and it's ensembles (and even other model suites), especially through the short and medium ranges.  It's like throwing a stick into a slow moving river and predicting where it will end up at a given time. 

However, when the atmosphere is more chaotic, meaning you have a very active pattern, highly amplified flow, and anomalously strong features (like a mega epo), it's like throwing a stick into a class 5 rapids and trying to predict where it's going to end up.  The Ensembles smooth out the chaos.  In this case, the GFS may end up being correct, but if you look at the ensemble mean, the changes made to the initial conditions of each individual member and then all of them run and blended together, you will see a fairly different picture than the GFS Op.  Plus, given that it looks different than other other models and their ensemble means, you can conclude that the GFS is an outlier and likely erroneously handling certain features within the chaotic flow.

You also can get a sense of the degree of the chaos of the atmosphere by the amount of flip-flopping a model does over a period of time.  We're seeing a lot of that.  What it should tell you is that there are lots of solutions on the table.  That said, the best approach in my opinionis to look at the trends of the ensembles over a period of time (days) and note things like:  How are height fields trending?  Does there continue to be a storm signal?  Are things like the PNA, NAO, EPO trending stronger or weaker with time?  That will help identify whether or not there is a realistic signal for a winter storm (or whatever you're looking for).

Winter storms around here are precarious to begin with.  It's always threading the needle. The best we can do is look for a signal and see if it has merit.  In this case, my analysis is that there is a legitimate signal for a widespread winter storm, and the eye of the needle is wider than it usually is.  So far, that is what I am seeing, and I feel pretty good about it.

that was a very good explanation CR, thanks!

[JovialWeather]

Sorry for a newbie question... Maybe it's my eyes, but sometimes the same model run spits out different images/results depending on what site I'm using. I might look at the 6-hour avg precip rate for the GFS on TT and it looks completely different than what someone's posted from the same run on Pivotal or another site. Is it a matter of resolution? What region you're zoomed into vs. a larger entire CONUS view? Or again, maybe it's just my eyes, but they sure do look different sometimes.

[SnowNiner]

11 minutes ago, Cold Rain said:

Still feeling really good about the threat around New Years.  I think it's going to be a big one.

Mack asked about the GFS and ensembles earlier and why the GFS is so bad against, or rather, so different from it's ensembles.  It's not always the case, but at times, and this is one, the ensemble mean looks totally different.  The reason is the chaotic state of the atmosphere.  That's an over simplification, but when you have a pretty stable atmospheric pattern, you generally get more agreement between a model and it's ensembles (and even other model suites), especially through the short and medium ranges.  It's like throwing a stick into a slow moving river and predicting where it will end up at a given time. 

However, when the atmosphere is more chaotic, meaning you have a very active pattern, highly amplified flow, and anomalously strong features (like a mega epo), it's like throwing a stick into a class 5 rapids and trying to predict where it's going to end up.  The Ensembles smooth out the chaos.  In this case, the GFS may end up being correct, but if you look at the ensemble mean, the changes made to the initial conditions of each individual member and then all of them run and blended together, you will see a fairly different picture than the GFS Op.  Plus, given that it looks different than other other models and their ensemble means, you can conclude that the GFS is an outlier and likely erroneously handling certain features within the chaotic flow.

You also can get a sense of the degree of the chaos of the atmosphere by the amount of flip-flopping a model does over a period of time.  We're seeing a lot of that.  What it should tell you is that there are lots of solutions on the table.  That said, the best approach in my opinionis to look at the trends of the ensembles over a period of time (days) and note things like:  How are height fields trending?  Does there continue to be a storm signal?  Are things like the PNA, NAO, EPO trending stronger or weaker with time?  That will help identify whether or not there is a realistic signal for a winter storm (or whatever you're looking for).

Winter storms around here are precarious to begin with.  It's always threading the needle. The best we can do is look for a signal and see if it has merit.  In this case, my analysis is that there is a legitimate signal for a widespread winter storm, and the eye of the needle is wider than it usually is.  So far, that is what I am seeing, and I feel pretty good about it.

Nice, glad to hear that! Which one are you specifically keying in on, the 28th/29th or January 3rd? Cause you know, we have so many winter events in NC it's hard to keep track....

I'm curious, what trends of the storm window are you looking at that make you feel confident? I like the EPS trends of pushing the 50/50 a bit farther south/east and less ridging in the SE for the 29th.