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Pattern Nippy November
- Thread starter jackendrickwx
- Start date
Obvious trend with the ridge starting to appear again 
raging -nao and a SER, gotta love weather models.
Seems to be entering from the gulf side? Maybe this is not a permanent fixture. I’ll take my chances with those heights over Greenland. Also, shocker our PNA is hot garbage ?
good spot... first week of Dec is certainly a transition week into 09-10 redux, only on steroids this time. That recurring -nao feature with come back every 3 weeks until the first of May. Earthwide AN background state will become a myth. Look for many areas south of I-20 seeing a 20 inch seasonal snowfall. Raleigh will bust too east for storm tracks though, oops.
Gfs definitely looks like it’s own ensemble around that time aswell, pacific pattern is disgusting but matches the MJO phase at that time 
the good news is we have ten days to collectively wishcast that pacific ridge further east by 1000 miles... We can do it!
The ridge although it looks ominous on modeling looks like it’ll be fairly short lived in general and even when it’s around we may have a good high pressure system funneling cold air down us so it’s not too warm .. warmest I saw it get was mid 70s for a few days... I’ll take it for a little relaxing ... I do have a feeling we are going to have a lot of crazy weather news in the next two weeks all across the United States
SnowNiner
Member
Overnight the GEFS lost the Greenland ridging in the long range. Starts around the 5th and it's completely gone by the end of the run. Last year redux? -NAO mirage for the winter? We'll see. I'm starting to think we revert to the -EPO for cold shots and hope for timing again. Persistence forecasting from the last 10 years.
It will come back by tonight. The rollercoaster continues.
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tennessee storm
Member
And it will be gone again by tomorrow afternoon ... models don’t have clue that far out... why even bother looking
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Brick Tamland
Guest
For real. No sense in getting worried about anything more than 10 days out at this time.
Ethan80963!
Member
Nobody needs to worry about what models show long-range they are bouncing around a lot here's an example. Here are the last 4 runs of the GEFS. As seen many big changes so I don't think there's anything to worry about yet.
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Brick Tamland
Guest
Yes, until we see some consistent runs for things past 7 days, there really is no telling what will happen further out than that.
There are some quasi-consistent features in that animation, though. I think the way to use LR guidance is to try and identify things that can influence the general pattern and go from there. Watching for trends in the strength and duration of those can provide clues to how things may develop over that period. Obviously, things won't turn out exactly like the models show, but you can glean some info about how the overall pattern is likely to evolve, which will then give you an idea of the general weather pattern we're likely to see in the SE. Then, refine that outlook as we move forward in time and the strength, configuration, and duration of these features become more clearly defined.
Getting married to a specific solution 10+ days out is unwise. But attempting to get a sense of how the general pattern may evolve can be a useful exercise.
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Brick Tamland
Guest
Unless the pattern 10 days out shows a massive snow storm, and then I'm picking out my dress!
Just be sure to hang onto your receipt!
From Maxar this morning, the GEFS cold bias has been bad in the SE US the last 30 days:
“The GFS EN is a colder outlier in the 6-10 Day period, projecting 116.7 GWHDDs. For comparison, our forecast is 110.5 GWHDDs, while other models are additionally warmer (GFS OP at 100.8; Euro OP at 106.6; Euro EN at 107.2). The GFS EN has carried a cold bias at this lead time of late, and thus the colder output may not be reliable. This bias is evident in the GEFS warmer output now projected in the 1-5 Day period when compared to that at 6-10 days lead. In the past 30 days of observations, the GFS EN has averaged too cold for average temperatures by 6° in Atlanta, Washington, DC and New York City, while cold biases of ~4° are in Cincinnati, Minneapolis, Philadelphia and St. Louis. The model has averaged too cold by 3° in Boston and 2° in Chicago. Using the observed biases of the past 30 days, the map at the end of this discussion shows what the 6-10 Day GFS EN would look like in its 0z run today with a bias correction applied. The data suggests that the risk to our forecast is additionally warmer along the East Coast. Our forecast is similar to the bias corrected data in the Midwest.”
“The GFS EN is a colder outlier in the 6-10 Day period, projecting 116.7 GWHDDs. For comparison, our forecast is 110.5 GWHDDs, while other models are additionally warmer (GFS OP at 100.8; Euro OP at 106.6; Euro EN at 107.2). The GFS EN has carried a cold bias at this lead time of late, and thus the colder output may not be reliable. This bias is evident in the GEFS warmer output now projected in the 1-5 Day period when compared to that at 6-10 days lead. In the past 30 days of observations, the GFS EN has averaged too cold for average temperatures by 6° in Atlanta, Washington, DC and New York City, while cold biases of ~4° are in Cincinnati, Minneapolis, Philadelphia and St. Louis. The model has averaged too cold by 3° in Boston and 2° in Chicago. Using the observed biases of the past 30 days, the map at the end of this discussion shows what the 6-10 Day GFS EN would look like in its 0z run today with a bias correction applied. The data suggests that the risk to our forecast is additionally warmer along the East Coast. Our forecast is similar to the bias corrected data in the Midwest.”
By "cold bias" does that mean the pattern its modeling is correct and temp departures are being over estimated? Or is it not even getting the pattern right?
It’s like Shane pointed out . The model uses algorithms in order to spit out a solution . You can’t just blanket a model and say it has a cold bias . There is a reason it spits out a cold solution . Now maybe there are flaws with how it comes up with those solutions but it’s not like it’s just spitting out cold to be cold
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