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November Medium/ Long Range


Weather Will
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As we head into the last full week of October, time sure flies doesn't  it, time to start looking into November.  Looking at EPS  weeklies, looks like temperatures return to near normal by mid/late November, and normal precipitation.  Maybe setting us up for a rocking December to remember!!! Showing 30 day maps and last week of November.

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After last winter's debacle with the extended/weeklies products, I will be even more cautious than usual with the pattern depiction, especially any suggestion of a wholesale change beyond the range of the ensembles. So with that said, the Euro Ens and GEFS both depict a +WPO/EPO pattern developing going forward, which is usually a warm one for us. GEFS look is probably warmer in the LR with a trough along the west coast into early November, while the Euro has a bit of a PNA ridge.

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21 hours ago, WxUSAF said:

+EPO/WPO very durable on ensembles for next 2 weeks. Doesn’t mean mega torch the whole time, but does mean no long duration BN temps anytime soon. Maybe just saving up the cold air for winter? :yikes:

The latest Ensemble runs are suggesting a -NAO develops the first week of Nov. That should help keep us seasonably cool, but with the persistent trough around AK the flow across NA will be of Pacific origin. Fwiw the extended products suggest the WPO trends towards neutral(slightly negative on the Euro Weeklies) for mid November.

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3 hours ago, CAPE said:

The latest Ensemble runs are suggesting a -NAO develops the first week of Nov. That should help keep us seasonably cool, but with the persistent trough around AK the flow across NA will be of Pacific origin. Fwiw the extended products suggest the WPO trends towards neutral(slightly negative on the Euro Weeklies) for mid November.

eps_z500a_namer_61.thumb.png.1097eac057c3b0098f3e8d05a48f0a18.png

BAMWx teasing a big pattern change by mid-Novie. Maybe that’s the start. GEFSX starts changing the EPO around the 10th, but more toward neutral than sharply negative. -AO/-NAO seems like the mechanism to cool us down. Looks wetter too FWIW.

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23 minutes ago, WxUSAF said:

BAMWx teasing a big pattern change by mid-Novie. Maybe that’s the start. GEFSX starts changing the EPO around the 10th, but more toward neutral than sharply negative. -AO/-NAO seems like the mechanism to cool us down. Looks wetter too FWIW.

So in two weeks the the forecast will suddenly and epically collapse, got it.

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1 hour ago, WxUSAF said:

BAMWx teasing a big pattern change by mid-Novie. Maybe that’s the start. GEFSX starts changing the EPO around the 10th, but more toward neutral than sharply negative. -AO/-NAO seems like the mechanism to cool us down. Looks wetter too FWIW.

The more I dig into this the more I think maybe its really simple.  There have been 16 times since 1950 where we entered the cold season with a deeply -PDO regime, averaging below 1.5 over the previous season.  Only once did that season end up above average snow at BWI, and that was 2000 which IMO was a total fluke.  The longwave pattern that winter was garbage 90% of the time and we got lucky the one week we had any chance of snow all winter.  

 

 

 

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16 minutes ago, psuhoffman said:

The more I dig into this the more I think maybe its really simple.  There have been 16 times since 1950 where we entered the cold season with a deeply -PDO regime, averaging below 1.5 over the previous season.  Only once did that season end up above average snow at BWI, and that was 2000 which IMO was a total fluke.  The longwave pattern that winter was garbage 90% of the time and we got lucky the one week we had any chance of snow all winter.  

 

 

 

If this year is a total dud (0-4” at the airports), I don’t think anyone will struggle to find the culprit. But I’m holding out some hope that the central/west equatorial PAC warmth and the warm water off the west coast can give us some favorable looks at times. If we can cash in on those, we can get a “good Niña” year.

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1 hour ago, WxUSAF said:

BAMWx teasing a big pattern change by mid-Novie. Maybe that’s the start. GEFSX starts changing the EPO around the 10th, but more toward neutral than sharply negative. -AO/-NAO seems like the mechanism to cool us down. Looks wetter too FWIW.

They're just setting up for the inevitable post where they gleefully exclaim the complete turnaround in mid-range modelling overnight shows us torching.  Seriously though I can't even get mad at the negative naysayers anymore because they are always right these days it seems.  The only time they have been wrong lately is last year when many of them were fooled by the universal agreement on the modelled nirvana pattern. 

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6 hours ago, psuhoffman said:

The more I dig into this the more I think maybe its really simple.  There have been 16 times since 1950 where we entered the cold season with a deeply -PDO regime, averaging below 1.5 over the previous season.  Only once did that season end up above average snow at BWI, and that was 2000 which IMO was a total fluke.  The longwave pattern that winter was garbage 90% of the time and we got lucky the one week we had any chance of snow all winter.  

Yeah, the PDO has a ridiculous correlation of late. More than I would expect it to.  It doesn't help that that PDO is near -3 right now, which is only #2 to 1955. 

This year we started getting Greenland troughs, which is a new pattern. That is cold on the H5 map, which wasn't really there 2020-2023. I was thinking it could spill over to help a -epo/+pna pattern, but I have seen through the Fall the staying power of the N. Pacific warm pool at 500mb. Because of this new +NAO pattern this year, it's not too far out that we could see possibly several 7-10 day favorable Pacific looks, but that is not expected to sustain in any way, because of the historical PDO correlation. I think when we warm up, it could be 60s and 70s at times. But the variance of the pattern will give us warm and cold periods.  Hopefully we capitalize on colder patterns, the global precipitable water continues to be very high. 

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4 hours ago, Stormchaserchuck1 said:

Yeah, the PDO has a ridiculous correlation of late. More than I would expect it to.  It doesn't help that that PDO is near -3 right now, which is only #2 to 1955. 

This year we started getting Greenland troughs, which is a new pattern. That is cold on the H5 map, which wasn't really there 2020-2023. I was thinking it could spill over to help a -epo/+pna pattern, but I have seen through the Fall the staying power of the N. Pacific warm pool at 500mb. Because of this new +NAO pattern this year, it's not too far out that we could see possibly several 7-10 day favorable Pacific looks, but that is not expected to sustain in any way, because of the historical PDO correlation. I think when we warm up, it could be 60s and 70s at times. But the variance of the pattern will give us warm and cold periods.  Hopefully we capitalize on colder patterns, the global precipitable water continues to be very high. 

Good points Chuck. If we go back to Feb 2015 we find a +NAO and a Eastern US Trough. +TNH Pattern. If I remember correctly, the QBO was Positive as well. Fly in ointment is definitely the -PDO. image.gif.acef7410cdbaf04209f2d27ddc8a58e4.gif

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21 hours ago, Stormchaserchuck1 said:

Yeah, the PDO has a ridiculous correlation of late. More than I would expect it to.  It doesn't help that that PDO is near -3 right now, which is only #2 to 1955. 

This year we started getting Greenland troughs, which is a new pattern. That is cold on the H5 map, which wasn't really there 2020-2023. I was thinking it could spill over to help a -epo/+pna pattern, but I have seen through the Fall the staying power of the N. Pacific warm pool at 500mb. Because of this new +NAO pattern this year, it's not too far out that we could see possibly several 7-10 day favorable Pacific looks, but that is not expected to sustain in any way, because of the historical PDO correlation. I think when we warm up, it could be 60s and 70s at times. But the variance of the pattern will give us warm and cold periods.  Hopefully we capitalize on colder patterns, the global precipitable water continues to be very high. 

The high correlation is probably related to the degree to which the PDO has been negative.  It's not just been negative, its been historically negative.  This was my biggest failure in last winter's prediction.  I did weight the PDO, but I found several -PDO years with other matching variables that ended up snowy.  What I failed to properly weight was that all of those years were -PDO but significantly less so heading into winter.  If we only look at deeply -PDO years, we see its VERY difficult to get a lot of snow in those regimes.  A less -PDO has more variability and can even be good for snow in a -NAO regime.  But if the PDO is deeply negative it is the dominant factor.  

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On 10/24/2024 at 1:01 PM, WxUSAF said:

If this year is a total dud (0-4” at the airports), I don’t think anyone will struggle to find the culprit. But I’m holding out some hope that the central/west equatorial PAC warmth and the warm water off the west coast can give us some favorable looks at times. If we can cash in on those, we can get a “good Niña” year.

I am not sold this is a total dreg no snow year.  There are some "decent" years within the set, but I think slightly below normal snowfall is the high end bar unless we just get freakishly lucky.  A year like 2022 is probably the best case scenario here.  

 

Oddly, and I've mentioned this before, there are still some in the enso thread "rooting" for the collapse of the nina to save winter...when in reality the 3 snowiest winters in the set of 16 similar PDO years I identified were all Nina's!  Our expected snowfall actually goes down according to my method if we end up enso neutral!  

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8 minutes ago, psuhoffman said:

I am not sold this is a total dreg no snow year.  There are some "decent" years within the set, but I think slightly below normal snowfall is the high end bar unless we just get freakishly lucky.  A year like 2022 is probably the best case scenario here.  

 

Oddly, and I've mentioned this before, there are still some in the enso thread "rooting" for the collapse of the nina to save winter...when in reality the 3 snowiest winters in the set of 16 similar PDO years I identified were all Nina's!  Our expected snowfall actually goes down according to my method if we end up enso neutral!  

How many of the neutral years were preceded by El Niños?

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1 hour ago, psuhoffman said:

I am not sold this is a total dreg no snow year.  There are some "decent" years within the set, but I think slightly below normal snowfall is the high end bar unless we just get freakishly lucky.  A year like 2022 is probably the best case scenario here.  

 

Oddly, and I've mentioned this before, there are still some in the enso thread "rooting" for the collapse of the nina to save winter...when in reality the 3 snowiest winters in the set of 16 similar PDO years I identified were all Nina's!  Our expected snowfall actually goes down according to my method if we end up enso neutral!  

21-22 was less than an inch away from climo at DCA.

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