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34 minutes ago, brooklynwx99 said:

the equatorward shift in the jet is really helping the -EPO

IMG_1485.thumb.gif.a722f8ea61f08520def90403cc78e3ca.gif

I have always loved the EPO as an indicator for snow in the NE. I will take a -EPO over just about any teleconnection. 

 

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9 hours ago, SnowGoose69 said:

It was either Eric Webb or BAMWX who nailed it back in October.   They kept showing how some of the indices indicated it would be a La Nina which more favored the poleward ridge over the E PAC/AK.  I have not seen any research on this one, not sure if Don has any stats on it.  Some others stated that a - AO/NAO episode in the 12/15-1/15 period or so, especially if its strong will tend to correlate with another episode the following winter in the same period.  I cannot really make sense of that but indeed that period did have a -AO/NAO in 23-24 and 24-25 but we've seen cases where that does not occur.  Example ragingly +NAO/AO in Dec 2001 and Dec 2011 following negative episodes in 2000 and 2010

I was discussing the +PNA mismatch La Niña potential for December into January back in the La Niña thread during October. The very robust MJO 5 this October I pointed out back in October thread preceded La Niña winters like 2020-2021 and 2017-2018. But at the time I was also highlighted that there were other things about this event that didn’t match past analogs. While we got the -EPO+PNA, and -AO, the Pacific Jet didn’t relax like it did during earlier mismatch La Niña Decembers into January. So we got the lowest snowfall for this type of pattern compared to previous years.

The clue I picked up on back in October was the change in tropical forcing from the 22-23 La Niña indicating that the warm MJO phases would be inactive this winter so far. And that has been the case with the recent patterns not matching the typical MJO phase composites. For some reason stronger MJO 5 October activity during La Ninas since 2010 have preceded weaker MJO 5s from December into January. And the La Nina’s with weaker MJO 5s in October followed with stronger MJO 5 into the early and mid winter. 

Click on top right arrow to read post

 

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24 minutes ago, EastonSN+ said:

Progression still on track for phase 8 in mid-February with a lag effect of the last week of February. 

It's definitely weakening however should still have an effect. 

image.gif.198589b1183f90b27d83ed12dcfc24e7.gif

It’s weakening because of the late bloomer La Niña strengthening and peaking in February. As soon as it hits the colder Niña waters and the very strong trades the convection is going to get sheared apart and run out of steam. I’m not so sure we’re going to see the MJO 8 effects you think it may. Maybe @donsutherland1 and @bluewave can chime in their thoughts here 

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6 hours ago, USCG RS said:

I have always loved the EPO as an indicator for snow in the NE. I will take a -EPO over just about any teleconnection. 

 

Haven’t we had a near non stop -EPO since the end of November? NYC has seen less than 10 inches of snow since then

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1 hour ago, bluewave said:

I was discussing the +PNA mismatch La Niña potential for December into January back in the La Niña thread during October. The very robust MJO 5 this October I pointed out back in October thread preceded La Niña winters like 2020-2021 and 2017-2018. But at the time I was also highlighted that there were other things about this event that didn’t match past analogs. While we got the -EPO+PNA, and -AO, the Pacific Jet didn’t relax like it did during earlier mismatch La Niña Decembers into January. So we got the lowest snowfall for this type of pattern compared to previous years.

The clue I picked up on back in October was the change in tropical forcing from the 22-23 La Niña indicating that the warm MJO phases would be inactive this winter so far. And that has been the case with the recent patterns not matching the typical MJO phase composites. For some reason stronger MJO 5 October activity during La Ninas since 2010 have preceded weaker MJO 5s from December into January. And the La Nina’s with weaker MJO 5s in October followed with stronger MJO 5 into the early and mid winter. 

Click on top right arrow to read post

 

Is the reason for this mismatch because it's a la nina after el nino? That explains why we usually have snowy winters in la nina after el nino.

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1 hour ago, snowman19 said:

It’s weakening because of the late bloomer La Niña strengthening and peaking in February. As soon as it hits the colder Niña waters and the very strong trades the convection is going to get sheared apart and run out of steam. I’m not so sure we’re going to see the MJO 8 effects you think it may. Maybe @donsutherland1 and @bluewave can chime in their thoughts here 

It's definitely going to get hit, hoping some semblance of the wave survives to affect our weather. 

That being said I still don't understand why phase one and two are not discussed more often. The rapidly rising Western Indian ocean temperatures should facilitate much stronger wave activity in phases 1 and 2 which are also colder phases. Also would explain why the deep South had a great winter and we had less precipitation which phase eight usually provides. The focus seems to be solely on lessening effects of phase 8 and greater effects of phases four five and six, which should not be the case when phases 1 and 2 should increase as well. 

 

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8 hours ago, USCG RS said:

I have always loved the EPO as an indicator for snow in the NE. I will take a -EPO over just about any teleconnection. 

 

Not all EPO's are created equal.  Positively or negatively tilted has very significant downstream impacts, as does amplitude.

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February is beginning to look alot like January on the 12Z GFS - cold and dry with suppression the first 1/3rd of the month at least little snowfall but chance of a coastal the 7th on a slow moving front - sound familiar ?prateptype_cat-imp.conus.png

prateptype_cat-imp.conus.png

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Even the Op GFS you can see how inside D10-12 or so its capable of seeing the shift to the cold pushing east like the Euro/EPS showed but its just unable to resolve the idea beyond that of the Pac jet again probably preventing the SER from being able to flex.  TBH even the EPS at 00Z after D13 tries again to build the SER.  I think as long as the TPV is not in SE Canada like in Jan/The AO is not strongly negative/The PNA is not positive that the models are going to keep trying to default to a 2018 like SER after 260 hours

 

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just for the sake of argument, the ECMWF shows why 500mb ridges in the east along with a -EPO don't really portend a lack of wintry weather... the E US is actually under an anomalous 500mb ridge here, but there's enough HP to the north to lock in colder air and lead to a heavy snow event

ecmwf-deterministic-namer-z500_anom-9016000.thumb.png.9c9e2ffdee6ab046bd279477ec4925d3.pngecmwf-deterministic-east-instant_ptype-9037600.thumb.png.c91a4c6c38496296b90987c071ef40a3.png

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3 minutes ago, brooklynwx99 said:

just for the sake of argument, the ECMWF shows why 500mb ridges in the east along with a -EPO don't really portend a lack of wintry weather... the E US is actually under an anomalous 500mb ridge here, but there's enough HP to the north to lock in colder air and lead to a heavy snow event

ecmwf-deterministic-namer-z500_anom-9016000.thumb.png.9c9e2ffdee6ab046bd279477ec4925d3.pngecmwf-deterministic-east-instant_ptype-9037600.thumb.png.c91a4c6c38496296b90987c071ef40a3.png

Imagine if I posted a 222 hour operational model run on here showing a torch lol

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that is also worth noting when looking at ensembles... a weak SE ridge on the mean with a -EPO doesn't really mean a lack of snow. sure, there are likely some periods of time and some members that are warmer, but it's not the same as a SE ridge with a +EPO. nuance is important. we are likely going to be near a gradient that will present opportunities after the 5th or so. it's going to be changeable and we'll likely have some warm days in there, but that doesn't preclude snow or some mixed systems

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25 minutes ago, brooklynwx99 said:

just for the sake of argument, the ECMWF shows why 500mb ridges in the east along with a -EPO don't really portend a lack of wintry weather... the E US is actually under an anomalous 500mb ridge here, but there's enough HP to the north to lock in colder air and lead to a heavy snow event

ecmwf-deterministic-namer-z500_anom-9016000.thumb.png.9c9e2ffdee6ab046bd279477ec4925d3.pngecmwf-deterministic-east-instant_ptype-9037600.thumb.png.c91a4c6c38496296b90987c071ef40a3.png

This is actually similar to what happened with the January 19th storm - a wave of LP develops on the slowly moving cold front - the GFS also shows it like I posted a few posts up BUT a day earlier

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49 minutes ago, brooklynwx99 said:

just for the sake of argument, the ECMWF shows why 500mb ridges in the east along with a -EPO don't really portend a lack of wintry weather... the E US is actually under an anomalous 500mb ridge here, but there's enough HP to the north to lock in colder air and lead to a heavy snow event

 

Yup. But this is true of most climate indices and telecons, especially during peak winter climo. The nuances of the 500mb evolution and configuration are key. Each combination is unique, and a minor feature can occasionally lead to local snow (particularly as you gain latitude and elevation) regardless of longwave pattern and telecon state.

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46 minutes ago, brooklynwx99 said:

my point was that just because there's a 500mb ridge overhead it's easy to assume that it's warm, but that isn't always the case when there's HP coming into Canada from a -EPO. but you're being obtuse for whatever reason

Ignore him. He's a troll. 

 

Ensembles look much better towards mid month .

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22 minutes ago, eduggs said:

Yup. But this is true of most climate indices and telecons, especially during peak winter climo. The nuances of the 500mb evolution and configuration are key. Each combination is unique, and a minor feature can occasionally lead to local snow (particularly as you gain latitude and elevation) regardless of longwave pattern and telecon state.

thats correct and how we got snow in February 2018.

you can even get an HECS in a torch winter like 2015-16

obviously completely different but any kind of pattern can result in a minor or moderate snowfall in the dead of winter (Jan/Feb)

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