Winter 2024/2025 February Thread

[AMZ8990]

I figured it was time to start the next monthly winter thread.  Let the speculation/discussion begin.

[nrgjeff]

12Z ECMWF is serving up the ol' Thunderstorms then chance of snow a few days later. Snow part is I-40 north. I'm less interested in an 11-15 day forecast than I am that I-40 is the usual routine. 

Even the thunderstorm part is a week or more out, and more likely Deep South than or forum. Mississippi maybe, but going into central/southern Alabama is Southeast.

[John1122]

Grim long range for winter lovers. Models are trying to have an Aleutian ridge, deep western trough. Hopefully that isn't the case, if it is, the first half of February will be tough for any snow chances. Late GFS has two systems with the rain/snow line in Michigan and Southern California getting snow. 

[nrgjeff]

Well Florida had its snow. SoCal be like, it's our turn! Sure beats fires. 

Perhaps that Western and Plains cold can ooze east to us in the 11-15 day. Guess we have to get through the thaw first. Baby steps.

[Carvers Gap]

Here is the time frame that I continue to watch along with the timeframe around roughly 1/30(give or take a few days).   The real question in my mind is where does the stationary front set up shop?  Is it the Cumberland Plateau or the Apps?  I have asked that question already once this winter.  Turns out, it was Pensacola!  This time frame sits just beyond deterministic and global ensemble range.  Gonna have to slog through a ridge or two to get to potentially this - beware!

 

[Carvers Gap]

I think the warmth we are seeing (to end the month and begin Feb) is the model reaction to the MJO passing through phases 4-6.  So far(famous last words), that looks like a pretty fast pass.  I was a bit perplexed that it hadn't shown up.  At one point there were below zero temps in the middle of my warm-up!  It is always possible that winter doesn't return, but I am rolling with '96 which had a warm-up in between cold shots.  Right now is halftime - I think.  A January thaw is almost always a staple of winter, and quite honestly, I could use one.  The treadmill sucks for running!  I don't do single digit wind chills.  I am older and smarter... As one in my family likes to state, "The fun begins at fifty."  Somehow, I don't think that is a compliment!!!

[Carvers Gap]

Speaking of the "fun begins at 50," do I dare admit that I thought I was in the January thread when I recommended a February thread get started?  

 

 

 

 

...and I was actually posting in the new February thread. 

[Daniel Boone]

2 hours ago, John1122 said:

Grim long range for winter lovers. Models are trying to have an Aleutian ridge, deep western trough. Hopefully that isn't the case, if it is, the first half of February will be tough for any snow chances. Late GFS has two systems with the rain/snow line in Michigan and Southern California getting snow. 

Yeah, that's the worry for sure. Pop that Ridge there and completely couple the Nina. I'm with Carver's on the MJO being the real Culprit. However, as mentioned yesterday, the worry is those warm Phases MJO Trek may help instigate a more La Nina Structure in the PAC. Hopefully, if so, the MJO goes steadily at a good Amplitude into the Cold Phases or Blocking set's up and flips the East back into a Wintery Pattern. 

     The Nina is weak so, even if it does fully Couple we can work with that with a good MJO Phase. 

[Carvers Gap]

I "think" we are looking at potentially very cold temps during the second week of Feb.  The AIFS at 12z hinted at this.  It is there about 2/3 of the time.

@Daniel Boone, I suggested(then deleted quickly!) that we start a February thread.  I thought I was in the January thread.  No, I was actually IN the new February thread asking for the February thread to be created!!!!   LOL!!!!  

[Daniel Boone]

37 minutes ago, Carvers Gap said:

I "think" we are looking at potentially very cold temps during the second week of Feb.  The AIFS at 12z hinted at this.  It is there about 2/3 of the time.

@Daniel Boone, I suggested(then deleted quickly!) that we start a February thread.  I thought I was in the January thread.  No, I was actually IN the new February thread asking for the February thread to be created!!!!   LOL!!!!  

Yeah, I knew what you were saying man. The Avatar of confused was a joking one of you being confused on which Topic, lol. That's that being a half Century old or older, lol. I can definitely relate to that .

[BNAwx]

A warm up is expected, but I do believe we’ll see a return to colder as we approach mid-February (if not a tad sooner).  Like many, I think February cold shots could be directed in a more central/western US manner and then spread eastward.  Where the boundary sets up will depend on the strength of the SER.  For kicks and giggles, I’m eyeing the Valentine’s Day period for a stalled front/overrunning setup.  Seems like that Valentine’s Day timeframe has brought storm or rumors of storms the past few years.

[nrgjeff]

Valentines Day and Presidents Day have been good to me both in Appalachia (skiing) and back in the Plains growing up (imby). One year I failed to prep my Valentines for school. Rescued by a snow day!

As for the 11-15 day period, most AI versions of Ensembles ooze the cold east eventually. GEFS does too. EPS and AIFS are a little slower and start warmer. EC warmer than USA stuff is kind of back to normal. I figure a slow go but eventually cold finds its way back in here. Favors BNAwx timing after the 11-15 day, more toward Day 20. 

We're also waiting for convection to gtfo the Maritime Subcontinent. When it shifts we can perhaps get more love from the MJO, again that Day 15-20 timing. Weekly models like days 15-20 also.

[Daniel Boone]

44 minutes ago, nrgjeff said:

Valentines Day and Presidents Day have been good to me both in Appalachia (skiing) and back in the Plains growing up (imby). One year I failed to prep my Valentines for school. Rescued by a snow day!

As for the 11-15 day period, most AI versions of Ensembles ooze the cold east eventually. GEFS does too. EPS and AIFS are a little slower and start warmer. EC warmer than USA stuff is kind of back to normal. I figure a slow go but eventually cold finds its way back in here. Favors BNAwx timing after the 11-15 day, more toward Day 20. 

We're also waiting for convection to gtfo the Maritime Subcontinent. When it shifts we can perhaps get more love from the MJO, again that Day 15-20 timing. Weekly models like days 15-20 also.

Agree. ETA fits really well with progression from where we're at.

[Carvers Gap]

1 hour ago, nrgjeff said:

Valentines Day and Presidents Day have been good to me both in Appalachia (skiing) and back in the Plains growing up (imby). One year I failed to prep my Valentines for school. Rescued by a snow day!

As for the 11-15 day period, most AI versions of Ensembles ooze the cold east eventually. GEFS does too. EPS and AIFS are a little slower and start warmer. EC warmer than USA stuff is kind of back to normal. I figure a slow go but eventually cold finds its way back in here. Favors BNAwx timing after the 11-15 day, more toward Day 20. 

We're also waiting for convection to gtfo the Maritime Subcontinent. When it shifts we can perhaps get more love from the MJO, again that Day 15-20 timing. Weekly models like days 15-20 also.

Convection in the MC is a pain in the neck!  LOL.   I think we get one more meaningful rotation through cold phases.    I think the worst of winter’s cold is behind us.  That said, December featured that 11-12 day warmup.  We may see something similar at the end of this month and early Feb.  But yeah, if we want the warmup to be a thaw and not a toasty Feb….the MJO has to get out of 6!

To clarify…worst of cold behind us.  But I have no idea about snow.  Feb can deliver when it is on!

[Daniel Boone]

It is crucial to get past MJO P 6 . I still think we will cash in with one or two formidable Snowfalls particularly if we hit P 8 at decent Amplitude.

[Holston_River_Rambler]

Honestly I think it is not going to move through 6 as quick as we'd like. Remember how it got hung up there earlier in the season because of the MC convection, I can't see any reason why it wouldn't do that again. Difference this year is that it actually wants to do something after that. BOM is worst case scenario and it has progress after Feb 20 or so:

I don't think it will look just like that, probably more of a hang up for several days even though models try to push it out. 

Still a lot over the Indian Ocean to flush through the MC as it moves east. 

 

 

[Holston_River_Rambler]

This is kind of what I expect, 15th - 26th of December. 

[Daniel Boone]

Probably be the case Holston. That will completely couple the Nina as well so ... Could mean a cold possibly Snowy early March however if it goes into the cold phases then. 

[BNAwx]

Slightly off topic, but does anyone know of a source that provides MJO verification info/scores for ALL models?  I’ve only been able to find verification scores for the GFS products.

[jaxjagman]

1 hour ago, Holston_River_Rambler said:

Honestly I think it is not going to move through 6 as quick as we'd like. Remember how it got hung up there earlier in the season because of the MC convection, I can't see any reason why it wouldn't do that again. Difference this year is that it actually wants to do something after that. BOM is worst case scenario and it has progress after Feb 20 or so:

I don't think it will look just like that, probably more of a hang up for several days even though models try to push it out. 

Still a lot over the Indian Ocean to flush through the MC as it moves east. 

 

 

See what happens the next few days into the IO.RW AND KW can cause chaos into the IO and cause constructive interference with the MJO signal where it could be further along,but every model i see is showing the the MJO will start to weaken the next couple days

[Holston_River_Rambler]

AIFS at least aiming the qpf hose at the TN Valley:

[Carvers Gap]

The American modeling handles the MJO very differently.  The Euro tends to underestimate amplitude.  American modeling has a bias for stalling in 6 IMHO.   It is going to warm up.  We just need it to hustle!   Most good winters have warm MJO rotations.   We called them thaws.  Now, we know some of the science.  The MJO can also end winter.  Deterministic modeling can just about see to the second week of Feb.  We will know the verdicts to our questions soon.

[Carvers Gap]

The deck is also stacked a bit differently this year.  NA is much colder than recent winters.   We likely don’t have to rebuild the could source in Canada after the warmup. Cold sources matter.

[John1122]

The AI is toasty, some of us may make a run at 80 in the southern areas of the forum per some of it's runs.

[jaxjagman]

Dunno,its a waiting game.CFS totally rocked the other models into the extended period last cycle,it showed what was going to happen into the IO while the other extended models wanted to kill the MJO off to fast

[Carvers Gap]

The 12z GEPS and EPS are not warm in the long range.  In fact, the EPS has a full blown trough progressing eastward from the nation's mid-section between d10-15.  The AIFS does get my attention, but it can swing wildly at that range....sometimes it can lead the way.  Just really watching to see if this is a thaw or a new pattern w/ a big SER.   I lean temporary thaw, but am not totally sold on that yet.  All it will take is one big cutter right along the MS River, and that cold air will refill eastern NA.  Tricky business.  Also, it is a good rule of thumb(and I forget it often) that sever cold over NA does wonky stuff to modeling.

[Carvers Gap]

Pretty big model war between the EPS/GEPS vs GEFS at 12z for d10-15.  Last time the GEFS didn't do so well.  However, what we are seeing is for sure differences in how the MJO is modeled both in amplitude and speed.  It could be a thaw or a pattern change.  I like the EPS right now as it tends to do a little better once we hit mid-winter.  Total crapshoot though until the MJO gets sorted out.  But I do know this 100%...when we start talking about the MJO, it is about to get really warm for an undetermined amount of time.  For now, I think we see a warm-up from Jan 28 to Feb 7th.  It could be longer.  Outside chance it could be shorter.  The SER is going to flex.  We just don't want it to become a standing wave.  

[jaxjagman]

I'd like to understand more about the solar cycles and why people even try and incorporate them into seasonal forecast.In 1996 we had back then one of the strongest PV's on record only to get surpassed by the 2020,this year the PV has been relentlessly strong even without a solar min.I'm just using 30hPa as reference what JMA shows

[*Flash*]

2 hours ago, John1122 said:

The AI is toasty, some of us may make a run at 80 in the southern areas of the forum per some of it's runs.

Also happened in February 1996.

[Carvers Gap]

36 minutes ago, jaxjagman said:

I'd like to understand more about the solar cycles and why people even try and incorporate them into seasonal forecast.In 1996 we had back then one of the strongest PV's on record only to get surpassed by the 2020,this year the PV has been relentlessly strong even without a solar min.I'm just using 30hPa as reference what JMA shows

I think the sun matters a lot.  In fact, it might the driver of Earth's weather over millennia. I just don't think we have a lot of research about how it impacts weather.  It might be worth its own thread.  I could write several posts on the topic.  Briefly, I would say that increased solar activity tends to put a ridge over the eastern US.