February Medium/Long Range Thread

[mitchnick]

23 minutes ago, TheClimateChanger said:

3" of snow over 15 days at Pittsburgh from an ensemble mean, which is probably being affected by a few low-probability outliers. That's like 40% of normal. Not a very impressive snow signal IMHO.

If you took the effort to look, you'd see it comes over a short window and not a little at a time. But you have you agenda, so...

[bncho]

31 minutes ago, TheClimateChanger said:

3" of snow over 15 days at Pittsburgh from an ensemble mean, which is probably being affected by a few low-probability outliers. That's like 40% of normal. Not a very impressive snow signal IMHO.

Dude... 3" of snow over 3-5 days is different. You make it sound like the end of the world.

[Weather Will]

Latest WB EPS extended is warmer than yesterday's run...will need to be watched for any new trends.

[psuhoffman]

30 minutes ago, Weather Will said:

Latest WB EPS extended is warmer than yesterday's run...will need to be watched for any new trends.

Because it’s still rushing. We probably don’t go left sustained cold until Feb 20 or later. 

[mitchnick]

Today’s Eps extended have the mean MJO wave dying in Phase 8 inside the COD after a brief stint in the warmer Maritime phases. That would probably be a good result if right, but again it's a mean of a lot of different member results. I've attached the RMM plot for the MJO along with the Euro time-longitude plat showing the easterly trades feeding the Niña base state will end around 2/11 IF it's correct. That too would work, I think, with enough time left in the season for 1 or 2 last gasps...hopefully.

[Weather Will]

Latest WB AI for the 12th.

[mattie g]

1 hour ago, Weather Will said:

Latest WB EPS extended is warmer than yesterday's run...will need to be watched for any new trends.

 

What do the TT or PW or SV EPS say?

[mitchnick]

16 minutes ago, Weather Will said:

Latest WB AI for the 12th.

More than that 6 hour panel has precip.  This is 24hr total while cold enough for snow.

[Scarlet Pimpernel]

44 minutes ago, psuhoffman said:

Because it’s still rushing. We probably don’t go left sustained cold until Feb 20 or later. 

Not sure if I totally understand what you're saying.  Both of those plots show the period after the Feb. 20 date you mention (they cover Feb. 22-Mar. 1).  I don't see what you mean by it's still "rushing" based on that.  Regardless, not going to fret over subtle changes in weeklies a month from now just yet.

[bncho]

8 minutes ago, mitchnick said:

More than that 6 hour panel has precip.  This is 24hr total while cold enough for snow.

Thats a nice 6-10" verbatim.

[Scarlet Pimpernel]

9 hours ago, WxUSAF said:

I like big splits and I can not lie

You other weenies can’t deny

When the strat walks in with an ittybitty waist and a round thing in your face

You get COLD!  

You win the interwebs today, sir!!  LOL!!!

And that plot...just seems like a @ravensrule bat signal right there!

[psuhoffman]

32 minutes ago, Scarlet Pimpernel said:

Not sure if I totally understand what you're saying.  Both of those plots show the period after the Feb. 20 date you mention (they cover Feb. 22-Mar. 1).  I don't see what you mean by it's still "rushing" based on that.  Regardless, not going to fret over subtle changes in weeklies a month from now just yet.

They’re warmer because week 3 shifted warmer. The rest is too far out to care and often just tries to to resume a status quo enso look.  They keep teasing a faster flip then backing off.  I think we do get a cold shot for a few days around Feb 10-13 but then warm up again. Any permanent flip is closer to or after Feb 20 and too far out for guidance to see yet.  What it does see is the AO starting to go negative again.  Without as hostile a PDO the warmth is on borrowed time once that happens.  

[87storms]

Busy workweek, but did check out the latest enso ppt last night. Seems like La Niña is starting to flex a bit. I guess we’ll need the mjo to swing back around and get the southern stream active again? Otherwise the upper level pattern the last few times I checked seemed reminiscent of last year. That said, I’ve got some catching up to do on this thread and the models.

[Scarlet Pimpernel]

11 minutes ago, psuhoffman said:

They’re warmer because week 3 shifted warmer. The rest is too far out to care and often just tries to to resume a status quo enso look.  They keep teasing a faster flip then backing off.  I think we do get a cold shot for a few days around Feb 10-13 but then warm up again. Any permanent flip is closer to or after Feb 20 and too far out for guidance to see yet.  What it does see is the AO starting to go negative again.  Without as hostile a PDO the warmth is on borrowed time once that happens.  

OK thanks...I see a bit more what you're saying.  So while the "Feb. 20 and beyond period" might be the true flip to predominantly colder (and hopefully snowier!), those weeklies appear "less cold" only because the prior period is not as cold right before that (hence, "rushing" the change).  Hope I worded that correctly.

[Daniel Boone]

23 minutes ago, psuhoffman said:

They’re warmer because week 3 shifted warmer. The rest is too far out to care and often just tries to to resume a status quo enso look.  They keep teasing a faster flip then backing off.  I think we do get a cold shot for a few days around Feb 10-13 but then warm up again. Any permanent flip is closer to or after Feb 20 and too far out for guidance to see yet.  What it does see is the AO starting to go negative again.  Without as hostile a PDO the warmth is on borrowed time once that happens.  

Exactly what the longer-range guidance does. Enso is factored in highest. Good explanation and points man.

[snowmagnet]

5 hours ago, Eskimo Joe said:

Holy moley that is terrible. Prime climo and we're torching. JFC.

It's not always bad. We frequently have big warm ups a couple days before a big storm. I'm pretty sure we were around 70 a couple days before Blizzard of 2016. 

[Maestrobjwa]

3 minutes ago, snowmagnet said:

It's not always bad. We frequently have big warm ups a couple days before a big storm. I'm pretty sure we were around 70 a couple days before Blizzard of 2016. 

Nah we were cold a solid week before that storm. It did hit 70 on Christmas Day the previous month though, lol

[dailylurker]

9 minutes ago, snowmagnet said:

It's not always bad. We frequently have big warm ups a couple days before a big storm. I'm pretty sure we were around 70 a couple days before Blizzard of 2016. 

The day after the 2016 storm was a bluebird 28 degree day. The next day was 70 lol. It was the tail end of a deep winter period that lasted about a week. Other than that stretch of cold it was a pretty mild winter. 

[CAPE]

 Hell of a front. Then back into the 60s by the 15th. Just an op run at range but looks like some volatility in the longwave pattern the first couple weeks of Feb. Buckle up. Probably a chance or 2 of frozen in there.

 

[CAPE]

Nice gradient pattern. A well timed wave could bring a moderate snow event. Op and ens guidance have been hinting for this timeframe.

[clskinsfan]

4 hours ago, TheClimateChanger said:

3" of snow over 15 days at Pittsburgh from an ensemble mean, which is probably being affected by a few low-probability outliers. That's like 40% of normal. Not a very impressive snow signal IMHO.

Who gives a shit about Pittsburgh bro?

[clskinsfan]

14 minutes ago, CAPE said:

Nice gradient pattern. A well timed wave could bring a moderate snow event. Op and ens guidance has been hinting for this timeframe.

That NAO though... Ugly. We'll see. 

[gymengineer]

1 hour ago, dailylurker said:

The day after the 2016 storm was a bluebird 28 degree day. The next day was 70 lol. It was the tail end of a deep winter period that lasted about a week. Other than that stretch of cold it was a pretty mild winter. 

I don't know why this gets repeated on here. That's just not true about the days following the 2016 Blizzard. 

Here's BWI: 

2016-01-22	28	19	23.5	-10.4	41	0	0.33	3.7	0
2016-01-23	28	22	25.0	-8.9	40	0	1.80	25.5	12
2016-01-24	34	14	24.0	-9.9	41	0	0.00	T	26
2016-01-25	38	8	23.0	-10.9	42	0	0.00	0.0	24
2016-01-26	52	19	35.5	1.5	29	0	T	0.0	22
2016-01-27	44	24	34.0	0.0	31	0	T	0.0	13
2016-01-28	42	17	29.5	-4.6	35	0	0.00	0.0	10
2016-01-29	41	25	33.0	-1.2	32	0	0.01	T	8
2016-01-30	43	18	30.5	-3.7	34	0	0.00	0.0	8

 

Here's DCA:

2016-01-22	29	22	25.5	-11.5	39	0	0.51	6.5	0
2016-01-23	29	24	26.5	-10.6	38	0	0.97	11.3	14
2016-01-24	35	19	27.0	-10.1	38	0	0.00	T	18
2016-01-25	42	16	29.0	-8.2	36	0	0.00	0.0	17
2016-01-26	52	30	41.0	3.8	24	0	T	0.0	10
2016-01-27	48	31	39.5	2.2	25	0	T	0.0	4
2016-01-28	40	25	32.5	-4.9	32	0	0.00	0.0	4
2016-01-29	43	28	35.5	-1.9	29	0	T	T	3
2016-01-30	42	24	33.0	-4.5	32	0	0.00	0.0

[CAPE]

31 minutes ago, clskinsfan said:

That NAO though... Ugly. We'll see. 

-NAO not always required for snow.

[anotherman]

Am I correct in saying we didn’t have one in 2013-14?

[CAPE]

13 minutes ago, anotherman said:

Am I correct in saying we didn’t have one in 2013-14?

Other than something  transient, -NAO wasn't a thing that winter.

[Stormchaserchuck1]

Monster -PNA ridge Days 10+ on the 18z GEFS. Unfortunately, a +300dm mean isn't likely to reverse in time for  verification time. We could be waiting until after mid-February for snow.. 

Does late Feb get colder? The MJO if it stays strong may go through favorable phases then, but I think the late blooming Nina is having somewhat of an impact and this may carry into the end of the month. -EPO tendency this Winter has been strong, but I almost feel like we are becoming "due" for a +EPO period going into the start of March.  They say the uniform +PNA we saw late Nov - mid January is something that comes back, but we seem to be doing just as an extreme -PNA catch up now, somewhat neutralizing the probability for what happens next.. 

[Stormchaserchuck1]

1 hour ago, CAPE said:

Nice gradient pattern. A well timed wave could bring a moderate snow event. Op and ens guidance have been hinting for this timeframe.

In the long range, you want to look at what's happening over the index regions.. That's a big +NAO/-PNA, the odds of snow in that pattern are slim to none. The hope maybe is that future models change on the H5 pattern, but there is a lot of adjustment that would need to happen. 

[mitchnick]

18zAI still likes 5th and 6th with a light to moderate threats.

There's a front end snow threat for late 8th thru 9th, which is new.

12-14th is now warm, but that could change completely at 0z so I'd stick with the ensembles because at that range, the AI is just another ensemble member.

[mitchnick]

16 minutes ago, Stormchaserchuck1 said:

Monster -PNA ridge Days 10+ on the 18z GEFS. Unfortunately, a +300dm mean isn't likely to reverse in time for  verification time. We could be waiting until after mid-February for snow.. 

Does late Feb get colder? The MJO if it stays strong may go through favorable phases then, but I think the late blooming Nina is having somewhat of an impact and this may carry into the end of the month. -EPO tendency this Winter has been strong, but I almost feel like we are becoming "due" for a +EPO period going into the start of March. We'll see.  They say the uniform +PNA we saw late Nov - mid January is something that comes back, but we seem to be doing just as an extreme -PNA catch up now, somewhat neutralizing the probability for what happens next.. 

I don't dispute the indexes, but when you look at mean 850 temps, they are cold thru days 10-15. It's not until day 16 when they are warm. The link below starts day 10.

https://www.pivotalweather.com/model.php?m=epsens_opendata&p=850tw-mean&rh=2025013012&fh=240&r=conus&dpdt=&mc=&pwplus=1