Medium Range-Long Range thread

[NaoPos]

Just to add to my previous post, 0z GFS hors 87-96 crank up a 75-85kt LLJ with heavy rains, (heaviest cape may to LI)... thats some serious windage potential.

[phlwx]

Wednesday's def going to torch and soak somewhat just in time to go back into the freezer (not as cold though).

[chubbs]

A nice series of threats once the cold air returns: 1) weak wave on arctic front friday, 2) clipper sunday, 3) a little stronger pacific/northern stream system D9 and then right on cue a  bigger southern stream system which reaches Ca around D10 as shown on Euro ensemble. 

[johnc]

Well SPC brings at least some of the CWA into the D4 (Wed) outlook.  Looks like from about Dover north to W Bucks Co and to the west.

 

Should be an interesting day.

[SnowGoose69]

Not sure what the hell the Euro is doing Days 7-10, keeps trying to drive sub 995 lows into NNE out of the Lakes.

[HM]

Here's what we know is true through mid-Feb:

 

1. Decreasing AO / -AO regime developing as descending SSW couples with favorable Tropical Pacific (huge wave breaker at 70mb right now with monster warming heading to NP).

 

2. NW PAC to Aleutian Low in the means NOT an Alaskan or GOA low. This means generally a positive to occasionally neutral PNA.

 

3. Cold source/PV sits in eastern Canada which will migrate south with the clipper parade pulling on it day 6-10. This should go nowhere through mid-Feb as source.

[Rainshadow]

Not sure what the hell the Euro is doing Days 7-10, keeps trying to drive sub 995 lows into NNE out of the Lakes.

I found out why. 

 

[Isotherm]

Here's what we know is true through mid-Feb:

 

1. Decreasing AO / -AO regime developing as descending SSW couples with favorable Tropical Pacific (huge wave breaker at 70mb right now with monster warming heading to NP).

 

2. NW PAC to Aleutian Low in the means NOT an Alaskan or GOA low. This means generally a positive to occasionally neutral PNA.

 

3. Cold source/PV sits in eastern Canada which will migrate south with the clipper parade pulling on it day 6-10. This should go nowhere through mid-Feb as source.

 

 

I think the pattern looks colder than normal overall through the 15th, the question is can we get some moisture in here? If the MJO can make it to phase 1, one would think the sub tropical jet activates a bit. Additionally, the GLAAM spike indicates we might see a pulse of storminess for early/mid feb. My primary concern right now is that we spend much of Feb cold and dry.

[anotherman]

We will get moisture. Just not on models yet.

[Isotherm]

We will get moisture. Just not on models yet.

 

 

The other concern w/ the lack of real -NAO blocking is that there's nothing to hold the cold in advance of sern stream stormiess. So I can also envision a scenario in which we're colder than normal, we warm up and rain, and then back into the freezer, due to the progressive NATL pattern. We'd probably see light events like we'll have tomorrow, but as far as 6"+ snows, the pattern looks questionable right now. We need the MJO wave to remain amplified and also good timing.

[HM]

I think the pattern looks colder than normal overall through the 15th, the question is can we get some moisture in here? If the MJO can make it to phase 1, one would think the sub tropical jet activates a bit. Additionally, the GLAAM spike indicates we might see a pulse of storminess for early/mid feb. My primary concern right now is that we spend much of Feb cold and dry.

The situation in the N PAC is a disaster with the NWP as several others have stated but the things I said are what we know is true. As the +AAM state takes over, the extended PAC JET around the subtropical High will become more "broken off" as the Aleutian Low takes control of the flow in the north. It doesn't matter exactly when this happens, but the split will occur from this...it has to. Let's say it happens by 2/5. The big low anomaly that the models are picking up on around then should come across the CONUS and bring a winter storm to us Feb 8-10.

[Rainshadow]

The other concern w/ the lack of real -NAO blocking is that there's nothing to hold the cold in advance of sern stream stormiess. So I can also envision a scenario in which we're colder than normal, we warm up and rain, and then back into the freezer, due to the progressive NATL pattern. We'd probably see light events like we'll have tomorrow, but as far as 6"+ snows, the pattern looks questionable right now. We need the MJO wave to remain amplified and also good timing.

 

In reality, this (struggling to get the pieces to fit together for a 6" + event) is closer to the climatological norm that what has occurred in recent winters. It looks like a bunch of nickel and dime events which is still better than last winter. The next two weeks still looks like the window. Assuming the MJO stays healthy and the torque runs its course (and without another ssw) the second half of the month doesnt look so good.  Good call on the Jan ssw occurring.

[am19psu]

Good call on the Jan ssw occurring.

Yeah, I've been meaning to say this too. Nice work, isotherm

[Rainshadow]

The other concern w/ the lack of real -NAO blocking is that there's nothing to hold the cold in advance of sern stream stormiess. So I can also envision a scenario in which we're colder than normal, we warm up and rain, and then back into the freezer, due to the progressive NATL pattern. We'd probably see light events like we'll have tomorrow, but as far as 6"+ snows, the pattern looks questionable right now. We need the MJO wave to remain amplified and also good timing.

 

I'm not good on pcpn event recognition beyond day 7, well maybe day 4, check that make it day 2.  . But the CPC 8-14 analog series is not that bad.  Very few shutouts, most had light to moderate events. Largest one was the "no surprise" storm in Jan 2000.

[Isotherm]

In reality, this (struggling to get the pieces to fit together for a 6" + event) is closer to the climatological norm that what has occurred in recent winters. It looks like a bunch of nickel and dime events which is still better than last winter. The next two weeks still looks like the window. Assuming the MJO stays healthy and the torque runs its course (and without another ssw) the second half of the month doesnt look so good.  Good call on the Jan ssw occurring.

 

 

Yeah, I've been meaning to say this too. Nice work, isotherm

 

 

Thanks guys! I agree Tony that the next couple weeks will be our best shot of the winter thus far. Even if we can't get any southern stream going, there look to be a couple clipper threats which could conceivably produce some light or mdt snow.

[Isotherm]

I'm not good on pcpn event recognition beyond day 7, well maybe day 4, check that make it day 2.  . But the CPC 8-14 analog series is not that bad.  Very few shutouts, most had light to moderate events. Largest one was the "no surprise" storm in Jan 2000.

 

 

Agree, and I think we're definitely in the game for light to moderate events. I posted in NYC about the lack of NATL blocking as I think that's hurting our chances for achieving a 10"+/KU storm out of the upcoming regime. Nothing to slow down the short waves in an otherwise progressive northern stream. Hopefully we can get a clipper to throw-back some moisture as it redevelops, and/or overrunning events.

[am19psu]

Energy mets throwing in the towel because the only thing they know how to use is the Euro ensemble.

[famartin]

Energy mets throwing in the towel because the only thing they know how to use is the Euro ensemble.

 

I saw one or two posts on FB about that...

[Quakertown needs snow]

light white on 0z euro for  sunday?

[tombo82685]

light white on 0z euro for sunday?

Yea we get some but the best is to our north where the low is. Also doesn't help that some of the precip gets robbed by the coastal. Need that to track further south the main low.

[Ralph Wiggum]

Seeing some signals in the feb 3-7 period for a SWFE and I for one have been gung-ho for this range for a little while now, but I seem to be alone, so maybe it will happen, maybe it won't. That would bode well for a solid overunning event anyway since we can't get any high latitude blocking to set in and coincide with a favorable MJO/Rossby period.

[HM]

Energy mets throwing in the towel because the only thing they know how to use is the Euro ensemble.

[chubbs]

Yea we get some but the best is to our north where the low is. Also doesn't help that some of the precip gets robbed by the coastal. Need that to track further south the main low.

 

Think we have a better shot with the next wave on Tiuesday . More of a Pacific system which may take a better track.

[Capt. Adam]

06Z GFS has some light frozen on Sunday (hrs 150-156), more to the east.

 

A 2/5 overrunning event is there on both 00Z and 06Z.  

 

I believe the run consistency of the GFS has been quite good this year in the 5-7 day timeframe.  No, it's not perfect, and yes, it has waffled some on individual runs, but overall, I think the GFS has been a good indicator of the likelihood of an event and general intensity this year.  Did I really just type that?

[HM]

I wanted to post this here before the arrival of the 12z stuff etc.

 

Besides the 2/5-2/10 window, Matt and I have been discussing things down the road on the analogs toward 2/20. This second potential next month has growing support for a few reasons:

 

1. Tropical-induced MT in East Asia will lead to second +PNA spike mid-month

2. STJ should be established

3. Another -AO period develops second week of Feb

 

Forget about the actual dates though and keep in mind that there is analog support and support from other factors for a few winter storms this month. Nothing stands out as a "KU" but they don't look like moose knuckle clippers either.

[am19psu]

But the Euro ensemble says +3 D11-15???

[CoastalWx]

But the Euro ensemble says +2 D11-15???

 

 

I guess maybe from an HDD standpoint they are worried? But from what I care about and 99.9999% of other people....I think the pattern gets somewhat interesting...especially up here and possibly down your way. Winter doesn't always have to mean 498 thicknesses moving towards the northeast.

[am19psu]

I guess maybe from an HDD standpoint they are worried? But from what I care about and 99.9999% of other people....I think the pattern gets somewhat interesting...especially up here and possibly down your way. Winter doesn't always have to mean 498 thicknesses moving towards the northeast.

Even then, it's a total overreaction, particularly in this pattern where we know the models are going to be worse than usual

[CoastalWx]

Even then, it's a total overreaction, particularly in this pattern where we know the models are going to be worse than usual

 

I did get a laugh at some of these photoshops of winter '12-'13 on a headstone..lol.

 

We'll see...I'll always have hope with a split flow look and ridging in NW Canada...sign me up anytime. Even a east based -NAO to "help" keep the PV and cold air source in Canada. Maybe it gets more hostile at towards the end of Feb.

[usedtobe]

I did get a laugh at some of these photoshops of winter '12-'13 on a headstone..lol.

 

We'll see...I'll always have hope with a split flow look and ridging in NW Canada...sign me up anytime. Even a east based -NAO to "help" keep the PV and cold air source in Canada. Maybe it gets more hostile at towards the end of Feb.

 

I like seeing signs of a subtropcial jet and a nice ridge in western canada but that realy doesn't get going until after the 11th or 12th of feb. before then, I don't see much more snow chances for DC to philly than clipper type events.  I think we tend to rush things in terms of the MJO. The AO ought to go negative and stay there awhile.