Winter 2013-14 Pattern Discussion III

[superjames1992]

Correct me if I'm wrong, but aren't surface temps closer to 40? Maybe my maps are just a bit too crude. 850's don't look bad though.

 

Edit: I looked again. Verbatim it looks like it would start as snow but change to rain for the heaviest precip.

 

I don't know; I don't have surface temperature detailed maps... I just see the 0C surface isotherm isn't too far north of us and it's hard for me to see that being rain if that setup played out (no doubt I'd rather have a better HP to the north, though).  I'm not positive what the model spits out verbatim, but I'd take my chances.  The 850 mb 0C line definitely gets very close to CLT and GSO and might even change us over for a bit, but I'd think you guys in the mountains would be golden.

 

Not that it really matters since the 00z GFS is about to spit out something different.

 

EDIT: 00z GFS flizzard for NC at hr 204.  All-in!

 

EDIT #2: And our February 27th storm looks like a Clipper or some BS on the 00z GFS.

 

Anyways, it's time for my to take a break from model-watching for a few days.  There's really no point in doing so at this point and it's time to enjoy the warm-up for a little bit.

[jacobr57]

I don't know; I don't have surface temperature detailed maps... I just see the 0C surface isotherm isn't too far north of us and it's hard for me to see that being rain if that setup played out (no doubt I'd rather have a better HP to the north, though).  I'm not positive what the model spits out verbatim, but I'd take my chances.  The 850 mb 0C line definitely gets very close to CLT and GSO and might even change us over for a bit, but I'd think you guys in the mountains would be golden.

 

Not that it really matters since the 00z GFS is about to spit out something different.

 

Yea, not much to model watching 240 hours out. I'm mostly just trying to get a better feel for reading the maps.

[FLweather]

Yea, not much to model watching 240 hours out. I'm mostly just trying to get a better feel for reading the maps.

 

Nothing wrong with that... but why in the hell are you over analyzing the surface map with something near 240 out.

 

Best to look at the 500 flow and surface to get an idea of the future. Good news is after Saturday the warm spell looks to be over.

[Jon]

Pretty strong signal for another branch hook-up 2/25-2/28...  

signal228.JPG

 

signal252.JPG

 

signal.JPG

18z GFS ens mean on-board, looking like the 27th right now, day 11.

 

18zgfsensmean.JPG

Looks like a huge win for the Euro weeklies, they were sniffing out this deep ridge with complimenting deep east coast trough starting 2/10, 420 hours out. I decided to post when a second run (2/13) showed it and what do you know, all models follow suit. I'm loving it.

Also folks don't get too involved with 850's and high placement, etc. this far out, it's going to change with various strengths of this trough depending on how much that ridge builds, we're going to get different scenarios (inland, off the coast, etc) and before you know it a weenie solution is going to be spit out (the Euro control has already done that). Hang tight and wait for it to sort itself out, and track when there's actually some consistency, haha.

[Shawn]

Here is what I put over on my forum.. and I think it applies to everyone here to an extent:

 

edit! (1800th post yay!)

 

 

Start looking towards the GGEM, JMA, and EURO.  They will handle what's about to happen better.

What I mean by this.. is the "overall" pattern.

There is a storm showing up with a potential "cold air source" instead of relying on a "high pressure" to set up damming.  But.. on the flip side... there are models showing many strong high pressures moving across/into the Northeast to potentially cause some havoc too.

The basic idea here is.. there will be a major cool down at the end of the month/into March.. but it could just be cold instead.  Widre had said something about the trough being too far east on the ensemble means.. and honestly it is.  The Southern stream could hook up again (phase) and we could see another overrunning event.  If you guys live in ATL/South and KCAE/South.. you want a Miller A track out to sea.  For you guys up in the NW upstate and NE GA; you'd have to worry about surpression of system off the Southern stream.  We are about 100% climo (time period) for big Winter storms into the deep/southern parts of the Southeast.  What I mean is you guys in the Northern areas could see some stuff.. but the heavy axis/good Winter QPF would be South of you due to a cold air mass being in place.

If tonight's EPS members (at least 5) jump on board of winter weather around these parts; I will definitely feel confident of a real threat happening.

[Iceagewhereartthou]

Snow rate trumps warm ground and sun angle.  If it snows hard enough, it will accumulate.

Are you including surface temps in this equation? If so what you say is only to a certain point. March 09 I saw Thundersnow with insane rates for hours but only managed about 4 1/2 inches because temps were 34 the whole time. Had it been below 32 we would easily had a foot or more. Have seen similar though less obvious examples many times before. 

[GaWx]

Folks,

 The 0Z Euro is very cold starting 2/25 with not one but two Arctic airmasses dropping into the region. :)

[SD1]

Latest from DT:

 

Wxrisk.com

http://www.youtube.com/watch?v=4kr0ibQAcYM

 

 

[GaWx]

1) The 0Z Euro ensemble mean fully supports the idea of two Arctic highs bringing solidly below normal temp 's last few days of Feb. followed by a hint of CAD and ZR threat ~3/1-3 for mainly WNC. Week # 2's Euro weekly this evening should look interesting.

2) The 6Z GFS has no fewer than 4 Arctic highs plunging down late Feb. into 3/5! It gets down to a frigid -16C at 850 at KATL on 2/27 (with light snow coming in with the intense cold in much of the SE fwiw).

[Cold Rain]

You and Jack Benny! Pretty good chance for blocking to show up now, especially if this is your first turn at 39 Goofy has kept the possibility open for a few days now. I'm expecting chances thru March, at least until the heater shows up, and so far, no heater....and rains still coming. T

It's the second attempt, actually, but the approximation is still valid. Earlier this winter, and even in several winter forecasts, there were indications that blocking would show up toward the second half/end of winter. Some modeling has been inconsistently showing this. Hopefully, we can start to see it unfold before winter is done. I haven't looked at the models in a couple of days, other than what's been posted here. I am off today and will get back on it tomorrow. Hopefully, there will still be some winter fun ahead.

[max100]

1) The 0Z Euro ensemble mean fully supports the idea of two Arctic highs bringing solidly below normal temp 's last few days of Feb. followed by a hint of CAD and ZR threat ~3/1-3 for mainly WNC. Week # 2's Euro weekly this evening should look interesting.

2) The 6Z GFS has no fewer than 4 Arctic highs plunging down late Feb. into 3/5! It gets down to a frigid -16C at 850 at KATL on 2/27 (with light snow coming in with the intense cold in much of the SE fwiw).

3 degrees, OMG..

[Tony Sisk]

 

Yep. I post this about 2 years ago. Interestingly, Floyd County VA. received almost 30" in this weeks storm.

 

Snowfall rate trumps everything else. The heaviest snow I was ever in occurred April 27 or 28 in Floyd County Va. in the late 70s. Long time ago and not exactly sure of the date. It had rained heavily over night and was still raining. We had just arrived at the HS school where I was teaching and was surprised to notice cars from the western end of the county with several inches of snow on them coming into the parking lot. As school started the change over occurred and it began to snow heavily. Even though the ground was wet and warm it covered completely in a few minutes. Puddles first turned to slush and then covered. The principal called NWS in Roanoke because the forecast was heavy rain but he was getting worried about bus travel. The met told him it could not be snowing because it was to warm. I won't repeat what he told the met. The met then said there must be a small pocket of cold air aloft and it would quickly change back to rain. An hour later we were dismissing school with 4 inches on the ground and snow pouring down. After the buses struggled out of the parking lot a Va HP car came into the lot to tell us not to dismiss because there was already 14" of snow in the western part of the county. 

 

The snow continued until just after noon and had deposited about a foot when it let up and the sun popped out. You could hear the water rushing down the gutters in the street. After 30 minutes it got very dark like just before a summer thunderstorm and then all hell broke loose. It poured snow with thunder and lightning every few minutes for several hours. I grew up in NW NJ and have never seen it snow like that. By 8pm we had over 30" in town even though it was still melting from the bottom. Reports of more in the higher western end of the county. Trees were leafed out and falling all over as the snow was extremely wet and sticky. Transformers flashing green as one after another they shorted out. I periodically went outside with a sedge hammer and whacked the trunks of my trees to relieve some of the weight from the banches. In those days the clocks weren't changed to DST until April so it seemed surreal to see it snowing on full leafed trees in daylight at 8pm.

 

So that snow fought very wet warm ground, extremely high sun angle and marginal temps and still put down the heaviest accumulation in the shortest time I have ever seen. Little to no notice was taken of this event outside the county. Floyd is very rural and even today, 30+ years later, there is only one stop light in the entire county. Temps approached 80 the next two days and the snow disappeared almost as fast as it had fallen. We did miss two more days of school for mud. Lots of dirt roads were bus routes. 

 

 

great story, thanks for sharing again!

I remember a couple years ago being at Timberline Ski Resort for their last weekend being open. The friday was Aloha Day. Girls were skiing in bikinis. It was 65 and everyone was in short sleeve shirts at the most.

The next day was heavy snow all day long. About 14" fell. Not near your story...but I promise you that we enjoyed it!

[GaWx]

3 degrees, OMG..

Yep, 3 F at 850 mb at KATL on 2/27 per the 6Z GFS and staying in the 20's on the ground all that afternoon per this run verbatim! The lows on 2/27-3/1 are all in the 18-19 F range. This winter is already in the quite memorable group, but this very cold late Feb . to early March period would be delicious icing on the cake. All indications are that this is not a mirage and that winter isn't done flexing its muscles. It would be an extra bonus if we could get still more wintry precip. out of it. I'd think that there'd at the very least be a threat of something minor for many areas. Another big impact event for a good number of even nonmountainous areas would be quite realistic with this kind of pattern. Of course, NC would be in the driver's seat, but I'd have a reasonable hope for GA/SC, too. Could we get a 2nd super-CAD event in the same season after a good number of years of none? Even if we just mainly get the cold, it would be an exclamation mark on a really good winter.

Edit: Now if we get a super-CAD and can get Tony nice sleet while keeping the ZR at bay....

[dsaur]

1) The 0Z Euro ensemble mean fully supports the idea of two Arctic highs bringing solidly below normal temp 's last few days of Feb. followed by a hint of CAD and ZR threat ~3/1-3 for mainly WNC. Week # 2's Euro weekly this evening should look interesting.

2) The 6Z GFS has no fewer than 4 Arctic highs plunging down late Feb. into 3/5! It gets down to a frigid -16C at 850 at KATL on 2/27 (with light snow coming in with the intense cold in much of the SE fwiw).

That's how Goofy got my interest a few days back...bring down the highs.  This last little dab melted by noon Wed.  If you aren't going to get cold air in behind, may as well be a March/April barely here before it's gone novelty, lol.  Need some real cold in after to cement it down.  Anyway, it's getting time for a triple phaser March repeat...a bit over 20 years is about right, lol.  I know I'm ready, as always.  T

[SnowNiner]

What I'm interested in seeing and I'm really going to put more stock in to is the development of the southern stream.  That made this last storm we had really.  The northern stream systems simply never seem to work out. 

 

So even through we get a nice big ridge out west and trough in the east, that's only have half of the equation.  Usually that's just cold and dry.  There needs to be an active southern branch or at least a split flow to get the storm. 

 

This year I'm good.  Got a nice storm so I'm completely satisfied.  Next year I'm really hoping for the Nino cause that active southern stream it brings usually helps us cash in more often than not. 

[MichaelJ]

Bastardi is trumpeting a potentially very stormy cold period in the 15-25 day time frame with multiple storms following a far southern storm track from Tx. to Ga. and then up with cold Highs to the North in what could be a snowy period for most in the SE and up the coast. He also thinks we could see near record cold by the end of February..

[mackerel_sky]

Would like to hear if Roberts thoughts are close to this? It looks to get much colder after this weekend. I guess the questions are how cold and will there be any storms to tap the cold?

[mackerel_sky]

Bastardi is trumpeting a potentially very stormy cold period in the 15-25 day time frame with multiple storms following a far southern storm track from Tx. to Ga. and then up with cold Highs to the North in what could be a snowy period for most in the SE and up the coast. He also thinks we could see near record cold by the end of February..

Did he actually mention wintry weather in the SE , or are you extrapolating ! Not that I don't believe you, he never mentions the SE, unless it going to somehow benefit theNE, lol

[CarlHill]

What I'm interested in seeing and I'm really going to put more stock in to is the development of the southern stream.  That made this last storm we had really.  The northern stream systems simply never seem to work out. 

 

So even through we get a nice big ridge out west and trough in the east, that's only have half of the equation.  Usually that's just cold and dry.  There needs to be an active southern branch or at least a split flow to get the storm. 

 

This year I'm good.  Got a nice storm so I'm completely satisfied.  Next year I'm really hoping for the Nino cause that active southern stream it brings usually helps us cash in more often than not. 

Kind of far away, but a big swing from 3 days ago.

[GaWx]

 Verbatim fwiw, the 12Z GFS gives a sig. snow for all of NC on 2/26 with even some in far NW GA and NE SC from a Miller A. It doesn't give a major (say 4"+) hit to most outside of N NC partially because the cold air is incoming at the same time instead of already being there. So, much of it is rain until late most areas.That's why ATL-AHN get little snow, if any..cold chasing away precip. Of course, NC is often in the driver's seat as far as wintry precip. chances per climo.

[FLweather]

Yeah there seems to be good agreement among the GFS/Euro about breaking down our temporary SE ridging after Saturday. Then developing a EC trough with PV in eastern Canada with ridging extending into Alaska along with a split flow.

 

Too early to get in on the specifics but looks like a repeat possible with energy dropping out the NW combining with energy embedded in the SJ. With such a broad scale trough the cold will be there... much like the last one.

[Shawn]

Haven't looked at other modeling yet.. but I can say the 00z EPS now has 4 members with frozen precip in kcae and 3 in ATL.

 

This is how it always starts with the Euro EPS.  If more members start to jump on board consistently per run with Winter precip around these parts... It'll definitely be worth tracking.

 

12z EPS members will be interesting.. especially looking at a couple images of the GFS posted above.

[GaWx]

Folks,

 The 12Z Euro continues with its strong suggestion of the return of intense and even record cold to some of the E US starting ~2/25 and remaining through the end of the month at the very least. Lows get down into the teens below zero in Chicago and much of the upper Midwest between 2/26 and 2/27! That would obliterate the record lows of -1/-6 at Chicago for 2/26/2/27 with 850's as cold as ~-25 C! The point is that it is showing it to get about as cold as it can get there in late Feb. Furthermore, there's another very cold airmass lurking in W Canada. This extreme cold sets up the possibility of a major CAD event to follow (say, ~2/28-3/3) as the cold reaches the NE US though that's would be past this run. We'll see. Neutral negative ENSO is as favorable as any ENSO phase fwiw.

[Shawn]

Interesting to see the CFS plant the deep south with snow well into march... even below avg temps into April!

 

I think this cool down is definitely real.  Now we have to start looking for storm signals.... the 12z GGEM has an interesting system around hour 240... too far out for specifics though.

[GaWx]

Interesting to see the CFS plant the deep south with snow well into march... even below avg temps into April!

 

I think this cool down is definitely real.  Now we have to start looking for storm signals.

 

Would you please provide a link to CFS snowcover? TIA.

[Shawn]

Would you please provide a link to CFS snowcover? TIA.

 

I'm using the pay maps; hopefully someone else knows where to get the free ones?  I'll try to google some up.

[GaWx]

I'm using the pay maps; hopefully someone else knows where to get the free ones?  I'll try to google some up.

 

Thanks. I bet today's Euro weeklies are going to look "delicious" for at least week 2.

[Shawn]

Thanks. I bet today's Euro weeklies are going to look "delicious" for at least week 2.

 

I'm seeing just a lot of grib data.  The pay ones i have on wxbell are pretty low resolution but some do show snow almost to the FL panhandle through mid March.  It is the CFS though.. and it's not that amazing.. its better to notice trends.. and it's down right below average for a big chunk of time.

[weatherheels]

Anytime I see a big western ridge being progged on the models I really get excited...  I really do think we're gonna have a pattern reload and go through a couple weeks of cold before we break into spring.  

[burgertime]

The 28th does look interesting on the GFS and Euro. @234 it looks like the Euro is playing it's bias of holding energy back. If that system ejected it could be another big one coming down the barrel.