Winter 2014-2015 Pattern Discussion Thread I

[tnweathernut]

Man that's a strong wave on the euro. Too bad it's the 10 day op.

Looks Canadian"ish", doesn't it?

[superjames1992]

The 12z Euro looks primed for a possible ice storm in the CAD regions post-D10, though it's hard to say for sure.  It's certainly not a snowstorm, though, aside from maybe the NW side of the ULL, where it seemingly pounds NW AR with heavy snow.

 

The 12z Canadian had a really bad ice storm for CAD Central with snow in the mountains at D10.

 

Of course, the 12z GFS has the low much further north and tracks it from N AL to N NC.  No snow/ice for anyone.

 

Not excited by any means, but I'm finally done with finals, so I might as well watch it.

[tnweathernut]

Good signal on the 12z Euro for a very moist storm, but cold air will obviously be a big issue, probably too big for most (if not all) to overcome.  JMO

[Webberweather53]

If my data is correct, here in KCAE the 1973 record snow storm in this state.. here were what the high temps looked like:

 

Feb 1, 70F

Feb 2, 70F

Feb 3, 55F

Feb 4, 64F

Feb 5, 68F

Feb 6, 68F

Feb 7, 54F

Feb 8, 64F

Feb 9, 48F - snow later on

Feb 10, 32F heavy heavy snow.

 

After those dates, we went to around normal or mainly above normal through the rest of the month.  If these #s are correct, that means we went from +8F above average to 32 and the biggest snow we ever saw within 48 hours.  We started the month +10 above average.

 

Yeah 1972-73 was a bit odd given the fact we had a rather extensive & supposedly a rapidly advancing Siberian Snowpack (I've noticed for a while it has been a glaring exception to the general trend of the SCE/SAI even the QBO was deeply entrenched into easterly phase. I suppose in looking at the SSTs preceding the winter, they really weren't favorable, w/ a strong gradient in SSTs in the upper portion of the Gulf of Alaska & a pocket warmer than normal water showing up in the Kurioshio-Oyashio Extension (likely a manifestation of the strong -PDO that was prevalent throughout the early-mid 1970s...) & warm water also showing up halfway between North America & Europe in & around 40N on what I have noted before as a "critical" latitude in this case was not a good signal for blocking over Greenland...)

 

I also suggest this El Nino's proximity to a preceding multi year warm ENSO event (1968-70) also contributed to the unusual behavior observed in 1972-73 with a +AO noted despite the aforementioned extensive October Eurasian snowpack which currently stands as the 7th largest on record. This year is of course about as far as we've ever been from a multi yr warm ENSO event w/ the last one ending in 2004, & is more in line w/ the big -AO El Nino winters. This shows there's certainly more to forecasting a winter's AO than looking at the Siberian snow cover extent and advance index...

 

For a strong El Nino, the temperature distribution of 1972-73, especially in the early stages of the winter was virtually the opposite of what's typically expected w/ such preset conditions. Anomalous warmth in the southeast & cold to the north & west??

 

 

 

Strong El Ninos (aside from 1972) Dec US temps

 

 

 

The 1972-73 winter finally behaved more "normally" in February...

 

 

[RONALD B]

Good signal on the 12z Euro for a very moist storm, but cold air will obviously be a big issue, probably too big for most (if not all) to overcome.  JMO

cut off lows if stronger enough carries it's own cold top left too bottom  side gets snow! track will be important but it can also tap in too cold as the model trends or gets closer ? 

[Cold Rain]

Southern stream cutoffs aren't the best for cold air production are they?

[tnweathernut]

cut off lows if stronger enough carries it's own cold top left too bottom  side gets snow! track will be important but it can also tap in too cold as the model trends or gets closer ? 

It's too far off to determine what type of system will be there, but there is a good signal for a storm of some kind. 

[RONALD B]

It's too far off to determine what type of system will be there, but there is a good signal for a storm of some kind. 

Yes i agree but it's some thing too track if a big trough was too get pulled down then we would be talking .

[BullCityWx]

Southern stream cutoffs aren't the best for cold air production are they?

I just don't see like the cold air.

[BullCityWx]

In my opinion, that map as depicted on the euro, is at best 35 and rain.

[burgertime]

I just don't see like the cold air.

 

Euro you can see is strong enough that it's creating it's own cold air on the backside....but it would have to be a monster like it is depicting which is not very likely. On the Euro there is def. no major cold air around.  Kind of ugly at the surface. 

[superjames1992]

In my opinion, that map as depicted on the euro, is at best 35 and rain.

 

The final frame of the Euro (which would be at about dawn on December 20th) has CLT at 34, GSO at 30, and RDU at 30.  The high the day before was in the low 40s.  The precip is still awhile away, but you are probably right, actually.  Looks like N GA gets nice mid-30s and RN.  Might end up being the same here once the clouds roll in.  Wind speeds are 4-6 knots out of the NE.  Dew points are in the low 20s.

 

850s are a couple degrees Celsius above freezing, so there's no snow, obviously.

 

It's a D10 plot, so I don't even know why I'm parsing it this much aside from boredom. 

[tnweathernut]

I just don't see like the cold air.

There isn't any.

[metwannabe]

It's too far off to determine what type of system will be there, but there is a good signal for a storm of some kind.

More interested in the period after that which takes us into christmas week

[LithiaWx]

Going to need a cold tap, there isn't one now, or one modeled in the next 10 days on any guidance.  We wait while met winter is evaporating little by little......

[RONALD B]

Yall need too realize this  12 model yesterday was crap an today it has trended toward last night 0 run which was colder looking an many cold highs too tap into too. tonight 0 run will be intersting but todays run was just a trend torwards what we want i n the long run maybe ?

[BullCityWx]

Yall need too realize this 12 model yesterday was crap an today it has trended toward last night 0 run which was colder looking an many cold highs too tap into too. tonight 0 run will be intersting but todays run was just a trend torwards what we want i nthe long run maybe ?

We should make you into a meme.

[Southern Track]

Euro you can see is strong enough that it's creating it's own cold air on the backside....but it would have to be a monster like it is depicting which is not very likely. On the Euro there is def. no major cold air around.  Kind of ugly at the surface. 

On the 0z  Euro that system was further south and east and there was more of a cold presence to our north on the Operational.  

 

It was a better look than the 12z, but it's irrelevant nine plus days out.

[tnweathernut]

More interested in the period after that which takes us into christmas week

I am more interested in seeing if we shut off the southern stream for a while when we finally do poke the ridge up in the west.  My fear is turning to a cold pattern at the same time we shut off the "wet" valve for 2-3 weeks.

[packbacker]

At day 10 for the system on the 12/17 the Euro was showing this...

 

 

 

Now, 3 days later it's showing this for the same system...

 

[metwannabe]

I am more interested in seeing if we shut off the southern stream for a while when we finally do poke the ridge up in the west. My fear is turning to a cold pattern at the same time we shut off the "wet" valve for 2-3 weeks.

No doubt it could be an issue but I feel like most would still take their chances with a western ridge even if the STJ shuts off. Would just need to find some energy diving in on the backside of the trough

[BNAwx]

I am more interested in seeing if we shut off the southern stream for a while when we finally do poke the ridge up in the west.  My fear is turning to a cold pattern at the same time we shut off the "wet" valve for 2-3 weeks.

 

Hopefully we keep or muster up a split flow.

[rduwx]

I am more interested in seeing if we shut off the southern stream for a while when we finally do poke the ridge up in the west.  My fear is turning to a cold pattern at the same time we shut off the "wet" valve for 2-3 weeks.

 

Hopefully we can keep the southern stream active as well.  If not, we all know Brick loves cold and dry!

[Webberweather53]

Holy sheet!! Get a load of the 12Z GEFS around Christmas. Talk about a pattern change! This is the coldest late week 2 run yet.

 

Hint: if this verifies closely, wow! Now that's quite a western ridge/eastern trough couplet!

 

I can somewhat buy into this sort of pattern but remain a bit more cautious than some & I think it's futile at this juncture to claim whatever is coming down the pipe as all rain or snow & make a confident determination on this, although liquid is a bit more favored by virtue of climo.... Considering that the CCKW is currently running the show in terms of equatorial forcing & is contaminating any actual MJO signal as evidenced by the RMM PCs trying to project "retrograde" the MJO back into the Maritime Continent (which doesn't make sense knowing the MJO propagates eastward only, thus the models are likely picking up on a resurgent CCKW not the MJO, we can give more credence to & treat the CCKW here more so like the MJO, just for the sake of simplicity. In saying this, the convectively enhanced phase of the CCKW will be crossing into the Indian Ocean in about 7-10 days or so (reminiscent to MJO phase 2), & in Dec in a +ENSO state, MJO phase 2 is generally the most conducive to cold/snow as the faucet starts to shut off on intraseasonal invigoration of the Walker Cell, forcing the Aleutian Low to lose amplitude & retreat, giving the ridge over the northern tier of the US/southern Canada an opportunity to briefly expand further north...

 

However, the handling of timing, strength, etc, by the models w/ packets of energy within the subtropical jet is usually atrocious at best, because the subtropical branch of the jet spans across relatively more data sparse regions of the northeastern Pacific (compared to the polar jet for example) & w/ appreciably less adequate & often accurate sampling of the environment encompassing systems within the jet, the models are often prone to significant errors, in many cases (as w/ the ECMWF over the southwestern US) even more so than what's observed w/ shortwaves in the northern branch of the jet...

 

I will be watching this closely though as I noticed last year w/ every major winter storm that hit NC, there was CCKW passage in the western Indian Ocean & Africa (30-60E)...

 

 

 

 

If you extrapolate the current CCKW filtered VP & try to attain a general idea on where we're headed over the next few weeks, it's plausible to think that we'll be nearing the 30-60E longitude near or just before Christmas... We'll see

[franklin NCwx]

Man alot of talk about a 10 day op run and a post about winter ticking away. Hopefully the other ensembles look as good as the gefs.

[metwannabe]

Man alot of talk about a 10 day op run and a post about winter ticking away. Hopefully the other ensembles look as good as the gefs.

Boy the 12z GGEM ensembles look really good as well

[Shawn]

If I'm not mistaken the GGEM is now using 4D, is that why we are possibly seeing it trying to "in some of our eyes" over do things on it's forecast now?  Maybe it's just because the resolution is better?  Opinions?

[franklin NCwx]

What a good looking pattern showing up on all ensemble guidance the week of Christmas. Maybe we can get help with the nao too.

[burgertime]

GFS parallel is a weenie dream in the LR on the 18z cold and shot after shot of moisture.

[Cold Rain]

GFS parallel is a weenie dream in the LR on the 18z cold and shot after shot of moisture.

Burger, do you get that out to 394? It only goes out to 240 on Tropical Tidbits. Good to finally see some weenie Op runs.