12Z Model Thread

[wxmeddler]

0Z ECM already showed this exact thing.

Once again the Euro leads the trend.

[CoastalWx]

Well that first wave setting off garbage cyclogenesis off the coast will be enough to disrupt the gulf stream baroclinic zone. I doubt we will see much through 180.

Yeah the first wave screws things up, but the next s/w just flies east and can't dig. The on and off, bomb vs OTS solutions seem classic for the flow depicted. It will be interesting to see how the ensemble mean looks.

[baroclinic_instability]

Should be worth noting about 1/4th of the GFS 00z/06z ensemble members showed potential, so it isn't all lost yet, but the GFS catching up to the ECM usually isn't a good thing. Still will prolly be model flip-flopping though as that southern stream wave...if it only track 100 miles N and a tad slower can change everything. A lot of meteorology needs to happen. But as I said in the 6z thread,this is a tad unusual noreaster event and highly sensitive to initial conditions. Nonetheless, I would give this a small chance of happening as essentially three differing upper level features need to phase at the exact same time. Not terribly likely.

[Ji]

HM knows that an La Nina storm that needs perfect phasing will probably not happen. I think we spent an entire winter once trying to phase storms and none of them worked out

[Guest someguy]

hr 81 rain for central va south...only light snow continues for northern va/dc

at hr 84 it starts to shear out....about .10-.25 of light snow for dc

it 90% over bny 81 hrs

[usedtobe]

HM knows that an La Nina storm that needs perfect phasing will probably not happen. I think we spent an entire winter once trying to phase storms and none of them worked out

As I noted yesterday, you need perfect timing of all the features. I think the 25% chance of happening reflected by the ensembles is probably about right. Of course that means there is a 75% chance of not happening.

[SBUWX23]

Well nothing really new, the GFS changes dramatically

Wonder if the ECM will follow suit

I think the bigger question is if the ECM continues to show what has been described in this thread because the 00z ECM was similar.

[Guest someguy]

[Ji]

As I noted yesterday, you need perfect timing of all the features. I think the 25% chance of happening reflected by the ensembles is probably about right. Of course that means there is a 75% chance of not happening.

Models will have an easier time in the El Nino with a STJ....models locked last year on the storm and never let up. There was not this much flip flopping. Discouraging run to say the least. If it dont snow soon, time will run up and it will be 60 degrees again

[buckeye]

yeah...crazy how fast this went downhill. seems like no matter how historic the pattern may be, the models only show a storm for about a day or two then lose it then stick with that. hopefully it's not the case this time but it seems to be another situation where everything has to go exactly right or we're stuck with cold/dry/occasional flurries.

meh, not really. Nothing in the modelling beyond 5 days has been very believable so far this season. The euro (as dt pointed out)....did nail this last storm over the midwest pretty consistently. But before that, the euro was showing a historic MECs for last wednesday from 8 or so days before.

In other words, stay tuned, wouldn't be a shock at all to see the 12z euro bring back a massive threat again..

Im just intriuged by the possiblility that we might have more accum snow coming in less than 3 days, when last night it looked like we (OV) were entering a long stretch of dry and cold. One step at a time, this pattern will probably hold a ton of surprises.

[baroclinic_instability]

As I noted yesterday, you need perfect timing of all the features. I think the 25% chance of happening reflected by the ensembles is probably about right. Of course that means there is a 75% chance of not happening.

Yes I agree, I would go even lower. Prolly more like 15/85 happening/not happening.

[Ridingtime]

Is the point of this post to show how bad the GFS is at handling the STJ?

[wxmeddler]

Should be worth noting about 1/4th of the GFS 00z/06z ensemble members showed potential, so it isn't all lost yet, but the GFS catching up to the ECM usually isn't a good thing. Still will prolly be model flip-flopping though as that southern stream wave...if it only track 100 miles N and a tad slower can change everything. A lot of meteorology needs to happen. But as I said in the 6z thread,this is a tad unusual noreaster event and highly sensitive to initial conditions. Nonetheless, I would give this a small chance of happening as essentially three differing upper level features need to phase at the exact same time. Not terribly likely.

This.. Alot needs to happen at once to make this happen. The meteorological equivalent of Robin Hood shooting an apple off our heads from 100 yards, even a little bit off and were . However, if you still want to hold out hope, then you need that southern stream about 12-18 hours earlier. Which is a tall order but not impossible with the (I know, broken record) sparse pacific data coverage. Oh and one more thing..

La Nina.

[Ridingtime]

Once again the Euro leads the trend.

How does going from one good model run to one bad model run define a trend? Don't you need at least 2 or 3 runs showing changes to call anything a trend?

[Ji]

meh, not really. Nothing in the modelling beyond 5 days has been very believable so far this season. The euro (as dt pointed out)....did nail this last storm over the midwest pretty consistently. But before that, the euro was showing a historic MECs for last wednesday from 8 or so days before.

In other words, stay tuned, wouldn't be a shock at all to see the 12z euro bring back a massive threat again..

Im just intriuged by the possiblility that we might have more accum snow coming in less than 3 days, when last night it looked like we (OV) were entering a long stretch of dry and cold. One step at a time, this pattern will probably hold a ton of surprises.

Euro is great at nailing midwest events but it flips like a dolphin with east coast events. Frustrating

[wxmeddler]

How does going from one good model run to one bad model run define a trend? Don't you need at least 2 or 3 runs showing changes to call anything a trend?

You cannot doubt that the GFS is playing catch-up to the Euro in the past 24 hours.

[usedtobe]

Yes I agree, I would go even lower. Prolly more like 15/85 happening/not happening.

I came up with those probabilities for a blog piece without only a quick look at the eyewall ensembles from last night which were a little more bullish. You're probably right. 17% probably of snow is still above climo which for 1.00" or more on Dec 19th at DCA is around 3%. I always thought some were hyping the potential a little too much based on yesterday's euro.

[Ridingtime]

You cannot doubt that the GFS is playing catch-up to the Euro in the past 24 hours.

I cannot doubt that the GFS is playing catch-up to one bad model run of the Euro, true. But before that the Euro showed a storm twice I believe. If the Euro shows a similar solution to the previous one you may have a stronger point, but as for now, there is nothing in my mind to call what we are seeing now a bad trend.

[Guest someguy]

the Low at 168 hrs is STILL there on the GFS.... and there are partial solutions to be considerted as well... it may not be either MECS or bust

[Guest someguy]

You cannot doubt that the GFS is playing catch-up to the Euro in the past 24 hours.

while that may be true it is NOT a trend

[Guest someguy]

anyone see 276 gfs?

[weatherweather]

Good point DT, while this storm may not be an MECS, it seems like there is a decent chance of a couple inches at east

[KEITH L.I]

have to say one thing about the 12GFS..it stays cold thru day 16..with other threats and the block is still there..should be a fun holiday

[Ridingtime]

anyone see 276 gfs?

I guess if anything, it's really nice to see the GFS long range forecast an overall stormy set up.

The GFS is so volatile though I feel, especially long range, but still, nice to see.

[earthlight]

GEFS means at 144 hours have a 1008mb surface low off the Outer banks

[ptb127]

Does the euro always have issues with systems in the STJ? And doesn't the GFS always have issues with a se bias?

Not saying anything... Just asking.

Sent from iPhone 4

[earthlight]

..And at 150/156 hours have the same low pressure heading just southeast of the 40/70 benchmark. A good bit further west than the 00z means.

[CoastalWx]

..And at 150/156 hours have the same low pressure heading just southeast of the 40/70 benchmark. A good bit further west than the 00z means.

Yeah, I was interested in how the ensembles look...not bad from being so far out. The op runs will struggle on the outcome, but always a good sign of the ensemble mean has it, especially if it goes west of the previous run from 12hrs ago.

[greg81988]

kind of an amateur, but why does the gefs show the storm while the gfs didnt show it for sunday? whats your take on the gefs showing the storm?

[earthlight]

Yeah, I was interested in how the ensembles look...not bad from being so far out. The op runs will struggle on the outcome, but always a good sign of the ensemble mean has it, especially if it goes west of the previous run from 12hrs ago.

Yeah I was surprised to see the good surface reflection on the means just off OBX. That's all we can really ask for right now. The track hooks just outside the benchmark. Not bad...and the good precipitation (for this range) gets to the I-95 corridor and east.