December 9-10, 2018 Wintry Weather Threat

[KamuSnow]

28 minutes ago, Stormman96 said:

Now we lost the nam.  We are going in wrong direction 

I saw that, I guess it can still go further south. Yikes. Not giving up yet tho!

Eta - even the CMC has us high and dry now. GFS close to 18z again. Slip sliding away....

[penndotguy]

6 hours ago, KamuSnow said:

I saw that, I guess it can still go further south. Yikes. Not giving up yet tho!

Eta - even the CMC has us high and dry now. GFS close to 18z again. Slip sliding away....

And if you look beyond this fading threat, the following Friday 44 with rain. We all know that will verify Lol. It’s only December lot of fun times ahead I hope

[The Iceman]

Mt. Holly still not calling this one dead on their morning afd. It's a really good read. However we should see changes at 12z if what they are saying has any merit. Seems like they are just keeping their bases covered based on the huge errors inside 4 days we've seen over the last few on top of the heat they likely received from the November surprise storm. This one is dead though imo

[The Iceman]

here is mt holly's afd from this morning, there's a reason people consider them one of the best in the country... A+ stuff

 

Quote

Focus with the medium-range forecast remains on the evolution
of a southern-stream system traversing the southeastern U.S.
this weekend before moving offshore early next week.

Operational models are beginning to converge on a solution for
the strong surface low that develops near the Gulf Coast this
weekend. The 00z CMC has trended farther south toward the
GFS/ECMWF solutions, though it does remain on the northern
fringe of the guidance envelope. However, noticeable variability
remains with the northern-stream perturbations that will
interact with the southern- stream perturbation this weekend,
particularly the predecessor trough in eastern Canada late this
weekend. Of particular note, the 00z ECMWF is most progressive
with this trough, which acts to slow the surface low near the
Carolina coast Sunday night but also prevents much poleward
progress. The CMC/GFS are noticeably slower, which allows the
low to lift farther northward but also provides more of a kick
to the southern-stream perturbation on Monday. The GFS has
trended deeper and somewhat slower with the northern-stream
system in the past 24 hours, which suggests the ECMWF solution
may be a lower probability one.

Meanwhile, a second northern-stream perturbation digs south-
southeastward into the central plains on Sunday night, which
adds substantial complexity to the interactions of the southern-
stream surface low with the northern stream. Volatility with
this perturbation is very high run to run and model to model.
Notably, the GFS has trended slower and a little weaker with
this second northern-stream perturbation, which may be
suggestive of a slower push to the southern-stream system.
Operational guidance seems to be converging on a solution in
which a secondary low develops on the coast Monday night in
vicinity of the first low 24 hours prior. The model tendencies
are similar to the first low (CMC farthest north; ECMWF to the
south), but the GFS is slower with this second low (an obvious
result of the slower trend to the central U.S. perturbation).

What does all of this mean? My conclusion is that the models
converging on a solution may be a tempting lure, but I am not
biting quite yet. The perturbations in play here remain offshore
(prior to the 00z simulations, anyway), so I suspect some
decent initialization errors are contributing to model
volatility. Perhaps as importantly, the complex interactions of
these perturbations are extremely sensitive to
positioning/orientation/strength of the individual phenomena,
which is a telltale sign to use caution in the use of
deterministic solutions as a forecast starting point. I used a
healthy blend of continuity, ensemble guidance, and multi-model
consensus as a starting point, only subtly modifying the
forecast to account for the increased southern-track consensus.
Finally, I should note that we are still in the time window in
which models tend to be too far south and too progressive with
the southern- stream portion of these systems, so I maintained a
broad-brush approach to distribution of PoPs (and timing) as a
result of the remaining large uncertainty.

 

[penndotguy]

2 hours ago, The Iceman said:

here is mt holly's afd from this morning, there's a reason people consider them one of the best in the country... A+ stuff

 

 

MT Holly does have some interesting AFD’s they break it down so even idiots like. Me can half understand, if I recall last winter was the same with major changes within 2-3 days

[The Iceman]

GFS ticked North, CMC ticked south. Nothing significant though, if anything seems like we are converging on a final solution. Even though the globals waffled in the 7-10 day period...they have had this nailed down pretty well for being 5 days out besides the cmc...still a little bit of time for changes but really looks like the writing is on the wall. 

[RedSky]

The old GFS nailed this non storm, and the new GFS gave sweet false hope. Aren't ya glad new GFS takes over next month lol

I for one am content with the miss as there wasn't a model variation that didn't give me lots of white rain, i didn't realize I have the climate here of the eastern shore of Maryland southeast of DC

 

[Ralph Wiggum]

I have my fork ready. 18z runs are the most important model runs since, well, um, 12z 

[The Iceman]

1 hour ago, Ralph Wiggum said:

I have my fork ready. 18z runs are the most important model runs since, well, um, 12z 

and if 18z fails throw it out, wait for fresh initialization at 00z...

[The Iceman]

Coastal storm rides up the coast day 9-10 on the euro...freezing line up in greenland though

[penndotguy]

5 minutes ago, The Iceman said:

Coastal storm rides up the coast day 9-10 on the euro...freezing line up in greenland though

That sounds about right, it’ll verify for sure if it’s rain

[hazwoper]

18Z is out.  Its over, folks.  Confluence to the NE is too strong.   Next

[Birds~69]

36 minutes ago, hazwoper said:

18Z is out.  Its over, folks.  Confluence to the NE is too strong.   Next

What next? We're in limbo...

 

[JTA66]

On 12/3/2018 at 3:50 PM, JTA66 said:

No model analysis here, just a thought on our overall weather since spring: It wants to precipitate.

Sure, this event may very well end up squashed/squished/slide off the coast. But jeez, it seems we can't go more than a few days w/o something falling from the sky. I'm not expecting a HECS or MECS, (heck, it might just be a cold rain). But given the pattern since spring, it's hard to believe we'll end up high & dry.

Guess you can only ride the pattern-persistence train for so long.

[Newman]

I'M STILL HOLDING OUT HOPE lol

We got the SREFS on our side.

[Newman]

Although that spread is extremely skewed by one or two members that give the area like 10" lol.

[zenmsav6810]

1 hour ago, Newman said:

I'M STILL HOLDING OUT HOPE lol

We got the SREFS on our side.

stick a fork in it! : https://www.youtube.com/watch?v=9Z_UiQ3ZRZE