0z Models 12/22/10

[HM]

Isn't the NE PAC low pushing the ridge axis east though which makes it hard to get an event that hits the coast solidly?

Oh I see, you want me to talk to you like everything is cool?

Look above the post you quoted, I talked about the delicate balance between everything. Yes, it is very likely that one thing over powers the other.

[ORH_wxman]

It sure is possible-- I mean this last storm was much less intense than this one is progged to be and didnt it deliver a foot of snow on the cape? But a Vet Day 1987 type scenario (snow south and snow north, but little in between) would make a lot of people disappointed-- not that the storm cares lol.

Norfolk to Boston storms are rare but they do happen...it happened on 12/26/04 and 2/25/89...and maybe one of the Jan/Feb 1987 storms? They do happen but are rare...but we are in a rare setup. The ridge is very far east so its all about phasing a hook to the left once that happens, and those types of setups can be great for everyone or they can turn into scrapers (or nothing) for NYC-DCA while SE VA and E NE get hit....its a tough call on those and usually they involve short term busts.

[HM]

Ah ok, got ya. Well I probably agree there. It has to amp up pretty good to slam the DC-PHL corridor since this storm wants to sort of start a wide turn to the east and then hook north. It needs to be pretty severe north turn like the Euro to hammer the further west I-95 cities like DCA and PHL vs the south towns (like RDU/ORF/RIC) and further north and east towns like BOS.

DT calls it a Norfolk to Boston storm when it does that.

Yes and JI and Chuck brought up the point that Jan 2 2002 had a storm which did something similar. Chuck said it was a decent general circulation analog. This may end up being the final solution and that would suck for your buddy HM...

[Cheeznado]

Adding some fuel to the fire- the 00Z Euro ensembles are MUCH less impressed- kind of a moderate mainly coastal event-the Op is a big outlier. Sorry, this increases my unease that we are all (including myself for a while) getting way too worked up about what may end up being a nice event for some, and a complete bust for others.

[ORH_wxman]

Adding some fuel to the fire- the 00Z Euro ensembles are MUCH less impressed- kind of a moderate mainly coastal event-the Op is a big outlier. Sorry, this increases my unease that we are all (including myself for a while) getting way too worked up about what may end up being a nice event for some, and a complete bust for others.

The worry is definitely too far east in this setup with the longwave ridge being so far east...those ensembles are def well east of the 12z run despite the 00z OP Euro being so amped up not too dissimilar to the 12z run.

[nzucker]

Oh I see, you want me to talk to you like everything is cool?

Look above the post you quoted, I talked about the delicate balance between everything. Yes, it is very likely that one thing over powers the other.

What was ever wrong? Everything was pretty cool I thought...

I totally see what you're saying about the balance...are you also thinking that this ridge positioning helps out the connection to the NAO block and thus tries to get more PV energy into the storm?

[A-L-E-X]

Norfolk to Boston storms are rare but they do happen...it happened on 12/26/04 and 2/25/89...and maybe one of the Jan/Feb 1987 storms? They do happen but are rare...but we are in a rare setup. The ridge is very far east so its all about phasing a hook to the left once that happens, and those types of setups can be great for everyone or they can turn into scrapers (or nothing) for NYC-DCA while SE VA and E NE get hit....its a tough call on those and usually they involve short term busts.

Will, it sounds like a tropical storm track that hits the southern MA and then hooks back up to catch E NE. If I remember correctly, 88-89 was a mod la nina too-- was that 2/89 storm the infamous one that dropped 19" of snow on ACY and nothing on Philly? We got like 2-5" here with that one.... closer to 2" lol.

That 12/04 gets forgotten because the winter ended up great overall for us, but that was the year of the miller B's and I have a memory of snow backing in from the east and delivering 2-3" of snow here-- maybe that was the one?

[earthlight]

Adding some fuel to the fire- the 00Z Euro ensembles are MUCH less impressed- kind of a moderate mainly coastal event-the Op is a big outlier. Sorry, this increases my unease that we are all (including myself for a while) getting way too worked up about what may end up being a nice event for some, and a complete bust for others.

Nice..any idea on QPF, or do you not have access? I know the 12z Ensembles had a very nice surface low track.

[A-L-E-X]

Yes and JI and Chuck brought up the point that Jan 2 2002 had a storm which did something similar. Chuck said it was a decent general circulation analog. This may end up being the final solution and that would suck for your buddy HM...

Hey that was a terrible winter, but I remember that in Jan 2002 they had a HECS on the Carolina coast that dropped over a foot of snow very close to the ocean! It was just dry and cold here and we wasted the only real snow "threat" we had that winter.

[ORH_wxman]

Will, it sounds like a tropical storm track that hits the southern MA and then hooks back up to catch E NE. If I remember correctly, 88-89 was a mod la nina too-- was that 2/89 storm the infamous one that dropped 19" of snow on ACY and nothing on Philly? We got like 2-5" here with that one.... closer to 2" lol.

That 12/04 gets forgotten because the winter ended up great overall for us, but that was the year of the miller B's and I have a memory of snow backing in from the east and delivering 2-3" of snow here-- maybe that was the one?

'88-'89 was a mega strong Nina. The 12/26/04 storm gave your area a few inches, but not much else west of you....it gave Norfolk over a foot and then crushed eastern MA....while everyone in between got whiffed.

[A-L-E-X]

Adding some fuel to the fire- the 00Z Euro ensembles are MUCH less impressed- kind of a moderate mainly coastal event-the Op is a big outlier. Sorry, this increases my unease that we are all (including myself for a while) getting way too worked up about what may end up being a nice event for some, and a complete bust for others.

Interesting. Did we have ensemble forecasting back in 2001 for the March 2001 event? I wonder if we did have it, if they would have clued us in on what was about to happen.

BTW, I read somewhere that for verification purposes that the 0z euro ensemble mean is the most accurate, followed by the 0z euro, followed by the 12z euro ensemble mean and then the 12z euro, followed by the 12z gfs. Something was done to the euro over the past year that made the ensemble means catch up to and pass the op runs in terms of verification.

[HM]

When Will starts throwing out Feb 1988 and Chuck throws out late Dec 01 into early Jan 02, one starts to develop nausea about this whole thing. Also, Tony brought up the GWO / overall state of the global AAM in my pinned thread. I think ultimately that signals the zonal flow that blasts in after the coastal storm, but it is a worry. I suggested in the thread that I was more worried about that than the dumb 50-50 low that everyone seems to be worried about. Yet, I think that is the feature that is the most appreciated.

[A-L-E-X]

'88-'89 was a mega strong Nina. The 12/26/04 storm gave your area a few inches, but not much else west of you....it gave Norfolk over a foot and then crushed eastern MA....while everyone in between got whiffed.

So Im going to mentally prepare myself for getting at least 2 inches lol.

[ORH_wxman]

When Will starts throwing out Feb 1988 and Chuck throws out late Dec 01 into early Jan 02, one starts to develop nausea about this whole thing. Also, Tony brought up the GWO / overall state of the global AAM in my pinned thread. I think ultimately that signals the zonal flow that blasts in after the coastal storm, but it is a worry. I suggested in the thread that I was more worried about that than the dumb 50-50 low that everyone seems to be worried about. Yet, I think that is the feature that is the most appreciated.

That feature is the reason the east coast (at least I-95) can talk about a snowstorm. Otherwise it would be an interior storm.

[HM]

That feature is the reason the east coast (at least I-95) can talk about a snowstorm. Otherwise it would be an interior storm.

Yes, thank you! It is also why the wavelengths get so short for this to happen. I bumped heads with DT yesterday about this being the possible thing that ruins the East Coast threat. In a phasing scenario, it would get the boot and allow for the East Coast low (for this particular situation). It is the Atlantic low's fault for the s/w dropping DUE SOUTH to phase with the STJ s/w.

If the PAC JET is going to blast into the CONUS, I am rooting for the 50-50 low to hang on even longer!

[weatherweather]

safe to say 6z nam is diggin the sw more through 54 than 0z or 18z. Matches up pretty well with 12z euro from yesterday

[HM]

So Im going to mentally prepare myself for getting at least 2 inches lol.

I am as well. I don't mean to be a downer this evening but there is certain evidence lining up that suggests that things may settle to a less than desirable track. The good news is that we still have a solution on the table that would have books written about it! So, it's not over yet.

[Dsnowx53]

Yes, thank you! It is also why the wavelengths get so short for this to happen. I bumped heads with DT yesterday about this being the possible thing that ruins the East Coast threat. In a phasing scenario, it would get the boot and allow for the East Coast low (for this particular situation). It is the Atlantic low's fault for the s/w dropping DUE SOUTH to phase with the STJ s/w.

If the PAC JET is going to blast into the CONUS, I am rooting for the 50-50 low to hang on even longer!

Yeah, the short wavelengths seem to be the way to go in La Ninas. I recall that we had pretty short wavelengths for the March 1-2, 2009 storm, too. And the short wavelengths mean that having a ridge axis centered east of Boise is not necessarily too far east.

[CooL]

the 6z NAM has a closed off vort in the TX panhandle at hr 57

[ORH_wxman]

Great....without the 50\50 it's congrats LEK....with it's congrats CC.....maybe someday you'll favor us.

You are looking better than 90% of the viewers for snow with your longitude (and to a lesser extent latitude), so I wouldn't complain.

[HM]

Yeah, the short wavelengths seem to be the way to go in La Ninas. I recall that we had pretty short wavelengths for the March 1-2, 209 storm, too. And the short wavelengths mean that having a ridge axis centered east of Boise is not necessarily too far east.

Right...the retrograding NAO block and 50-50 low allow the flow to buckle significantly to the point that the ridge out west can be displaced a bit east of where we generally like to see it. DT made that point well tonight I thought. However, if we nudge the ridge a little bit east each run, the phasing gets nudged a little bit east each run and before you know it...well...you get it.

[jcwxguy]

safe to say 6z nam is diggin the sw more through 54 than 0z or 18z. Matches up pretty well with 12z euro from yesterday

500vort is closed off at hr 60 edit: and is still closed off at hr 66 but opens on hr 72

[atownwxwatcher]

Does CISCO have an ECM bias?

PRELIMINARY EXTENDED FORECAST DISCUSSIONNWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD312 AM EST WED DEC 22 2010 VALID 12Z SUN DEC 26 2010 - 12Z WED DEC 29 2010 ...EUROPEAN CENTRE GUIDANCE STAYS THE COURSE ON POWERFUL EASTCOAST STORM DECEMBER 26-27...WILL STICK WITH THE CONSISTENT ECMWF FOR THE PRELIMINARY FRONTSAND PRESSURES FOR DAYS 3-7. FOR THREE CONSECUTIVE MODELCYCLES...THE DETERMINISTIC ECMWF HAS INDICATED AMASSIVE...DEEP...SLOW-MOVING CYCLONE HUGGING THE CAROLINA AND MIDATLANTIC COASTS THE TWO DAYS FOLLOWING CHRISTMAS. THE ECMWF ANDUKMET WERE THE FIRST OF THE GLOBAL NUMERICAL MODELS TO SWITCH FROMTRACKING THIS WAVE ALONG 40N THROUGH THE MIDWEST...TO A SUPPRESSEDPATH ACROSS THE DEEP SOUTH. SINCE THIS BREAK-AWAY...THE UKMETSPLIT OFF EVEN FARTHER SOUTH...WITH THE ECMWF LOCKING ONTO ANEVOLUTION THAT TAKES THE DEVELOPING LOW TO THE FLORIDA PANHANDLEAND THEN SHARPLY UP THE EASTERN SEABOARD. THE GEM GLOBAL FOLLOWEDTHE EUROPEAN CENTRE TRACK ON ITS 00Z/21 RUN...BUT HAS SWUNG THESYSTEM OUT WIDER OVER THE ATLANTIC THE LAST TWO RUNS. THE GFS HASSHIFTED TO THE SOUTHERN ROUTE ACROSS THE GULF STATES ON ITSCURRENT RUN...BUT LIKE THE GEM GLOBAL...DIRECTS THE CYCLONE WELLSOUTH AND EAST OF CAPE HATTERAS. THE ECENS MEMBERS HAVE AVERAGEDCLOSE TO THE DETERMINISTIC ECMWF...WITH MANY MEMBERS FOLLOWING ITEXACTLY...AND OTHERS TRACKING A BIT FARTHER OFFSHORE. THEEUROPEAN CENTRE GUIDANCE HAS THE ADVANTAGE IN DEVELOPMENTALSYSTEMS WITH ITS HIGH RESOLUTION...AND IS FURTHER AIDED BY ITS4D-VAR ANALYSIS IN GENERAL. ITS ENSEMBLE MEMBERS ARE MORE HIGHLYRESOLVED THAN THE GEFS MEMBERS...AND WITH DYNAMIC...DEVELOPMENTALSYSTEMS...THE EUROPEAN GUIDANCE SHOULD HAVE THE EDGE. INDEED...THE GEFS MEAN HAS BEEN CONSISTENTLY FLATTER WITH THE PATHOF THE BIG STORM...WHICH IS CERTAINLY IN LINE WITH THE LOWERRESOLUTION. EVEN SO...FOUR 00Z/22 GEFS MEMBERS STILL TRACKEDCOMPARABLY TO THE ECMWF...SHOWING A DEEP NOREASTER AND A HIGHIMPACT STORM FOR THE MAJOR METROPOLITAN AREAS ASTRIDE INTERSTATE95 FROM WASHINGTON TO BOSTON. TO WIT...THESE GEFS MEMBERS AREGOING AGAINST THEIR LOWER RESOLUTION/LESS DEVELOPMENTAL NATURE. THE ECMWF HAS MUCH CLIMATOLOGY ON ITS SIDE AS WELL...WITH ITSTRACK WEST OF THE GULF STREAM...AND THE BOMBING PHASE NEAR ANDNORTH OF CAPE HATTERAS.THE MOST UNUSUAL...AND THREATENING...ASPECT OF THE ECMWF FORECASTIS THE RELATIVELY LOW LATITUDE AT WHICH THE STORM MATURES ANDSTALLS/LOOPS. MORE TYPICALLY...SYSTEMS WILL CLOSE OFF AND HOVEROVER THE WATERS SOUTH OF NOVA SCOTIA...AS WITH THE MOST RECENTCYCLONE STILL AFFECTING DOWNEAST MAINE. THE ECMWF SHOWS THEUPCOMING CIRCULATION COMING TO A HALT JUST EAST OF THE DELMARVAPENINSULA...WHICH PUTS THE VERY POPULATED AREAS OF THE EASTERN MIDATLANTIC...LONG ISLAND...AND SOUTHERN NEW ENGLAND IN A PROLONGEDPERIOD OF HIGH WINDS AND HEAVY PRECIPITATION...MOSTLY SNOW. THEEXTRAORDINARY NEGATIVE NAO THIS MONTH COULD CERTAINLY SUPPORT SUCHAN ANOMALY. EVEN BEFORE THE RAPID DEEPENING PHASE OF THESYSTEM...AREAS OF THE DEEP SOUTH FROM THE INTERIOR GULF COASTSTATES TO GEORGIA AND THE MOUNTAINS AND PIEDMONT OF THE CAROLINASMAY SEE A VERY RARE WHITE CHRISTMAS...AGAIN...CONSISTENT WITH THEREMARKABLE DISRUPTION AT HIGH LATITUDES.WHILE THE EASTERN VORTEX RELOADS AND EXPANDS...THE FLOW STREAMINGOFF THE PACIFIC WILL BE LARGELY SHUNTED FARTHER NORTH THAN RECENTDAYS...WITH THE POLAR JET TAKING AIM AT THE WASHINGTON COAST. SOME FLOW WILL SPLIT INTO THE FAR SOUTHWEST...BUT WITH NOT NEARLYTHE ROBUSTNESS OF THE PAST WEEK.CISCO

Let me reword that ..is what he says not true?

[HM]

Just one little thing though about the whole "trending east thing."

The 00z ECMWF is actually slower with the Pacific energy slamming the West Coast on 12/25 and the ridge axis is actually further west ...when compared with the 12z run from earlier today.

[earthlight]

500vort is closed off at hr 60 edit: and is still closed off at hr 66

The vort being closed is a good sign, but what's more important is the involvement of the northern stream...which looks to be better on the 06z NAM. The ridge axis is also slightly further west/amplified. No bad things thus far.

[ORH_wxman]

I will complain after last season....sue me. lol

Mod event doesn't atone for that.

You avg 62" of snow per year....and are looking fairly good for this event...you don't have much to complain about even after last year on the main wx side. Sit tight and wait to see how this develops for another 24-48 hours...if this some how improbably buries everyone but you, then you can complain.

[A-L-E-X]

The vort being closed is a good sign, but what's more important is the involvement of the northern stream...which looks to be better on the 06z NAM. The ridge axis is also slightly further west/amplified. No bad things thus far.

So we have some good signs and some not so good signs going forward-- nothing new lol. Just time to sit tight and hope for the best-- no reason for panic or excessive jubilation.

[40/70 Benchmark]

You avg 62" of snow per year....and are looking fairly good for this event...you don't have much to complain about even after last year on the main wx side. Sit tight and wait to see how this develops for another 24-48 hours...if this some how improbably buries everyone but you, then you can complain.

Sorry for carrying on here....forgot which thread this was.

[Dsnowx53]

I know we have the strong westerlies from the fast Pacific flow La Nina pattern, but I would think the strong westerlies would actually help the northern stream act in our favor. Considering there is blocking to the east and north, westerlies and north westerlies from a La Nina would actually help to push the northern stream south and south east. As Will alluded to before, perhaps without the strong westerlies, you get the phase job too far west, and the low could ride up the Hudson Valley, since the westerlies help to have some sort of eastward component to the northern stream's dive. Obviously, you don't want too much of that, but I'm pretty sure that without the strong westerlies, this would cut up the Hudson Valley.

[Jebman]

WE knew these models were going to change throughout the week.

I'm still holding out for the closer to the coast solution by late Wed and Thursday.

Not ready to jump ship just yet.