12z Models

[am19psu]

Did we ever get confirmation that the UKMET was way OTS?

It is well offshore

[ag3]

Did we ever get confirmation that the UKMET was way OTS?

Yes. Its way out to sea. Its out on ewall.

[mitchnick]

euro is cold and obnoxiously dry throughout almost the entire run after tomorrow (DCA/BWI)

[PhineasC]

euro is cold and obnoxiously dry throughout almost the entire run after tomorrow (DCA/BWI)

cold/dry or warm/wet

Those are your choices in a Nina.

[JERSEYSNOWROB]

wonder if that sw bais of the euro is affecting how it is handking s/w in STJ as it comes into the sw states ?

assuming it is and based on everything else you see on the Euro maps, can I assume that we still have a legit shot that this comes much closer to the coast?

[Inudaw]

Day 3 Euro/gfs 500mb height comparison

Euro is actually further north and west with the pv in Canada than the gfs at this time frame.. I would think the you'd like the further "west" portion.. but for phasing I'd think you'd want it to to drop further south as well as west..

Other than that.. there not much difference in the broadness of the trough over the united states this time. GFS is though slightly deeper with the base of the trough verses the Euro.. which really gets noticed in the next frame.

Day 4 Euro/gfs 500mb height comparison..

GFS is noticeably more amplified with the height increases in the front of the trough at day 4.. Where the euro is a much flatter flow off the coast at this time. This allows the low that develops on the GFS to come up more and the reason why the Euro rides it out to sea..

[Atlas]

ill say one thing the day 7 EURO looks very condusive for a snowstorm developing for days 8-10.

[am19psu]

ill say one thing the day 7 EURO looks very condusive for a snowstorm developing for days 8-10.

It's way too early to think about, but D10 is well offshore with the next low on Christmas Day.

[Baroclinic Zone]

HPC hugging the GFS solutions.

12Z GFS REMAINS THE MOST AGGRESSIVE MODEL WITH ITS STRONGER

SHORTWAVE AMPLIFICATION AS IT APPROACHES THE EAST COAST SATURDAY.

ITS MID LEVEL CONFIGURATION BY DAYS 4-5 FITS THE 00Z ECMWF ENS

MEAN PATTERN. ITS EXACT TRACK IS CRITICAL TO PCPN CHANCES AND

AMOUNTS ALONG THE NORTHEAST COAST ESPECIALLY NEW ENGLAND. GOOD

AGREEMENT BY THE 12 GFS ENS MEAN AND 12Z CMC BUT CONTINUED FLAT

AND WELL AT SEA BY THE UKMET AND 12Z ECMWF. UNCERTAINTY CONTINUES

WITH TWO SEPERATE CAMPS. RAPID OFFSHORE DEEPENING SCENARIO BY THE

GFS RUNS SEEMS MORE LIKELY AS THE SHORTWAVE AND DEVELOPING SFC LOW

ENCOUNTER AN UNSTABLE MARINE ENVIRONMENT WITH INCREASED

BAROCLINICITY FROM THE CURRENT STRONG COLD ADVECTION FLOW OVER

RELATIVELY WARM OCEAN WATERS.

SOME COASTAL RAIN ALONG THE SOUTHEASTERN SEABOARD SATURDAY WITH

SOME POSSIBLE LIGHT SNOW ALONG THE NRN EDGE OF PCPN ACROSS ERN

VA/SRN MD/DELMARVA/ COASTAL NJ. DEEPENING LOW NEAR THE NORTHEAST

40/70 BENCHMARK AND CLOSED OFF MID LEVEL AND WELL DEVELOPED H850

LOW SETTING THE STAGE FOR POTENTIAL HVY SNOWFALL INTO ERN AND

COASTAL NEW ENGLAND LATE SUNDAY AND MONDAY. CONTINUED WELL BELOW

NORMAL TEMPS EAST OF THE MS VALLEY WITH AGAIN WINDY CONDITIONS AND

LAKE EFFECT SNOWS TUESDAY-ONWARD INTO THE WEEKEND. ANOTHER COLD

SURGE POTENTIAL DEEP EXTENDING AGAIN INTO FLORIDA LATE NEXT WEEK

AND WEEKEND.

[psuhoffman]

cold/dry or warm/wet

Those are your choices in a Nina.

January 2000 IAD had 21" of snow in the middle of a la nina pattern. This came from a great 2-3 week period surrounded by extreme warmth. While it is unlikely we get a great winter start to finish in a nina, it is not impossible to get a significant storm or a good period of winter weather. Just less likely, not impossible.

[Baroclinic Zone]

Model diagnostics.

HPC model diagnostics disco:

...WAVE NEARING THE CALIFORNIA COAST FRI...

PREFERENCE: GFS/UKMET/CANADIAN GLBL COMPROMISE

THERE IS STILL A DECENT AMOUNT OF SPREAD BY FRI... WITH THE NAMLEANING TO THE SLOW SIDE OF THE SPREAD AND THE 00Z/12Z ECMWF ONTHE FAST/SERN SIDE OF THE ENVELOPE. THE 12Z UKMET/CANADIANGLBL/REG GEM GENERALLY ADD SUPPORT FOR AN INTERMEDIATE SOLNBETWEEN THE NAM AND 00Z ECMWF EXTREMES. THE 12Z ECMWF IS A LITTLEFLATTER THAN OTHER SOLNS WITH MID LVL FLOW REACHING NRN CA AS OFF48 EARLY FRI... SO WOULD RECOMMEND THE MOST SIMILAR CLUSTERING OFGFS/UKMET/CANADIAN GLBL SOLNS.

[OSUmetstud]

HPC

GFS RUNS SEEMS MORE LIKELY AS THE SHORTWAVE AND DEVELOPING SFC LOW

ENCOUNTER AN UNSTABLE MARINE ENVIRONMENT WITH INCREASED

BAROCLINICITY FROM THE CURRENT STRONG COLD ADVECTION FLOW OVER

RELATIVELY WARM OCEAN WATERS.

[PhineasC]

Model diagnostics.

Taken together, it sounds like HPC pretty much tossed the 12Z Euro.

[Eskimo Joe]

HPC

GFS RUNS SEEMS MORE LIKELY AS THE SHORTWAVE AND DEVELOPING SFC LOW

ENCOUNTER AN UNSTABLE MARINE ENVIRONMENT WITH INCREASED

BAROCLINICITY FROM THE CURRENT STRONG COLD ADVECTION FLOW OVER

RELATIVELY WARM OCEAN WATERS.

Nick, could you please explain how their analysis is laughable? I looked at the National Data Buoy Center and indeed have found ocean water temperatures of nearly 50 degrees at Delaware Bay Buoy (440009) this morning.

I'm curious about your thoughts.

[RUNNAWAYICEBERG]

Taken together, it sounds like HPC pretty much tossed the 12Z Euro.

and last nites 0z and yesterdays 12z......i wonder what the verification scores are like for the EURO in LaNinas . anyone??

[stormtracker]

HPC

GFS RUNS SEEMS MORE LIKELY AS THE SHORTWAVE AND DEVELOPING SFC LOW

ENCOUNTER AN UNSTABLE MARINE ENVIRONMENT WITH INCREASED

BAROCLINICITY FROM THE CURRENT STRONG COLD ADVECTION FLOW OVER

RELATIVELY WARM OCEAN WATERS.

Explain to us layfolks...why the laugh?

[OSUmetstud]

Nick, could you please explain how their analysis is laughable? I looked at the National Data Buoy Center and indeed have found ocean water temperatures of nearly 50 degrees at Delaware Bay Buoy (440009) this morning.

I'm curious about your thoughts.

I find the reasoning pretty lackluster. The difference is with the southwest shortwave. The GFS is more robust...the ECMWF basically loses it. Some low level baroclinicity because of warm SSTs isn't just going to blow up a low when the shortwave isn't there...

[JERSEYSNOWROB]

I find the reasoning pretty lackluster. The difference is with the southwest shortwave. The GFS is more robust...the ECMWF basically loses it. Some low level baroclinicity because of warm SSTs isn't just going to blow up a low when the shortwave isn't there...

Have you considered the Euro's S/W bias though, hence why it loses it?

[OSUmetstud]

I think the Euro SW energy bias is a legitimate reasoning for going with the GFS/GGEM/GFSEnsembles vs. the UKMET/ECMWF. In situ cold advection over warm SSTs does not have anything to do with it.

[CAPE]

HPC

GFS RUNS SEEMS MORE LIKELY AS THE SHORTWAVE AND DEVELOPING SFC LOW

ENCOUNTER AN UNSTABLE MARINE ENVIRONMENT WITH INCREASED

BAROCLINICITY FROM THE CURRENT STRONG COLD ADVECTION FLOW OVER

RELATIVELY WARM OCEAN WATERS.

Although if you read the whole discussion, they certainly are not throwing out either camp..and there is clearly still a high degree of uncertainty. Plus even with HPC leaning towards the North American model camp, at this point the expectation is for light snow for only coastal areas of VA-MD-NJ. The chance for heavy snow would be for new england as the storm deepens as it moves north. All subject to change of course but thats how HPC sees it as of now.

[OSUmetstud]

Although if you read the whole discussion, they certainly are not throwing out either camp..and there is clearly still a high degree of uncertainty. Plus even with HPC leaning towards the North American model camp, at this point the expectation is for light snow for only coastal areas of VA-MD-NJ. The chance for heavy snow would be for new england as the storm deepens as it moves north. All subject to change of course but thats how HPC sees it as of now.

You're missing the point...the decision to lean towards the North American camp is not an issue...I would also...the reasoning was BS imo.

[NorEaster27]

You're missing the point...the decision to lean towards the North American camp is not an issue...I would also...the reasoning was BS imo.

Agreed current CAA over "warm" ocean temps isnt much of an argument to say we should have rapaid cycolgenesis in 100 hours over the same area.

[CAPE]

You're missing the point...the decision to lean towards the North American camp is not an issue...I would also...the reasoning was BS imo.

I see what you are saying..but there is a wave on the GFS, its the the Euro that loses it. and besides in an abrieviated discussion such as that, they certainly cant give all their rationale for why there may be a storm.

[NorthShoreWx]

You're missing the point...the decision to lean towards the North American camp is not an issue...I would also...the reasoning was BS imo.

Nick, I'm thinking that was just some inelegant wording to say that there is a lot to work with over the ocean, given that there will be a shortwave to work with it, which seems to be their thinking. Or maybe I am an HPC apologist

[CAPE]

Nick, I'm thinking that was just some inelegant wording to say that there is a lot to work with over the ocean, given that there will be a shortwave to work with it, which seems to be their thinking. Or maybe I am an HPC apologist

Agree

[CT Rain]

12z Euro ensemble mean is also southeast of the 00z mean. Bad sign.

5 straight op Euro runs of a miss (for SNE, especially) coupled with a southeast trend in the op and ensemble mean definitely is a bad sign to me.

Euro may be having problems resolving the southwestern US s/w and subsequent interaction with northern stream and PV but it's been so insistent it's very hard to ignore.

[cpickett79]

well euro has what 2 cycles ....3 max to get on board or we likely toss it (storm). I mean how much longer can HPC throw out the euro?