Feb 15 clipper/redeveloper

[Ginx snewx]

NCEP may have been taken over by James.  Fear the Gulf Stream.

 

MID-SOUTH TO ATLANTIC CANADA SYSTEM FRI-SUN

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PREFERENCE:  SOLUTION CLOSE TO THE GFS

CONFIDENCE:  ABOVE AVERAGE

ACROSS MISSOURI, ALL THE AVAILABLE GUIDANCE WAS A FEW HPA TOO WEAK

WITH THEIR SURFACE LOW, WHICH IS LIKELY AN ISSUE THAT FOLLOWS

THROUGH THE FIRST DAY OF THEIR FORECASTS.  WHILE THE 12Z GFS SHOWS

CONVECTIVE/GRIDSCALE FEEDBACK NEAR AND OFFSHORE THE EAST COAST

WHICH STRENGTHEN ITS UPPER LEVEL CIRCULATION AND COULD LEAD TO

SOME EXCESSIVE PROGRESSION, THE INITIALIZATION ISSUES IN THE

GUIDANCE MAKE THE STRONG GFS SOLUTION APPEAR MOST PLAUSIBLE.

PLUS, WITH THE CYCLONE PATH NEARING THE GULF STREAM SATURDAY, A

STRONGER SOLUTION STANDS A GOOD CHANCE OF VERIFYING.  THE

PREFERENCE IS FOR A STRONGER SOLUTION CLOSE TO THE 12Z GFS WITH

ABOVE AVERAGE CONFIDENCE BASED ON INITIALIZATION ERRORS AND

POSSIBLE GULF STREAM INTERACTION.

SOME EXCESSIVE PROGRESSION

[wxsniss]

Holy crap, is there any interest in this thing:

 

 

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Anyway, the ECM did get schooled by the GFS earlier in the season re the N-stream amplitude and timing.  So it's not exactly unprecedented.  It's just rarer.  Having just seen the GFS ensemble individual members, there a more like the operational GFS than like the Euro (in terms of cross model support).   Gosh that's a lot of weight. 

 

Edit:  duh, I just reviewed the 00z -- what a dumb ass; still, rumor has it the 12z is similar

 

Agree with you TT. We are all freshly burned by GFS in prior system, but objectively, this system is totally different (Miller B, alot simpler synoptically imo) and verification from the last system may be totally irrelevant. And Euro was not exactly perfect with the last system either... the 0Z run within 24 hours of the storm had a huge hit for eastern MA on the front-end, and we all know how that turned out.

 

Objectively, GFS has been dead on for 4 cycles, with GEFS support.

Add to that NAM and RGEM have trended towards the GFS solution.

 

Also, not sure how informative this is, but take a look at the Model Diagnostic Disco 1118am... GFS favored for "mid-south to atlantic canada system fri-sun" and GFS/EC compromise for the "northern plains to virginia system fri-sun".

[CoastalWx]

I don't recall anyone saying to toss the GFS...just approach the 10-15" near BOS as something that may be a bit questionable. Nothing wrong with that approach.

[Typhoon Tip]

I would also point out that "Convective Feedback" does not mean 'no convective feedback.'  The phrase is tossed around because sometimes it's a negative to accuracy, but sometimes ... convection does enhance/morph a system.   

 

I actually hadn't considered that this current system is advecting a cold air mass over the interface in the west Atlantic, so there is going to be a lot of baroclinicity evolving ...which to then have a a 40+ unit vort-max and attedent jet dynamics running out over top, ...

 

Whether the GFS is right about hitting eastern NE or not, there IS going to be a bomb!

[CoastalWx]

I would also point out that "Convective Feedback" does not mean 'no convective feedback.'  The phrase is tossed around because sometimes it's a negative to accuracy, but sometimes ... convection does enhance/morph a system.   

 

I actually hadn't considered that this current system is advecting a cold air mass over the interface in the west Atlantic, so there is going to be a lot of baroclinicity evolving ...which to then have a a 40+ unit vort-max and attedent jet dynamics running out over top, ...

 

Whether the GFS is right about hitting eastern NE or not, there IS going to be a bomb!

Absolutely.

[Chrisrotary12]

Ya know.  I was just comparing the GEFS (12z) and European Ens (00z) mean for the SLP placement tomorrow night at 00z.  The placement differences is really small.  Something like 50 miles.

 

But boy does that 50 miles mean everything. 

[CoastalWx]

For Tip.

 

NAM FOUS for a fixed point east of Chatham by about 50 miles I believe.

 

FOUS78 KWNO 141200
TTPTTR1R2R3 VVVLI PSDDFF HHT1T3T5
BTNM3
00///938423 00706 772141 41050099
06002773326 -7012 902651 33019496
12000763509 -1911 022640 30029793
18000694523 -2416 102725 35029697
24000625660 00013 132806 35039898
30000708354 -3605 101115 38040198
36057969450 16303 980539 43020200
42122969645 30308 843565 43009700
48044783337 00518 993046 28009389
54000693420 -3817 062935 23989287
60000693815 -3115 122928 18989088
 

 

65 kt boundary layer wind.

[Typhoon Tip]

A day late and a dollar short.

 

Yeah you beat me to it by like 5 minutes.

 

Jerk   

 

But that's interesting commentary about the Gulf Stream.   

[Clinch Leatherwood]

SOME EXCESSIVE PROGRESSION

 

It's all about the gulf stream, and ball bearings.

 

UKMET/NAM/RGEM/GGEM are all pretty similar all things considered.  UKMET fails to get as much moisture west in that extension like the GFS is pulling.

Euro toyed with that a few times, so let's see.

[Clinch Leatherwood]

Yeah you beat me to it by like 5 minutes.

 

Jerk   

 

But that's interesting commentary about the Gulf Stream.   

 

Haha....I'm finally first in something.

 

It's one of the most aggressive statements I've ever seen them make and that's not a deliberate exaggeration.  It's extremely ominous if correct.

[OceanStWx]

For Tip.

 

NAM FOUS for a fixed point east of Chatham by about 50 miles I believe.

 

65 kt boundary layer wind.

 

Ocean Prediction Center throwing out a 54 kt forecast for the Gulf of Maine.

[Typhoon Tip]

For Tip.

 

NAM FOUS for a fixed point east of Chatham by about 50 miles I believe.

 

FOUS78 KWNO 141200

TTPTTR1R2R3 VVVLI PSDDFF HHT1T3T5

BTNM3

00///938423 00706 772141 41050099

06002773326 -7012 902651 33019496

12000763509 -1911 022640 30029793

18000694523 -2416 102725 35029697

24000625660 00013 132806 35039898

30000708354 -3605 101115 38040198

36057969450 16303 980539 43020200

42122969645 30308 843565 43009700

48044783337 00518 993046 28009389

54000693420 -3817 062935 23989287

60000693815 -3115 122928 18989088

 

 

65 kt boundary layer wind.

 

 

Ah hahahaha   ..

 

no words - 

 

I like how fast it ramps it up too... It's like this peaceful quiescent morning with a gentle breeze BAAAAAAAAAM!

[HoarfrostHubb]

It's all about the gulf stream, and ball bearings.

UKMET/NAM/RGEM/GGEM are all pretty similar all things considered. UKMET fails to get as much moisture west in that extension like the GFS is pulling.

Euro toyed with that a few times, so let's see.

One word: plastics

Seriously, I think the Euro will hold serve

[baroclinic_instability]

I would also point out that "Convective Feedback" does not mean 'no convective feedback.'  The phrase is tossed around because sometimes it's a negative to accuracy, but sometimes ... convection does enhance/morph a system.   

 

I actually hadn't considered that this current system is advecting a cold air mass over the interface in the west Atlantic, so there is going to be a lot of baroclinicity evolving ...which to then have a a 40+ unit vort-max and attedent jet dynamics running out over top, ...

 

Whether the GFS is right about hitting eastern NE or not, there IS going to be a bomb!

 

I agree, baroclinic dynamics are going to play a much larger role in the very important first 6-12 hours of cyclogenesis as this evolves over the Atlantic, not moist processes as HPC seems to be referring to, especially on the heels of this first bomb. Just looking at WV sat and surface obs over the Ozarks the mid level anomaly/associated low seem to be 1-2 hpa stronger than progged even in the GFS solution...which is going to be important as the low transitions lee of the Apps...with some level of vertical stretching. I still think it makes sense, however, that the frontogenesis max ends slightly farther E given the wiped out Gulf Stream and the more likely position of the warm front.

[Clinch Leatherwood]

One word: plastics

Seriously, I think the Euro will hold serve

 

At one time there was an insistence that the UKMET led the way on what the Euro would do.  Although it's a monster low it does not toss precip as far back as the GFS by any means and maintains this as a major hit only for the Cape.

We shall see as the Euro is rolling out now.

[baroclinic_instability]

Probably linked somewhere else, but this succinctly depicts the evisceration of the deep Gulf Stream moisture: http://tropic.ssec.wisc.edu/real-time/mimic-tpw/natl/main.html

[eduggs]

The radar looks a little wetter than most 12z guidance.  The NAM has almost no QPF in AR.  Radar shows good returns from NAR, through SE MO, and into IN.

[dryslot]

12z Euro looks a few tics west early on then 0z

[Typhoon Tip]

I agree, baroclinic dynamics are going to play a much larger role in the very important first 6-12 hours of cyclogenesis as this evolves over the Atlantic, not moist processes as HPC seems to be referring to, especially on the heels of this first bomb. Just looking at WV sat and surface obs over the Ozarks the mid level anomaly/associated low seem to be 1-2 hpa stronger than progged even in the GFS solution...which is going to be important as the low transitions lee of the Apps...with some level of vertical stretching. I still think it makes sense, however, that the frontogenesis max ends slightly farther E given the wiped out Gulf Stream and the more likely position of the warm front.

 

To employ some euphemism ... this thing is a hornet sting on the charts.  

 

I'm having trouble locating the PP tapestry, as far as curved delineation on where to place warm fronts and cold fronts.  This centric barographic layout is exceedingly symmetric and round, owing to something unusual going on there.  Hmm.

[weathafella]

Euros gonna be good. A tad sharper this run earlier.

[dryslot]

Euros gonna be good. A tad sharper this run earlier.

 

Oh yes

[baroclinic_instability]

Agree with you TT. We are all freshly burned by GFS in prior system, but objectively, this system is totally different (Miller B, alot simpler synoptically imo) and verification from the last system may be totally irrelevant. And Euro was not exactly perfect with the last system either... the 0Z run within 24 hours of the storm had a huge hit for eastern MA on the front-end, and we all know how that turned out.

 

Objectively, GFS has been dead on for 4 cycles, with GEFS support.

Add to that NAM and RGEM have trended towards the GFS solution.

 

Also, not sure how informative this is, but take a look at the Model Diagnostic Disco 1118am... GFS favored for "mid-south to atlantic canada system fri-sun" and GFS/EC compromise for the "northern plains to virginia system fri-sun".

 

IMHO, in this scenario, having GEFS support doesn't mean a whole lot as differences among the guidance seem to be more related to physics and convective params than to initialization. GEFS only perturbs the initial conditions in its ensemble, whereas the Canadian and SREF have some mix of perturbation and convective params which more realistically (in model world terms) depict differences in how various physics and convection schemes may alter the outcome. In other words, at this juncture, ECENS/GEFS are probably going to be relatively similar to the operational (although both operational runs do indeed run at a higher res). 

[wxsniss]

ticked west apparent by 24h

[NJwinter23]

Euro is definitely trying to come around through 30 hrs

[weathafella]

Game on!

[Typhoon Tip]

Probably linked somewhere else, but this succinctly depicts the evisceration of the deep Gulf Stream moisture: http://tropic.ssec.wisc.edu/real-time/mimic-tpw/natl/main.html

 

It all seems to be coming together... 

 

NCEP noted that the other guidance were a bit underdone and missed some potency in their respective initialization.  Well, that would effect a less dive into the TV.

 

Contrasting, the more digging taps the Gulf theta-e with more proficiency, and that transitively leads to it being ripped N to where it gets involved ... 

[CoastalWx]

Euro is a little bit closer.

[dryslot]

Game on

[CoastalWx]

Yeah that's a nice hit for BOS.

[CoastalWx]

Really nails SE MA.