March 14/15 W & NNE weenies jumping from the Tobin Coastal Storm Discussion

[Damage In Tolland]

Yeah the idea of this being  in and out in 8 hours with backedge already visible on radar isn't correct. It's not hauling and we will continue to see models slow it down . Fits the overall setup

[OceanStWx]

5 minutes ago, backedgeapproaching said:

Because it was west of ensemble mean and solution was so different from 12z.

There may have been some more detail, but the general theme I think.

Actually I think they said that it was slower and more amplified upper air pattern, which did not match the EPS mean. That may have ultimately led to a more west surface track, but that's not why they tossed it.

[OceanStWx]

3 minutes ago, WxWatcher007 said:

Really interesting. Probably a dumb question, but where can someone in the general public find that information?

http://breezy.somas.stonybrook.edu/CSTAR/Ensemble_Sensitivity/EnSense_Main.html

I would suggest reading the "Learn to Use this Website" link before diving too deep. I'm pretty sure that site should work for anyone, except the ECWMF. You need a password for that.

[OceanStWx]

4 minutes ago, Damage In Tolland said:

Yeah the idea of this bring in and out in 8 hours with backedge already visible on radar isn't corrrct. It's not hauling and we will continue to see models slow it down . Fits the overall setup

Better root for your favorite model then. 

[USCAPEWEATHERAF]

Models show winds gusting past 65mph on the Outer Cape and Nantucket Tuesday afternoon, HIRES NAM, I know its the NAM is between 60-70 knots in gusts and is also east of the NAM in line more so with the GFS on track and intensity of precipitation.  GFS dumps all snow on Cape Cod with amounts nearing 20" in Chatham, Harwich could see more given that we are appreciably colder than Chatham is during any storm.

[ROOSTA]

06z GFS if taken verbatim tracks inside BM just outside ACK. Screams climo ie: CF, orographic enhancement. Appears to be shaping into a New England Classic. 
QPF gets one in the ballpark but it truly is the individual players that determine  the ultimate outcome. That's why the game is played.

[WxFreak11]

Flying into Providence on Thursday at noon..so bummed I'm missing the big event. At least there will be snow on the ground. Didn't realize how much I would miss snow after moving to the south. Any chance I'll see snow next weekend? I'm crossing my fingers!

[RUNNAWAYICEBERG]

13 minutes ago, backedgeapproaching said:

Because it was west of ensemble mean and solution was so different from 12z

And 12z was way east of the mean, not following the logic.

The h7 low tracks ideal for WSNE, finally.  

[RUNNAWAYICEBERG]

1 minute ago, USCAPEWEATHERAF said:

Models show winds gusting past 65mph on the Outer Cape and Nantucket Tuesday afternoon, HIRES NAM, I know its the NAM is between 60-70 knots in gusts and is also east of the NAM in line more so with the GFS on track and intensity of precipitation.  GFS dumps all snow on Cape Cod with amounts nearing 20" in Chatham, Harwich could see more given that we are appreciably colder than Chatham is during any storm.

Deff, we go euro yesterday and gfs this morning. Pick your model, any model. 

[SouthCoastMA]

1 minute ago, USCAPEWEATHERAF said:

Models show winds gusting past 65mph on the Outer Cape and Nantucket Tuesday afternoon, HIRES NAM, I know its the NAM is between 60-70 knots in gusts and is also east of the NAM in line more so with the GFS on track and intensity of precipitation.  GFS dumps all snow on Cape Cod with amounts nearing 20" in Chatham, Harwich could see more given that we are appreciably colder than Chatham is during any storm.

Good luck with locking in the GFS. I'd temper your expectations to 3-6" down there unless models shift back East at 12z

[ORH_wxman]

The h7 low could track over ORH or it could track over cape cod. We can't say where yet. That 75-100 mile range is what the final 48 hours will try and nail down but I'd be very careful about making confident statements about it yet. 

[RUNNAWAYICEBERG]

10 minutes ago, OceanStWx said:

Actually I think they said that it was slower and more amplified upper air pattern, which did not match the EPS mean. That may have ultimately led to a more west surface track, but that's not why they tossed it.

Right, but you mention 12z may come in slower based on roabs etc. 

[backedgeapproaching]

4 minutes ago, RUNNAWAYICEBERG said:

And 12z was way east of the mean, not following the logic.

The h7 low tracks ideal for WSNE, finally.  

I agree, OceanStWx clarified a bit on my post what they were thinking.

[USCAPEWEATHERAF]

Oh I am not confident in anything right now.  these models are still doing a difficult job of understanding the atmosphere, they are again used as tools for guidance, but we have to use our intellect.  Given that at least two blockbuster snowstorms have beaten you in the past with the rain/snow line you think is going to impact Cape and Islands snowfall and were wrong should keep you from making the same mistake given the storm is taking the same general track, across the benchmark, that will lock in the low level cold air mass in place and keep the mild ocean air at bay and mainly over Nantucket and not over the rest of the Cape and Martha's Vineyard.  I believe in the models that show the most reasonable track, I am not just saying it out of my a$$.  I see this happening just like the Blizzard of 2015, but the only exception is this is more widespread given the gulf of Mexico influence of moisture.

[JC-CT]

I am so surprised James thinks that.

[USCAPEWEATHERAF]

This is as an ideal setup as you want for a major nor'easter.  You want an intense upper level low to dive into the Great Lakes, you want an intense clipper system to dump 5-8" of snow over a widespread area of the northern plains and Midwest and Great Lakes region, you want a robust southern stream system and an arctic jet stream disturbance to dive down in the form of the upper level low that develops over the Great Lakes, and you want Gulf of Mexico moisture to stream out ahead of the northern stream system in the form of thunderstorms.  Then the convection develops off the East Coast of NC and SC and GA and then there is your seeding for the coastal nor'easter to rapidly deepen offshore.  Models just need to get better handle on the dynamics at play and stop waffling around needlessly.  This is the setup other than moving more progressively, this is the setup you want for a historic snowstorm over New England and the I95 corridor from Boston to DC.  Classic bomb here we come.  Also this is the type of storm where you expect the QPF to come back to the original idea of copious amounts of moisture and a stronger intensity low.

[dendrite]

6z Adolf and Konoe look pretty juicy into the deep interior. more like the euro than the gfs. No word on the Mussolini yet.

[jbenedet]

45 minutes ago, OceanStWx said:

So 12z raobs up in Canada are all showing higher heights than models forecast (06z GFS and 00z Euro). 

EPS sensitivity would suggest that means the Euro could have another slower and westward tick left in it at 12z. More likely slower than westward.

Looks like the GEFS would favor a slower tick too for the 12z GFS. Not so much left or right shift though.

Thanks for posting. This was my positive "caution" yesterday when the 12z euro came way east. I've noticed guidance in general trending that PNA ridge more amplified just about every run. This should also translate into a more robust northern Stream shortwave. Seems they are still playing catchup--some more than others. My expectation is this should materialize in a better/earlier N Stream phase and the guidance already picking up on this like the GEM, euro and Ukie are closer to verifying at this juncture. 

[JC-CT]

Ryan's station did go conservative to start with 6-12 (+) for the whole state.

Putting a + there is kind of cheating though. That means 30" would technically make you verify. I don't think so.

[jbenedet]

James makes a good point regarding deep shortwaves traversing near the GOM. The GOM really helps to pump downstream ridges via deep convection that translates into UL latent heat release. This is something typically downplayed by guidance--even inside 48 hrs.

[Semper911]

16 minutes ago, USCAPEWEATHERAF said:

This is as an ideal setup as you want for a major nor'easter.  You want an intense upper level low to dive into the Great Lakes, you want an intense clipper system to dump 5-8" of snow over a widespread area of the northern plains and Midwest and Great Lakes region, you want a robust southern stream system and an arctic jet stream disturbance to dive down in the form of the upper level low that develops over the Great Lakes, and you want Gulf of Mexico moisture to stream out ahead of the northern stream system in the form of thunderstorms.  Then the convection develops off the East Coast of NC and SC and GA and then there is your seeding for the coastal nor'easter to rapidly deepen offshore.  Models just need to get better handle on the dynamics at play and stop waffling around needlessly.  This is the setup other than moving more progressively, this is the setup you want for a historic snowstorm over New England and the I95 corridor from Boston to DC.  Classic bomb here we come.  Also this is the type of storm where you expect the QPF to come back to the original idea of copious amounts of moisture and a stronger intensity low.

 

Nice post, James. Way to stand your ground. It may not be historic with the snow amounts, but it is going to be a doozy with the wind. 

Batten down the hatches, and good luck out there in Harwich.

[JC-CT]

2 minutes ago, jbenedet said:

James makes a good point regarding deep shortwaves traversing near the GOM. The GOM really helps to pump downstream ridges via deep convection that translates into UL latent heat release. This is something typically downplayed by guidance--even inside 48 hrs.

Last year's mid atlantic / NYC blizzard comes to mind.

[Typhoon Tip]

I'm not privy/up to speed on all that's been covered in this thread since late yesterday (probably should get around to starting a new one with this one ringing in at over a 1,000 posts!) ...but, this 00z suite across all majors was an incomplete phase, where the proficiency left some to be desired..

The simple description that illustrates that (without tediously posting annotated images) was the definitive dumbbell structure of the total 500 mb surface region in the trough, centered on 72 hours. 

What's going on here is just an ever slight syncing issue in wave-space timing between the southern impulse and the subsuming SPV fragment diving through the Lakes. We almost need the southern component to slow down; he's like a lead that's outpacing the gal in the cyclonic dance..  As a result, it squirts the southern component and attending surface structure almost out of reach...but then at last does "partially" capture...  We see this in how the vestigial vorticity/height core stalls over NE Maine, while the N-stream core does that quasi Fuji Wara pivot S of LI out there through 96 hours. 

That is really in total pretty agreed upon by the guidance' 00z evolution.  Despite the agreement, there may yet be time for a better fusion of those cores ...and by 'better' we don't really even need it to be perfect to bring this baby over the top in to a top 10 ordeal.  If even close the gap some, with some better percent total proficiency, the surface structure and accompanying dynamics/mechanics would all slow down, and probably be stronger too -

It's fascinating - this winter certainly left the best entertainment of last!  If there is any virtue at all to the old adage 'work before pleasure,' we certainly put in our time didn't we!

So anywho...I say start a new thread.. Maybe title it "the blizzard of the ides" just to be kitchy

[dendrite]

3 minutes ago, jbenedet said:

James makes a good point regarding deep shortwaves traversing near the GOM. The GOM really helps to pump downstream ridges via deep convection that translates into UL latent heat release. This is something typically downplayed by guidance--even inside 48 hrs.

Yes, but pumping up the downstream ridge is probably going to conflict with his hopes of more snow on the cape.

[OceanStWx]

32 minutes ago, ORH_wxman said:

The h7 low could track over ORH or it could track over cape cod. We can't say where yet. That 75-100 mile range is what the final 48 hours will try and nail down but I'd be very careful about making confident statements about it yet. 

This is why I've been saying I'm confident in a 4-8 or 6-10" WAA thump, but beyond that it is up in the air. Slip that H7 low 75 miles SE and I'm nude up here.

[Damage In Tolland]

8 minutes ago, JC-CT said:

Ryan's station did go conservative to start with 6-12 (+) for the whole state.

Putting a + there is kind of cheating though. That means 30" would technically make you verify. I don't think so.

His thoughts are 12-20"

[OceanStWx]

14 minutes ago, jbenedet said:

Thanks for posting. This was my positive "caution" yesterday when the 12z euro came way east. I've noticed guidance in general trending that PNA ridge more amplified just about every run. This should also translate into a more robust northern Stream shortwave. Seems they are still playing catchup--some more than others. My expectation is this should materialize in a better/earlier N Stream phase and the guidance already picking up on this like the GEM, euro and Ukie are closer to verifying at this juncture. 

It's not totally the PNA ridge that has higher heights than modeled, it is the northern stream shortwave too. That whole region of Canada has higher heights than either the GFS or Euro forecast, except for the Pac NW where the Euro was a little too amped with the ridge. But the ensembles are keying on the northern stream shortwave the most, so that's where the heights count.

[jbenedet]

14 minutes ago, dendrite said:

Yes, but pumping up the downstream ridge is probably going to conflict with his hopes of more snow on the cape.

Well, likely , but not in invariably. This isn't my forecast but if iit translates into an earlier and better phase he could stay cold -sectored longer while the best dynamics are overhead. 

[jbenedet]

20 minutes ago, OceanStWx said:

It's not totally the PNA ridge that has higher heights than modeled, it is the northern stream shortwave too. That whole region of Canada has higher heights than either the GFS or Euro forecast, except for the Pac NW where the Euro was a little too amped with the ridge. But the ensembles are keying on the northern stream shortwave the most, so that's where the heights count.

 

Great thanks for the clarification. I made that point too yesterday as a "persistence forecast" how N Stream shortwaves have been coming in more amped off the pacific than guidance almost all season. 

Definitely a positive for the crowd wanting something bigger.

 

 

[dendrite]

5 minutes ago, jbenedet said:

Well, likely , but not in invariably. This isn't my forecast but if iit translates into an earlier and better phase he could stay cold -sectored longer while the best dynamics are overhead. 

Well the more westward solutions from days ago had higher heights in the wrn Atlantic.

Anyway...the nam looks a bit more amplified so far. We shall see how it translates.