We hoist, huge drought busting rains with potential coastal flooding. Sep 29-30

[USCAPEWEATHERAF]

Just like the CAT II it had for Erika. HWRF is HBARF. 

 

If the hurricane models are useless, then why does the NHC use them?

[JC-CT]

Just like the CAT II it had for Erika. HWRF is HBARF.

Or the cat 5 that Danny was supposed to be after surviving the Caribbean.

[CoastalWx]

If the hurricane models are useless, then why does the NHC use them?

 

They look at them as guidance, but mentioned numerous times that those solutions can be ridiculous. I'm not saying it's 100% wrong, but I don't trust the HWRF much.

[Juliancolton]

Kevin, that shear will relax and move northwestward as the trough becomes amplified over SC and NC.  The flow backs towards the southeast rather than southwest and an upper level anticyclone parks itself over the cyclone within 48 hours.

 

It's dead, Jim.

 

[moneypitmike]

There are many videos of Irene out there, but here's a taste of what happened out here in Shelburne.  Being on top of a hill--and having no power or internet--we had no idea this was going on just a couple miles away.  If we have anything similar, I'm going to out recording stuff.

 

[wxeyeNH]

It looks like shear is relaxing over TD11.  Looks like the thunderstorms are expanding to the NW as the LLC moves south into them.  Wonder if we could have pretty rapid intensification?  Intensification forecasts seem less reliable than track forecasts.  Tomorrow will be interesting to say the least.

[Voyager]

Wow...that last half of that video is simply incredible!

[OceanStWx]

rainy soeaster, winds are minimal Gale

 

Probably would get stronger winds if it stays a more Euro route and developed a nice NE LLJ.

 

[TalcottWx]

If we can't get the winds lets just get a ton of rain. At least choices seem to be one or the other and not out to sea.

[OceanStWx]

I would rather have damaging winds than torrential rains to be honest.  We rarely get house damaging winds here let alone flooding rains.  80mph winds would be devastating with the amount of leaves on the trees still.  If the HWRF shows a 940mb hurricane there has to be a good reason.

 

Because it's a model built to develop hurricanes?

 

In all seriousness, there is a good reason because the model physics support it. The same way the model physics support the Euro tossing one to DCA, with mostly minor impacts to everyone outside of coastal New England. A scenario which the GFDL seems to be supporting now too.

 

[TalcottWx]

or run a facility, I am all set

Just realized we play @New Haven on Saturday afternoon. Depending on how this evolves I'm either going to be soaked or the game will be canceled. Can't see the school letting us take the bus trip down there if it's anything stronger than a TS.

[Typhoon Tip]

Because it's a model built to develop hurricanes?

 

In all seriousness, there is a good reason because the model physics support it. The same way the model physics support the Euro tossing one to DCA, with mostly minor impacts to everyone outside of coastal New England. A scenario which the GFDL seems to be supporting now too.

 

 

People should take a note from Sandy, too, when you see a +PP anomaly NNE of Maine and turn any kind of significant low pressure into the mid and upper MA coastal plain; you'll see an expansion of gale to storm force wind field quite far up the coast...

[OceanStWx]

People should take a note from Sandy, too, when you see a +PP anomaly NNE of Maine and turn any kind of significant low pressure into the mid and upper MA coastal plain; you'll see an expansion of gale to storm force wind field quite far up the coast...

 

And ensemble support is there for upper level wind anomalies to help turn this thing towards the coast. Easterlies are -2 SD, not quite Sandy level, but still significant enough to pay attention to.

[OceanStWx]

I think we've got ourselves a named system.

[Typhoon Tip]

And ensemble support is there for upper level wind anomalies to help turn this thing towards the coast. Easterlies are -2 SD, not quite Sandy level, but still significant enough to pay attention to.

 

Right, and if there is a causal-linear sort of relationship (thinking vector addition) there, Sandy really took a hard left. I mean she really hooked..  

 

The easterly anomalies in this case might balance and promote coming in at a slantwise trajectory (less sharp west) ...I don't see surge concerns being that less problematic at Categor 1 or 2, to the coast, from the Del Marva all the way up to Cape Cod.  Long swell would be punishing on SSE and SE gradient flow, pushing incidental surge criteria into favored locations all along that distance ...more obviously closer to the TC core of course, but - 

[Typhoon Tip]

I noticed as the oblique daylight faded into night over this zygote that the previously exposed llv center was seemingly yanked S and disappeared into the N edge of persisting convective canopy ...

[OceanStWx]

Right, and if there is a causal-linear sort of relationship (thinking vector addition) there, Sandy really took a hard left. I mean she really hooked..  

 

The easterly anomalies in this case might balance and promote coming in at a slantwise trajectory (less sharp west) ...I don't see surge concerns being that less problematic at Categor 1 or 2, to the coast, from the Del Marva all the way up to Cape Cod.  Long swell would be punishing on SSE and SE gradient flow, pushing incidental surge criteria into favored locations all along that distance ...more obviously closer to the TC core of course, but - 

 

Current GFS depiction is several days of some sort of southerly flow over the NW Atlantic from Joaquin to Cape Cod. We might need Ginx to check in on Taylor from time to time.

[TalcottWx]

I noticed as the oblique daylight faded into night over this zygote that the previously exposed llv center was seemingly yanked S and disappeared into the N edge of persisting convective canopy ...

Seems like IR confirms that too with a nice burst of cooler tops near the low level circ

[Typhoon Tip]

heh ...if things break right, this could be Bob-like in terms of short porch lead warning -

[weatherwiz]

And ensemble support is there for upper level wind anomalies to help turn this thing towards the coast. Easterlies are -2 SD, not quite Sandy level, but still significant enough to pay attention to.

 

How much of an influence would the development of the 500mb trough influence here?  I had no idea about those -2SD easterlies...but I was wondering/thinking earlier that if this trough does not dig as advertised, or if the trough axis is too far east, the system may end up escaping east (still with moisture being thrown back)...although the trough did have a decent negatively tilted look.  

 

Also, where can you go to check those SD's you mentioned...I remember there was one site for that but I lost it.  

[OceanStWx]

How much of an influence would the development of the 500mb trough influence here?  I had no idea about those -2SD easterlies...but I was wondering/thinking earlier that if this trough does not dig as advertised, or if the trough axis is too far east, the system may end up escaping east (still with moisture being thrown back)...although the trough did have a decent negatively tilted look.  

 

Also, where can you go to check those SD's you mentioned...I remember there was one site for that but I lost it.  

 

http://cms.met.psu.edu/sref/ensembles/gefsp.html

 

The key could be developing a more closed circulation aloft in the east, so that winds would become more easterly in that quadrant of the trough. In that sense, you don't necessarily need a negative tilt. You could have extreme negative tilt and get Sandy II a la the Euro, or like Tip says you could get a screamer coming in at a more shallow angle to the NNW. Current ensemble guidance seems to argue more for the latter.

 

[Typhoon Tip]

By the way ... the correlated -NAO is west based - 

[Chrisrotary12]

Geezers this is a first in my life

 

Berks crushed by one heck of a deformation band in this snowstorm eh?  495 belt doesn't do to bad either. 

[Typhoon Tip]

The 18z HWRF is entertaining...  Slams a Cat 3 hurricane into the N half of the Jersey coast, surely bringing one helluva tidal surge smack quintessentially into the NY Bite!  wow...  Then, the whole Basin is left in a veritable petridish for new potential..  

 

What the heck.  Head scratcher - could we be on the brink of a special era?   

[Typhoon Tip]

Berks crushed by one heck of a deformation band in this snowstorm eh?  495 belt doesn't do to bad either. 

 

The recently inducted term "epicosity" certainly gets a work out - 

 

Considering the more than half of that would likely fall centric to the cyclone, woof

[weatherwiz]

http://cms.met.psu.edu/sref/ensembles/gefsp.html

 

The key could be developing a more closed circulation aloft in the east, so that winds would become more easterly in that quadrant of the trough. In that sense, you don't necessarily need a negative tilt. You could have extreme negative tilt and get Sandy II a la the Euro, or like Tip says you could get a screamer coming in at a more shallow angle to the NNW. Current ensemble guidance seems to argue more for the latter.

 

250WIND-20.gif

 

Thanks for the link!

 

Wouldn't developing a closed off circulation though be a bit of a negative for us...well if it happened too early?  Wouldn't this make for occlusion and essentially working to shut off moisture influx?  Or is the interest in the closed off circulation over the fact that if it happens at a favorable location, this could yield stronger impacts from a surface circulation?  

[OceanStWx]

Thanks for the link!

 

Wouldn't developing a closed off circulation though be a bit of a negative for us...well if it happened too early?  Wouldn't this make for occlusion and essentially working to shut off moisture influx?  Or is the interest in the closed off circulation over the fact that if it happens at a favorable location, this could yield stronger impacts from a surface circulation?  

 

The Euro would be a "too early" example.

[weatherwiz]

The Euro would be a "too early" example.

 

perfect...thanks!  

 

It's awesome to start tracking something so highly interesting...always a ton of fun dealing with all these features and evaluating how each model and run is handling the progression of the mid/upper level features.  

 

Regardless of how the evolution occurs I feel more confident than not that we are going to be getting some decent rains regardless of what happens (unless something crazy happens and the system either craps out or gets kicked way, way east).  I guess the question is how much rain and if we are dealing with other possibilities.  

[ORH_wxman]

Still a tad early to worry about the maximum spots, but this appears to be a primarily E to NE boundary level flow for the event...except at the very beginning.

 

E/NE boundary layer flow would favor SE NH to E MA for enhanced rainfall going by previous heavy rainfall research over SNE. The SW flow in the mid-levels early on will really pump up theta-e and probably cause some really really excessive amounts. The WAA gets shut off eventually in the mid-levels and we go more cold conveyor, but that setup could easily change depending on what happens after 48-60 hours.

[weatherwiz]

Still a tad early to worry about the maximum spots, but this appears to be a primarily E to NE boundary level flow for the event...except at the very beginning.

 

E/NE boundary layer flow would favor SE NH to E MA for enhanced rainfall going by previous heavy rainfall research over SNE. The SW flow in the mid-levels early on will really pump up theta-e and probably cause some really really excessive amounts. The WAA gets shut off eventually in the mid-levels and we go more cold conveyor, but that setup could easily change depending on what happens after 48-60 hours.

 

If that were to be the case some areas could get nailed.  One aspect with this system that could come into play is the potential for quite a long duration of heavy rains.  There are several ingredients presented that suggest this could be one slow moving system and as long as the moisture inflow doesn't get shut off this system will crank out precip.  

 

Also, some of the areas of interest for this weekend or among some of the same areas which could get the jackpot tomorrow through Wednesday.