Atlantic Hurricane/Invest Thread 2012/2013

[mezzacyclone]

It`s all go!

Invest 92L has a closed surface circulation according to noaa OceanSAT 25km wind obs over the 12N 44W region.

The only problem for development is that up to 44kn shear is forecast ahead with nothing <22kn in the next 120hrs?

SB`s MJO phase notion (In the TS Andrea thread) may well be valid in terms of the early active start to the season?

Will keep an eye on those Shear values and the susceptibility to change as an upper level trough is not evident West of its path (as far as I can see?) so I cannot determine why those values are so high but welcome someone "enlightening" me? ;o)

Edited June 6, 2013 by mezzacyclone

[summer blizzard]

Certainly good to see something so far east at this time of year.

 

Ships kills it within 3 days, GFS does the same but has an interesting track as below.  The big problem for the next few days is a supressed Kelvin Wave causing subsidence but it it's still alive when it gets to the Winwards, it has a chance.

 

 

 

[mezzacyclone]

It looks like the STJ is keeping 92l well in check right now along with very high shear (50kn?)

but should the environment turn more favorable for development then the majority of the model tracks look dangerous skirting NE just off the lesser ants & Turks before going through the Bahamas for a SE (Miami?) FL landfall?

Daylight circulation obs coming along now to decide if monitoring will continue or not.

(sorry sb, just caught your post after/during i scribbled this one lol)

Edited June 7, 2013 by mezzacyclone

[Somerset Squall]

92L is certainly impressive for this time of year but it is simply in the wrong place at the wrong time. Tropical cyclones this far east in June are rare, but there have been a few cases of these strong disturbances becoming tropical depressions prior to climatology (strong shear and lukewarm sea temps) destroying them. Eg. Tropical Depression Two in June 2003, Tropical Depression Two in 2000.

[summer blizzard]

92L is dead. Worth watching to see if it gets itself declared 93L.

 

MJO should enter phase 7 in very late June so best chance for developments is into early July.

 

[summer blizzard]

Just created my own forecast for the season using primarily the years of 1990, 1995 and 2004 as analogues.

 

My prediction is 16/9/4.

[mezzacyclone]

Just created my own forecast for the season using primarily the years of 1990, 1995 and 2004 as analogues.

 

My prediction is 16/9/4.

with a little hindsight from accuweathers SB?  (16,8,4)

Any thoughts on NCEP models predicting a development of at least an invest around the far W caribbean sea, Yucatan and Bay of Campeche region coinciding with the MJO timing you stated?

The MDR is currently under a vast SAL plume, that may have nothing to do with the previously mentioned area favored for development? but decreasing GOM shear values support the models although a continuous ridge over the southern states looks to keep any TS formation transitting Northwards?

As a matter of interest in your prediction: can you decipher if any ENSO neutral state lead you to conclude your numbers?

I guess its only a matter of time too that those E Atlantic SST high anomolies propogate westwards foreboding the beginning of numerous cape verde disturbances but the last thing anyone wants in another 2005.

Edited June 15, 2013 by mezzacyclone

[summer blizzard]

with a little hindsight from accuweathers SB?  (16,8,4)

 

Any thoughts on NCEP models predicting a development of at least an invest around the far W caribbean sea, Yucatan and Bay of Campeche region coinciding with the MJO timing you stated?

The MDR is currently under a vast SAL plume, that may have nothing to do with the previously mentioned area favored for development? but decreasing GOM shear values support the models although a continuous ridge over the southern states looks to keep any TS formation transitting Northwards?

 

As a matter of interest in your prediction: can you decipher if any ENSO neutral state lead you to conclude your numbers?

 

I guess its only a matter of time too that those E Atlantic SST high anomolies propogate westwards foreboding the beginning of numerous cape verde disturbances but the last thing anyone wants in another 2005.

 

Ha, nope. I simply get the data, compile analogues, weight them, drop the highest and compile an average. I've not actually seen their forecast.

 

I've been reading about it and it looks like we could get a TS which i suppose is good for the time of year however the charts i was using for the ECWMF and GFS now require subscription (do you know of anything decent?) so i'm reliant on bits and bats. Yes, the MJO looks good into early July (hopes for an Emily 05 repeat) so we should be in luck for the next few weeks. Yes, the models suggested a stable atmosphere post Andrea well in advance.

 

My forecast takes into account the PDO, QBO, MEI and GLAAM. In this case the GLAAM, MEI and QBO were not disimilar to 1990 and 2004 in particular (they saw neutral-positive MEI) however the ENSO outlook is i think going to swing either side of neutral with building warm anomolies to the west, a PDO that's finally positive but an east Pacific that's a bit Nina ish.

 

Speak for yourself, i would be in heaven with a repeat. In terms of hurricane landfalls in Florida/US Gulf Coast 1990 had 0, 1995 had 3 (less than 20%) and 2004 had 4 (just over 25%) so we could either get a lot of strong FISH storms or 3/4 hurricane landfalls in Florida/Gulf Coast.

[mezzacyclone]

however the charts i was using for the ECWMF and GFS now require subscription (do you know of anything decent?) etc

Iv`e got around a hundred bookmarks? SB all on tropical info which puts me in a real muddle most of the time but I`ll have a recce and see as i`m sure I found some when trawling?

but meantime thanks to a Trop Wave moving fully through the Caribbean sea then,

93L anyone?

But if it has a go at a TD then its got its work cut out with minimal sea track over the gulf of Honduras before landfall over Belize then maybe a little more time over the southern most Bay of Campeche as it slows forward speed but its running up against the ULT resident in the area causing it to look more impressive than it actually is with the visible outflow simply provided predominantly by the troughs SE flank causing SW winds on the waves NW edge. (still with me I hope?)

So most likely a big rain maker for Mexico where it might? fizzle out altogether courtesy of the strong TX ridge.

ECM hooks the MJO into region 1 (&2) sharply for the first third of July so we`ll see then if anything can hop on the bus and take advantage but prior to that maybe a EPAC system during phase 8 toward the end of June?

But we have something to keep an eye on full of a few "If`s" and "But`s" which ain`t bad for June

[summer blizzard]

Yeah it's just purely a model output centered over the tropical Atlantic that i need so i can admire model fodder category 7 hurricanes slamming the USA.

 

In regards to 93L anyway its track is the main issue but it does look pretty good...

 

 

Small chance it gets into the GOM which would be good...

 

[Gray-Wolf]

Looks like we are getting a few 'disturbances' dropping off Africa now? I wonder when we can expect our first TS on our side of the pond?

[summer blizzard]

Looks like we are getting a few 'disturbances' dropping off Africa now? I wonder when we can expect our first TS on our side of the pond?

 

A good month or so away yet for that however conditions west of the Antilles look good enough for a medium track cane to form (can still get a beast like Emily). 

[Gray-Wolf]

Well two named storms already and I'm informed the second storm is not usually due until early Aug?

[summer blizzard]

Yup, it's pretty good.

[mezzacyclone]

CMC are really cranking up the current EPAC 94E development as shear lowers and conditions improve for intensity over the weekend but GFS keep hinting on a caribbean development and conditions are not exactly benign at the moment (would not rule out NHC plotting a new Invest tomorrow dependant on convergence increasing with a current disturbance SW of the Bahamas) with shear forecasts lowering by the day so theirs lots of interest about and plenty to monitor.

[Gray-Wolf]

It does look as though it wants to organise? Maybe todays convection will finally persuade it to get it's act together?

 

Still seeing some heavy storms fall off Africa into the Atlantic and keep wondering about the possibilities of the 're-curves' up the African coast this season? For whatever reason I'm seeing a very differnt 'pattern' to our weather in the UK with far more H.P. permanently on the charts? If we are seeing a H.P. dominated Atlantic then the chance of a 'block' steering storms directly north has to be increased?

Edited June 21, 2013 by Gray-Wolf

[summer blizzard]

It does look as though it wants to organise? Maybe todays convection will finally persuade it to get it's act together?

 

Still seeing some heavy storms fall off Africa into the Atlantic and keep wondering about the possibilities of the 're-curves' up the African coast this season? For whatever reason I'm seeing a very differnt 'pattern' to our weather in the UK with far more H.P. permanently on the charts? If we are seeing a H.P. dominated Atlantic then the chance of a 'block' steering storms directly north has to be increased?

 

Most years have a strong high in the Atlantic, what's important to recurves is whether there's a cut-off low near the Azores to turn them early or whether there's a high over the north east to provide Caribbean cruisers.

[summer blizzard]

Nice low level rotation to 97E.

 

[mezzacyclone]

Nice low level rotation to 97E.

 

 

,,,and plotted <30km with development from the SW Mexican shore alongside the states of Michoacan & Colima around Manzanillo City thus heightening to current 70% cyclone formation?

[summer blizzard]

Looks good from this weekend, especially the ensemble hints in about 2 weeks..

 

[mezzacyclone]

Looks good from this weekend, especially the ensemble hints in about 2 weeks..

 

I hold mr Cowan in high regards SB in his simple ethical opinions with his blog so it will be very interesting to follow the mid July (14th 15th thereabouts) promising wave West of cape verde,

Great info on the current high trades and the convergence aloft between the upper lows activity holding back GOM developments but bringing heavy precip to parts of FL AL & Georgia,

Funnily enough the models were keen on BOC activity in anticipation of the trough clearing NW out of the Gulf along with the Bermuda ridge retrograding Westward but although a low may hook out of the yucatan area and curve northward it favors nothing more than a minimal vorticity low for welcome rain east of mobile bay for southern TX?,,,,but bits to keep a lookout for and heightened potential whenever MJO`s in 1-2.

early days 

Edited July 4, 2013 by mezzacyclone

[mezzacyclone]

Well it looks like the GOM disturbance aka Inv 94L is nothing more than a basic storm and rain event as the surface trough axis has pushed ahead NW of the convective mass with a southerly windflow sending it all for a "welcome" downpour for TX & Lou with minor attempts at forming Low centres and circulation failing to transpire fully on a few occasions thus far.
95L however is looking quite a visible feature 900 miles SW of cape verde with brief images of possible banding visible on its SE periphery but its not just a fast transit & closeby prominent SAL that are most likely to hold it back but ever increasing proximity to the low level strong Easterly trade winds that make any circulation more difficult the more it gains in latitude, "IF" this keeps further south, not moving much further North on its 8-15° Lat path until it leaves the Atlantic, then it may have a better chance at TD and more once it slows down after the less antiles?

NHC are keen on this in hindsight and currently have it on "Orange" 30% so a watch is on but the Mid-July activity for developments East of the Caribbean are most definitely on target and 95l is merely the beginning.

What`s equally intriguing is the timing of these waves and relative nearby TUTT & ULL`s and such in wether they lay victim to diminishing any chances of enhancing thunderstorms by "shredding" them or the opposite by aiding waves if their further away by clearing out upper diverging air well ahead of any tropical wave?

Edited July 6, 2013 by mezzacyclone

[Somerset Squall]

95L has now been given a 60% chance (red) of development by NHC. Mezza has summed it's chances up perfectly in his post above, but if a low can close off beneath that deep convection, a tropical storm could form very soon (winds are 35kts in association with the invest).

[Gray-Wolf]

Well things are looking a little more certain from the30% chance disturbance with it now up to a red 60% chance of formation?

 

EDIT: Snap!!!

Edited July 7, 2013 by Gray-Wolf

[mezzacyclone]

GFS have chopped and changed plotting development of waves south of cape verde in recent days but NHC have just heightened an observation from 10% to 30%  (can`t recall seeing an obs so far East @ 20° W longtde?) and declared Inv 98L

Receiving lots of publicity already but may well diminish in the Mid-Atl in days ahead but has every chance at organising & strengthening (TS Dorian?) as it crosses the 80° Lon/lesser ant position, moreso if it adapts a low trajectory (current steering renders this unlikely) and low pace to avoid the brunt of taking in the full SAL plume and an upper lev low on the southern flank of the mid atl ridge around 20lat 40-50long but it has good convection to start with and no strong shear with a small AC currently over/near it so something to follow, but CMC, (regular over forecasting model), go with a closed low as early as later tomorrow/early weds likely down to current size, conv and favorable conditions before the ride becomes more tricky mid atl with raised shear forecast, borderline 24-25C ssts and inhibitors as above?

Edited July 22, 2013 by mezzacyclone