Atlantic Tropical Action 2013 - Part 2

[phil882]

Looks like 96L has a closed llc... too bad its starting to be substantially impacted by strong southerly shear form the ULL to its west.

 

[Ed Lizard]

Looks like 96L has a closed llc... too bad its starting to be substantially impacted by strong southerly shear form the ULL to its west.

 

 

000

ABNT20 KNHC 280251

TWOAT

SPECIAL TROPICAL WEATHER OUTLOOK

NWS NATIONAL HURRICANE CENTER MIAMI FL

1050 PM EDT FRI SEP 27 2013

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SPECIAL OUTLOOK ISSUED TO UPDATE DISCUSSION OF AREA OF DISTURBED

WEATHER EAST-NORTHEAST OF THE LESSER ANTILLES.

UPDATED...SATELLITE IMAGES AND SATELLITE-DERIVED WIND DATA INDICATE

THAT A SMALL LOW PRESSURE SYSTEM HAS DEVELOPED ABOUT 700 MILES

EAST-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS AND IS PRODUCING

WINDS NEAR GALE FORCE.  HOWEVER...THE ASSOCIATED SHOWERS AND

THUNDERSTORMS ARE BEING DISPLACED NORTH OF THE CENTER OF THE LOW

DUE TO STRONG UPPER-LEVEL WINDS.  ENVIRONMENTAL CONDITIONS

ARE EXPECTED TO BE MARGINALLY CONDUCIVE FOR ADDITIONAL DEVELOPMENT

DURING THE NEXT COUPLE OF DAYS WHILE THE LOW MOVES GENERALLY

NORTHWARD AT ABOUT 15 MPH.  THIS SYSTEM HAS A MEDIUM CHANCE...40

PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS

AND A MEDIUM CHANCE...50 PERCENT...OF BECOMING A TROPICAL CYCLONE

DURING THE NEXT 5 DAYS.  ADDITIONAL INFORMATION ON THIS SYSTEM CAN

BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER

SERVICE.

OTHER SYSTEMS WITH FORMATION POTENTIAL BEYOND 48 HOURS...

A BROAD AREA OF LOW PRESSURE IS EXPECTED TO FORM OVER THE

SOUTHWESTERN CARIBBEAN SEA DURING THE NEXT COUPLE OF DAYS...AND

CONDITIONS COULD BE CONDUCIVE FOR SOME DEVELOPMENT NEXT WEEK WHILE

THE SYSTEM MOVES TOWARD THE NORTHWESTERN CARIBBEAN SEA AND

SOUTHEASTERN GULF OF MEXICO.  THIS SYSTEM HAS A LOW CHANCE...NEAR 0

PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS

AND A LOW CHANCE...20 PERCENT...OF BECOMING A TROPICAL CYCLONE

DURING THE NEXT 5 DAYS.

&&

HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE CAN BE

FOUND UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

FIVE-DAY FORMATION PROBABILITIES ARE EXPERIMENTAL IN 2013. COMMENTS

ON THE EXPERIMENTAL FORECASTS CAN BE PROVIDED AT...

WWW.NWS.NOAA.GOV/SURVEY/NWS-SURVEY.PHP?CODE=ETWO

$$

 

Not very photogenic.

 

[HurricaneJosh]

That Mandarin is mind-blowingly boring, in my opinion-- just ugly, cheap, low-potential, high-latitude schlock.

 

Let's hope the SW Caribbean thing develops.

[Ed Lizard]

That Mandarin is mind-blowingly boring, in my opinion-- just ugly, cheap, low-potential, high-latitude schlock.

 

Let's hope the SW Caribbean thing develops.

Wouldn't you rather chase a Karen?

 

 

Best thing for the Caribbean system would be to stay in the Caribbean longer than the 18Z GFS forecasts it to stay down there.

Edit to Add: 18Z FIM9 has a tropical storm coming through the Yucatan Channel into the Gulf, then weakening rapidly as it approaches the Florida Panhandle, not quite landfall at the end of the 168 hour run.

[phil882]

Sometimes I don't know how to interpret these weak systems from the NHC. Yes they are insignificant in the long run, but if you have a closed circulation with winds near gale force and its producing convection thats as organized as Humberto was for a 12-24 hour period, isn't that a tropical cyclone? These are the systems that really reveal how ambiguous the marginal TC identification process is.  

[TropicalAnalystwx13]

Sometimes I don't know how to interpret these weak systems from the NHC. Yes they are insignificant in the long run, but if you have a closed circulation with winds near gale force and its producing convection thats as organized as Humberto was for a 12-24 hour period, isn't that a tropical cyclone? These are the systems that really reveal how ambiguous the marginal TC identification process is.  

I think the primary reason Humberto was kept a tropical cyclone was for continuity. After all, the first NHC advisory after regeneration called for the system to re-attain hurricane intensity within 120 hours. The vertical wind shear from the upper-level low was forecast to lessen...but it never did. If shear was forecast to remain high right off the bat, I don't think they would've re-designated it as a cyclone.

But yeah, the definition is ambiguous/subjective: 

 

[phil882]

That Mandarin is mind-blowingly boring, in my opinion-- just ugly, cheap, low-potential, high-latitude schlock.

 

Let's hope the SW Caribbean thing develops.

 

snob

 

But yes you are right... from a chasing perspective this system is low grade stuff you typically ignore. The system in the Caribbean is perhaps slightly more interesting, but compared to the potential here to 95L and Ingrid its lower (WAY too dry + too much VWS). Sorry. 

[Cheeznado]

00Z GFS has a low west of SW Florida at 144, and actually the shear over it is not that horrific. Not expecting a gangbusters system but even a strong TS threatening the US would be an improvement in this P.O.S. season.

[HurricaneJosh]

snob

 

But yes you are right... from a chasing perspective this system is low grade stuff you typically ignore. The system in the Caribbean is perhaps slightly more interesting, but compared to the potential here to 95L and Ingrid its lower (WAY too dry + too much VWS). Sorry. 

 

Well, the 00Z GFS is coming in now, and it shows something in the SE Gulf that's a lot more robust than anything else we've seen modeled recently.

[phil882]

I think the primary reason Humberto was kept a tropical cyclone was for continuity. After all, the first NHC advisory after regeneration called for the system to re-attain hurricane intensity within 120 hours. The vertical wind shear from the upper-level low was forecast to lessen...but it never did. If shear was forecast to remain high right off the bat, I don't think they would've re-designated it as a cyclone.

But yeah, the definition is ambiguous/subjective: 

 

The vertical wind shear did lessen, but the upper-level jet dynamics never overcame the marginal SSTs + relatively dry mid-latitude air. Once another much larger mid-latitude trough came to take its place, the convection over Humberto wasn't deep enough to have any sort of jet impact that could have allowed baroclinic enhancement.

 

But yes your point remains, continuity does play a role in these operational real-time forecasts, and hopefully thats something that ultimately gets cleared up by the TCR at the end of the season. With 96L, ultimately it wouldn't take much more convective organization to make this system a TC.

[HurricaneJosh]

00Z GFS has a low west of SW Florida at 144, and actually the shear over it is not that horrific. Not expecting a gangbusters system but even a strong TS threatening the US would be an improvement in this P.O.S. season.

 

Yep, was just noticing this as well (see my last post).  It's actually strengthening up to Day 5 or 6.  At least the trend is positive.

[phil882]

Well, the 00Z GFS is coming in now, and it shows something in the SE Gulf that's a lot more robust than anything else we've seen modeled recently.

 

Yep the new 00z GFS is quite a bit stronger, but still doesn't suggest anything we didn't already see with Ingrid (sheared high end TS / low end HU). A lot of the intensification in the GOM is due to a favorable upper-level trough interaction enhancing poleward outflow. We'll see how much that exceptionally dry air in the GOM can moisten up over the next 48 hours, since its clear this disturbance won't be in a low shear environment and could struggle against frequent dry air intrusions into the core. 

[U_Thant]

The setup looks good for a Florida TC. The mid level trough axis is far enough west (W of 85) and there is stout ridging over the western Atlantic, east of the trough, to provide southerly as opposed to SW steering. If it forms, I don't see it escaping out to the NE underneath south Florida and through the Bahamas. Josh, if I lived on the west coast, I'd invite you over for dinner and babysitting, but you may be looking at a late season FL gulf coast chase next week!

[HurricaneJosh]

The setup looks good for a Florida TC. The mid level trough axis is far enough west (W of 85) and there is stout ridging over the western Atlantic, east of the trough, to provide southerly as opposed to SW steering. If it forms, I don't see it escaping out to the NE underneath south Florida and through the Bahamas. Josh, if I lived on the west coast, I'd invite you over for dinner and babysitting, but you may be looking at a late season FL gulf coast chase next week!

Well, this is encouraging. I like your take a little more than Phil's. What do you think of its prospects, intensity-wise, once it gets into the Gulf? Are you as negative on it as Phil?

[U_Thant]

Well, this is encouraging. I like your take a little more than Phil's. What do you think of its prospects, intensity-wise, once it gets into the Gulf? Are you as negative on it as Phil?

 

I think the increasing shear from about 25N northward should be counteracted by the fact that it looks strongly divergent, which is essentially saying the same thing as Phil (i.e. the jet is enhancing poleward outflow).

 

A lot will depend on how fast/to what extent it spins up before it emerges north of the LAT of Cuba.

[thewxmann]

The 0Z GFS solution only has validity if the ECWMF also latches onto it.

[U_Thant]

The 0Z GFS solution only has validity if the ECWMF also latches onto it.

 

The ECM actually showed a very similar solution last night. Now for tonight, it trended weaker and much farther west. I hope it's a blip and not "The Great Black Cloud of 2013 TC Suckiness" rearing its ugly head again.

 

More importantly, however, I didn't get Josh's hopes up for the prospect of a late season FL chase for no reason. 

[HurricaneJosh]

The ECM actually showed a very similar solution last night. Now for tonight, it trended weaker and much farther west. I hope it's a blip and not "The Great Black Cloud of 2013 TC Suckiness" rearing its ugly head again.

 

More importantly, however, I didn't get Josh's hopes up for the prospect of a late season FL chase for no reason. 

 

Don't worry-- I'm pretty numb at this point-- and also starting to think beyond North America for action.

 

There's just some kind of curse sitting over the continent this year.  I suppose we all might have felt this way in 1982 or 1983-- but this year somehow feels uniquely bad.

 

I've been advised that another MJO pulse is going to be coming through the EPAC in a week or two and the NATL a little after that.  Let's see if that can bring any last hurrahs.

[thewxmann]

Don't worry-- I'm pretty numb at this point-- and also starting to think beyond North America for action.

 

There's just some kind of curse sitting over the continent this year.  I suppose we all might have felt this way in 1982 or 1983-- but this year somehow feels uniquely bad.

 

I've been advised that another MJO pulse is going to be coming through the EPAC in a week or two and the NATL a little after that.  Let's see if that can bring any last hurrahs.

 

1983 was eons better... at least we had Alicia.

[HurricaneJosh]

1983 was eons better... at least we had Alicia.

Alicia was awesome, but besides that, it was really pretty bad.

[bluewave]

My guess why this year was so quiet so far compared to recent years is the change in SST's

coupled with the dry and more stable conditions that we have been seeing in recent years.

While 2011 and 2012 had their share of dry and more stable conditions, I believe the warmer

SST's may have helped both years not get shut down to the extent that we saw this year.

The change in SST's this year relative to the last 2 years shows cooler SST's over the Tropical

Atlantic and Caribbean along with the Far North Atlantic. Notice how the Tropical Atlantic

and Caribbean along with areas east of Florida had more suppressed convection compared

to the last two years. The enhanced African Convection during 2011 and 2012 was able to

extend west to over the Tropical Atlantic while it got shut down this year with the cooler SST's.

 

 

 

 

 

 

[Ed Lizard]

0Z FIM-9 more cheerful, 18Z FIM took a tropical storm through the Yucatan Channel, and then started weakening it during is entire trip through the Gulf, probably not even a TS at the end of the run while still offshore.

 

Still not onshore at Hour 168, but 60-65 knots, and heading slightly East of due North towards MS/AL/Western Panhandle.  And it is strengthening in the Gulf.  No Ivan or Opal, but beggars and choosers and all that.

[TropicalAnalystwx13]

My guess why this year was so quiet so far compared to recent years is the change in SST's

coupled with the dry and more stable conditions that we have been seeing in recent years.

While 2011 and 2012 had their share of dry and more stable conditions, I believe the warmer

SST's may have helped both years not get shut down to the extent that we saw this year.

The change in SST's this year relative to the last 2 years shows cooler SST's over the Tropical

Atlantic and Caribbean along with the Far North Atlantic. Notice how the Tropical Atlantic

and Caribbean along with areas east of Florida had more suppressed convection compared

to the last two years. The enhanced African Convection during 2011 and 2012 was able to

extend west to over the Tropical Atlantic while it got shut down this year with the cooler SST's.

 

 

SSTB.png

 

SST.png

 

A13.png

 

A12.png

 

A11.png

Sea surface temperatures have been 28-29C throughout. I doubt that's the issue.

[Srain]

Deep tropical convection continues to fester in the Western Caribbean and the 00Z Multi Ensemble TC Genesis Probabilities continue to increase. The reliable models suggest a general slow NW motion over the next several days. I suspect we will see 97L before the weekend is over. A strong fall cold front is expected to drop S into the Southern Plains and Texas next weekend. If this disturbance can lift far enough N into the Gulf during the mid week time frame, conditions may be conducive for development before westerly shear begins to impact this potential cyclone.

[Ed Lizard]

How many more days until the Wilma Florida anniversary?

 

8 years w/o a Florida hurricane would be the biggest fail yet. 

 

I now know why Steve's ensemble probabilities are always so optimistic, usually far too optimistic.  Every CMC ensemble generating a Cat 6 will skew the numbers.

 

But the FIM is on board, GFS is showing it, even the Euro hinted at it.  More than glass half full on an invest.  The big chore, getting at least a Cat 1 to hit Florida before the Wilma anniversary.

 

 

http://www.youtube.com/watch?v=T4FFdatvTtM

 

Nostalgia...

 

Oh good, have almost a month...

[DopplerWx]

well 12z GFS has a weak ts making landfall on the sw coast of florida around 126 hrs.

[HurricaneFrances04]

Eh. Just more false hope. 

[AutoPenalti]

Ugh. Jeez, at least it's something.

[Ed Lizard]

The shear doesn't look super favorable, but this thing would still have a chance if the shear didn't have so much dry air to push into the system.

[HurricaneJosh]

How many more days until the Wilma Florida anniversary?

 

8 years w/o a Florida hurricane would be the biggest fail yet. 

 

I now know why Steve's ensemble probabilities are always so optimistic, usually far too optimistic.  Every CMC ensemble generating a Cat 6 will skew the numbers.

 

But the FIM is on board, GFS is showing it, even the Euro hinted at it.  More than glass half full on an invest.  The big chore, getting at least a Cat 1 to hit Florida before the Wilma anniversary.

 

 

http://www.youtube.com/watch?v=T4FFdatvTtM

 

Nostalgia...

 

Oh good, have almost a month...

 

Ha ha ha, thanks for posting this.  

 

Wilma was awesome.  No, it wasn't a tight-core deal when it hit FL, but it was just very robust and powerful.  It was a great storm.  I'll never forget that backside, after the eye passed-- how potent it was.