Atlantic Tropical Action 2013

[phil882]

Good News! The 00z Run of the GFS ingested a lot of the dropsondes (full tropospheric profile (~100mb to surface)) from the Global Hawk flying out by the Cape Verde islands.

20130825_00z_GFS_dropsondeijestion.gif

 

So basically the 00z GFS does have a much better than typical sense of the SAL profile currently in the far east Atlantic. The 00z GFS also looks a lot closer to what the 12z ECMWF (in terms of the mid-level ridging) looked like earlier today. 

[Ed Lizard]

 

 

The 500 mb heights at that time are pure, um, 'hard core weenie prawn'.

[GaWx]

1) For still another day, the Euro and GFS ensemble means are predicting the strongest near peak season MJO phase 1 since at least 1979, when David and Frederic were spawned. Actually, the MJO is just about to head pretty strongly into phase 8.

 

2) The 0Z GFS and Euro op,. runs are now both showing a more robust TC than their respective prior runs showed. They suggest that IF this is going to threaten the US, it would be around 9/7-8.

 

3) Early this month, I predicted a major H hit on the US sometime this season based on a combo of neutral negative to weak La Nina ENSO and a very cool start to August. Just food for thought.

[CoastalWx]

It looks like ensembles have an ULL west of the Canary Islands. Lower heights extend SW a bit so we'll have to see how that goes, but it should stay far enough north for now...especially with the system not really developed yet.

[wxmx]

Looks like SWerly shear on 95L is abating markedly looking at the first vis images. Should have no problem to become namewaster TS Fernand. Wind observations around the coast shows a distinct closed low. Not certain of position yet...but should be in the Sern portion of the main blob...around 19.5N 94W

[Ed Lizard]

Looks like SWerly shear on 95L is abating markedly looking at the first vis images. Should have no problem to become namewaster TS Fernand. Wind observations around the coast shows a distinct closed low. Not certain of position yet...but should be in the Sern portion of the main blob...around 19.5N 94W

 

Depressing, it looks so good on vis but hasn't cleared 20N yet.

[Srain]

Looks like SWerly shear on 95L is abating markedly looking at the first vis images. Should have no problem to become namewaster TS Fernand. Wind observations around the coast shows a distinct closed low. Not certain of position yet...but should be in the Sern portion of the main blob...around 19.5N 94W

RECON will likely find a TD or TS this afternoon. This will likely be onshore somewhere between Tuxpan to Tampico by noon on Monday as a moderate TS.

 

[EasternUSWX]

Nice storm, too bad it has limited room to work with.

 

[Srain]

One has to think the GFS is benefiting from the additional data from the Global Hawk mission and that trend continues with the 12Z GFS that we saw last night with the 00Z suite of guidance.

[phil882]

Nice storm, too bad it has limited room to work with.

Yep... a pretty obvious TD/TS right now... NHC is just waiting on recon this afternoon.

 

[GaWx]

1) For still another day, the Euro and GFS ensemble means are predicting the strongest near peak season MJO phase 1 since at least 1979, when David and Frederic were spawned. Actually, the MJO is just about to head pretty strongly into phase 8.

2) The 0Z GFS and Euro op,. runs are now both showing a more robust TC than their respective prior runs showed. They suggest that IF this is going to threaten the US, it would be around 9/7-8.

3) Early this month, I predicted a major H hit on the US sometime this season based on a combo of neutral negative to weak La Nina ENSO and a very cool start to August. Just food for thought.

The 12Z gfs develops two TC's during what would be a potent MJO phase 1 though these two fish. The important thing to note is the trend of the models being finally toward much more robust tropical cyclone development, which makes sense considering the strong phase 1 being forecasted. Now, whether or not any TC that forms during this period will ever end up as a US threat is obviously still way too far out in time to predict. Two prior GFS runs hit the US: S FL and ME. At the least, the total boredom in the MDR appears like it is FINALLY about to end. The lead disturbance that develops is just now leaving the African coast (designated "pouch 25" by the pouch gang). This could easily attain invest status within the next couple of days.

[wxmeddler]

Dam, if it only had more water to work with. That said, the HWRF makes it into a Hurricane in the EPAC. I wonder if they will keep the name (if it gets named).

[Ed Lizard]

Dam, if it only had more water to work with. That said, the HWRF makes it into a Hurricane in the EPAC. I wonder if they will keep the name (if it gets named).

 

 

I believe if it loses an identifiable low level vortex, it gets a new name.  It has to reach the other side as a named tropical depression, which almost certainly won't happen.

 

Tehuanepec appears the only place in Mexico where a cyclone could cross and remain a named cyclone.  Texas only October major, the 1949 Freeport hurricane, may have crossed from the Pacific as a pre-existing cyclone.   For a storm following a likely Atlantic TC path, Nicaragua looks like the only clear path

 

Edit to add- despite the mountain range, and on the idea a well established mid level low could quickly develop a new surface low that would appear essentially continuous with the old disrupted low, Atlantic storms probably can (and have) gotten through Costa Rica.

 

 

[Ed Lizard]

Not just weenie optimism, while 12Z GFS storm that develops in the next week is a verbatim fish, the 500 mb pattern at the end of the higher resolution suggests rather small changes would allow a US threat.  It isn't a deep full latitude trough approaching the East Coast.

[EasternUSWX]

Not just weenie optimism, while 12Z GFS storm that develops in the next week is a verbatim fish, the 500 mb pattern at the end of the higher resolution suggests rather small changes would allow a US threat.  It isn't a deep full latitude trough approaching the East Coast.

 

I just want a storm to form, then we can worry about where it is going lol

[GaWx]

Not just weenie optimism, while 12Z GFS storm that develops in the next week is a verbatim fish, the 500 mb pattern at the end of the higher resolution suggests rather small changes would allow a US threat.  It isn't a deep full latitude trough approaching the East Coast.

 

 The idea that any threat from the first TC would be the better part of two weeks away and the fact that two recent GFS runs hit the US (today's 6Z hit ME and earlier run hit S FL) is way more than enough to tell me that this is far from being an obvious fish at this point. My educated guess is that slower development than what the 12Z GFS shows would favor a more westward reaching track. Also, fwiw, I believe that neutral negative ENSO tends to be more of a favorable factor than an unfavorable factor for US threats from the MDR. I'm not saying a US hit from this is likely per se this far out, but anyone assuming it is an almost definite fish as of now with so much uncertainty is probably too confident from my perspective, especially since it hasn't even formed into a TC yet.

[Ed Lizard]

 

Nicole Mitchell

 

About to go investigate the disturbance in the Bay of Campeche. We'll see if it's our next Tropical Depression!

[Snow_Miser]

Simulated IR seven days from now.

[hurricaneman]

It seems as though recon hasn't taken off. Was it canceled due to being too close to Mexico?

[Amped]

Looks like another sea breeze spin up in the BOC. It only has a few hours to work with so they better

 

Nice storm, too bad it has limited room to work with.

 

 

 

Funny when TW are close to land they always spin up fast. No problems with competing centers, wind shear, or any of that other junk you'd see when the system was over open water.

[EasternUSWX]

 

 

 

 

Funny when TW are close to land they always spin up fast. No problems with competing centers, wind shear, or any of that other junk you'd see when the system was over open water.

 

Just likes to frustrate us. 

[phil882]

It seems as though recon hasn't taken off. Was it canceled due to being too close to Mexico?

 

They might be just having radio transmission issue... NHC scheduled another mission for 12z tomorrow so its unlikely they would cancel do to anything other than communication/plane issues.

 

With that said, even if recon doesn't go in, this is a TD looking at visible, surface obs and radar imagery. I would be absolutely shocked in NHC doesn't upgrade.

 

[GaWx]

  Also, fwiw, I believe that neutral negative ENSO tends to be more of a favorable factor than an unfavorable factor for US threats from the MDR.

 

Followup: Since 1950, whereas only ~30% of years that weren't neutral negative to weak Nina ENSO had a major US strike, a whopping ~55% of neutral negative to weak Nina ENSO (like what we have this year) did have a major US hit. So, this ENSO status appears to be associated with almost double the risk for a US major H hit. The major H hits on the US since 1950 during neutral negative to weak Nina were King of 1950, Gracie of 1959, Carla of 1961, Beulah of 1967, Allen of 1980, Alicia of 1983, Elena of 1985, Hugo of 1989, Andrew of 1992, Opal of 1995, and Fran of 1996. The three 2005 major hits were a close call and could have been counted depending on how ENSO was tallied. However, I didn't include them.

 

 I didn't include Carmen of 1974 as a major US hit only because Josh said he's expecting it to be downgraded to a cat. 2 hit once reanalysis is completed.

[PennyForYourThoughts]

RENUMBER

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06, 2013082518, , BEST, 0, 194N, 951W, 30, 1006, LO, 34, NEQ, 0, 0, 0, 0, 1011, 100, 50, 0, 0, L, 0, , 0, 0, SIX

[wxmeddler]

 I hope the plane breaks down on the tarmac, I want Ferdanand for the next CV wave.

[klw]

Ignorant question of the day:  Is there a Mexican Weather Service which issues warnings?

[phil882]

Ignorant question of the day:  Is there a Mexican Weather Service which issues warnings?

 

To my knowledge the NHC coordinates with the Mexican government for watches and warnings from tropical cyclones. 

[wxmeddler]

Ignorant question of the day:  Is there a Mexican Weather Service which issues warnings?

 

Yes, the NHC gives recomendations but it's ultimately up to them. They also have their own radar network:

http://smn.cna.gob.mx/index.php?option=com_content&view=article&id=56&Itemid=59

[Mike.Ventrice]

Hi guys,

 

Thought I'd share an email that I sent out to the t-storm list folks. Some of this stuff on here I've already talked about so feel free to skim through to the fun stuff:

 

Hi all,

 

I believe this is a good time to introduce a new Madden Julian Oscillation (MJO) index that is built very similar to the popular real-time multivariate MJO (RMM) indices (Wheeler and Hendon 2004) but uses zonal wind anomalies at both 200-hPa and 850-hPa but now uses velocity potential at 200-hPa instead of OLR. The index is called the velocity potential MJO (VPM) indices (manuscript) and can be found running in real-time on my webpage.

 

One of the benefits of this index is that it captures more MJO-related variance over the Western Hemisphere during boreal summer.  Now with regards to the current evolving MJO event over the East Pacific, the GFS operational forecast for 8/29 in the VPM framework is for phase 8 at amplitude 1.85.

 

 

If verified, this would rank as the 3^rd strongest MJO event over the Western Hemisphere in the month of August dating back to 1989. The strongest VPM phase 8 in August occurred in 2001 on 8/22. 2nd strongest occurred on 8/15/2012, then the current event on 8/29, followed by 8/22/2004, then 9/23/2002.

 

So top 5 in form of date (amplitude):

1. 8/22/2001 (2.34 sigma)

2. 8/15/2012 (2.33 sigma)

3. 8/29/2013 (1.85 sigma) *FORECAST*

4. 8/22/2004 (1.84 sigma)

5. 8/23/2002 (1.76 sigma)

 

For these years from the date where the VPM read the strongest value in August and ending in September, there were 31 named tropical cyclones, 21 of which formed over the MDR in the form of a “Cape Verde” disturbance.  Furthermore, 21 out of the 31 (68%) tropical cyclones reached at least a category 1 hurricane in strength. 

Named storms from the first date when the VPM indices read phase 8 to the end of following September, each year in rank of strongest VPM phase 8 in August.

 

A. 2001

1. TS DEAN 8/22

2. H-3 Erin 9/1

3. H-3 Felix 9/7

4. H-1 Gabrielle 9/11

5. TD9 9/19

6. H-2 Humberto 9/21

 

B. 2012

1. H-2 Gordon 8/15

2. H-1 Isaac 8/20

3. TS Joyce 8/31

4. H-2 Kirk 8/28

5. H-1 Leslie 8/28

6. H-3 Michael 9/2

7. H-1 Nadine 9/10

 

C. 2013

???

 

D. 2004

1. H-4 Francis 8/25

2. H-1 Gaston 8/27

3. TS- Hermine 8/27

4. H-5 Ivan 9/2

5. TD10 9/7

6. H-3 Jeanne 9/13

7. H-4 Karl 9/16

8. H-1 Lisa 9/19

 

E. 2002

1. TS Dolly 8/29

2. TS Edouard 9/1

3. TS Fay 9/5

4. TD 7 9/7

5. H-2 Gustav 9/8

6. TS Hanna 9/12

7. H-3 Isidore 9/14

8. ET Joseph 9/17 (*counted as a tropical cyclone in this analysis*)

9. H-1 Kyle 9/20

10. H-4 Lili 9/21

 

Best Regards,

Mike V.

[phil882]

Also looks like recon is finally in flight, probably will be able to make a fix before TD6 makes landfall.