Atlantic Tropical Action 2014

[IsentropicLift]

The long range forecast on this hurricane seems correct. May not have a Cat 2 all year.

Arthur was a Cat 2.

[jcwxguy]

pretty sure they meant cat 3 

[Ground Scouring]

By all indications, the next potential wave behind 90L (if it even develops as much as the GFS indicates, which I don't believe it will) will be too far north to even have a chance to impact the U.S. and the NE Caribbean. The clock is tick, tick, ticking on this season...

[AvantHiatus]

By all indications, the next potential wave behind 90L (if it even develops as much as the GFS indicates, which I don't believe it will) will be too far north to even have a chance to impact the U.S. and the NE Caribbean. The clock is tick, tick, ticking on this season...

I can understand your pessimism, considering Florida's recent history. However, this season already holds more value than 2013. Give credit where it is due. 

 

Edit: 90L looking good + African Wave Train

http://rammb.cira.colostate.edu/ramsdis/online/loop_meteosat.asp?data_folder=tropical/tropical_met_14km_visir2&width=640&height=480&number_of_images_to_display=24

[Ground Scouring]

I can understand your pessimism, considering Florida's recent history. However, this season already holds more value than 2013. Give credit where it is due. 

"Florida's recent history"? I'm talking about the U.S. in general, as well as the NE Caribbean. There have been no major landfalls in the U.S. since 2005. The NE Caribbean hasn't seen a hurricane impact since Omar 2008. The last hurricane impact in the Windward Islands was Tomás 2010. The last hurricane to hit TX was Ike 2008. In the contiguous U.S., only the Carolinas and LA have seen (relatively minor, intensity-wise) hurricane impacts since 2008. For nearly two years we've seen too much shear for homegrown hurricanes to develop in the W Caribbean and most of the Gulf. We haven't seen a major, long-lived hurricane develop in the MDR since 2011. We've seen very few TC days in the basin since 2011--certainly nothing like what we saw earlier in the +AMO phase. Compared to 1995-2005, 2006-2014 (particularly 2011-2014) have been weak in a large number of indicators. We've seen record levels of SAL and stability, along with an increasingly persistent mid-ocean TUTT since 2008, and especially since 2011.

 

You may be interested in even a crappy TS/weak hurricane that goes fishing, but to serious followers of the tropics--especially those who chase--it isn't much to write home about. A major fish would be more notable, but we haven't eked out a major hurricane in the ATL since Sandy 2012. ACE basin-wide has been running at near-record lows since 2011. I'm sure that you know of all the other statistics knowledgeable people here have mentioned. You may be interested in 90L and what follows it, but if a system either 1) doesn't impact land somewhere or 2) isn't very long-lived/intense, I'm not going to follow the tropics for anything other than ACE-peddling. And the majority of subtropical storms during peak season, and most subtropical storms generally, don't count as legitimate systems worthy of concern in most cases. Most STSs, barring land impacts, aren't as damaging as a hurricane or even many TSs. If we're lucky to see even a STS in peak season, then that shows how dead 2014 has been.

[Ground Scouring]

On another, more subjective note, even the recent +AMO phase (1995-present) hasn't been so impressive in some respects.

 

Even including 2004-2005, the 1995-present period has not been as impressive as the last +AMO phase between 1926-1969. That phase saw at least five large Category 4 landfalls in the U.S.: September 1926, September 1928, September 1947, August 1949, and Carla 1961. The period also saw Cat.-4 U.S. hits in 1932, 1945, 1948, 1950, 1960, and probably 1965 (Betsy). The storms in 1960 and 1969 were of at least moderate size at landfall, while the rest were compact. There were two Cat.-5 hits (both >145 kt) in 1935 and 1969. As far as Cat.-4+ landfalls are concerned, we've only seen small-sized Hurricane Charley (2004) since 1995. Almost of the major hits--except Charley--since 1995 have been weakening Cat.-3 cyclones at U.S. landfall. Cat.-4/5 impacts were definitely more frequent in 1926-1969 than in 1995-2014, even considering the shorter period of the latter.

 

You can argue that while in other respects we've seen some impressive stats--the number of Cat.-5 TCs, including the LFs of Dean and Felix 2007, between 2004-2007; the size of storms like Katrina, Rita, Ike, and Sandy; overall damages, inflation-adjusted, from recent impacts; etc.--some of these statistics may be unreliable, considering that we don't have a good sample of wind radii prior to the late 1970s (the modern satellite era) and that population increases may mask just how damaging storms in the past could be if they were to hit today. Additionally, while the number/frequency of major hurricanes seems greater since 1995, we must not forget that many of the 1926-1969 storms, even those that preliminary reanalysis downgrades, occurred prior to the satellite era. Even the reanalyzed data may thus not account for a major hurricane whose peak was not captured by reconnaissance or surface data, particularly over the open sea. In terms of raw intensity, a surprisingly large number of the U.S. impacts have been rather "average" even for major hurricanes. Of course, we can't dismiss the fact that we've seen impressive impacts outside the U.S., but most of the audience here is from the U.S. and thus may be more interested in U.S. hits.

[Kory]

"Florida's recent history"? I'm talking about the U.S. in general, as well as the NE Caribbean. There have been no major landfalls in the U.S. since 2005. The NE Caribbean hasn't seen a hurricane impact since Omar 2008. The last hurricane impact in the Windward Islands was Tomás 2010. The last hurricane to hit TX was Ike 2008. In the contiguous U.S., only the Carolinas and LA have seen (relatively minor) hurricane impacts since 2008. For nearly two years we've seen too much shear for homegrown hurricanes to develop in the W Caribbean and most of the Gulf. We haven't seen a major, long-lived hurricane develop in the MDR since 2011. We've seen very few TC days in the basin since 2011--certainly nothing like what we saw earlier in the +AMO phase. Compared to 1995-2005, 2006-2014 (particularly 2011-2014) have been weak in a large number of indicators. We've seen record levels of SAL and stability, along with an increasingly persistent mid-ocean TUTT since 2008, and especially since 2011.

You may be interested in even a crappy TS/weak hurricane that goes fishing, but to serious followers of the tropics--especially those who chase--it isn't much to write home about. A major fish would be more notable, but we haven't eked out a major hurricane in the ATL since Sandy 2012. ACE basin-wide has been running at near-record lows since 2011. I'm sure that you know of all the other statistics knowledgeable people here have mentioned. You may be interested in 90L and what follows it, but if a system either 1) doesn't impact land somewhere or 2) isn't very long-lived/intense, I'm not going to follow the tropics for anything other than ACE-peddling. And the majority of subtropical storms during peak season, and most subtropical storms generally, don't count as legitimate systems worthy of concern in most cases. Most STSs, barring land impacts, aren't as damaging as a hurricane or even many TSs. If we're lucky to see even a STS in peak season, then that shows how dead 2014 has been.

The fact that you just said Louisiana had minor impacts from hurricanes since 2008 is a joke. Seriously? Did you even follow hurricane Isaac? It sent a 8-10 foot storm surge into the city of LaPlace, Louisiana, a city of over 30,000 people. People had to be rescued off roofs. It was one of the most costly category 1 hurricanes on record. You lost all credibility in my book.

[Ground Scouring]

The fact that you just said Louisiana had minor impacts from hurricanes since 2008 is a joke. Seriously? Did you even follow hurricane Isaac? It sent a 8-10 foot storm surge into the city of LaPlace, Louisiana, a city of over 30,000 people. People had to be rescued off roofs. It was one of the most costly category 1 hurricanes on record. You lost all credibility in my book.

You're right. I know that Isaac and Arthur were both locally (and, in Isaac's case, nationally) significant. By "minor," however, I meant in terms of intensity, not overall impact. I have since edited my post to clarify the matter. I have made clear in my other post that I was primarily talking about LF intensities rather than overall destructive potential and actual impact.

[Kory]

On another, more subjective note, even the recent +AMO phase (1995-present) hasn't been so impressive in some respects.

Even including 2004-2005, the 1995-present period has not been as impressive as the last +AMO phase between 1926-1969. That phase saw at least five large Category 4 landfalls in the U.S.: September 1926, September 1928, September 1947, August 1949, and Carla 1961. The period also saw Cat.-4 U.S. hits in 1932, 1945, 1948, 1950, 1960, and probably 1965 (Betsy). The storms in 1960 and 1969 were of at least moderate size at landfall, while the rest were compact. There were two Cat.-5 hits (both >145 kt) in 1935 and 1969. As far as Cat.-4+ landfalls are concerned, we've only seen small-sized Hurricane Charley (2004) since 1995. Almost of the major hits--except Charley--since 1995 have been weakening Cat.-3 cyclones at U.S. landfall. Cat.-4/5 impacts were definitely more frequent in 1926-1969 than in 1995-2014, even considering the shorter period of the latter.

You can argue that while in other respects we've seen some impressive stats--the number of Cat.-5 TCs, including the LFs of Dean and Felix 2007, between 2004-2007; the size of storms like Katrina, Rita, Ike, and Sandy; overall damages, inflation-adjusted, from recent impacts; etc.--some of these statistics may be unreliable, considering that we don't have a good sample of wind radii prior to the late 1970s (the modern satellite era) and that population increases may mask just how damaging storms in the past could be if they were to hit today. Additionally, while the number/frequency of major hurricanes seems greater since 1995, we must not forget that many of the 1926-1969 storms, even those that preliminary reanalysis downgrades, occurred prior to the satellite era. Even the reanalyzed data may thus not account for a major hurricane whose peak was not captured by reconnaissance or surface data, particularly over the open sea. In terms of raw intensity, a surprisingly large number of the U.S. impacts have been rather "average" even for major hurricanes. Of course, we can't dismiss the fact that we've seen impressive impacts outside the U.S., but most of the audience here is from the U.S. and thus may be more interested in U.S. hits.

You even said it yourself, we're only about half way through this +AMO phase. You're really splitting hairs over incomplete data comparing a 40 year period versus a 20 year period.

[GaWx]

 The Euro ens and GEFS are in agreement that we will go from phase 4 through the COD to phase 1 by ~9/13. After that, GEFS stays in 1 while the more reliable Euro moves to phase 2 after 3-4 days in 1. By avoiding moving into phases 5-8, the strictly 1995-2012 MJO based chances (i.e., ignoring other factors) for genesis wouldn't go low for the next two weeks (including while within COD) as per below:

 

 I looked at the number of TC geneses 1995-2012 in September for each MJO phase and came up with these overall % chances for genesis per day:

 

Phase 1: 24% (Ivan of 2004)

Phase 2: 17% (Ike of 2008 and Jeanne of 2004)

Phase 3: 6%

Phase 4: 16%

Phase 5: 8% (Humberto of 2007)

Phase 6: 6%

Phase 7: 14%

Phase 8: 15%

In Circle: 21% (Rita of 2005, Isabel of 2003, Lili of 2002, Floyd of 1999, Georges of 1998, Opal of 1995)

 

ALL        16%

 

- So, phase 1 has had the highest daily rate of genesis in Sep. during 1995-2012 (24% vs. only 14% in Aug.). So, with just three days of phase 1, genesis is actually more likely than no genesis.

- Being within the circle in Sep. is actually more conducive than average with 21% (vs. 16% overall) unlike in August when it was only 10%/lower than Aug. average.

- Surprisingly, phase 3 had only a 6% daily genesis rate, tied for the bottom in Sep. Compare this rate to a whopping 38% in August, the top rate by a wide margin!

- All but one (90%) of the CONUS H hits and all of the major CONUS H hits from Sep. geneses 1995-2012 were from geneses during phase 1, phase 2 , or within the circle. That's a lot considering that 1/2/COD made up only 58% of the days.

[IsentropicLift]

Hard to believe this was only given a lemon. It looks more organized than Bertha did as a Hurricane.

 

[Kory]

Microwave satellite image shows a center almost completely closed.  ASCAT should be very telling in seeing if a center is completely closed off.  

[Superstorm93]

Microwave satellite image shows a center almost completely closed.  ASCAT should be very telling in seeing if a center is completely closed off.  

 

Not even close to resembling a simple wave, let alone a closed circulation:

 

[Kory]

Not even close to resembling a simple wave, let alone a closed circulation:

 

 

Well scratch my last statement...looks a lot better on satellite than it actually is. 

[Kory]

Well, now that the convection is displaced from the center, it DOES appear 90L did actually have a low level center all along.

 

[wxtrackercody]

Invest 91L has a good deal of spin to it despite a decrease in convection since yesterday (not uncommon for waves just emerging). Wind shear and mid-level moisture as analyzed by the SHIPS are sufficient for development over the next few days, but the convectively-suppressed kelvin wave that was talked about earlier in this thread is currently passing over the wave; this might slow development. The ECMWF continues to develop this, while the GFS, which originally showed this as an intensifying hurricane in 4-5 days, now shows this as a broad tropical depression at the same time. After day 5, it looks like dry air might become of an issue. The NHC is currently giving the wave a 30% chance of developing over the next 2 days and a 60% chance of developing over the next 5 days. Overall steering looks west-northwestward.

 

[wxmeddler]

Dr. Ventrice just posted this on twitter. ECMWF Ens are less excited about 91L than the GEFS.

[Kory]

^^^ Curious, what are the black lines off the Gulf Coast in that image?

[wxmeddler]

^^^ Curious, what are the black lines off the Gulf Coast in that image?

 

Oil rigs I believe. Unrelated.

[GaWx]

So, last five GFS runs' furthest west longitude for 91-L (in degrees): 55, 63, 57, 60, 50. This is not the least bit threatening to the SE US.

Chance of 91-L hitting the U.S. based on numerous model runs/pattern of E US trough: 5% at best imo. I'd say that its only chance of a threat to the SE US is if it stays at a good bit further south latitude than has been modeled, goes through the Caribbean, and then comes up north. Otherwise, the E CONUS/far W ATL trough will almost definitely capture it and keep it safely E of the SE US. N NE might have a slightly better chance but even that would be a remote chance imo.

Keep in mind that, overall, something forming well east out in the MDR in Sep. only has ~20% chance of hitting the CONUS. The current chance is a good bit lower than the already rather low climo of 20%.

[wxmeddler]

HS3 is scheduled fly out to 91L and release a bunch of sondes on either Tuesday or Wednesday (Wx at the HS3 base at Wallops Is.,VA permitting.)

[Snow_Miser]

The invest way out in the Eastern Atlantic continues to produce deep convection. I'm not exactly sure why the NHC lowered the chances of development today.

And that would be why NHC lowered chances for development.

[IsentropicLift]

And that would be why NHC lowered chances for development.

If it was closer to shore and they had gotten recon in they may have found a depression yesterday.

[Weather.St]

I have still been looking at the chances of a development over those areas. The curve to the due north is looking a little more likely given the GFS solutions tonight, but it could change back and forth over the next few runs anyways, we learned that well with Cristobal and Arthur.

 

 

This image was made yesterday and still seems to be quite valid, the chances that the storm can move back to the west on the models is still there, however, we still are watching any changes in the ensembles through noon on Wednesday to see what kind of blocking pattern develops along the eastern seaboard, or if a front will kick it straight out to sea as it approaches. Going to be an interesting watch

[Kory]

I have still been looking at the chances of a development over those areas. The curve to the due north is looking a little more likely given the GFS solutions tonight, but it could change back and forth over the next few runs anyways, we learned that well with Cristobal and Arthur.

 

 

This image was made yesterday and still seems to be quite valid, the chances that the storm can move back to the west on the models is still there, however, we still are watching any changes in the ensembles through noon on Wednesday to see what kind of blocking pattern develops along the eastern seaboard, or if a front will kick it straight out to sea as it approaches. Going to be an interesting watch

I think the troughing is going to win out.  It's been persistent this whole season.  Both of the big global models are showing a deep East Coast trough in the 7-10 day time frame.  Should turn anything back out to sea.  

[Kory]

I think 91L has the best chances for any development in the MDR we've seen all season (that isn't saying much though).

 

 

[Srain]

I think 91L has the best chances for any development in the MDR we've seen all season (that isn't saying much though).

 

 

 

The best chance this fish storm has if it develops would be W of 55.

 

 

[Ground Scouring]

Personally, I really doubt that 91L will develop. The ECMWF, for run after run, has only been showing a weak depression at most through day six (with a weak, recurving TS in the very long range NE of the Leeward Islands), and until recently more than half of the GFS ensembles weren't even developing 91L. The dynamical intensity models (HWRF, GFDL) have been roughly as bullish as the ECMWF over the past several days. Given the still-very-dry conditions evident on visible satellite imagery, I would not bet the ranch on 91L's developing--and if it does develop, it won't be higher than a depression. I agree with Srain that the most likely prospects for development are in the long range (days seven through 10) as the system gains longitude, moving NW of the dry MDR and entering the subtropics.

 

On another note, as I have expected, models have toned down the prospects for homegrown development. The GEFS no longer shows development in days three through five over the W Caribbean / BOC. This trend is in agreement with the ECMWF, which still shows low pressures (though not as low as on previous runs), but no development. All in all, despite the arrival of MJO Phase I, nothing other than 91L looks to develop through September 18. As a seasonal indicator, shear has been and remains too high for development in the W Caribbean, the BOC, and most of the Gulf of Mexico. Expecting conditions to improve as we head later into the season is just not plausible.

 

Everything is following my expectations (though I may be getting little credit for being right, even for the right reasons).

[MarkSC]

No love for the home brew potential in the Bahamas? Euro and CMC both show something in a few days from apparent interaction of a tropical wave near Puerto Rico with the upper low currently over the Bahamas. 

[Srain]

Today marks the 114th Anniversary of the Great Galveston Hurricane of 1900. While the exact death toll will never been known, it was probably well above the official 8000 that has been reported.

 

http://celebrating200years.noaa.gov/magazine/galv_hurricane/welcome.html#pred