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Disorganized 99L May Develop Before Reaching the Caribbean; Fiona No Threat

By: Jeff Masters and Bob Henson 4:38 PM GMT on August 20, 2016

A large but disorganized tropical wave (Invest 99L), located in the tropical Atlantic midway between Africa and the Lesser Antilles Islands on Saturday morning, was headed west at 15 - 20 mph. Residents of the islands in the eastern Caribbean should closely monitor this disturbance, as it has the potential to develop into a tropical depression or tropical storm before moving into the Lesser Antilles Islands on Tuesday night. The most impressive thing about 99L when viewing satellite loops is its very large size and impressive amount of spin. A large region of the atmosphere has been put in motion by this disturbance, which is both good news and bad news: good news because such large disturbances typically take a long time to spin up into a tropical cyclone, but bad news because once they do, they affect a large area and will resist rapid weakening. The other notable feature of the storm Saturday morning was the relative lack of heavy thunderstorm activity, due to dry air from the Saharan Air Layer (SAL), as seen in water vapor satellite imagery. However, this dry air was only moderately dry, with humidities at mid-levels of the atmosphere between 500 - 700 mb running 65 - 70%. Other conditions were generally favorable for development, with wind shear a moderate 10 -15 knots and sea surface temperatures (SSTs) 27.5 - 28°C (82 - 83°F), which was about 1°C (1.8°F) above average.


Figure 1. MODIS visible satellite image of 99L and a new tropical wave about to emerge from the coast of Africa, taken on Saturday morning, August 20, 2016. The next name on the list of “Invests” is 90L. Image credit: NASA.

Track forecast: 99L a potential long-range threat to Hispaniola, the Bahamas, Cuba, and the U.S.
A strong ridge of high pressure will keep 99L headed slightly north of due west over the next few days, and the storm should enter the Lesser Antilles Islands by Tuesday night, spreading heavy rains and gusty winds. By Wednesday, the storm will likely respond to a weakness in the ridge of high pressure steering it, taking a more west-northwesterly track close to Puerto Rico, reaching Hispaniola or the Southeastern Bahamas by Thursday. The uncertainty about the track increases greatly thereafter, and the entire U.S. coast from Texas to Maine could potentially be a target for 99L in the 7 -10 day time frame.


Figure 2. The dry air of the Saharan Air Layer (SAL) as analyzed by satellite at 8 am EDT Saturday, August 20, 2016. The SAL was interfering with both Fiona and 99L, but was not as concentrated as we saw early in August. Image credit: University of Wisconsin CIMSS/NOAA Hurricane Research Division.

Intensity forecast for 99L: NBD or OMG?
As usual, the intensity forecast is a challenging one. The 8 am EDT Saturday run of the SHIPS model showed moderately favorable conditions for development through Wednesday, with wind shear in the moderate range, 10 - 15 knots, a relatively moist atmosphere, and SSTs near 28°C (83°F.) The total heat content of the ocean will steadily increase as 99L moves westwards, as well. Working against development of 99L will be the dry air of the SAL to its north, plus large scale sinking air over the tropical Atlantic imparted by the Madden-Julian Oscillation (MJO). The active portion of the MJO is currently located in the Western Pacific, which is leading to increased tropical cyclone activity there—three named storms were active there on Saturday morning. This positioning of the MJO typically leads to compensating sinking air and surface high pressure over the tropical Atlantic, with reduced chances of tropical cyclone development there. However, by Wednesday, forecasts from the GFS model predict that the MJO will weaken, allowing large scale rising air to set up over the eastern Caribbean—potentially increasing the chances for 99L to develop.

Some of the runs of the GFS model on Friday showed development of 99L into a tropical storm or hurricane in the eastern Caribbean, but the Saturday morning (00Z and 06Z) forecasts from the model have backed off on that idea. Given 99L’s large size and current state of disorganization, the earliest it is likely to become a tropical depression is Monday, so the Lesser Antilles Islands are not going to see a hurricane from this storm. The Saturday morning (00Z) operational runs of our three reliable models for predicting tropical cyclone genesis—the European, GFS and UKMET models—had only one of the three--the UKMET model—showing development of 99L into a tropical storm over the next five days. However, at least five of the twenty members of the 00Z Saturday GFS ensemble showed 99L eventually becoming a hurricane after seven days, as did eight of the fifty members of the European model ensemble. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave 99L 2-day and 5-day development odds of 10% and 50%, respectively. The next name on the Atlantic list of tropical storm names is Gaston—but it is possible that the tropical wave emerging off the coast of Africa on Saturday night could become a named storm before 99L develops, in which case 99L would grab the name Hermine.

A new tropical wave emerging from the coast of Africa may develop
A large new tropical wave with plenty of spin will emerge from the coast of Africa on Saturday night, and the Saturday morning operational runs of the European, GFS and UKMET models all showed development of this wave into a tropical depression in 3 - 5 days. In their 8 am EDT Saturday Tropical Weather Outlook, NHC gave this disturbance 2-day and 5-day development odds of 10% and 50%, respectively. The wave will head west-northwest to northwest over the next five days on a path similar to Fiona’s, into a region of ocean where very few tropical cyclones ever make the long trek westwards to hit the U.S.


Figure 3. Infrared image of Tropical Storm Fiona as of 1515Z (11:15 am EDT) Saturday, August 20, 2016. Image credit: NOAA/NESDIS.

Tropical Storm Fiona is having a rough weekend
Tenacious Tropical Storm Fiona is fighting its way across the central Atlantic in the midst of moderate to strong vertical wind shear (20-30 knots) that is forcing dry Saharan air into the storm. As of the 11 am EDT Saturday advisory, Fiona was centered near 20.3°N, 47.8°W and moving west-northwest at 14 mph. Fiona is now a minimal tropical storm, with top sustained winds estimated of just 40 mph (at best). The storm’s convection had largely dissipated until early Saturday morning, when a new burst of showers and thunderstorms developed on the northeast side of the low-level center of circulation. Although the HWRF model (currently the most reliable at short-term intensity forecasts) strengthens Fiona briefly over the weekend, the strong consensus among models, including HWRF, is that Fiona will weaken below tropical storm strength by early next week. It could maintain its identity as a tropical depression for at least another day or two after that.

Fiona’s west-northwest motion should continue till around Tuesday, when we can expect it to begin arcing northward between around 60°W and 65°W, toward a weakness in the broad ridging that covers most of the Atlantic subtropics. By this point, wind shear may relax and SSTs beneath Fiona will have risen to 29-30°C, which could help keep Fiona clinging to life if it survives till then. The stronger Fiona is at this point, the more northward a track it would take. Fiona could end up passing near Bermuda around the middle of next week, although it seems unlikely there would be much more than gales and squalls (if that) associated with it.


Figure 4. Residents flee flooded Baton Rouge as waters rose on Saturday, August 13, 2016. (Phin Percy)

Louisiana disaster survivors with disabilities need your support after historic flooding
The Portlight.org disaster relief charity, founded and staffed by members of the wunderground community, is responding to this week's devastating floods in Louisiana. The disaster is particularly troublesome for a state that is still in recovery from major flooding just last March, and many resources are completely depleted because of the March flooding. That storm left more than 5,000 homes damaged or destroyed and cost $1.5 billion across a three-state area. With at least 40,000 homes damaged or destroyed, this week's flooding will cost at least $2 billion, and perhaps much more, according to insurance broker Aon Benfield. There is an urgent need for durable and consumable medical supplies as well as housing. Portlight will be working with the American Red Cross, local stakeholder organizations, and federal partners to respond to this historic flooding event. Your support is needed to make this happen! Please consider making a donation to Portlight's disaster relief fund at the portlight.org website to further their reach and response in the state of Louisiana. Thank you for any support you can offer!

Attention Bay Area readers: Tell us what you think
WU is holding two focus group sessions in San Francisco aimed at gathering input on our products and services. The sessions will take place on Wednesday, August 31, and Thursday, September 1, from 7:45 to 9:45 pm PDT. If you are interested in joining either of these, please fill out this survey. In addition, we always welcome your input via our Customer Feedback website.

Jeff Masters and Bob Henson

Hurricane

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Hi Barb, DJ...
was having trouble posting pics, hopefully the problem's solved.
Dexter says Hi WUuuuuuuuuuooooooo!

Thanks to fellow blogger, HurricaneHistory for pointing out that 1950 Hurricane "King" had been upgraded to cat 4 status.
Also thanks to Christopher Landsea for giving me the link to "the official U.S. hurricane record that we've revised".
After rechecking, I found 2 other hurricanes that had changed categories:
> Hurricane #7 (Sep 22, 1948) changed from cat 3 to cat 4
> The "Miami Hurricane" (Oct 5, 1948) changed from cat 3 to cat 2.



The same storms by month (plus the C5's).
Pretty obvious when majors get their groove on.


BTW, the above formula for Eye Diameter to RMW is also from Landsea:
"RMW to eye diameter conversion: Based upon a paper by Kimball and Mulekar, we can convert eye diameter (which is something reported often from aircraft or ground based radar from the 1950s onward) simply by:

RMW = (Eye Diameter) times 0.75"
Quoting 999. 19N81W:


Yuck this is just nasty


Hell on earth. Dry everywhere.
1003. 19N81W
So it's all going north? Don't expect it to do much anyway as is the norm these days but would have been nice to have a td nearby
Quoting 992. wunderkidcayman:



Yep mission planned for Tues 15Z




Well speck is just N of the center
Quoting 982. SavannahStorm:

In other news, we are at 60 consecutive days and counting over 90F in Savannah (previous record was 56 days). There is no end in sight, either. Next 10 days are forecasted to reach at least 91F+ each day. Could flirt with 100F today...


True, but I can't remember the last time it officially hit 100 here. Has been a long time. The average daily highs have been above normal but we have escaped the extremes. No records lately. It are the daily lows that are noticeably warmer.
Quoting 993. ProgressivePulse:

Would't it surprise anyone looking at this mornings models that Fiona ended up threatening the US and 99L never developed, lol. Fiona will be out of the shear in less than 24hrs.
I wouldn't be surprised.... I remember Andrew.
I do expect 99L will develop anyway, though perhaps not as strongly as some people have been thinking.

Either way the situation seems to be shaping up for some kind of impact on the Bahamas, and threats to the Caribbean and FL.
Quoting 993. ProgressivePulse:

Would't it surprise anyone looking at this mornings models that Fiona ended up threatening the US and 99L never developed, lol. Fiona will be out of the shear in less than 24hrs.

lol I was secretly thinking this. I mean she has had a tendency to not listen all that well to where she should be going and seems like she is holding on the best she can. (something to think about) 99L looks like a bust compared to models. That theme can always go both ways. Fun to watch.
1007. scott39
Good morning all, from now on no more expectations from the Atlantic hurricane season and there will be no disappointments.
1008. 19N81W
It is isn't it another "rainy" season without rain or way less than we should be having.
Interesting that it never makes any news
Quoting 1002. CaribBoy:



Hell on earth. Dry everywhere.
Quoting 1004. JParsons:



True, but I can't remember the last time it officially hit 100 here. Has been a long time. The average daily highs have been above normal but we have escaped the extremes. No records lately. It are the daily lows that are noticeably warmer.
We went through that a couple years ago ... it felt like being in an inescapable sauna.
Quoting 993. ProgressivePulse:

Would't it surprise anyone looking at this mornings models that Fiona ended up threatening the US and 99L never developed, lol. Fiona will be out of the shear in less than 24hrs.

With a building ridge...
1011. scott39
Looks like Harp worked in the Atlantic.... I'm only kidding ..... calm down. LOl
Quoting 987. Hester122:

99L = falling apart. 90= another Fiona. Fiona= naked swirl barely hanging on fish storm. Zzzzzzzzzz. Wake me up when something exciting happens.

Models are shifting with Fiona US not out of play
fiona did not let 99 develop if she were not there 99 would of had a name by now
So when did the NHC drop 99L? I have not seen that happen yet.

Patience
Quoting 1006. George1938:


lol I was secretly thinking this. I mean she has had a tendency to not listen all that well to where she should be going and seems like she is holding on the best she can. (something to think about) 99L looks like a bust compared to models. That theme can always go both ways. Fun to watch.
Anybody who expected 99L to develop before tomorrow was not thinking about things. Just when all the over-anxious ones give up on it, that's when it'll start to take off. When 99L gets as far west as Fiona is now, we'll start to see some development.
1016. scott39
Quoting 1005. BahaHurican:

I wouldn't be surprised.... I remember Andrew.
I do expect 99L will develop anyway, though perhaps not as strongly as some people have been thinking.

Either way the situation seems to be shaping up for some kind of impact on the Bahamas, and threats to the Caribbean and FL.

You are going to get a Bahamian Rock Lobster and everyone else will probably get taco's or fish.
1017. beell
CIMSS 5 Day Meteosat Loop

A backwards look. 99L following Fiona.

Quoting 1014. Hurricanes101:

So when did the NHC drop 99L? I have not seen that happen yet.

Patience



ok smarty pants
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN AUG 21 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Fiona, located about 750 miles east-northeast of the
Leeward Islands.

Disorganized showers a few thunderstorms associated with a tropical
wave are located about 1150 miles east of the Lesser Antilles.
Environmental conditions are forecast to be marginally conducive for
development during the next few days, and any development should be
slow to occur. This system is expected to move westward and then
west-northwestward at 15 to 20 mph across the tropical Atlantic
Ocean, through the eastern Caribbean Sea, and then near the Greater
Antilles.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...50 percent


it was 30/60 at 2am now its 20/50
Quoting 1018. thetwilightzone:




ok smarty pants
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN AUG 21 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Fiona, located about 750 miles east-northeast of the
Leeward Islands.

Disorganized showers a few thunderstorms associated with a tropical
wave are located about 1150 miles east of the Lesser Antilles.
Environmental conditions are forecast to be marginally conducive for
development during the next few days, and any development should be
slow to occur. This system is expected to move westward and then
west-northwestward at 15 to 20 mph across the tropical Atlantic
Ocean, through the eastern Caribbean Sea, and then near the Greater
Antilles.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...50 percent


it was 30/60 at 2am now its 20/50



ok smartest of all the pants.
The dropped the odds slightly, but have not dropped the invest.
Quoting 1018. thetwilightzone:




ok smarty pants
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN AUG 21 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Fiona, located about 750 miles east-northeast of the
Leeward Islands.

Disorganized showers a few thunderstorms associated with a tropical
wave are located about 1150 miles east of the Lesser Antilles.
Environmental conditions are forecast to be marginally conducive for
development during the next few days, and any development should be
slow to occur. This system is expected to move westward and then
west-northwestward at 15 to 20 mph across the tropical Atlantic
Ocean, through the eastern Caribbean Sea, and then near the Greater
Antilles.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...50 percent


it was 30/60 at 2am now its 20/50



Drop as in stopped tracking it. Clearly that has not happened smarty pants
Quoting 1013. islander101010:

fiona did not let 99 develop if she were not there 99 would of had a name by now


yep Finona out flow winds did a # on 99L
Quoting 1015. BahaHurican:

Anybody who expected 99L to develop before tomorrow was not thinking about things. Just when all the over-anxious ones give up on it, that's when it'll start to take off. When 99L gets as far west as Fiona is now, we'll start to see some development.


Personally I was thinking SE Bahamas before we would see anything. Right now I am just trying to come up with excuses to not clean out the garage today, lol. Must stay focused, see you all this afternoon.

For those who are complaining, look what I found.
Quoting 1015. BahaHurican:

Anybody who expected 99L to develop before tomorrow was not thinking about things. Just when all the over-anxious ones give up on it, that's when it'll start to take off. When 99L gets as far west as Fiona is now, we'll start to see some development.


Yeah agreed

As I said earlier Im not expecting 99L to do much until it gets about 45-50W give or take a degree or two
Quoting 1014. Hurricanes101:

So when did the NHC drop 99L? I have not seen that happen yet.

Patience


They didn't and I don't think they will

Quoting 1019. daddyjames:



ok smartest of all the pants.
The dropped the odds slightly, but have not dropped the invest.


Yep

Quoting 1020. Hurricanes101:



Drop as in stopped tracking it. Clearly that has not happened smarty pants


Umm no they didn't they are still tracking it
Quoting 1022. ProgressivePulse:



Personally I was thinking SE Bahamas before we would see anything. Right now I am just trying to come up with excuses to not clean out the garage today, lol. Must stay focused, see you all this afternoon.
I also gotta get outta here ... LOL have fun with the garage......
1028. ackee
What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP
Quoting 1028. ackee:

What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP

B
Interesting to see Fiona strengthened to 45kt overnight before weakening again:



Come on Fiona, hang in there! She's done a nice job setting up the path for 90L which looks to develop very soon!
Dexter the Wunderdog says:
Inventory your Disaster Kit!

Be prepared!
This could be why 99L goes ots on the latest runs. [Link] Da-duh-duh-daa.

Unless its also aided by a weakness in the ridging to its north
1033. Tcwx2
I don't think 90L is another Fiona. First of all it's probably going to be way stronger, maybe even a major hurricane. And secondly Bermuda may take a huge hit from it.
Quoting 987. Hester122:

99L = falling apart. 90= another Fiona. Fiona= naked swirl barely hanging on fish storm. Zzzzzzzzzz. Wake me up when something exciting happens.
Current GFS run brings 90L to 912 mb/Cat 5 and once that moves out of the way, 99L really gets going between the Bahamas/Bermuda and strengthens into a strong category 1/category 2 hurricane with a very interesting wave train setting up behind. The GFS is showing a big uptick in activity in the Atlantic in the coming couple weeks.

Quoting 1011. scott39:

Looks like Harp worked in the Atlantic.... I'm only kidding ..... calm down. LOl


Watch out there's a gag order here.
Quoting 1024. wunderkidcayman:



Yeah agreed

As I said earlier Im not expecting 99L to do much until it gets about 45-50W give or take a degree or two
The NHC has been saying for days development of 99L not expected until the middle of the week so I don't understand why some people are ready to write it off. It has shown small signs of improvement and should continue to do so.
Quoting 1034. Envoirment:

Current GFS run brings 90L to 912 mb/Cat 5 and once that moves out of the way, 99L really gets going between the Bahamas/Bermuda and strengthens into a strong category 1/category 2 hurricane with a very interesting wave train setting up behind. The GFS is showing a big uptick in activity in the Atlantic in the coming couple weeks.




Say what??
Compass is about to make landfall over Hokkaido Prefecture.
Mindulle has about few hours until it makes landfall near Shizuoka Prefecture


Japan Meteorological Agency
21:00 PM JST August 21 2016
=========================

TROPICAL CYCLONE WARNINGS

About 70 KM Southwest Of Kushiro (Hokkaido Prefecture)
At 12:00 PM UTC, Tropical Storm Kompasu (1000 hPa) located at 42.5N 143.9E has 10 minute sustained winds of 35 knots with gusts of 50 knots. The cyclone is reported as moving north northeast at 20 knots.

Gale Force Winds
============
180 NM from the center in southeastern quadrant
60 NM from the center in northwestern quadrant

Dvorak Intensity:

Forecast and Intensity
===============
24 HRS: 50.7N 146.1E - Extratropical Low In Sea of ​​Okhotsk

--------------------------------

Sea South Of Japan
At 12:00 PM UTC, Tropical Storm Lionrock (990 hPa) located at 29.4N 133.4E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving west southwest slowly.

Gale Force Winds
============
120 NM from the center in northern quadrant
90 NM from the center in southern quadrant

Dvorak Intensity: T2.5

Forecast and Intensity
===============
24 HRS: 28.9N 133.3E - 50 knots (Severe Tropical Storm/CAT 2) South of Japan
48 HRS: 28.4N 133.0E - 55 knots (Severe Tropical Storm/CAT 2) South of Japan
72 HRS: 27.9N 132.5E - 70 knots (Strong Typhoon/CAT 3) South of Japan

--------------------

About 180 KM South of Hachijo-jima (Izu Islands)
At 12:00 PM UTC, Severe Tropical Storm Mindulle (985 hPa) located at 31.5N 139.7E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving north at 19 knots.

Gale Force Winds
==============
130 NM from the center

Dvorak Intensity: T3.0

Forecast and Intensity
===============
24 HRS: 37.5N 140.4E - 50 knots (Severe Tropical Storm/CAT 2) Overland Near Koriyama (Fukushima Prefecture)
48 HRS: 51.3N 147.6E - Extratropical Low In Sea of ​​Okhotsk
Quoting 1030. Envoirment:

Interesting to see Fiona strengthened to 45kt overnight before weakening again:



Come on Fiona, hang in there! She's done a nice job setting up the path for 90L which looks to develop very soon!


Done an even better job of smacking 99L in the face with shear.

Later all.
No persistence of the convection from last night on 99L........guess it's wait and see time.
Quoting 1028. ackee:

What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP



C or D
Quoting 1039. win1gamegiantsplease:



Done an even better job of smacking 99L in the face with shear.

Later all.


yep agreed
don;t write off 99L just yet. There is still a lot of vorticity and a large area of real estate still to traverse. 1000 miles to the islands is quite a distance and with the system getting into warmer SST ,there could be that chance of reorganisation. The next 24 hrs will tell the tale.
99L was doing way better a few days ago then it ran in too Fiona out flow wind shear and 99L open up too a open wave


99L may not do march of any thing at all now if we did not have Fiona then we could have seen 99L a named storm by now
Quoting 1034. Envoirment:

Current GFS run brings 90L to 912 mb/Cat 5 and once that moves out of the way, 99L really gets going between the Bahamas/Bermuda and strengthens into a strong category 1/category 2 hurricane with a very interesting wave train setting up behind. The GFS is showing a big uptick in activity in the Atlantic in the coming couple weeks.




The GFS has been showing an uptick in activity in it's 240 hour outlooks since late June and is batting .000 on the season in that regard.

I know we still have a lot of season left (40%), but the conditions in the Atlantic have to change. No MJO and too much dry air out there. Everytime the MJO swings around to the Atlantic it becomes rather suppressed and diluted, then only hangs around for a week here, where as it swings back to the West Pacific for a month or more.

Atlantic ACE is below normal to date and Fiona and 99L are not going to add anything significant to it. Will 90L? Guess we will see. September is rolling up quick. Window will get smaller from here on out...
Quoting 1028. ackee:

What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP



E - Hurricane.
Quoting 1032. win1gamegiantsplease:

This could be why 99L goes ots on the latest runs. [Link] Da-duh-duh-daa.

Unless its also aided by a weakness in the ridging to its north

However, this trough doesn't even effectively make it down to the Gulf Coast. I remember in the last several years when storms were going OTS left and right, we WOULD BE getting a big blast of cooler dry air from fronts making it all the way this far south.
other major win for European model for 99L wish showed it really doing march of any thing at all and that look like the case we are seeing here
99L getting squeezed, but there's still an anticyclone, vorticity, and SSTs, so relax
It ain't over til it's over and the fat lady sings
1050. hydrus
Quoting 1049. Chicklit:

99L getting squeezed, but there's still an anticyclone, vorticity, and SSTs, so relax
It ain't over til it's over and the fat lady sings

Its a weird one...90L has mojo..Gusto more appropriate.
1051. ackee
Quoting 1048. thetwilightzone:

other major win for European model for 99L wish showed it really doing march of any thing at all and that look like the case we are seeing here
true best tropical model GFS False alarm again
Models are least talented at forecasting intensity.
99L is large. Warmer water may overcome sinking air.
Stay tuned.
can 90L split in two?


This is great, you can talk about tropical weather but you can't disseminate local weather to your subscribers. Is there a place on WU where you can actually ask why we can no longer get local Alerts or Radar ? Big storms coming this afternoon, but I can't see them because your products don't function any longer. Thank God I don't live in Tornado Alley, your inept software people could cost people their lives. Sorry, is that off topic ? This is what happens when the TWC takes over.
whelp, this is about 99L's nadir if it's going to survive
1056. hydrus
Quoting 993. ProgressivePulse:

Would't it surprise anyone looking at this mornings models that Fiona ended up threatening the US and 99L never developed, lol. Fiona will be out of the shear in less than 24hrs.
Nothing surprises me with these things..They fickle in more ways than one.
Quoting 1028. ackee:

What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP



B
adios amigos
expect to see either improvement or demise after my golf game
2013 nightmare is back.
Quoting 1046. mikatnight:



E - Hurricane.
D- RIP
1062. MahFL
Quoting 1036. stormwatcherCI:

The NHC has been saying for days development of 99L not expected until the middle of the week so I don't understand why some people are ready to write it off. It has shown small signs of improvement and should continue to do so.


Vorticity is still good with 99L :

Do you realize that we only got 0.4" since august 1st !!
Quoting 1054. Gerryusa:

This is great, you can talk about tropical weather but you can't disseminate local weather to your subscribers. Is there a place on WU where you can actually ask why we can no longer get local Alerts or Radar ? Big storms coming this afternoon, but I can't see them because your products don't function any longer. Thank God I don't live in Tornado Alley, your inept software people could cost people their lives. Sorry, is that off topic ? This is what happens when the TWC takes over.


I notice a lot of links not working and images no longer appearing in their hurricane history...
99Ls low level structure is getting better organised as seen on rgb vis shortwave sat

Spin getting more pronounced
If areas like the Gulf are going to have a big threat this year, I'm thinking that we should really more be on the lookout for something that forms closer to home. Unless things REALLY change in September, it seems that it's going to be REALLY hard for a Cape Verde storm to happily coast West in/around the Caribbean under favorable conditions. Now I could see the East coast of FL with more of a chance, but otherwise, I'm not really expecting to see an Ivan-type storm blossoming and plowing through the Caribbean.
Quoting 1060. Wannab4castr63:

D- RIP


Guess that is the safest bet. I mean, bound to happen eventually!
Quoting 1065. wunderkidcayman:

99Ls low level structure is getting better organised as seen on rgb vis shortwave sat

Spin getting more pronounced


Lack of convection makes it more evident. But lake of convection is a problem.
Quoting 1028. ackee:

What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP

None of the above. A Hurricane. The Vorticity still very good. TPW great. Better water heat content upcoming,Cllimatolgy, MJO COMING, ANTICYCLONE. Too many things positive for this not to happen.
Quoting 1065. wunderkidcayman:

99Ls low level structure is getting better organised as seen on rgb vis shortwave sat

Spin getting more pronounced


i can really see that now it no long looks has open wave has it was this AM when i checked on 99L

it looks 99L got its spin back





am no longer calling 99L RIP am now calling for 99L too RI now we this need some T storms and we have are self a TD and then TS
Dry/sinking air again :/
It is like the weather collectively kicked everyones' dog in here

Geez.

Patience
Hopefully RI after 55W
90L/Gaston has a good chance of becoming the first major of the season. It looks like it will be exciting to track, and should last a long time. It should rack up quite a bit of ACE too.

Quoting 1065. wunderkidcayman:

99Ls low level structure is getting better organised as seen on rgb vis shortwave sat

Spin getting more pronounced

In my opinion 99L is over. I expect it to be dropped soon
Statistics mean nothing. Two of the most damaging storms to affect South Carolina occurred well after the peak of the hurricane season [Hazel and Hugo].

What's interesting is that, since 1993, every time South Carolina has had an evacuation, our county Emergency Coordinator has either been out of the area, or having surgery. He's just had surgery, so, by that logic, 90, 99, or Fiona should be affecting SC.

We'll have to wait for 99L to get better organized to see what happens so the models have more accurate data to work with.
Quoting 1036. stormwatcherCI:

The NHC has been saying for days development of 99L not expected until the middle of the week so I don't understand why some people are ready to write it off. It has shown small signs of improvement and should continue to do so.


Yes indeed

Quoting 1028. ackee:

What will become of 99L ?

A TD
B. TS
C. OPEN wave
D. RIP



At this time I'd say B TS

Quoting 1043. stoormfury:

don;t write off 99L just yet. There is still a lot of vorticity and a large area of real estate still to traverse. 1000 miles to the islands is quite a distance and with the system getting into warmer SST ,there could be that chance of reorganisation. The next 24 hrs will tell the tale.


More like next 48hrs will tell

Quoting 1049. Chicklit:

99L getting squeezed, but there's still an anticyclone, vorticity, and SSTs, so relax
It ain't over til it's over and the fat lady sings



Yes indeed

Quoting 1062. MahFL:



Vorticity is still good with 99L :




Very good

99L has a vary strong ANTICYCLONE over wish is helping it 99L could really RI soon now if we could get some T storms going on 99L then we have a TD
1079. hydrus
Good thing the tail end of that front is not over the gulf.. Louisiana could get another round..

Quoting 1039. win1gamegiantsplease:



Done an even better job of smacking 99L in the face with shear.

Later all.


Shear isn't the issue with 99L, it's dry air. Plus Fiona's a small storm that is getting sheared to death itself, hardly able to enhance shear across 99L.

Quoting 1045. ILwthrfan:



The GFS has been showing an uptick in activity in it's 240 hour outlooks since late June and is batting .000 on the season in that regard.

I know we still have a lot of season left (40%), but the conditions in the Atlantic have to change.


It hasn't - it's been showing a ghost storm or two but not 4 storms in a row including two within the next 5-7 days. Partially due to climatology as well.

Quoting 1059. CaribBoy:

2013 nightmare is back.


How so? We've already had a hurricane and look set to have a potential major from 90L. We had to wait until mid September for our first hurricane then. Hopefully 99L will ramp up once it's out of the dry air and give you some rain!
Quoting 1068. CaribBoy:



Lack of convection makes it more evident. But lake of convection is a problem.


That should start building soon maybe today maybe tomorrow morning

Quoting 1073. CaribBoy:

Hopefully RI after 55W


Nah maybe a little quicker than steady strengthening but that about it

Quoting 1075. juracanpr1:


In my opinion 99L is over. I expect it to be dropped soon


Very very unlikely

Infact 99L is just now getting started

Quoting 1073. CaribBoy:

Hopefully RI after 55W

If this very remote possibility (nearly 0 %) were to occur the corresponding cyclone would pass well to the NE of the islands
So basically we can pretty much expect 99L to be a hurricane in the near future and possibly a hurricane in the GOM? But that's all we can say with some certainty for now, right? When we will be able to make a better guess on potential land fall location? A week? Of course I know that the more time we go out, the more accurate the models. I know that patience is the key here, but when will those spaghetti lines start to merge together? Also, could we be looking at a Florida landfall then into GOM for a Texas, LA, MS or AL landfall? I can probably answer my own question - yes that's possible at this point. For some reason I like other people to answer my questions that I kind of already know the answer to. Lol
1084. dflam
This is an analysis i made of the Hebrew Luni/Solar calendar vs the number of hurricanes in the atlantic since records began. https://en.wikipedia.org/wiki/Hebrew_calendar

What it shows that the day before Jewish New Year (Rosh Hashana - which is always a new moon] is the peak hurricane day. This year it is October 1st.

It also misses the more pronounced double peak that is visible in the usual gregorian calendar analysis.

This seems to suggest that the peak of the hurricane season is the new moon of the beginning of the autumn.
So this needs further investigation. It also suggests that this year we will see a "longer" or "later" season than usual.



1086. beell
99L's structure has changed little over the last 2 days-although it may be slightly weaker overall and still lacking a thermodynamic environment for decent convection. That said, there is still a sizable chunk of atmosphere slowly turning. Centered near 15-16N/43-44W. It will not suddenly stop spinning unless it gets sheared out.

It does not cost much to keep it on the "watch list".
:)

Quoting 1083. truecajun:

So basically we can pretty much expect 99L to be a hurricane in the near future and possibly a hurricane in the GOM? But that's all we can say with some certainty for now, right? When we will be able to make a better guess on potential land fall location? A week? Of course I know that the more time we go out, the more accurate the models. I know that patience is the key here, but when will those spaghetti lines start to merge together? Also, could we be looking at a Florida landfall then into GOM for a Texas, LA, MS or AL landfall? I can probably answer my own question - yes that's possible at this point. For some reason I like other people to answer my questions that I kind of already know the answer to. Lol


Right now we cannot say anything with cartainty (regardless of what some would want you to believe). It could do anything at this point. The general idea of the system being in the SE Bahamas is a pretty good one though, but it could likely only be a tropical wave at that point.
Good thing there is cold front approaching the Eastern Seaboard, a low level circulation has developed east of North Carolina coastline. It is devoid of any convection likely due to some shear present from the northwest, but vorticity is decent and shear is lowering to the west of it which should spread over the low level circulation which is currently over the very warm Gulf Stream, so until it moves out of the way, development is still possible as long as shear lowers in time.
wind shear for 99L is a none issue right now has it has a vary strong ANTICYCLONE over it

Quoting 1075. juracanpr1:


In my opinion 99L is over. I expect it to be dropped soon


With the exception of a handful of runs on Thursday, in which 99L was shown as potentially forming a closed circulation, 99L is doing what the GFS prognosticated all week - nothing.

So those giving the ECMWF all the credit - the GFS shares in that too. Where the GFS indicated any initial development may occur was as 99L approaches the Antilles. We have quite some time to go before we can chalk any success to one model or another. Both are on the mark thus far.
Quoting 1090. daddyjames:



With the exception of a handful of runs on Thursday, in which 99L was shown as potentially forming a closed circulation, 99L is doing what the GFS prognosticated all week - nothing.

So those giving the ECMWF all the credit - the GFS shares in that too. Where the GFS was indicating any initial development may occur was as 99L approaches the Antilles. We have quite some time to go before we can chalk any success to one model or another. Both are on the mark thus far.


Yup, it is like saying a baseball game that is 2-0 in the 4th inning is over lol
Quoting 1083. truecajun:

So basically we can pretty much expect 99L to be a hurricane in the near future and possibly a hurricane in the GOM? But that's all we can say with some certainty for now, right? When we will be able to make a better guess on potential land fall location? A week? Of course I know that the more time we go out, the more accurate the models. I know that patience is the key here, but when will those spaghetti lines start to merge together? Also, could we be looking at a Florida landfall then into GOM for a Texas, LA, MS or AL landfall? I can probably answer my own question - yes that's possible at this point. For some reason I like other people to answer my questions that I kind of already know the answer to. Lol


Let's just deal the the Caribbean first yeah
The Caribbean will get impacted before the US so Caribbean get priority ok so chill ya
Quoting 1070. thetwilightzone:



i can really see that now it no long looks has open wave has it was this AM when i checked on 99L

it looks 99L got its spin back





am no longer calling 99L RIP am now calling for 99L too RI now we this need some T storms and we have are self a TD and then TS



It also looks like the strong East to West (ITCZ) flow; that was hampering the Southern half of 99L circulation, has eased up quite a bit.
99L Low level spin is growing although elongated its getting better

Elongated NE-SW 14N 43W to 13N 45W moving W 270

Quoting 1076. MBSCEOCHam:

Statistics mean nothing. Two of the most damaging storms to affect South Carolina occurred well after the peak of the hurricane season [Hazel and Hugo].

What's interesting is that, since 1993, every time South Carolina has had an evacuation, our county Emergency Coordinator has either been out of the area, or having surgery. He's just had surgery, so, by that logic, 90, 99, or Fiona should be affecting SC.

We'll have to wait for 99L to get better organized to see what happens so the models have more accurate data to work with.


On that thought, the last few times SEFL was impacted by a major storm, my folks were out of town (Andrew and Wilma). BRB - have to make a phone call! :)
According to this GFS run there are two more systems coming right behind 90L


Link
Quoting 1096. bluehaze27:

According to this GFS run there are two more systems coming right behind 90L


Link


False alarm maybe.
Quoting 967. thetwilightzone:





you are 100% way way way way wrong on that if African wave stay weak they head W in order for African to go right out too sea they need too be all ready a mod TS or strong TS or at lest a TD

11N is where 90L is at

found one


the 138 new england hurricane would be a good track from 90L in the same area it made it all the way too the E coast

Link

Lol so in 150plus years you found ONE!!! I guess every storm that gets pulled north out of the caribbean will turn into Sandy too right???
Quoting 1096. bluehaze27:

According to this GFS run there are two more systems coming right behind 90L


Link
There has been some good ensemble support for them even though in the long range, the GFS really wants Ian and Julia to start out early September.
Classic Fujiwhara going on over in the west pacific
The tropical Atlantic is looking pretty sick this morning. I seriously doubt that either 99L or 90L will ever become anything more then what they are right now which is garbage. As in the last few years, the Atlantic continues to be contaminated with an over abundance of dry stable air which is making it almost impossible for anything to develop. That is also why I've said many times not to put very much into these computer models as they don't always seem to have the pulse of what is really going on in the atmosphere. Right now, 99L is looking anorexic and 90L is looking like it's struggling. Can either of these systems come back to life? Yes. But the chances look pretty slim at this time.
1103. beell
Quoting 1093. QueensWreath:




It also looks like the strong East to West (ITCZ) flow; that was hampering the Southern half of 99L circulation, has eased up quite a bit.




Can you just imagine what we would be looking at if all those skinny little spiral lines were to explode with convection?

...just a thought!
I didn't want Ian to be a trash system but seeing how 2016 has gone so far I wouldn't be surprised if it is :(
Another factor against 99L is its fast translation at 20 MPH.
Quoting 1095. daddyjames:



On that thought, the last few times SEFL was impacted by a major storm, my folks were out of town (Andrew and Wilma). BRB - have to make a phone call! :)


I think I'll put the EOC's power supply in the car. It tops 25 pounds and I won't be able to lift that much for a few weeks...getting cataract surgery this week.
Quoting 1098. hurricaneryan87:


Lol so in 150plus years you found ONE!!! I guess every storm that gets pulled north out of the caribbean will turn into Sandy too right???


that was one of a life time kind of track that we will never see agine in are life time that sandy pulled
1108. Patrap
Pass da Tabasco'


Quoting 1092. wunderkidcayman:



Let's just deal the the Caribbean first yeah
The Caribbean will get impacted before the US so Caribbean get priority ok so chill ya


The NE Caribbean then the SE Bahamas.
Quoting 1087. Hurricanes101:



Right now we cannot say anything with cartainty (regardless of what some would want you to believe). It could do anything at this point. The general idea of the system being in the SE Bahamas is a pretty good one though, but it could likely only be a tropical wave at that point.


Thank you hurricanes101

We will wait and see then. Hoping it avoids LA. So much devastation here already. I don't think people realize how MANY homes were flooded in so MANY towns. It's really sad. Most of them in places/neighborhoods that have NEVER flooded before. no one saw this coming :(

Sorry to go off topic. Back to 99L, the only thing I can add to the discussion is that I see spin. It looks healthy enough to respect at the moment
TS Fiona weakens

Back down to 40mph and 1007mb

Soon to be a TD

And a rem low in a few days

Dissipated by day 5

There is some talk about if and just if very small Fiona can survive the hostile environment over the next 72 hrs it could be possible it might redevelop but that's a big if

And cone has been shifted S for 3 days day 4 and 5 showing that NW track W of Bermuda


Over all I'd say farewell Fiona
1112. ackee
We have track invest and tropical system by our top models as of today which model as preform the best honestly ?

A Euro
B GFS
C CMC
D HwrF
E. Ukmet
So model runs are taking 99L away from SE CONUS?
What 99L is currently telling us...
Quoting 1102. HurriHistory:

The tropical Atlantic is looking pretty sick this morning. I seriously doubt that either 99L or 90L will ever become anything more then what they are right now which is garbage. As in the last few years, the Atlantic continues to be contaminated with an over abundance of dry stable air which is making it almost impossible for anything to develop. That is also why I've said many times not to put very much into these computer models as they don't always seem to have the pulse of what is really going on in the atmosphere. Right now, 99L is looking anorexic and 90L is looking like it's struggling. Can either of these systems come back to life? Yes. But the chances look pretty slim at this time.


That's the problem with 90L. It needs to do well in the next 24 hours as more Saharan air is forecast to drive into the picture. After that, 90L does have decent conditions to work with: shear should be moderate, oceans are running in the 27-28C range ahead of it. But yes for the next few days there's not a whole lot of convergence/divergence going on putting a lid on anything explosive.
1116. Patrap
Sorry, I never pole on a Sunday,dem blue laws are tuff here.
🌎
Quoting 1109. luvtogolf:



The NE Caribbean then the SE Bahamas.


E Caribbean

I think Bahamas may not be in play with this one

We will have to wait and see

I guess you never know with the Atlantic, but 90L looks like the real deal. It should become a powerful cyclone as it moves west then northwest. Could be a big ACE producer. Too early to lock in a long term track, but given its place of origin out to sea seems likely, probably east of Bermuda.
Quoting 1105. juracanpr1:

Another factor against 99L is its fast translation at 20 MPH.


Same story.... always in a hurry to crash into Dominica.

Central Antilles trash like 97L
Quoting 1112. ackee:

We have track invest and tropical system by our top models as of today which model as preform the best honestly ?

A Euro
B GFS
C CMC
D HwrF
E. Ukmet



Overall, the Euro is the best model. It's not perfect, but it's the best model (I've even heard that coming from the people doing the upgrades to the GFS).
1121. Siker
Albeit it's very long range, the Euro and GFS (and their ensembles) both agree on a very healthy wave with development potential emerging off the African coast in 9-10 days and another in 12-13 days. In fact, the 15 day GFS and the 15 day Euro control run are virtually identical in depicting a hurricane NE of the Caribbean and a TS WSW of Cape Verde.
1122. Tcwx2
Hey, I thought that naked swirls was a Atlantic thing?!!
Quoting 1101. HurrikanEB:

Classic Fujiwhara going on over in the west pacific

Quoting 1112. ackee:

We have track invest and tropical system by our top models as of today which model as preform the best honestly ?

A Euro
B GFS
C CMC
D HwrF
E. Ukmet



I would hand it to the Euro, but I don't think the reason it kept 99L weak is what's happening. It predicted a ULL to develop towards the Bahamas which it has since dropped. I think the HWRF is best once the system is either closed or very near it, it needs a good place to start for initialization.

Bye
Quoting 1117. wunderkidcayman:



E Caribbean

I think Bahamas may not be in play with this one

We will have to wait and see




There is a lot of time befor 99L get near the E Caribbean and a lot can change within that time
I still believe that 99L and 90L will both develop into something formidable, there is a newly developing surface circulation northeast of North Carolina over very warm gulf stream that could pop convection at any moment. Also 90L looks primed to develop rapidly it is already moving quickly towards the northwest and developing good to great amount of spin already.
Also the GFS in the next 36-48 hours keeps Fiona on a wnw tracking.
1128. Siker
.
Quoting 1092. wunderkidcayman:



Let's just deal the the Caribbean first yeah
The Caribbean will get impacted before the US so Caribbean get priority ok so chill ya


Impacted with what? There's nothing there but a skeletal broad disorganized circulation.
I'm interested in seeing what 99L will looks like this evening in terms of its low level structure seeing how it evolves

I'm also interested in seeing what 99L looks like tomorrow morning with the convection now that we have a circulation developing it will be interesting to see how the convection build with that overnight into DMax

Also 90L is more southwest this run on the GFS and is at 999mb south of 20N and west of 40we
Quoting 1118. MAweatherboy1:

I guess you never know with the Atlantic, but 90L looks like the real deal. It should become a powerful cyclone as it moves west then northwest. Could be a big ACE producer. Too early to lock in a long term track, but given its place of origin out to sea seems likely, probably east of Bermuda.

Agreed. I think 90L/Gaston will probably struggle at first, but once it gets out of the MDR, it will enter very favorable conditions and could strengthen into a major hurricane.
I picked up my juice box this morning only to come the blog to find this TRASH system. I threw down my juice box and threw a gigantic fit. My mom is still mad that I threw my new toy she got me yesterday through the computer screen.

Just like I have been saying for years [with exception of every time the GFS/Euro/HWRF show cyclone genesis], THE ATLANIC IS DEAD.

(Whiners are out in full force this morning)
Quoting 1134. HurricaneFan:


Agreed. I think 90L/Gaston will probably struggle at first, but once it gets out of the MDR, it will enter very favorable conditions and could strengthen into a major hurricane.
It starts to take off once at 20N.
Quoting 1129. HurriHistory:



Impacted with what? There's nothing there but a skeletal broad disorganized circulation.


At the moment we got a developing organising low level spin with little in the way of convection buy by the time 99L reaches the E Caribbean it should and will be a diffrent story
Quoting 1112. ackee:

We have track invest and tropical system by our top models as of today which model as preform the best honestly ?

A Euro
B GFS
C CMC
D HwrF
E. Ukmet



For Fiona the UKMET is beating out the ECMWF at 12, 24, 48 and 72 hours.


GFS has Fiona near and potentially impacting Bermuda by Thursday as a TD or TS, so impacts to the island by Fiona still remain a possibility.
1140. Patrap
Yeah,.....the Atlantic is your calamity playground.

I remember a time when the wu bloggers banded together to relive folks from the calamity storms bring.

Yeah, trash the whole Atlantic..

She has only flooded 43,000 so far.


Pffffth'

Mericah'

Quoting 1093. QueensWreath:




It also looks like the strong East to West (ITCZ) flow; that was hampering the Southern half of 99L circulation, has eased up quite a bit.

It definitely has a good spin. Not writing this one off until is out to sea. I might even go as far as to say TD by Wednesday. Or it completely dissipates and I am wrong as usual =)
Quoting 1084. dflam:

This is an analysis i made of the Hebrew Luni/Solar calendar vs the number of hurricanes in the atlantic since records began. https://en.wikipedia.org/wiki/Hebrew_calendar

What it shows that the day before Jewish New Year (Rosh Hashana - which is always a new moon] is the peak hurricane day. This year it is October 1st.

It also misses the more pronounced double peak that is visible in the usual gregorian calendar analysis.

This seems to suggest that the peak of the hurricane season is the new moon of the beginning of the autumn.
So this needs further investigation. It also suggests that this year we will see a "longer" or "later" season than usual.






Is there an easily accessible dataset of storms? Also it doesn't seem the standard image of frequency vs date shown has any more of a "double peak" than does your image. If the peak hurricane day is more consistently lined up with a new moon (idk what the correlation is) than it is randomly distributed around ~Sept 10, I actually don't know what would explain that... I'd have to browse the literature as it doesn't strike me as a likely or even plausible outcome. Seems more likely that that 'new moon' is as equally varied as is the actual yearly peak day to the average peak of sept 10.
Quoting 1141. SecretStormNerd:


Sorry, double post. I guess I quoted myself instead of modifying lol....It definitely has a good spin. Not writing this one off until is out to sea. I might even go as far as to say TD by Wednesday.
Quoting 1106. MBSCEOCHam:



I think I'll put the EOC's power supply in the car. It tops 25 pounds and I won't be able to lift that much for a few weeks...getting cataract surgery this week.


Best to you and the upcoming surgery. Hopefully recuperating is all that you'll have to be concerned with.
model runs are not showing that this is going out too sea with 99L



One thing I noticed is GFS ensembles are becoming less and less enthusiastic about 99L once it gets near the Bahamas, and now with that it appears the 12z GFS drops 99L totally with showing not even a low pressure, but a wave.
12z CMC on the other hand is not.
Quoting 1142. GeorgiaStormz:



Is there an easily accessible dataset of storms? Also it doesn't seem the standard image of frequency vs date shown has any more of a "double peak" than does your image. If the peak hurricane day is more consistently lined up with a new moon (idk what the correlation is) than it is randomly distributed around ~Sept 10, I actually don't know what would explain that... I'd have to browse the literature as it doesn't strike me as a likely or even plausible outcome.


Did they take leap months in to account?
12z GFS once again shows a possible Fiona regeneration, in addition to a strengthening Hurricane Gaston:
1151. Gearsts
Actually it does form a low pressure, but with the Tropics, the motto wait and see is enforced greatly.

Wouldn't be surprised to see that "94%" increase to 100% since the 12z CMC develops 90L. There is basically unanimous model agreement that 90L will become Gaston.


Vort much improved on this gfs run.
The CMC and GFS are nearly identical
Quoting 1154. chrisdscane:



Vort much improved on this gfs run.
Stronger High this run too, 90L getting pushed more west.
Is he shading WU?
Ian Livingston ‏@islivingston 17h
It's fortunate we have legions of people tracking showers over the Atlantic for days and days keeping us safe.
Models being very consistent with Gaston being a strong system, more west with ridging to the north through 7 days on 12z GFS. Unless it spins up quickly like shown that ridge may block an out to sea scenario that's if the ridge holds firm and pushes more south. Lets hope it goes out to sea with a system like that. Many days to watch everything including 99L.
1160. Grothar
Yep. Definitely moving west.

JeffMasters has created a new entry.
99L has regained it's vigorous surface circulation. it lacks serious convection, but i suspect when the system passes 50W and gets over warmer SST, then we will see a different system. The next 24 hrs could say whether the lesser antilles will be impacted with a tropical system or just a period of squally and blustery conditions.


latest surface wind map. 99L looking pretty rough, while 90L already getting its act together it seems.
Quoting 1122. Tcwx2:

Hey, I thought that naked swirls was a Atlantic thing?!!


It looks cooler in the WPAC for some reason. lol
ok looking at the low level structure of 99L I see two possibilities

either one large elongated spin
or two small spins within this elongated gyre

either way its moving W about 270 and a decent speed it does need to slow down some



or

1168. MahFL
Quoting 1139. Climate175:

GFS has Fiona near and potentially impacting Bermuda by Thursday as a TD or TS, so impacts to the island by Fiona still remain a possibility.


Lol, impacts on Bermuda of a TD ?, that place is built like a concrete bunker.
70% of activity in Atlantic happens after August 20th. All I can say to some is watch what you wish for folks.

Quoting 1140. Patrap:

Yeah,.....the Atlantic is your calamity playground.

I remember a time when the wu bloggers banded together to relive folks from the calamity storms bring.

Yeah, trash the whole Atlantic..

She has only flooded 43,000 so far.


Pffffth'

Mericah'


Quoting 986. ProgressivePulse:

There is a "Speck" over the supposed center. lol all big things start with a speck I guess.




Its dissapated
1171. dflam
Quoting 1142. GeorgiaStormz:



Is there an easily accessible dataset of storms? Also it doesn't seem the standard image of frequency vs date shown has any more of a "double peak" than does your image. If the peak hurricane day is more consistently lined up with a new moon (idk what the correlation is) than it is randomly distributed around ~Sept 10, I actually don't know what would explain that... I'd have to browse the literature as it doesn't strike me as a likely or even plausible outcome. Seems more likely that that 'new moon' is as equally varied as is the actual yearly peak day to the average peak of sept 10.


Ok.

According to my calculation, October 2nd will be hurricane peak this year, September 21 2017, September 9,2018 etc.

Data:

http://www.nhc.noaa.gov/data/
1172. vis0
Washi115s luck 2016Ian forms AFTER it passes the NE USofA, HUH?
Imagine the "G", "H" TS form in the ATL then a mini pouch comes off the SE hangs around a bit loops past southern NJ and as it turns eastward becomes a TS

...wooooOSSSH

                HZZOOoooow................

...........woooooooooOOSSHH

why are anime "make up" pencils embedding themselves into my buildings mortar?
99L approaching warmer SST at 55W.