Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Tropical Wave Thread


Recommended Posts

Posted
  • Location: Taunton, Somerset
  • Weather Preferences: Snow, thunder, strong winds
  • Location: Taunton, Somerset
Case of wait and see then.. Cheers SS.. :)

As always. :unknw: The peak of the season is the latter half of August and into September, but unless the ITCZ moves north then most of the waves will continue to dive southwards along northern parts of South America and into the Eastern Pacific, which incidentally has had it's 4th storm develop today.

Anyway, my knowledge is very basic, hopefully Kold can enlighten us more on the situation and how things may develop.

Link to comment
Share on other sites

Posted
  • Location: s yorks
  • Weather Preferences: c'mon thunder
  • Location: s yorks

Tuesdays Atlantic discussion says it all then:

"VERY QUIET CONDITIONS

EXIST ACROSS THE CENTRAL AND W ATLC. RIDGING ALOFT IS ALSO THE

THEME IN THE E ATLC EXTENDING W FROM AFRICA ALONG 25N TO 43W. AN

UPPER LOW IS OVER THE CANARY ISLANDS...BUT LITTLE WEATHER IS

ASSOCIATED AT THE MOMENT. IN FACT...THE LARGE SHIELD OF

SUBSIDENCE IS CAPPING THE TYPICAL SCATTERED LOW-LEVEL

STRATOCUMULUS DECK ACROSS MOST OF THE ATLC DISCUSSION AREA.

THE SFC PATTERN IS EVEN MORE TRANQUIL WITH THE ENTIRE AREA

DOMINATED BY THE BERMUDA-AZORES RIDGE. THIS IS PRODUCING

MODERATE TO FRESH TRADES ACROSS A GOOD PORTION OF THE CENTRAL

AND E ATLC."

the quiet before the storms? like our settled spring before the infamous June floods?

((I wish i had a basic/better understanding of all this and its relation to our domestic unsettled weather of late (BERMUDA-AZORES RIDGE?) but its nonetheless very interesting fellas, keep it up pls! ;-))

Link to comment
Share on other sites

Posted
  • Location: Tunbridge Wells, Kent
  • Location: Tunbridge Wells, Kent
((I wish i had a basic/better understanding of all this and its relation to our domestic unsettled weather of late (BERMUDA-AZORES RIDGE?) but its nonetheless very interesting fellas, keep it up pls! ;-))

From our perspecive we need the Azores High (semi permanent feature) to ridge NE to affect the UK. To date it has been ridging NW (to Greenland) and W to Bermuda (hence Azores Bermuda Ridge)

It has therefore contributed to keeping the tropical atlantic quiet while not being near enough to our own shores to influence us. We could still experience summer like weather if there was a block to our east, however this has also been absent this year (unlike 2006).

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

I think the fairly average start to the hurricane season probably has something to do with the strong northern blocking in June, what this appears to have done was to surpress the Azores/Bermuda high core further south (hence why we saw such a wet June!) and this had two effects:

1: Kept the subtropical jet fairly far south and so that meant that shear was a factor and so this obviously has kept any disturbances from organising.

2: The strong jet has actually led to a strong Azores high, while we may not think so pressure ha sbeen higher then average over that reigon of the world thanks to the flat jet stream causing large pressure differences. This has meant that with a bigger circulation the Azores high has dragged quite a lot of dust into the Atlantic which obviously chokes any system to death with both more stable air and less moisture.

One other thing that the shear and the southerly high pressure cells have allowed is some impressive warmign up in the Gulf of Mexico and the Caribbean with SST's so far reading above average for that reigon of the world but even more impressive is the heat content which is amazing in the southern Gulf of Mexico and also in the Caribbean which means a lot of energy would be present for any tropical disturbances that end up in that region of the tropics.

Link to comment
Share on other sites

Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
I think the fairly average start to the hurricane season probably has something to do with the strong northern blocking in June, what this appears to have done was to surpress the Azores/Bermuda high core further south (hence why we saw such a wet June!) and this had two effects:

1: Kept the subtropical jet fairly far south and so that meant that shear was a factor and so this obviously has kept any disturbances from organising.

2: The strong jet has actually led to a strong Azores high, while we may not think so pressure ha sbeen higher then average over that reigon of the world thanks to the flat jet stream causing large pressure differences. This has meant that with a bigger circulation the Azores high has dragged quite a lot of dust into the Atlantic which obviously chokes any system to death with both more stable air and less moisture.

One other thing that the shear and the southerly high pressure cells have allowed is some impressive warmign up in the Gulf of Mexico and the Caribbean with SST's so far reading above average for that reigon of the world but even more impressive is the heat content which is amazing in the southern Gulf of Mexico and also in the Caribbean which means a lot of energy would be present for any tropical disturbances that end up in that region of the tropics.

I think with the Azores Bermuda High dispaced towards the Carribean, the main problem is that any waves coming out of Africa are dead by the time they get into the Carribean, they then simply dont have enougth time to develop before hitting land in the favourable Carribean environment.

Link to comment
Share on other sites

Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Quietest year ever???? Still if it ends up that way it'll be still down to global warming.

Link to comment
Share on other sites

Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

http://www.nhc.noaa.gov/gtwo_atl.shtml

It looks like we will have a number of potential systems entering the Carribean in a few days, possibly things hotting up.

Link to comment
Share on other sites

Posted
  • Location: ilminster Somerset
  • Location: ilminster Somerset

possible action, first for weeks

ATLANTIC OCEAN...

THE MAIN AREA OF FOCUS THIS AFTERNOON CONTINUES TO BE THE N

PORTION OF THE CARIBBEAN TROPICAL WAVE THAT IS NOW BEING

ANALYZED AS A SURFACE TROUGH ALONG 24N65W 19N68W. THIS...ALONG

WITH UPPER DIFFLUENCE BETWEEN THE UPPER LOW NEAR 26N67W AND AN

UPPER RIDGE EXTENDING NNE FROM THE LEEWARD ISLANDS...IS

SUPPORTING THE DISORGANIZED CLOUDINESS AND SHOWERS EXTENDING NE

FROM PUERTO RICO INTO THE ATLANTIC FOR SEVERAL HUNDRED MILES.

UPPER-LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR

DEVELOPMENT...BUT COULD BECOME MORE FAVORABLE DURING THE NEXT

COUPLE OF DAYS. ANOTHER CLUSTER OF MODERATE CONVECTION IS

ROTATING AROUND THE NE PERIPHERY OF THE UPPER LOW N OF 28N

BETWEEN 61W-66W. LIGHTNING DATA AGAIN SHOWS ISOLATED TSTMS IN

THE FAR WRN ATLC...MOSTLY OVER THE GULF STREAM AND AHEAD OF A

COLD FRONT MOVING TOWARDS THE SE US. ANOTHER BROAD UPPER LOW IS

NEAR 27N50W...SUPPORTING ISOLATED TSTMS N OF 26N BETWEEN

49W-53W. THE REMAINDER OF THE DISCUSSION AREA IS WIDELY

DOMINATED BY THE SRN PERIPHERY OF A STATIONARY 1033 MB HIGH NEAR

38N42W. THIS IS PRODUCING ABUNDANT FAIR WEATHER AND MODERATE

TRADES E OF 45W. THE TRADES ARE LITTLE STRONGER WITHIN 400 NM OF

THE AFRICAN COAST N OF 20N...WHERE THE GRADIENT REMAINS TIGHTER.

A FAIRLY DENSE AREA OF AFRICAN DUST NOTED ON BOTH SIDES OF THE

TROPICAL WAVE NEAR 47W...MOST CONCENTRATED E OF 30W.

$$

WILLIS

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

Signs of possible activity over the next 2 weeks BUT I've not got the time right now to go into depth, i'll try tomorrow, areas to watch right now is the area between Bermuda and the N.Caribbean with a large area of convection, presently fueled by the jet stream though so looks like it'd be baroclinc, reacon could fly if it needs to. Also just watch for a low forming off the east coast, right on the gulf stream. final area to watch is a strong wave coming off Africa right now, still not quite right for tropical development there yet but its a nice wave...

Finally, heat content is actually even higher in the caribbean and the Gulf of Mexico on average then it was in 2005, so any systems that reach that area with a favorable atmopshere are going to explode into life!

Link to comment
Share on other sites

Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

http://www.nhc.noaa.gov/gtwo_atl.shtml

Yes Kold, this is the tropical wave you are reffering to, and while i do think that it may reach Tropical Depression status, it will be turning to the north, and encounterng cooler waters, therefore i do not expect Tropical Depression status to be reached.

A LARGE AREA OF DISORGANIZED CLOUDINESS AND SHOWERS...EXTENDING FROM

HISPANIOLA NORTHEASTWARD INTO THE ATLANTIC FOR SEVERAL HUNDRED

MILES...IS ASSOCIATED WITH AN UPPER-LEVEL LOW INTERACTING WITH A

TROPICAL WAVE. UPPER-LEVEL WINDS ARE GRADUALLY BECOMING MORE

FAVORABLE...AND SOME DEVELOPMENT IS POSSIBLE IN THIS AREA OVER THE

NEXT DAY OR TWO.

The next wave of interest to me is the wave exiting Africa, which has a well defined mid-level cirulation...

TROPICAL WAVE OFF THE COAST OF AFRICA ALONG 19W S OF 17N MOVING

W 15 KT. WELL DEFINED MID LEVEL CYCLONIC ROTATION IS ALONG THE

WAVE AXIS NEAR 13N WITH LITTLE TO NO EVIDENCE OF A SURFACE LOW

AT THIS TIME. CLUSTERS OF MODERATE CONVECTION ARE FROM 8N-12N

BETWEEN THE 18W-22W.

In my opinion, we could have a Tropical Depression from this in 2-3 days time.

Link to comment
Share on other sites

Posted
  • Location: Dorset
  • Location: Dorset

A large Upper low is currently in mid Atlantic, it's got a Wave embedded in it, hence the inclusion in this thread.

This should give the wave and activity a) time to develop and not get destroyed by the upper high that's been in place all season and :D A chance at circulation.

Certainly the best chance so far this year.

"ATLANTIC OCEAN...

DEEP LAYERED TROUGH OVER THE E US AND GULF OF MEXICO EXTENDS

INTO THE NW ATLC N OF 27N W OF 74W WITH THE ASSOCIATED FRONTAL

BOUNDARY EXTENDING INTO THE REGION NEAR 32N73W ACROSS FLORIDA

INTO THE GULF OF MEXICO NEAR LAKE OKEECHOBEE. THE UPPER HIGH N

OF HISPANIOLA NEAR 21N69W COVERS THE REMAINDER OF THE W ATLC W

OF 55W GIVING THE FAR W ATLC SCATTERED SHOWERS/THUNDERSTORMS S

OF THE FRONTAL BOUNDARY W OF 72W WITH THE HIGHEST CONCENTRATION

OF THUNDERSTORMS OVER THE CENTRAL BAHAMAS. AN UPPER LOW JUST N

OF BERMUDA IS INTERACTING WITH THE SAME UPPER HIGH TO GIVE A

SMALL AREA SCATTERED SCATTERED SHOWERS/ISOLATED THUNDERSTORMS

FROM 26N-30N BETWEEN 60W-69W. VERY LARGE UPPER LOW COVERS THE

CENTRAL ATLC CENTERED N OF THE REGION NEAR 34N45W AND COVERS THE

AREA FROM 31W-55W. AN UPPER RIDGE COVERS THE E ATLC E OF 30W

EXTENDING E/W ALONG 22W. A SURFACE RIDGE AND DRY STABLE AIR

COVERS THE ATLC E OF 60W WITH ONLY FAIR WEATHER CLOUDS OVER THE "

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

Various waves about right now but none that really strike me as likely to develop. The NAM model develops a tropical wave that is currently in the SW Gulf of Mexico and takes it NW towards Mexico/Texas region and develops a strong tropical storm but the NAM model is way to quick in developing tropical low pressure systems but now i have a decnt length of time off college I can get a better grasp of whatis likely to develop and so I'll watch it just in case. The tropical wave currently in the GOM is the remains of Invest 97L. It is showing some impressive convection right now with some cold cloud tops suggestive of deep convection but it clearly has little organisation to it presently with some shear also present over the Gulf right now with the clouds being stretched out to the east thanks it appears to a jet streak. The only saving grace for this wave is the shear does appear to be decreasing quite quickly now as the jet starts to lift further north as the high pressure bands which have remained rather surpressed are finally starting to show signs of gaining latitude.

There is also another wave coming in quite sharply behind the one mentioned above that may need watching, esp as it'll spend more time in a slightly better environment. On a side note it may not be long before waves hold togther better as they exit Africa. Ther eis still a easterly jet stream present in the region but this too is also lifting out. Also compared to 15 days ago the SAL has also decreased quite nicely with a far greater moisture spread present with the ITCZ having moved further nirth as well as is normal. Heat content is still very impressive in the Caribbean and Mexico and higher in the Atlantic then 2006 but its the Caribbean reguion that is really impressive right now in terms of the Oceanic heat content, even beating 2005 right now!

Link to comment
Share on other sites

Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

WSI has issued a revised forecast which expects less tropical activity than they initially expected a few months ago. WSI is a private forecasting company.

http://news.yahoo.com/s/nm/20070724/sc_nm/...es_forecasts_dc

It will be interesting to see if NOAA will follow with a revised forecast.

Karyo

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

Interesting Karyo, I suspect Dr.Gray's numbers will be lowered a touch though an active August/September could still easily see 11-14 storms so a high total is still possible.

Anyway interesting developments showing themselves. A strong wave is currently over E.Africa with some pretty deep convection present and a pretty decent latitude as well. Water vapor loops show that while dry air is starting to amass to the systems NE (as you'd expect given the circulation of the wave is quite strong and hence picking up dust from the Sahara to its NE) however there is quite a large region of moisture ahead of the system thanks to a couple of previous weak waves. The only slight downside of this atmosphere is some fairly stable air to its north thanks to the currently elongated Azores high which is dragging in more stable air around its southern flank. The best way to tell this is the stratocumulus that is present which usually indicates more stable air and the visables show quite nicely:

post-1211-1185465921_thumb.jpg

post-1211-1185466287_thumb.jpg

What also makes this wave a little more interesting is the fact that the last 3 out of 4 GFSmodel runs have developed a tropical cyclone out of this system and send it westwards quite a way coming close to the east coast. Now of course that is FI GFS however the GFS does develop this wave around the 48-72hr range and then steadily develops it heading westwards. While the GFS has a habit of developing waves that don't actually form we are now getting very close to the time of year where any system needs to be watched just in case they develop and in this case the wave is fairly strong in terms of convection and while the environment could be improved still in that part of the world we are now close to the time when tropical features can be supported out there.

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

A brief update needed---wave heading into the Atlantic, may pulse down a little once it heads into the cooler temps over sea and lower lapse rates but it looks quite potent and so may well adapt better then most of the waves we've seen so far this year. May only be 24hrs before we have a new invest.

Still looks like a decent environment out there for development, there is some SAL present but its not too deep and thick.

What is truly interesting is many models are developing a LP pressure in about the same area as where the LP will be in about 48-72hrs. Both the ECM and the GFS plus the CMC develop this over the longer term and send it westwards along the underbelly of the Azores high. Its too far away to really forecast such a system as it hasn't evn developed yet but the signs are pretty decent for a tropical cyclone, probably one of the best signals this year so far for a tropical system to form. The GFS for example takes the system WNW into the north Caribbean then ENE towards Florida before sending it into the Carolinas. IF it develops then it will have a shot at becoming a hurricane I reckon.

Finally it may be worth watching the wave in the eastern Atlantic right now, it is flaring up a touch and while convection is pretty disorganized the environment isn't too bad in that part of the basin right now and shear is decreasing and while there is more SAL the most westerly wave is helping to moisten out the dry air providing a more moist atmosphere for the waves behind.

Edited by kold weather
Link to comment
Share on other sites

Posted
  • Location: New Zealand
  • Location: New Zealand

post-4339-1185640949_thumb.png

000

ABNT20 KNHC 281459

TWOAT

TROPICAL WEATHER OUTLOOK

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

1130 AM EDT SAT JUL 28 2007

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

1. AN AREA OF DISTURBED WEATHER HAS FORMED ABOUT 100 MILES EAST OF THE

CENTRAL BAHAMAS IN ASSOCIATION WITH A WEAK LOW PRESSURE SYSTEM.

THERE IS SOME POTENTIAL FOR DEVELOPMENT AS THE SYSTEM MOVES

NORTH-NORTHEASTWARD OVER THE NEXT DAY OR TWO.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE

NEXT 48 HOURS.

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook
Finally it may be worth watching the wave in the eastern Atlantic right now, it is flaring up a touch and while convection is pretty disorganized the environment isn't too bad in that part of the basin right now and shear is decreasing and while there is more SAL the most westerly wave is helping to moisten out the dry air providing a more moist atmosphere for the waves behind.

Wave mentioned here looks very likely to be the next invest and system we need close watching, Sat.Imagery shows decent convection present at the moment which flared up last night with some low level cyclonic turning present though its a little hard to tell whether its a closed low or not, I'd suspect not right now but its needs watching as convection is plentiful though it is a touch ahead of the main wave axis which is around 44-45W.

Anyway wave is currently heading westwards in a pretty favorable environment. Mid level moisture is decent though there is drier air to the north which may surpresses the northern edge if the system gets going. Shear also shouldn't be too much of an issue from the looks of things as its heading into an area right now of limited shear with generaly only 5-10kts present which isn't going to prevent a closed low forming and indeed if there isn't one already present given the favorable condtions presently chances are it will start to develop one sooner rather then later. SST's also look good enough and while the heat content is a touch marginal it is on the right side of marginal for a tropical system to form, esp given the condtions as well that are present.

So this is one to watch for the future given the good set-up ahead. Its current lattiude is quite southerly and a strong subtropical high is building to its north as well presently which should keep the wave on a generally westerly track. On its current track and latitude I'd have thought it could be a sizeable risk to the Caribbean, esp given how high the heat content is presently there.

post-1211-1185799847_thumb.jpg

Edited by kold weather
Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

A few areas of intrest right now out there. Firstly we have a developing Mid level circulation developing in the northern section of the gulf of mexio on a diving cold front. Models are hinting on development from this system tohugh if anything does form it won't have long before it is whisked back NE out to sea following in from the weakness that was left by Chantal.

Other then that there are two waves currently further east of 99L that may need watching, the first is prehaps the more immediate system to watch and if 99L doesn't form though right now it doesn't loo too menacing it has to be said. Stronger wave just coming off Africa right now will also need watching in the very long term (10-20 days) given by that time the condtions in the main zone should be starting to get close to peak condtion so to speak. Its a strong wave however it should flare-down over the next 24-48hrs as the coolers waters reduce the lapse rates and general instablity present. Both waves should be westerly runners given a strong subtropical belt is setting itself up to the north.

Link to comment
Share on other sites

Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

http://www.nhc.noaa.gov/gtwo_atl.shtml

It looks like we have several areas of interest, however the weakness left by Chantal will probably not allow the system near Florida to develop, and i am expecting the wave entering the Carribean to take a more north westward track, becoming a threat to Florida northward if it develops, unless it 'threads the needle'.

The two waves behind it are of interest to me however and should they enter the Carribean, they look far enougth south to have a chance of major development.

Link to comment
Share on other sites

Posted
  • Location: Dorset
  • Location: Dorset

The waves really need to travel a tight rope atm too far south and they don't get the rotation going, too far north and they get killed.

They might survive though.

Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

Yeah some good waves present coming off the ITCZ, still a long way off yet but there are threats there for the next 10-14 days.

Something far closer to the USA right now is an area that is moving into the gulf, it may well get an invest because of its position right now and indeed it is being watched by the NHC for further development. While it hasn't developed any since last nights post convection is still plentiful along a decaying frontal system and with some pretty impressive heat content present it wouldn't take much for a weak low to form and a weak tropical system to form, indeed its a pretty dependable way to develop a weak tropical cyclone tohugh usually it happens earlier in the season. Still the models do support development and do form a weak closed low pressure system. Even if it doesn't develop by the time the moisture moves back inland could see some decent rainfalls.

By the way recon is possible tommorow if it looks like developing.

Edited by kold weather
Link to comment
Share on other sites

Posted
  • Location: Liphook
  • Location: Liphook

the GOM system still has not developed since last eveing however it still needs watching. Radar is showing a Mid level circulation but its far from closed off looking at the loops. Recon is still ready to investiage this however it may not be needed as it hasn't really organised too much. Still needs to be watched however because they can develop quite quickly out here, howveer there aren't many signs right now.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...