Hurricanes/Typhoons/Cyclones of 2017.

Thought it might be an to idea keep these in one thread for a calendar year. Currently threatening the NE Australian coast is Cyclone Debbie (13P). One minute wind speeds of 105 kts. Gusts to 130. Due to reach land in the next few hours.

stevek93

Hope all everyone including the Irish will be OK.

Not sure how accurate that JTWC advisory is now, as the Australian Bureau of Meteorology are indicating a maximum 10 minute wind speed of 95 kts with gusts to 130. Pretty strong. Daylight now in eastern Australia. The eye has yet to come onshore.

http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDQ20018.txt



Local radar image. Distinct eye feature can be seen.

http://www.bom.gov.au/products/IDR242.loop.shtml#skip

Gaoth Laidir

10-minute mean speeds will always be lower than 1-minute. That's why pound for pound, a 100-knot typhoon is stronger than a 100-knot hurricane because the typhoon's 100 knots are measured over 10 minutes whereas the NHS use 1-minute mean speeds.

Bsal

Hamilton Island

YBHM 272248Z AUTO 12093G118KT 0150 // OVC008 32/32 Q0974= (SPECI)
YBHM 272246Z AUTO 12092G118KT 0150 // OVC008 31/31 Q0972= (SPECI)
YBHM 272233Z AUTO 12093G105KT 0250 // BKN008 OVC012 31/31 Q0973= (SPECI)
YBHM 272230Z AUTO 12079G116KT 0300 // BKN008 OVC012 30/30 Q////= (SPECI)
YBHM 272227Z AUTO 12081G116KT 0300 // BKN008 OVC012 31/31 Q0975= (SPECI)
YBHM 272215Z AUTO 12097G120KT 0250 // SCT006 OVC012 29/29 Q0975= (SPECI)
YBHM 272212Z AUTO 12086G120KT 0300 // SCT006 OVC012 26/26 Q0974= (SPECI)
YBHM 272200Z AUTO 13086G104KT 0200 // SCT005 SCT008 OVC012 26/26

Captain Snow

http://www.aljazeera.com/news/2017/04/atlantic-storm-hint-early-hurricane-season-170420093408155.html



It may have formed in open water, well away from any human habitation, but Sub-Tropical Depression One has already made a name for itself.
It shows on satellite imagery as a swirling mass of thunderstorms, located about 1,170km to the westsouthwest of The Azores. It has sustained winds of 55 kilometres per hour (km/h) and it is heading towards the north at 22km/h.
Such low pressure systems are usually confined to the hurricane season, which runs from June 1 to November 30. This depression seems to have beaten the odds, becoming only the fourth such depression recorded in the Atlantic, according to NOAA's Historical Hurricane Track website.
The formation of these tropical or sub-tropical lows usually requires sea surface temperatures (SSTs) of at least 26.5C. Currently, SSTs in the region are only 20C, and the disruptive effects of wind shear (the change of wind speed and direction with height) are quite high.
This depression seems to have sustained itself because of the very cold air extending through the atmosphere, which has supplied the atmospheric instability for thunderstorm formation, required for One's classification.
Only one of the previous April depressions - Tropical Storm Ana in 2003 - went on to become a named storm.
It is possible for systems to develop into full-blown storms outside the hurricane season. This happened in 2016, with Hurricane Alex in January and Tropical Storm Bonnie in May.
There are many state and private organisations that issue predictions of the coming hurricane season. The general consensus seems to be that activity will be slightly below average, with a total of 11 to 12 named storms, four to six hurricanes, and between zero and three major hurricanes.
It is unlikely that Sub-Tropical Depression One is going to cause any revision of the forecasts. If SSTs had been well above average, then that might have been a different matter. But seasonal hurricane forecasting is still in its relative infancy, so forecasters will be closely monitoring the situation in the Atlantic in the weeks ahead.

Source: Al Jazeera and news agencies

bnt

TD upgraded to a Tropical Storm and named: Arlene.

M.T. Cranium

Want to enter a 2017 tropical season forecast contest?

I have been running these on American Weather Forum for several years.

To enter, you would need to join that forum and then follow the link below

Entries are welcome into early June without penalty.

This is where to go if you're interested ...

http://www.americanwx.com/bb/topic/50014-2017-north-atlantic-tropical-storm-hurricane-forecast-contest/

Thanks.

star gazer

Two notables forecast to develop further.

bnt

Nothing happening in the Atlantic, but in the Pacific, Typhoon Noru has rapidly intensified to Cat. 3 and is slowly heading in the general direction of Kyūshū, Japan's southernmost island.

Rikand

bnt wrote: »

Nothing happening in the Atlantic, but in the Pacific, Typhoon Noru has rapidly intensified to Cat. 3 and is slowly heading in the general direction of Kyūshū, Japan's southernmost island.

How the storm has intensified looks pretty cool

24 hours ago






Now






And look at the clouds inside the eyewall - it almost looks like theres a face smiling out at you

bnt

Noru has weakened to Cat. 1, but is very slow-moving and is projected to strengthen to Cat. 2 as it approaches Kyūshū. Most of the rainfall associated with the storm is over the ocean, but there is still a flood risk for the Ryūkyū Islands and SW Japan.

Meteorite58

Not a hurricane but Tropical Depression 8 will be interesting to follow it's track to see if it maintains some energy to have an impact on our weather in any way.

Meteorite58

Well, Tropical Depression 8 became Tropical Storm Gert and is expected to become a Hurricane shortly and then complete extratropical transition within about 72 hrs then gradually weaken over the N Atlantic before it merges with a larger extratropical cyclone in 4 or 5 days .



https://twitter.com/NOAASatellites/status/897193673183682561





http://www.nhc.noaa.gov/text/refresh/MIATCDAT3+shtml/142047.shtml

Thereafter it looks like a large area of LP that steers in a NE'ly direction between Iceland and Scotland.

Will be interesting to see it's effect on our weather next weekend around Sat, Sun ,Mon. Will it hold that track , increase in intensity or decrease . Could there be a lot of rain from it ( likely IMO ). Its a huge area of LP but the winds don't look too significant at this stage but I would imagine that there would be a huge swell from it.

sryanbruen

Of the way things are going with the models currently, I think Gert will be near our shores by the end of its path but by the time it starts to make landfall, it begins to weaken like with ex-hurricane Cristobal on 31 August 2014. That ex-hurricane brought a ridge from the Azores and gave us one of, if not our driest September on record - and also one of the warmest.

The fine spell is in FI so could all change but this is what I think will happen give the current setup the models are showing.

hatrickpatrick

Argh, I was really hoping for a dry night on August 26th/27th The idea of a PTC reaching our shores is usually kinda cool and appealing, but please not next weekend...

sryanbruen

sryanbruen wrote: »

Of the way things are going with the models currently, I think Gert will be near our shores by the end of its path but by the time it starts to make landfall, it begins to weaken like with ex-hurricane Cristobal on 31 August 2014. That ex-hurricane brought a ridge from the Azores and gave us one of, if not our driest September on record - and also one of the warmest.

The fine spell is in FI so could all change but this is what I think will happen give the current setup the models are showing.

Looks like the BBC is agreeing with me in that Gert could cause a resurgence of "Summer". Sunday could be a very wet day with it.

Storm 10

Daily Star I would expect nothing less from this rag

http://www.dailystar.co.uk/news/latest-news/637816/uk-weather-forecast-storm-gert-hurricane

Meteorite58

Things hotting up a bit with new systems developing.

https://twitter.com/NASAHurricane/status/897796003629334528

Meteorite58

Daily Star I would expect nothing less from this rag

A bit more of a restrained discussion on Gert then the Star !


https://twitter.com/metoffice/status/897773362751164417

Meteorite58

The track has changed more towards Ireland the last few runs. Wind would not seem to be a problem at this stage but rainfall could be high all right, very hard to know at the moment how much. That cold front part of the system could become a trailing front drawn up over Ireland Sun into Mon perhaps.

Meteorite58

Gert is now Cat 2 Hurricane , first Cat 2 Hurricane of the season, got a lot stronger then originally anticipated I think, will be interesting to see how it interacts with the system coming out of Canada.

Meteorite58

Just to see ex Gert or the remnants of Gert through , noticing that the models are differing quite a bit over Sun and Mon. Interesting to see the UKMO seem to show the system reorganize as it approaches our shores.The Jet might just put a bit of energy into it as it approaches ? Would think there could be a lot of rain and maybe windy if these charts materialize. This wont be nailed down for a couple of days yet.

star gazer

Tropical Storm Harvey, having reformed in the last couple of days, is forecast to become a hurricane and potentially not move far from the Texas coastline for a number of days.
Rainfall maximum forecast of 10 to 15 inches up to localised maximum of 25 inches.
NHC advisory 15A

star gazer

Harvey is now forecast to strengthen fast and become a Major Hurricane before making landfall on the Texas coast with the strongest winds on the North Eastern side.
The current minumum central pressure is down to 982mb.
Discussion 16

With Harvey now strengthening at a faster rate than indicated in
previous advisories, the intensity forecast has become quite
concerning. Water vapor images indicate that the cyclone's outflow
is expanding--indicative of low shear--and Harvey will be moving
over a warm eddy of high oceanic heat content in the western Gulf of
Mexico in about 24 hours. As a result of these conditions, several
intensity models, including the ICON intensity consensus, are now
explicit showing Harvey reaching major hurricane intensity. What's
more astounding is that some of the SHIPS Rapid Intensification
indices are incredibly high. As an example, the guidance is
indicating a 70 percent chance of Harvey's winds increasing by 45 kt
over the next 36 hours. Based on this guidance, the NHC official
intensity forecast now calls for Harvey to reach major hurricane
strength by 36 hours, before it reaches the middle Texas coast.

Meteorite58

Set to become a Major Catoegory 3 before making landfall in Texas on Saturday.

https://twitter.com/NOAASatellites/status/900751957106864128

https://twitter.com/TropicalTidbits/status/900747910618521600

Meteorite58

Looking very serious now, seems to be a very slow moving Hurricane dumping an enormous amount of water.

https://twitter.com/TropicalTidbits/status/900781159348568069

star gazer

That stalling in the forecast looks very ominous alright, like getting 50%+ extra on rain than might be expected with floodwaters eventually coming up against storm surges and there being no place for the water to go but back and out of normal channels. Up to 35 inches of rain in some spots up to Wednesday forecast, that's enormous. It's bad enough when people are stuck in place for a day, this could lead to a number of days of inaccessibility in some areas first with wind, then with water. Minimum Central Pressure now 976mb. Max sustained wins now 140km/h 85mph, Category 1. Houston looks set to get a worrying amount of rain. Corpus Christi could be close to the centre as it makes landfall. Let's hope that the fact it is August doesn't affect preperations, particularly informing tourists of what to do where they are, which social media should help with.
Water vapour.

Akrasia

Meteorite58 wrote: »

Looking very serious now, seems to be a very slow moving Hurricane dumping an enormous amount of water.

https://twitter.com/TropicalTidbits/status/900781159348568069

Wow
There can't be anywhere in the world that wouldn't be devastated by a 6 to 12 foot storm surge along with 2 feet of rain and 80 -100mph+ winds lasting several days....

I hope the people in its path heed the warnings and get to safety

Supercell

My wife sent me this Chinese footage of the storms effects, pretty incredible stuff.

https://www.youtube.com/watch?v=T4C0FEI1XO4

star gazer

https://twitter.com/NHC_Atlantic/status/901904799339302912
Advisories starting on tropical Cyclone 10 which already put a lot of rain on parts of Florida.

Meteorite58

Potential Tropical Cyclone Ten.


Very early to say how this one might effect us but at the moment to me the models showing it running out of power and dispersing just off the W of Ireland around next Sun or so as it comes up against a HP system centered over the UK. Too early to say how windy or wet .

star gazer

I was premature in not calling it a "potential" tropical cyclone. Though it may (40% chance) or may not fully become one, that doesn't mean it doesn't pack a punch further on: Discussion 7

INIT 29/0900Z 33.5N 78.5W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 29/1800Z 35.4N 76.0W 40 KT 45 MPH
24H 30/0600Z 38.0N 71.5W 50 KT 60 MPH...POST-TROP/EXTRATROP
36H 30/1800Z 39.5N 66.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
48H 31/0600Z 41.0N 61.0W 70 KT 80 MPH...POST-TROP/EXTRATROP
72H 01/0600Z 44.5N 50.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 02/0600Z 50.0N 33.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 03/0600Z 55.0N 19.0W 30 KT 35 MPH...POST-TROP/EXTRATROP

As Meteorite58 pointed out above, there's potential for this to impact on Ireland later on in some weakened shape.

Also another potential near Cape Verde.

star gazer

It'll be a little time before it can be reasonably accurately forecast where Irma will end up and how big a threat (if any at all) it is to populated areas but for now it is forecast to develop quite a bit over the Atlantic.

Kermit.de.frog

Be watching this one for a while!

star gazer

Hurricane Irma has developed very quickly with max sustained winds up to 155km/h already (Category 2 hurricane), 979mb min central pressure.
It is forecast to become a major hurricane in the next 12 hours. It is definitely one to watch over the coming five days to see where it is going to be headed after that and how intensely it may have developed. Right now it is a fair bit from any land, about 3,000km East.

savj2

Looking at the models for Irma and no doubt they could change many times, GFS has the storm moving up the Carolina coast and merging with an upper trough.

Currently the GFS is showing a Super Storm Sandy like scenario by the 11th September.

The ECM model shows the storm going over the Florida keys and into the Gulf where it would strengthen again.

Early days of course but this hurricane could be the biggest of the lot this season.

hatrickpatrick

Irma is now rapidly intensifying. There's talk on Wunderground of a potential Eyewall Replacement Cycle which may be just getting underway, in which case intensification will temporarily stall, but it's being widely predicted that this thing will easily reach category four before it even gets as far as the Lesser Antilles. I don't think I've ever heard of rapid intensification occurring this deep into the MDR before - usually the term is associated with either the Gulf of Mexico, or the West Atlantic just East of Florida. With RI occurring this far out, the storm's potential track as well as future intensity is anyone's guess.

Conditions in the Gulf of Mexico seem to be radically different in Harvey's wake - not only is there more wind shear there now, but Harvey has dredged cold water up from the deep, so there isn't as much potential in that region as there was when Harvey first traversed it - although a lot can change in a week, and the NHC is already forecasting a possible tropical depression developing there after the weekend.

BumperD

Cat 3 confirmed and still strengthening. The Euro models have proved more accurate. This storm is taking a very strange path and may break rules and lots more if it hits the islands.

BumperD

https://weather.msfc.nasa.gov/cgi-bin/post-goes


https://www.nnvl.noaa.gov/MediaDetail2.php?MediaID=2090&MediaTypeID=1

https://www.wunderground.com/cat6/irma-intensifying-eastern-atlantic-big-long-range-questions

bnt

I suspect Hurricane Irma will be getting its own thread soon. Forecast strengthening is modest for the next few days, but then it looks like it will hit much warmer water off the Antilles islands, and then we're off to the races.

The chances of Irma crossing in to the Gulf of Mexico are getting lower, forecasts trending more towards a move up the east coast. It's still early days, though.

Gaoth Laidir

The Atlantic season's activity so far is normal, as measured by the latest ACE figure.



Overall, the total global tropical activity is well below normal so far, with only about 83% of the climatological ACE acheived. The NW Pacific, despite the large SST anomalies, is only at 64%.

There is also a small feature further southeast of Irma, at about 10N, that could become something in a few days. It's down as 0% potential development in the next 48 hours, but the models over the past few days have been showing a small but deep system developing and moving towards the southern Windwards, which is about as far south as hurricanes can develop due to little or no Coriolis force that near to the Equator.

Rikand

Looking at this twitter video of Irma's path, that *Disturbance* behind seems to turn out towards the north Atlantic by day5. If true, future TS Jose will be no threat to much of anyone


https://twitter.com/RyanMaue/status/904747133210898436

^^ credit meteorite58 for that link in hurricane Irma thread

star gazer

Tropical Storm Jose is forecast to become a Hurricane shortly and unfortunately it may have some impact on islands already heavily impacted by Hurricane Irma



Katia does not look like moving towards the Houston area so badly hit by Harvey, though it may come close to Hurricane strength before making landfall near where it is now in Mexico, with Mexico city potentially getting the Depression left over from TS Katia to move nearby.

bnt

bnt wrote: »

I suspect Hurricane Irma will be getting its own thread soon.

Yep - here it is.

hatrickpatrick

Jose and Katia have now formed (the first ever Hurricane Katia in 2011 some of ye might remember as having ended up in Ireland as a post-tropical storm was a very wet and windy weekend in Dublin and I can only imagine what it might have been like in the southwest where it first made landfall here. Katia looks set to hit Mexico, but before it can reach hurricane strength. Jose's track on the models is fairly erratic - I'd imagine this won't be the actual track, but that they're having trouble forecasting it because of the remaining uncertainty as to what Irma will end up doing. As it stands, it's due to stall just off the southeast coast near Florida and the Carolinas, and meander in a loop around there while strengthening considerably And finally, both the GFS and ECM predict yet another tropical wave to arrive in the Atlantic around day 8/9 and develop almost immediately into a tropical storm, skipping the tropical depression stage.

star gazer

Jose has increased to Hurricane strength with the forecast putting it up to Major Hurricane strength in around 48 hours. Still some impact potential on islands hit by Hurricane Irma in two days.

star gazer

Katia is also now a hurricane. It's a tough time to be a forecaster, but it is such an important job when the impacts of the weather can be (and right now are) so severe for people. Knowing where the danger is going to be next is so vital for saving lives.

hatrickpatrick

star gazer wrote: »

Katia is also now a hurricane. It's a tough time to be a forecaster, but it is such an important job when the impacts of the weather can be (and right now are) so severe for people. Knowing where the danger is going to be next is so vital for saving lives.

NONE of the models saw that coming when Katia first formed :eek: There's obviously something going on this year akin to 2005, wherein some factor the models can't take into account is causing storms to repeatedly outperform expectations.

Meteorite58

Interesting piece here about the weight of the water that fell from Harvey causing the Heuston area to sink by 2cm.




https://www.theatlantic.com/technology/archive/2017/09/hurricane-harvey-deformed-the-earths-crust-around-houston/538866/