Thursday, October 03, 2019

Extratropical Cyclone Lorenzo: October 2, Update A

A quick update for today as I sip my evening grape juice... Lorenzo has fully transitioned from a tropical cyclone to an extratropical cyclone. We caught him beginning this transition yesterday. He's still on track to visit Ireland and England on his tour... 

If you are in Ireland, or are interested in his progress in Ireland, I'd look at the Met Eireann website (met.ie) for more info. If you go to this site, click on winds on the right side, and hit the 'play' button in the image, you can watch the forecasted winds increase and then decrease as he crosses Ireland (or you can view the rain or pressure). Here's a few screen captures showing Lorenzo (The Low) as he approaches Ireland overnight on Friday:


And here he is leaving, after moving from the northwest to the southeast, a few hours later: 


From the pressure fields the forecast shows that he won't be quite so as bad as he gets to Wales and crosses the southwest UK later in the day on Friday (a blustery sort of day): 

If you are interested in the UK side of things, the best source of data is my old work place (I say with pride) - the UK Met Office. In this case, go to metoffice.gov.uk and you can type in the location for the forecast. 

As this is now extratropical and we know where he's going, this is my last update on Lorenzo. But of course, if you are in Ireland and the UK - be careful, be safe! 

Must run... things to do, people to see, wine to drink, ice cream to eat, world to save... the usual stuff.

Toodle pip,
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Wednesday, October 02, 2019

Hurricane Lorenzo: October 1, Update A

Mr. Lorenzo and his tropical storm conditions are now pretty much at the Azores, which are getting more of the windy weather than the rainy weather...

He is at 39.1N, 32.7W, heading NE at a really really rapid 40mph. Wind speeds are estimated to be 100mph, central pressure is 960mb. This makes him officially a weak cat 2 storm (cat 2 range: 95-110mph). 

However, there isn't a good eye (as you can see in the satellite imagery above) and his convection is very weak for a cat 2, so you wouldn't be mistaken in thinking he's not really a classic cat 2 storm - because he's not. His wind speed is actually weaker, but because he is moving forward at that ridiculously fast speed, the effective winds being felt are a lot stronger! This is why they have maintained his cat 2 status. 

There are a couple of unusual things about this Lorenzo. First, his forward speed. This is something we usually see with a storm that has been caught up in a low pressure front. The circulation in the lower levels of the troposphere are beginning to shift towards the signal we see with a front, but his circulation in the upper troposphere still has the circulation pattern of a hurricane, so I would say he is still very much a hurricane (for today at least).

Second, he is over cold water - colder than 26 deg C at the surface. This is why his convection is not very strong. But it also means he isn't going to be getting much energy from underlying warm water - again, something we see with a extratropical storm, not a tropical storm. So overall, I'd say he is transitioning from one type of storm to the other.  

The NHC maintain his hurricane status until Thursday - because of his wind speeds as he races across the north Atlantic.

As for his track... well...hmm...

Lorenzo says, "I must tell thee all. She hath directed..." (Merchant of Venice). Oh how true. Yesterday I did mention he was going to the Ireland/UK area to weigh in on Brexit, and where better than to the seat of it all - London...? It is, after all, October 2019... 

What does this mean for Ireland and the UK? 

Well, Ireland should be getting ready for a storm on Thursday as there's a possibility that winds will be at strong Tropical Storm level/weak cat 1 hurricane still - around 70-75mph. This sort of storm at those latitudes can result in trees being uprooted etc. so be prepared. The good news is that there is some wind shear ahead of him, so, in addition to the cold water, he should weaken a bit before getting to Ireland. It's tricky to say how much, but he won't grow. A big issue will be the waves on the west coast - expect them to be ginormous (and move away from the coast if you are in an area which gets coastal erosion in winter storms)! 

After crossing Ireland, and once in England, he will still have some decent wind and maybe a little rain (because it rains with every gust over there and I don't think they've had enough this week). This will still be at Tropical Storm level (or strong gale force if you like) - maybe with winds close to 55-65mph - it'll be a very blustery day on Friday (uh-oh, I feel a song coming on...):

Hum dum dum dum ditty dum
Hum dum dum
Oh, the wind is lashing lustily
And the trees are thrashing thrustily
And the leaves are rustling gustily
So it's rather safe to say
That it seems that it may turn out to be 
It feels that it will undoubtedly 
It looks like a rather blustery day...

(from a very famous bear).

Remember, he could go anywhere in that white cone of uncertainty - so you should all be prepared. I'd stay at home on those days with a lovely cup of tea, if you can! (and maybe stock up on a few candles, just in case). 

More tomorrow! 
Ciao for now,
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Tuesday, October 01, 2019

Hurricane Lorenzo: September 30, Update A

I thought we'd leave Lorenzo alone for a few days to practice some of his dance moves, and boy did he practice. He's still out there in the Atlantic but he did become a major hurricane (cat 3). He's slightly weaker at the moment due to wind shear, although still a decently strong cat 2 storm with winds of 105mph (cat 2 range: 96 - 110mph). Central pressure is 956mb. 

Lorenzo has been generally quite well behaved and is still on track to visit the Azores on Wednesday, en route to the Ireland/UK portion of the world... to weigh in on the looming Brexit fiasco, no doubt: 
He's currently at 32.0N, 41.2W, heading NE at a rapid 20mph. Interestingly, the cone of uncertainty is very narrow which means that the track forecast is good - this is good news. The more of this level of forecast there is, the sooner I can retire! ;-) 

Lorenzo remains a big boy (as we saw a few days ago) and his outer bands are already over the Azores, which are over 800 miles from his center still!

I'd agree with his cat 2 status - there is very good circulation in all levels of the troposphere, but the convection is not very symmetric around the eye and we can see that wind shear is playing a role in keeping him in check with the clouds streaming off to the north east: 

If you are on the Azores, I'm sure you know what to do! Be careful of the water - especially the storm surge and waves - the force is strong with this one.

There are a couple of other blobs in the Caribbean, but until they develop a bit, I'll just keep an eye on them.

More tomorrow, but for now, it's... Toodle pip!
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Thursday, September 26, 2019

Tropical Storm Karen and Hurricane Lorenzo: September 25, Update A

Not much going on in the Atlantic today... well, ok, maybe that was a slight exaggeration. There's little Tropical Storm Karen and Hurricane Lorenzo. Guess which one is which? 

Ok, Lorenzo is easy - he clearly looks like a hurricane. The NHC finally upgraded him to the hurricane he so richly deserves to be. His current wind speed is 100mph, central pressure is 974mb. This makes him a weak-to-mid-size cat 2 hurricane (Cat 2 range: 96-110mph).  I think he's a little weaker than this because his eye is not fully developed, but he's definitely a hurricane so it's close enough... what's 6 or 7 mph between friends anyway? It looks like he'll topple over to being a major hurricane as a cat 3 tomorrow. I see no reason that this won't happen - there is very little wind shear, he's got some nice warm water etc. But have a look at the size of him! He's a BIG storm. From one outer-band side to the other, he would cover the entire eastern Caribbean! 

He's currently at 14.7N, 38.1W, heading WNW at 15mph, and is expected to remain in the Atlantic: 

As for TS Karen... did you find her in the infrared imagery? No? Well, have a glass of wine because that makes everything clearer. ;-) She's at 24.4N, 63.3W, heading NNE at 15mph. She's barely hanging on to that Tropical Storm status with winds of 40mph (TS range: 39-73mph), central pressure of 1003mb. Actually, I don't think she's a Tropical Storm anymore - there is some circulation in the lowest levels of the troposphere, but that's all. And her convection is nothing to write home about - it's that blob north of Puerto Rico. The forecast has her meandering around in that area and fizzling out. Based on all that, this will be my last update on TS Karen. 

I'll be back in a couple of days - we'll see how Lorenzo is doing then as he is forecast to head towards the Azores around the middle of next week. By a strange coincidence, just before writing this entry, I was looking up the antipode to Sydney, Australia (as you do) and it turns out to be Relva, Azores, Portugal! If I were living in a Dirk Gently novel (Douglas Adams), I would say that's a sign that I should visit. 

Do you know where your antipode is tonight? 

And with that useless fact now stuck in your head (you can thank me when that's the winning answer to a $1m quiz that you entered), I'll be away. 

Toodle pip,
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Wednesday, September 25, 2019

Tropical Storms Jerry, Karen, and Lorenzo: September 25, Update A

Not much time to dilly dally today, but a quick note that I'm not sure that my old listserve method of delivery is functioning anymore (it was bound to go bye-bye at some point - it has been almost 14 years!). So, here am I, competing with cat videos for your attention on social media... (I'd prefer to be watching the cat videos too actually). :-) 

Tropical Storm Jerry
He's fairly weak now, which is a jolly good thing for Bermuda. Winds are currently 45mph, central pressure is 996mb. This makes him a very weak Tropical Storm (TS range: 39-73mph). He's a fairly ragged looking little fella:

He's that very lightly grey swirling group of clouds just to the west of Bermuda, which is that little white speck north of Puerto Rico, which is that island under that very very dark red area in the Caribbean, which is Tropical Storm Karen. 

His center is at 31.4N, 68.7W, and he's heading NNE at a very slow 5mph. The wind shear and dry air did really take its toll on Jerry, so any convection he does have is now to his east. He'll pass close to Bermuda, but looks like the center will stay to the north tomorrow, which is groovy:
So for Bermuda, it'll be a bit of a blustery day (not very strong though) but not much more of the raindrop things. Unlike the situation on Puerto Rico and the VIs with TS Karen today...

(This is most likely my last update on Jerry). 

Tropical Storm Karen
Another weak Tropical Storm, which just like Jerry, also had winds of 45mph, central pressure of 1002mb. However, as I mentioned yesterday, she had some very warm and deep-warm water to cross in the northern Caribbean, which meant she would have a lot of moisture to pick up and dump onto the mountainous terrains of Puerto Rico and the Virgin Islands. We see this in the infrared imagery - the dark red over Puerto Rico is strong, torrential and thundery downpours and I'm sure it's quite a flooded mudslide soggy mess on the US VIs and Puerto Rico.  

TS Karen is currently at 19.1N, 65.0W, heading NNE at 14mph. Earlier today, she passed close to (or made landfall in) Vieques, and then Culebra. She's now officially cleared the islands, however her convection is still very strong as we can see in the IR imagery. Puerto Rico is having a bad 24 hours - there was a 6.0 magnitude earthquake near the island yesterday evening, and this deluge today.  

They are not quite out of it yet with that heavy convection still over the island, so we'll know the full extent of the impact tomorrow. She is now heading into the Atlantic... 
... but I see Bermuda has put up a Force Field which she will get to on Thursday and will stop her from progressing north, thus shielding themselves from windy weather that inhibits their golfing (one day I really have to visit as friends have planted an image in my head that this is all they do, apparently). We'll revisit the real reason why she is going to behave so oddly when I have a bit more time. 

Tropical Storm Lorenzo
Meanwhile, out in the Atlantic is the actual strong storm of today (fortunately far from anyone). Lorenzo now has estimated winds of 70mph, and an estimated central pressure of 993mb. I think he is much stronger than this - easily a cat 1 hurricane as I mentioned yesterday because his circulation is strong in all levels of the troposphere. He has decent convection:

He is currently at 13.2N, 32.4W, heading WNW at 16mph, and the NHC will upgrade him soon according to their forecast:
I can see his track heading northward now in the pressure fields, so I agree with the NHC forecast track for Lorenzo.

That's all for today, we can go back to our cat videos... Stay safe out there! 
Ciao for now,
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Tuesday, September 24, 2019

Tropical Storms Jerry and Lorenzo, Tropical Depression Karen: September 23, Update A

Welcome to the first day of Autumn...
(self-portrait ;-))

Tropical Storm Jerry
Jerry is still a relatively strong Tropical Storm with winds of 65mph (TS range: 39-73mph), central pressure 991mb. The intensity continues to be impacted by strong wind shear plus some dry air at the moment. Here are the water vapor imagery for Jerry (top mass of clouds) and Karen (bottom mass of clouds):
He has got circulation in all levels of the troposphere, so if it wasn't for the wind shear, I think he would be a hurricane. The official forecast calls for his intensity continuing to decrease slowly over the next few days. I'd still be a little wary as he gets closer to Bermuda (tomorrow), as it looks like the wind shear may decrease (but just a little) - however, the dry air will continue. We can already see from the infrared that Bermuda has had a few raindrops... (cancel the golf!):

He is moving N at 7mph, and is currently at 29.2N, 68.3W. The forecast track has shifted to the south, which now takes him much closer to the island: 
He could go anywhere in that cone of course. How close he gets depends on when he makes that turn to the NE... that's what we are watching for tomorrow. The NHC are pretty good within a day, so I expect that turn will happen as they forecast. The best scenario is that he passes Bermuda to the north because that stronger convective weather is to the north of his center, so the worst of the weather will remain away from the island (and golfing can resume much sooner). 

Tropical Depression Karen
She has weakened since yesterday as she ran into some very dry air. However, as we can see from the water vapor satellite images above, that dry air is disappearing and the corresponding infrared imagery shows that her convection is returning. She is currently not quite a Tropical Storm, with winds of 35mph (TS range: 39-73mph), central pressure 1008mb. She is at 16.1N, 65.8W, heading NW at 10mph. 

She is heading towards Puerto Rico and the Virgin Islands and should really reach them tomorrow:
Luckily she's not very strong (in terms of wind speed), but she does have quite a lot of convection (rain and stuff (technical jargon for 'even more rain')), which means she'll bring that thing we jokingly like to call weather. And with the mountainous terrain, she may cause some flooding. I don't see the convection really decreasing between now and the islands because she is over waters that are 28 deg C, with the upper 100-125m being warmer than 26 deg C - plenty of warm water for her to feed on and then dump over the islands. 

We'll worry about her attempt to get to Bermuda later... (she's just trying to follow her bigger brother, who in turn was trying to follow his big sister and so the story goes...). For now, listen to your emergency managers, and don't forget - hide from the wind, run from the water. Which means that if you are in an area that is prone to flooding, move away! Water is the biggest cause of loss of life in a storm, not the wind. 

Tropical Storm Lorenzo
TD 13 has moved on... Tropical Storm Lorenzo is developing into something. He's currently at 11.6N, 26.7W, heading W at 15mph. He is a mid-size Tropical Storm with winds estimated to be 50mph, central pressure estimated to be 1002mb. I have to say, the Force is strong with this one. The NHC think he'll be a hurricane by tomorrow evening - I think he's already almost a hurricane; there is really good circulation in all levels of the troposphere. Plus, when we look at the infrared satellite imagery, we can already see that he is looking far more robust than Jerry: 

I would put his wind speed at closer to 75-80mph at the moment. The forecast track takes him into the Atlantic as a major hurricane in a few days: 
We'll have to keep an eye on him though - as that is a long-range forecast and the track forecast isn't that great that far out at the moment. 

That's all for ce soir. Good luck and stay safe to all my friends in Puerto Rico and the VIs - I hope it's all just a few drops in a rusty bucket somewhere. 

Ciao for now,
J.

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Monday, September 23, 2019

Tropical Storms Jerry and Karen, TD 13, and a quick recap of Humberto and Imelda: September 22, Update A

A huge groveling apology for the radio-silence... I was stuck in a time corridor as my TARDIS malfunctioned (you know how that goes) and missed two storms that I see caused some havoc. I'm sure my intelligent friends and readers in Bermuda and Texas are ok (because they read this of course) and had stocked up on ice cream and wine (and canoes!) to get through it all! Anyway, TARDIS is mostly fixed and I'm back, so first, a quick recap on what I missed and then we'll see who else has been invited to Mother Nature's party.

Hurricane Humberto started life as a little storm just north of the Bahamas well over a week ago, but stayed clear (fortunately for that part of the world) and instead made a sharp turn to visit Bermuda. They had a very dark and storm night about 5 days ago, as he zoomed past as a cat 3 storm with winds of 120mph. Fortunately his eye (and strongest winds) remained north of Bermuda, so although most of the island was without power, all made it through. 

Tropical Storm Imelda was a very quick storm that popped up in the Gulf of Mexico around the time Humberto was approaching Bermuda. She barely made tropical storm strength with winds of 40mph (TS range: 39-73 mph), but she had a LOT of rain which she dumped over Texas after making landfall near Freeport late last week. Unfortunately, it looks like at least 5 people died and the flooding was extreme.

I think that brings us up to today...

Tropical Storm Jerry
This little guy formed about 5 days ago in the mid-Atlantic, headed towards the northern end of the Caribbean, became a cat 1 hurricane three days ago, but fortunately decided to avoid the islands (clever chap). He is now heading in the general Bermuda direction and is back to being a strong Tropical Storm with winds of 65mph, central pressure of 993mb. It looks like he'll pass to the north of Bermuda as a Tropical Storm on Tuesday. He is moving NNW at 10mph, and is currently at 27.4N, 67.2W.


He is under some wind shear and has some dry air ahead of him, which we can see in the satellite imagery (the yellow area):
This means that he should slowly decrease in intensity over the next few days. By the way, that little red speck to the north of the strongest convection (shown by the green in this image) is not a smudge on your screen... that is the fearless place we call Bermuda. In this case, if it wasn't for the wind shear, he'd be a hurricane as well because there is some circulation in all levels of the troposphere. So hurray for wind shear! 

Tropical Storm Karen
She formed today (phew, finally caught up!). She is currently at 13.1N, 63.5W, heading WNW at 12mph. 

She's barely a Tropical Storm with winds of 40mph, central pressure of 1007mb, and she's not very big in size yet either (especially if you compare her to Jerry who is to the north), but she has some fairly strong convection in her center, which we can see in the infrared satellite imagery here: 

The NHC don't think she will intensify much over the next two days, as she approaches the islands in the northern Caribbean (Puerto Rico/Virgin Islands) because of wind shear. I don't see the wind shear in the data I'm looking at though. Also, the water she is passing over as she crosses the Caribbean is warm with the upper 100-125m being warmer than 26 deg C. These two factors suggest a gradual increase in intensity, however the big thing working against that is that there is some dry air between her and the northern Caribbean: 
This will really inhibit her growth for the next couple of days. At the most, she'll be a strong Tropical Storm as she gets close to any land, but it's more likely that she'll be a weak TS. 

Tropical Depression Thirteen
I'd like to think 13 is a lucky number. It's too soon to say where he'll head at the moment as he just left Africa, but the next name is Lorenzo. I'll stop here for today as I still have some minor repairs on the TARDIS to finish off...

Toodle pip!
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Monday, September 09, 2019

Post-Tropical Cyclone Dorian Gray and Tropical Storm Gabrielle: September 8, Update A

I had a couple of days off because Dorian Gray was behaving pretty much as expected (I've read the book) so I took advantage of the time and caught up on current global political events by watching the new Dark Crystal. ;-)

Post-Tropical Dorian Gray
Meanwhile, over the last 2 days we all saw Dorian Gray zip up the US east coast and on to Canada as a very blustery post-tropical/extratropical storm with hurricane-strength winds. His remains are currently at around 52.1N, 53.4W, heading ENE at 24mph. He's still got Tropical Storm force winds of 60mph and a low central pressure of 980mb, but he's definitely winding down.

He's actually not been a Tropical Storm for a couple of days - he began transitioning into an Extratropical Storm, or, as the NHC called him, a Post-Tropical Storm, and has now fully transitioned. Uh-oh... I feel a <Science Alert!> coming on....

<Science Alert!> A quick overview of storm systems... 

Extratropical Storm: These usually form or exist in the extratropics (i.e. north of 30 deg N or south of 30 deg S) and have cold air at their core. A cold air mass meets a warm air mass, and as as the warm air rises (because it is lighter than the cold air), it releases potential energy that results in these storm systems or fronts. Because warm air rises, a low pressure is formed which is why these are also called low pressure systems. Because these storms are formed by the collision of air masses these systems can occur over land or water, and occur frequently in the winter. They are often associated with snowstorms/blizzards and, in the US, these are also Nor'easters. Before around 2010, Tropical Storms that had moved far enough north and had the same characteristics of an Extratropical Storm (or merged with a low pressure front) used to be called (quite sensibly) Extratropical Storms. 

Post-Tropical Storms: These are Tropical Storms that take on the meteorological characteristics of Extratropical Storms, so really, they are Extratropical Storms. The NHC changed the name from 'Extratropical Storm' to 'Post-Tropical Storm' around 2010 in a concerted effort to make things more confusing and less scientific. Sigh. I'll get over it one of these years. 

Tropical Storm: These usually form in the tropics and have warm air at their core. The energy source for these differ from Extratropical Storms. These storms form over water only and the energy source is latent heat. Warm water evaporates into the air. As the rising warm moisture-laden air in the center reaches colder altitudes in the atmosphere, the water vapour condenses to form clouds and latent heat is released. The heaviest rains and winds are, as you know, in the bands closest to the center. No fronts are associated with these storms (although 'waves' in the atmosphere are) - which makes it difficult to determine too far ahead of time when a storm will develop. Tropical Storms are named when they have a closed circulation and wind speeds are greater than 39mph. Before that, a closed circulation with wind speeds between 17-39mph are called Tropical Depressions.  

Subtropical Storm: These contain some characteristics of both extratropical and tropical systems. For example, imagine an extratropical storm moving over warm water. Now that storm begins to get some energy from latent heat as well, and the cold air in the center (near the surface) is replaced by warm air, so the storm core can change from cold to warm. The heaviest rains and winds in this case are not near the center though. Like a tropical system, a subtropical storm is when the winds are greater than 39 mph (34 knots). If the winds are less than that, it is a subtropical depression. 
<End Science Alert!>

As I didn't want you to be still reading this next week, I didn't get into Potential Tropical Storms (a nomenclature that the NHC added just 2 years ago!), Could-Be-Tropical Storms, If-You-Squint-Tropical Storms, or You-Must-Be-Joking-Tropical Storms (please note: the last three don't currently exist as formal naming convention for storms, but I'm sure will be added over the next 4-5 years). 

But back to Dorian Gray... thank goodness he is almost gone! It's been only one week since Dorian arrived at Abaco and the images and reports from there and Grand Bahama are terrible. There is still not a full accounting of the loss of life. The destruction he caused there and beyond, and also in the VIs and Caribbean prior to that, means that we will never see another Hurricane Dorian - this is a name that will be retired after this season.

This is my last update on Dorian! 

Tropical Storm Gabrielle
Our little Gabrielle is still hanging out in the Atlantic and is currently at 36.5N, 49.3W, heading N at 15mph. The forecast has her turning to the NE, which seems about right. Heading over to the UK for a cup of tea and jaffa cakes seems like a sensible thing to do. 

She's currently a strong Tropical Storm with winds of 65mph (TS range: 39-73mph) and an estimated central pressure of 995mb. The circulation is pretty good in the lower half of the troposphere, but the signal isn't quite as well developed in the upper troposphere yet, so I think this is about right - she's definitely a Tropical Storm and not a Hurricane at the moment. 
(imagery from Tropical Tidbits as the NOAA site has been taking too long to download!). 

The upper ~75m of the water column is warmer than 26 deg C, but as she gets closer to 40 deg N, this will decrease and she'll be over colder water which will inhibit her development. But before then, it looks like the wind shear drops down a little so there is a small chance for her to get a bit stronger - but then wind shear picks up again so even if she gets to hurricane strength, it doesn't look like it will be for long. 

That's it for this lovely day. More tomorrow (or possibly the next day unless someone is in the middle of the Atlantic...?). 
Toodle pip, 
J. 

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Friday, September 06, 2019

Hurricane Dorian Gray and Tropical Storm Gabrielle: September 5, Update A

Thursday... "I never could get the hang of Thursdays." (Arthur Dent/Douglas Adams).

Hurricane Dorian Gray
The menace that is Dorian is still traveling the US east coast and is currently at 33.8N, 77.4W, heading NE at a much more respectable speed of 13mph. He continues to bring windy and wet weather to a good portion of that coastline as we can see in this infrared satellite image. 

The red/orange areas that moved on-shore are an indication that parts of the Carolina's got some very heavy convection - including severe thunderstorms and tornadoes, although most of the area is under clouds or simply rain. He is now officially a mid-size cat 2 storm (cat 2 range: 95-110mph) with winds of 100mph, central pressure of 958mb. You can clearly see that strong wind shear is pulling the clouds away to the northeast. This, combined with cooler waters will mean he'll steadily decrease in intensity, but will still be a hurricane for at least another day.

As before, between the storm surge and the rain, there is flooding. From the tidesandcurrents.noaa.gov data, it looks like Wilmington, North Carolina, is currently under around 1.5-2ft of storm surge:

Although the pressure is still dropping: 
(in case you missed how to look at storms surge along the US coast, it's in this post: http://jyotikastorms.blogspot.com/2019/07/tropical-storm-barry-july-12-update-a.html).

The forecast track is pretty much the same as yesterday as he heads up to Canada. 
Long before he gets there though, he'll transition from being a tropical storm to an extratropical storm (he'll be moving forward closer to (or faster than) 20 mph by then). However, they still have him as a hurricane up north because they think the winds will be close to (if not) hurricane strength. 

Tropical Storm Gabrielle
She's way out there in the Atlantic at 24.3N, 36.6W, heading NW at 14mph. Winds are now estimated to be as low as 40mph, central pressure is 1004 mb - this makes her barely a Tropical Storm (TS range: 39-73mph). I would agree with this. Since yesterday, her circulation in the upper troposphere has decreased, so she's really only got good circulation in the lowest levels of the troposphere now. Also, she doesn't have much in the way of rain really... 

(satellite imagery from tropicaltidbits.com) 

This will be my last update on Gabrielle unless she picks her socks up... I'll keep an eye on her though, just in case. 

That's it for today, kids. Stay safe out there - Dorian may be getting weaker, but he's still a hurricane!  
Ciao,
J.

Twitter: jyovianstorm
--------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
--------------------------------------

Thursday, September 05, 2019

Hurricane Dorian Gray, the remains of Tropical Storm Fernand, Tropical Storm Gabrielle, and the Atlantic Blob: September 4, Update A

So. Much. Stuff. 

But 'tis approaching the peak of Hurricane Season, with the week of Sept 10th statistically being the turning point in a typical season... 


Hurricane Dorian Gray
He's currently at 31.3N, 79.6W, heading N at a slowish clip of 7mph (although this is much faster than traffic on the highways in Los Angeles at rush hour). He is skirting the coast, but on his current northward path, it looks like he will get quite close to Charleston, South Carolina (and may actually get onto land in some places):

He is officially a weak cat 3 storm again with winds of 115mph (cat 3 range: 111 - 129mph), central pressure 957mb. His circulation is still very strong at all levels of the troposphere, so although the wind shear took a little toll, that deep warm water underneath him in the Gulf Stream has kept him going. Fortunately, most of the really bad weather that is under the red part in the infrared satellite imagery below (heavy thunderstorms, tornadoes etc.) is staying offshore: 

(it's not your screen - the satellite imagery has a white screen that rolls through (a glitch) - don't worry about it, I think it's just window wipers cleaning the satellite lens... ;-)). 

I agree with the NHC on their assessment that he will continue to get weaker as he moves further north, but that he will remain at hurricane strength winds as he gets to Canada - he just won't have the really bad convection as he gets there. 

Water is going to be the biggest issue in the Carolinas - storm surge plus some places which will get a few buckets of rain. A few places along the coast are close to 1ft above normal (from tidesandcurrents.noaa.gov). 

Not too much more to say on Dorian Gray for now as he's behaving pretty much as expected. 

Tropical Storm Fernand
He also behaved as expected and made landfall in Mexico this evening. He wasn't a very strong storm at all, and mostly brought rain (which, over the mountains can cause flooding) - he's now inland and just a mass of clouds. This is my last post on this little guy. 

Tropical Storm Gabrielle
She was named today and is currently at 21.;5N, 34.4W, heading NW at 7mph. 

Officially she's a weak Tropical Storm with winds of 50mph (TS range: 39-73mph), and central pressure is estimated to be 1002mb. I think she's actually stronger than that. She has decent circulation in the lower half of the troposphere, but she also has some in the upper levels, which is an indication of a storm approaching hurricane strength. I would estimate that she's closer to 65-70mph at this point. 

Her forecast track takes her well away from any land:
And no-where near Bermuda at 5 days... so, er, get your wellie boots ready just in case. ;-) 

Atlantic Blob
This one is currently somewhere around 34N, 62W, so he's already extra-tropical really as the tropics are between 30N and 30 S! Not sure he'll develop into much of a muchness, but I'll keep a quarter of an eye on him. If he were to become something, we'd call him Humberto because that's a lovely name. :-) 

It's nap time here so that's it for today. Until tomorrow. 

Be safe my friends in the Carolinas (and along the US east coast)!
J. 

Twitter: jyovianstorm
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DISCLAIMER:
These remarks are just what I think/see regarding tropical storms. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast. This is not an official forecast.
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