Hurricane Irma & TS Lidia

[JamesG161]

TS Irma was being noteworthy by world forecasters last Sunday.

This 2017 season, African storm "spin offs" have been formed very South of the normal birth area. Two storms, Don and Harvey, followed the this formation path. I will avoid the Harvey discussion, since the news will keep you informed, but note that we are passing midseason for 2017 [ Solar Energy in waters in Southern Caribbean is High.]
_______
The HIGH pressure fronts currently over Bahamas and Carolinas with push TS Irma and keep it on the Southern track. This will move this very intense storm into the Antilles by Wednesday.
Two more HIGH's over CO and KS [ the ones pushing Harvey NE] will tend to shield the Gulf from Hurricane Irma as it passes South of Cuba.
_______
The Bad News is that part of the Caribbean Has a lot of Storm fuel or HEAT.

Here is NOAA's Heat [not temperature} which includes the top ≈20 feet of water.
They use the term Tropical Cyclone Heat Potential [TCHP]
Hopefully that link works, if not then click on LOOP on this one.
Tropical Cyclone Heat Potential Loop
________
Last season, the forecasters missed the intensity predictions when storms passed this far south. They had slim information on deeper water temperatures, which info has improved this season. The islands just north of Venezuela were considered Desert Islands or little tropical storm activity.
Jim...

PS: Although this is not a consolation for TX and LA et.al., note on that link how Harvey removed Gulf Heat along the Gulf Coast line.

 

[Gene Neill]

Good grief. Just earlier this morning, all the spaghetti noodles on TV showed Irma curving north, missing the Antilles altogether. Stupid pasta!

 

[JamesG161]

Stupid pasta!

Here is what is happening at NOW Aug 31 2017

The HIGH push LOW. They normally move at 10-12 mph shown by my arrows and direction.

Irma curved ESE this morning for the now Strong High NNE of Dominican Republic. Those Atlantic HIGH's should make Irma move WWS and why I suggested this morning... look out Lesser Antilles!

Not wishing or forecasting harm to anyone...

But I am trying to help USA Gulf and others to prepare long in advance.
If you do the math, Irma is moving W at 15 mph. Highs over NM/TEX heading up Irma or just use your fingers to do the same as a navigational plotting compass.
We will have a HIGH over the Gulf when Irma is south of Cuba.
______
Here is the unknown at this time...
LOWs follow HIGH's like waves. Does the Timing of Irma force it south until mountains of Honduras or get sucked into the LOW and head North.
In about 5 days NOAA will have more info on the Irma Track and then 5 day forecast. You will know by the news cycle then.
Jim...

 

[JamesG161]

Since the "models" are now closely watching Irma, I am just monitoring the info, like most of us.

But I noticed, that the Model that I watch, started to show a North West trend versus West.

I was puzzled as to what was driving those models to react.

Are you ready for the key reason that Irma would turn more North?

HARVEY!

It appears that as TD Harvey is guided between two High Pressure waves, and it will emerge over VA back into the Atlantic. Thus pulling Irma, as the two HIGH shown in my Pict above, helps the shove into Harvey.
I am NOT suggesting the storms will merge.

That will teach me NOT to dismiss Harvey's LOW so quickly.
Jim...

PS: Timing of weather changes is everything, during Hurricane season.

 

[Gene Neill]

Hooray for spaghetti! Of course, now the northeast needs to sit up and start paying attention ....

 

[JamesG161]

But Beware at the Antilles.
Timing is everything.
Jim..

 

[JamesG161]

Hooray for spaghetti!

I couldn't resist.

Yep I know for sure Irma path.
Must be the noodle with the most RED sauce on it.
Jim...

 

[justsomeguy]

Live update from TS Lidia: she's currently lightly battering Baha, and I'm in the SE quadrant.
Winds got up around 50 kts but have subsided to about 30-40.
Very little damage so far, at least on my dock, with the exception of this dock box.

My first named storm!

 

[Gunni]

Nobody knows where little Irma will end up, she's still arching southwest with a potential to turn northwest. But it is worth noting that the models show a 30% chance she will stagger into the extra warm waters of the Gulf, and then it is Katie bar the door.

 

[JamesG161]

stagger into the extra warm waters of the Gulf, and then it is Katie bar the door.

To see if we need many "Katie's" to bar the door on Irma.
Looks at the NOAA looped graphic for HEAT [TCHP].

Tropical Cyclone Heat Potential Loop

and not this...

Sea Surface Temperature Loop

The TCHP takes into effect the subsurface water temperatures that a storm STIRS up.

If Irma goes south of CUBA....
BIG TUFF Katie will be needed to bar that proverbial Door.
Jim...

PS: NOAA uses TCHP for intensity forecasts. Trust me NOAA knows exactly where Irma is going 5 days in advance.

 

[Gunni]

Models all showing a move to the eastern seaboard. Potential impact as early as 9 September. I am moving into prep mode on the upper Chesapeake.

 

[JamesG161]

moving into prep mode

1) Irma is bucking some upper altitude head winds that keep it from gaining strength right now.
2) ExHarvey [Low] merged with a Arctic Low and exited USA further north. Irma course more WWN today.

the Big if....

Jet Stream is strong NNE, along East coast and should force Irma almost due North, if Irma maintains current course and speed [ it will be obvious by Wednesday].
.
_________
I would do, as @Gunni is, and prepare now all along the East Coast.

It took me 5 days to pull, clean, inspect and test my Hurricane lines [not full time, of course]. I am checking my ground tackle this weekend.

It will take me 3 days just to prepare the cabin area for high seas. It is set for comfort and not for 8+ foot seas.
Jim...

 

[Rick486]

Here's another page I use frequently. If you look in the correct latitudes there is a good visualization animation for what this could look like as she approaches the East Coast
http://www.passageweather.com/#

 

[JamesG161]

Models all showing

Models are too plentiful...

Here is what the local officials are getting from NOAA and it is updated every 4 hours my them. Forecast for 5 days which is most accurate. Left to Right by days.

Note: The collision of a HIGH and LOW pressures makes a wave front shown by Red Half circles and Blue Half Arrow pointing in direction of flow and why they are projecting the curve to the north.

Wishing all Good luck...
Jim...

 

[Gunni]

Well, it is definitely headed into south Florida now, after that it looks like it will expend itself running the length of Florida before the remains ride up that trough into the Ohio River valley.

 

[Don S/V ILLusion]

As of now, the only effect is rising gas prices and a run on generators which everyone should have. The rest is speculation. Most of us on the Sunshine Coast are varnishing the teak and polishing the chrome at least until Thursday.

 

[pateco]

Not looking good for South Florida at this point.

 

[Rick486]

Not looking good for South Florida at this point.

View attachment 140534

From that graphic it looks kinda bad for anyone east of the Mississippi.

 

[JamesG161]

Other than a round of applause for the Hurricane Hunters who risk their lives .for Inside Irma winds and Dropsonde buoy drop through the storm. It is more a cool graphic of their flight.

Their most recent flight is superimpose on Sat picture show wind speed in Knots. Each full feather on the wind arrow is 10 knots.

Imagine the wing bounce from 137+ knot wind!!
Jim...

 

[Johnnyreb]

ok, if this thing hits savannah, I may be living on the boat for awhile and doing patrols