ATL: HERMINE - Post-Tropical - Discussion

[Alyono]

It was right about Erika last year and the GFS has known issues with overblowing storms this time of year. The simple fact of the matter here is the Euro has been more consistent in not developing this, while the GFS has been all over the place.

The Atlantic was an entirely different environment last year due especially to the raging super El Nino. A lot of storms suffered the same fate. So I wouldn't use just one storm as an example. Right now ENSO conditions are pretty much neutral and should be through the rest of the season. Hence why the amount of storms for the season increased from CSU, NHC and others.

Once the storm actually develops (if it does), then the models will have a much better grasp on the environment, strength and track. Any waves that get closer to the CONUS are going to have a much easier time developing due to the high heat content just to name one factor.

Another storm, and this is a trophy in the Euro's stack. Joaquin. Against every other model, and even against it's own ensembles which all pointed to a mid-atlantic landfall after development. Euro was the lone wolf out to sea. It beat everything all by it's lonesome against it's own family too. One of the greatest model beat downs I can ever remember.

The euro can be slow on genesis however, but you'd like to see it on the camp of development as a reinforcement to confidence along with other guidance.

The Euro was the FIRST to show a US landfall for Joaquin

[Ntxw]

The Euro was the FIRST to show a US landfall for Joaquin

Yes but it then went OTS while everything else went to land including the majority of it's individual ensemble members in the time period when a call to preparation was needed. That's impressive.

[Ntxw]

99L this morning, it doesn't matter what model we talk about. There isn't much there yet for them to really zone in on.

[TheStormExpert]

Looks like 99L's circulation is starting to wrap and tighten up.

[cycloneye]

99L this morning, it doesn't matter what model we talk about. There isn't much there yet for them to really zone in on.

http://i67.tinypic.com/261f4zt.gif

Exactly.Neat loop that shows the sun glare and the broad turning but little convection so far.

[Hurricaneman]

Looks to be SAL that will keep 99L in check the next day or 2 as there seems to be an anticyclone over it


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[cycloneye]

Tentative first mission to 99L next Tuesday at 15:00 UTC.

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1100 AM EDT SAT 20 AUGUST 2016
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 21/1100Z TO 22/1100Z AUGUST 2016
TCPOD NUMBER.....16-086

I. ATLANTIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
3. ADDITIONAL DAY OUTLOOK: POSSIBLE LOW-LEVEL INVEST MISSION
INTO CENTRAL ATLANTIC SYSTEM FOR 23/1500Z.

[SFLcane]

 https://twitter.com/adriansweather/status/767019723271704578

[sunnyday]

Does anyone else hear that? The fat lady singing, I mean....

[Ntxw]

Something to remember, SAL is more than Saharan dust. Warm air layer above and cooler marine layer below is essentially a lid for thunderstorms (convection to pop). While dust is easily washed out and doesn't prevent convection I wonder what the upper air sounding above 99L is right now and if that temperature inversion is keeping a lid on convection?

[centuryv58]

Does anyone else hear that? The fat lady singing, I mean....

Nope.

[abajan]

Does anyone else hear that? The fat lady singing, I mean....

No. You may need to see a shrink. (Just kiddin' )

[Steve]

Does anyone else hear that? The fat lady singing, I mean....

What's the fat lady singing on an invest, a divest? This is what 36 degrees west? No offense sunny, but a lot of y'all don't seem to have enough patience for the tropics this year. A wave doesn't move or develop at the speed of Twitter or the speed of the average American's attention span. It's rarely going to be as cut and dry as people want things to be. If it was, where would the fun be in anticipating potential threats?

[tarheelprogrammer]

LLC becoming better defined it looks like the last few frames of Satellite. How could this be without convection?

[psyclone]

well that visible loop tells quite a story. lots of clear skies and distinct sun reflection..indicating a calm sea state. I'm thinking a surface recon mission with a 6 pack, a canoe and sunblock is doable. Having said that I won't write off even the most lame disturbance at this time of the year. You can't. OTOH, I'm not biting on any bullish model runs until we have a legit period of development and a real cyclone on our hands. The burden of proof is on the basin to produce and this is the time of year to do it.

[gatorcane]

That's a pretty decent area of vorticity for sure:

[cycloneye]

A broad area of low pressure, associated with a tropical wave, is
located about midway between the west coast of Africa and the Lesser
Antilles. The associated shower activity remains disorganized, and
any development during the next couple of days should be slow to
occur due to its large size and proximity to dry air. Environmental
conditions are forecast to be more conducive for development beyond
a couple of days, and a tropical depression could form by the middle
of next week while the system moves westward at 15 to 20 mph across
the tropical Atlantic Ocean and into the eastern Caribbean Sea.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...medium...60 percent

[gatorcane]

Up to 60%:

[gatorcane]

Atlantic wide-view, 99L is quite a large system with a lot of cyclonic spin and also is moving pretty quickly west:

[psyclone]

My inclination is to agree with the NHC re better than even long term development odds. the system just has a massive sprawling vorticity that is likely to A.) remain intact and B.) eventually find decent conditions to develop. it's going to be over tropical waters for a long time and it's late August. Eventually something will likely come of this...I'm guessing maybe a three out of four chance over the next week.