Models Developing a Strong Tropical Wave to Move Off Africa

[Derek Ortt]

I do discuss the wave at PNJ this evening. I am now expecting a significant hurricane out of this. Cannot ignore the models with this much consistency

[PTrackerLA]

That track is just beyond horrific, I had to laugh as well as I watched in enter the gulf. Wonder where the 00z will take it, GOM or EC? Like Brent said, the fact that the GFS continues to show a major hurricane threat for the US is alarming but nothing to be overly concerned with yet.

[KWT]

Looks very interesting Derek, as you say this could well become one of the stronger hurricanes of this season, given the models are bullish I suspect we will have a decent strength hurricane in 5-6 days time...pray the ECM is right but I'm worried it won't pick up as much latitude as the ECM expects between 96-120hrs given the ridge has been strong enough to send Td2 a little bit to the WSW.

[Thunder44]

No matter what run it is, the GFS will probably take this storm anywhere from the Yucatan to Nova Scotia, after 7 days.

[tolakram]

I asked a question further back that no one answered.

How well do the models handle the increased shear in an El Nino year?

[cycloneye]

ABNT20 KNHC 122330
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED AUG 12 2009

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

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
DEPRESSION TWO...LOCATED ABOUT 710 MILES WEST OF THE SOUTHERNMOST
CAPE VERDE ISLANDS.

A VIGOROUS TROPICAL WAVE IS EXPECTED TO PASS WELL TO THE SOUTH OF
THE CAPE VERDE ISLANDS WHILE MOVING WESTWARD AT 10 TO 15 MPH ON
THURSDAY. ALTHOUGH THE SHOWER ACTIVITY IS LIMITED AT THIS
TIME...CONDITIONS APPEAR TO BE FAVORABLE FOR SLOW DEVELOPMENT
DURING THE NEXT FEW DAYS. THERE IS A MEDIUM CHANCE...30 TO 50
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER AVILA

[Aric Dunn]

I asked a question further back that no one answered.

How well do the models handle the increased shear in an El Nino year?

well the big problem is that they do not include to the best of my knowledge any data on if its a el nino year or not since on a week time scale the effects of El-nino may not play a role as there may be very favorable conditions.

[tolakram]

I asked a question further back that no one answered.

How well do the models handle the increased shear in an El Nino year?

well the big problem is that they do not include and data if its a el nino year or not since on a week time scale the effects of El-nino may not play a role as there may be very favorable conditions.

So then the models are telling us that given decent conditions these storms may develop, but shear might also do them in.

[Aric Dunn]

I asked a question further back that no one answered.

How well do the models handle the increased shear in an El Nino year?

well the big problem is that they do not include and data if its a el nino year or not since on a week time scale the effects of El-nino may not play a role as there may be very favorable conditions.

So then the models are telling us that given decent conditions these storms may develop, but shear might also do them in.

yeah its all based on current data. So if the conditions are there for development or strengthening then they will initialize it and produce a forecast based on many dynamical parameters.

[Wx_Warrior]

no planes are sent out, etc.....take the end results with a grain of salt. It's been said numerous times on here, just know models are developing something. Worry about the track a week from now.

[Stormcenter]

Is it just me or does the GFS seem to destroy N.O. every season with at least one of it's phantom runs? This is the kind of stuff that causes "unnecessary" stress for people along the U.S. coastlines.

[Ivanhater]

I knew the models would continue to swing..still a few more days til they start locking in on a region..

[clfenwi]

Three notes for the price of one:

- Some of this discussion is bringing back memories of an idea for a novella entitled "Cat 6", the basic plot of which is the panic a man is stricken with when he sees that the 600 hour output of a forecast model known as "The Mexican" shows an annular hurricane headed straight at his neighborhood.

- As Aric indicates, the models know not/care not what oscillations are in play. They work with current conditions. Any limitations they have in analyzing shear, relative humidity, etc. are valid regardless of what El Nino/MJO/YAO/ is doing.

- The TWD mention of the wave is as perfunctory as it gets:
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 19W/20W TO THE SOUTH OF 22N MOVING WESTWARD 15 KT. SHOWERS AND THUNDERSTORMS ARE
FROM 14N TO 15N BETWEEN 18W AND 19W.

[Ivanhater]

Good God

[Ivanhater]

GFDL

[jinftl]

depends on what the shear is at the key moments.....shear is not constant. generally, el nino season do experience more shear..but it is not a 'special' shear and it absolutely fluctuates. Shear is not like below normal water temps that would serve as a constant hinderance to develop.

Plus keep in mind, shear is not a new phenomenon. Not a 2009 el nino season occurrence. Every season....every one...has shear of varying degrees. Not sure how, for example, 20kts of shear around a system this year would be...or need to be....considered above and beyond what 20kts of shear would be in a neutral or la nina year.

If this, or any other system, is able to avoid areas of intense shear....there is no surprise 'knock out punch' of shear that el nino would deliver. The models all take into account the upper air environment around and ahead of systems. Perhaps I am not understanding the question...

I asked a question further back that no one answered.

How well do the models handle the increased shear in an El Nino year?

[HurricaneBelle]

Good God

The "Bill" comes due.

[jinftl]

katrina's brother....it hurt to even type that....but that was my first reaction

Good God

The "Bill" comes due.

[Macrocane]

Is it just me or does the GFS seem to destroy N.O. every season with at least one of it's phantom runs? This is the kind of stuff that causes "unnecessary" stress for people along the U.S. coastlines.

GFS doesn't destroy N.O it just predicts a system making landfall on the Louisiana coast, I agree sometimes are phantom stroms but sometimes real hurricanes have made landfall very close.

[bob rulz]

Are INVESTs only declared at a certain time? Or do they declare them at the exact time where they feel like they've become worth tracking? (Hopefully that question made sense, I chose some awkward wording! haha)