Long Range Models

[cycloneye]

GFS continues at the 18z run to be consistant showing the West Africa low.

[Extremeweatherguy]

GFS continues at the 18z run to be consistant showing the West Africa low.

Yes, you're right. The 18z also moves this low further west in the Atlantic than previous runs too, placing it just northeast of the Bahamas in 384 hours..

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[Recurve]

At 324hr it has a massive low up north and an east coast trough to break down the western edge of the high and suck "the system" up to the Bahamas, if that's right what I'm seeing.

[boca]

I waited for the 00zGFS to come out and the African low is in the same place as shown in the 18zGFS. I did notice that the trough moves passed the low and it just leaves it hanging their until the high builds in again and the troughs lifts out NE.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[Meso]

It's also deepening it more now than in previous runs. 00z at 150 hours its already 1006mb.Wonder how long till it gets some model support.Although the EURO also does show a weak low around that area some time.

[Scorpion]

Interesting how the GFS is consistently showing this feature.. reminds me of Dean from last year.

[Meso]

Here is the 00z EURO

A weak low off Africa

No other model support as of yet

[KWT]

The ECM is showing the disturbance but not reallt doing much with it, the GFS however deepens the low a bit and takes it WNW as it strengthens.

[Meso]

Peaks at hour 168 with a pressure of 1005



Traaain

[Frank2]

384 Hours?

Let's remember the old rule:

"A 384-hour forecast map is as factual as last night's dream"

[Meso]

What do you mean? No one is looking at the 384 hour forecast for anything important,it's just posted for the sake of showing the general atmospheric pattern.Everyone is fully aware of how inaccurate the long range GFS is (Though not 100% inaccurate)

The main aspect as to what is being concentrated on is the vicious wave which the GFS is showing developing off Africa in 5 days

[Frank2]

Extremeweatherguy and recurve both mentioned the 368 and 324 hour forecasts, that's why I mentioned it...

As others said, anything that strong that far east is often pulled northward very early...

[KWT]

Quite often yep Frank though this time its being helped by a strong low pressure system over the UK between 120-168hrs which takes it NW for a breif while then it gets shunted back westward as it getsunder the steering influence of the Azores high.

[Ed Mahmoud]

384 Hours?

Let's remember the old rule:

"A 384-hour forecast map is as factual as last night's dream"

Well, back before I joined Storm2K, but was a subscriber to the AccuWx PPV site, the GFS 384 snow cover map showed snow on the ground in Houston on one of the runs, for Christmas Eve 2004, +/- a day. About every third GFS run after, for almost a week, showed snow in Houston. Then the GFS lost it.


Now, my house had just enough snow to dust my car and palm trees, but the 2004 Texas Christmas Eve Miracle did occur much as was predicted by the GFS.

McAllen Texas



I will say, in the last three years, the GFS has consistently let me down on Houston snow fall predictions beyond 180 hours.

[Extremeweatherguy]

Extremeweatherguy and recurve both mentioned the 368 and 324 hour forecasts, that's why I mentioned it...

As others said, anything that strong that far east is often pulled northward very early...

yeah, that far out I am definitely looking at the models for more of an entertainment purpose, and wouldn't take anything they show too seriously. In this case though, the GFS is starting to show a system developing off Africa only 5-6 days down the road, which sparks my interest a bit due to its closer proximity in time and also due to the fact that the model has been consistent with the feature for several runs now. I do agree though that if the system develops as fast as the GFS indicates, it will most likely turn out to sea and never be a real issue. What we will need to watch for is if the system does not develop quite as quickly as shown. A weaker system might be able to make it further west in the Atlantic and could potentially become an issue many days down the road as it approaches the islands.

[Meso]

108 the low emerges off Africa...

144 Hours carries on the trend

[Ed Mahmoud]

That low doesn't seem to move fast.

BTW, looking at 200 and 300 mb winds, looks like the system would be experiencing shear from the East.






150 hours- still close to the Coast.


However, I think conditions could be getting favorable for the frontal remnant East of Florida...

[KWT]

Westerlies just waiting in the wings there Ed on that link for that frontal remnant though maybe there might be a small window who knows I doubt anything will happen. As for the wave, yep ther eis some shear present with it though clearly not enough to stop the GFS from developing it further once it comes offshore.

[Ed Mahmoud]

Westerlies just waiting in the wings there Ed on that link for that frontal remnant though maybe there might be a small window who knows I doubt anything will happen. As for the wave, yep there is some shear present with it though clearly not enough to stop the GFS from developing it further once it comes offshore.

Just watched Joe B's 'Big Dog". No mention of a SE development, but based on strength of wave train and his theory (and the two E-Pac invests seem to confirm) of an MJO related upward motion pulse heading Eastward, he expects one, maybe two, African waves to come off the coast looking good, fizzle a bit mid-Atlantic, and then develop into a named cyclone between Day 10 and Day 20 as they get further West, or roughly centered on the July 10 date he picked back in May, along with a late August period, as peak times for the tropics.


Of course, the late August repeat of the ~40 day pulse will be close to the peak of the season...

[Extremeweatherguy]

That idea sounds about right to me Ed. I think we will see a burst of stronger waves with perhaps one or two of them developing during the month of July as they try to push westward. Definitely seems like we are coming upon a much more interesting time than what we have seen recently in the tropics.


BTW, just for fun, here is a look at a few of the more notable July storms to have formed in the Atlantic east of the islands...

Dennis (7/4/05 - 7/13/05): http://en.wikipedia.org/wiki/Image:Denn ... _track.png
Emily (7/10/05 - 7/21/05): http://en.wikipedia.org/wiki/Image:Emily_2005_track.png
Bertha (7/5/96 - 7/14/96): http://en.wikipedia.org/wiki/Image:Bert ... _track.png
Dean (7/31/89 - 8/9/89): http://en.wikipedia.org/wiki/Image:Dean_1989_track.png
Claudette (7/15/79 - 7/29/79): http://en.wikipedia.org/wiki/Image:Clau ... _track.png

(This list does not include less notable storms and/or storms that formed west or northwest of the windward islands [a.k.a. storms such as Erin '95 and Danny '97])