Long Range GFS - First Cape Verde Cyclone?

[ronjon]

For the first time, the 18Z GFS shows low pressure developing in the east Atlantic ocean. It's nearly two weeks out and we all know how unreliable these model predictions are but perhaps it's a sign to come. I have noticed that the storm track seems to be suppressed fairly southward - around 10 degrees latitude due to a strong mid-oceanic ridge that is persistent according to the models.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml" target="_blank" target="_blank

[windstorm99]

With the major trof setting up in the next couple of days it will be hard for anything for anything to make it across.

[windstorm99]

Having said that i would tend to agree with the GFS here as the positive MJO is set to be moving across the atlantic during the first half of july.

[ronjon]

With the major trof setting up in the next couple of days it will be hard for anything for anything to make it across.

Actually the GFS shows the northwestern part of the Atlantic Ridge eroded by the trough but maintains the core of it over the central Atlantic. Of course, this is two weeks out and a lot can change. But we may be seeing signs of the Atlantic Ridge becoming established over a large portion of the ocean. Not to be alarmist or anything, but this set up (minus the east coast trough) is similar to the 2004 setting.

[wxmann_91]

Rule of thumb #1: if you see something on the 18Z run that wasn't there before, discard it.
Rule of thumb #2: climatology is a good guideline on whether something forecasted on a model is "possible" or very, very unlikely
Rule of thumb #3: never trust any model forecasts of small-scale features, like TC's, more than 96 hr out.

I'd give the probability of this happening... less than .01%

[storms NC]

For the last few years a Cape Verde Cyclone has had it trouble getting across. I wonder if this year will let the storms come across. I havn't looked at any maps yet to see how much dry air etc.. is yet.

the east just may see a CV storm this year on the east coast. JMO

[Frank2]

Another strong EC trough will be moving off the U.S. in the next few days (highs in the low 60's in northern New England, which is hard to imagine at this time of year - lows are forecast to be in the 40s in northern NY, VT, NH and ME later this week), so, this does seem to be part of a long-term weather pattern, since this has been happening on a regular basis for many weeks...

As someone else said here, with such a strong trough, it'll be difficult for anything to make it too far west at this time...

[WindRunner]

Rule of thumb #1: if you see something on the 18Z run that wasn't there before, discard it.
Rule of thumb #2: climatology is a good guideline on whether something forecasted on a model is "possible" or very, very unlikely
Rule of thumb #3: never trust any model forecasts of small-scale features, like TC's, more than 96 hr out.

I'd give the probability of this happening... less than .01%

Well, you're in a generous mood today, aren't you?


Rule of thumb #4: Don't bite on the GFS with cyclogenesis until you see support from two other models or the EC.

[TheShrimper]

Hey Frank, you obviously have never spent any time in NE have you? It is not unheard of to have PM temps in the 40's in Northern NE at this time of year. I remember in May, 1977, it snowed in the southern suburbs of Boston. It has been in the mid 90's outside of Beantown the past 2 days, and forecasted to be close to that tommorrow. When a trough coming through the NE influences the temps here in S. Fla, then I will give creedence to it having some effect on anything that may be happening south of 20N. If it does not, it's foolish to make any assumptions regarding this frontal passage to the north, effecting areas that far to the south. Harp on it as you may, a low runner will not be influenced by what may drop the temps 10 degrees below normal for a short period of time up there.

[Windtalker2]

Hey Frank, you obviously have never spent any time in NE have you? It is not unheard of to have PM temps in the 40's in Northern NE at this time of year. I remember in May, 1977, it snowed in the southern suburbs of Boston. It has been in the mid 90's outside of Beantown the past 2 days, and forecasted to be close to that tommorrow. When a trough coming through the NE influences the temps here in S. Fla, then I will give creedence to it having some effect on anything that may be happening south of 20N. If it does not, it's foolish to make any assumptions regarding this frontal passage to the north, effecting areas that far to the south. Harp on it as you may, a low runner will not be influenced by what may drop the temps 10 degrees below normal for a short period of time up there.

Yes it is very rare to see a cold front pass GA this time of year yet alone pass through FL

[Meso]

The 06z Run

[EDR1222]

Of note....in 2004, there was an unseasonably strong cold front in early August right as Charley was approaching the Gulf. As I am sure everyone knows...the strong SW flow out ahead of it cause Charley to take a late October like track across Florida, so these cold fronts, although not common in the summer, have definitely been known to occur.