IsentropicLift Posted September 2, 2014 Share Posted September 2, 2014 Although likely a fish the 9/2 12z GFS marks the third run in a row to quickly develop a disturbance emerging off of Africa near 15N into a formidable tropical cyclone. If correct, the Cape Verde Islands could be in for a significant impact in 48-72 hours as the GFS takes the developing TC center very close to southern portions of the island chain. Although statistically the odds of this making it west of 70W are near zero given the location of development, the 12z GFS does keep rubilding the ridge overhead through at least 40W while keeping the system near 15N. In any event, the odds appear to be a bit lower than average for an early recurve. The 12z GFS also continues to develop a second system in about 5-6 days in roughly the same spot. Looks like the far eastern Atlantic could be heating up very soon. Link to comment Share on other sites More sharing options...
AvantHiatus Posted September 2, 2014 Share Posted September 2, 2014 Nice 500mb setup for a high-laditude long-tracker. Link to comment Share on other sites More sharing options...
IsentropicLift Posted September 2, 2014 Share Posted September 2, 2014 Nice 500mb setup for a high-laditude long-tracker. at the 300hr GFS. The secondary TC attempts to absorb the first system, which fails. Then the lead system is sent back on a westward track while the secondary system cuts off near 40W/35N. Meanwhile a strong TC develops near where Dolly did by 9/13 and suddenly a basin that has been very quiet all season has three well developed systems at the same time. And while we're at it, lets not forget the Gulf of Mexico cane at 384hrs. It's nice to at least get some good model porn for a change. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Share Posted September 2, 2014 at the 300hr GFS. The secondary TC attempts to absorb the first system, which fails. Then the lead system is sent back on a westward track while the secondary system cuts off near 40W/35N. Meanwhile a strong TC develops near where Dolly did by 9/13 and suddenly a basin that has been very quiet all season has three well developed systems at the same time. And while we're at it, lets not forget the Gulf of Mexico cane at 384hrs. It's nice to at least get some good model porn for a change. We are locked in a pattern that favors the E Atl and W Carib/GoM...GFS has been showing three disturbances entering the GoM from the Caribbean after Dolly for more than a few runs. I'm a bit hesitant to go hook, line and sinker with the GFS, but it shows that some interesting things might be down the line. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Share Posted September 2, 2014 GFS and Euro look like they are hinting at this years Humberto for the East Atlantic. track.gif Cyclones are just trying to avoid all the dry air in the Central Atlantic and Eastern Caribbean, it appears. Link to comment Share on other sites More sharing options...
Kory Posted September 2, 2014 Share Posted September 2, 2014 We are locked in a pattern that favors the E Atl and W Carib/GoM...GFS has been showing three disturbances entering the GoM from the Caribbean after Dolly for more than a few runs. I'm a bit hesitant to go hook, line and sinker with the GFS, but it shows that some interesting things might be down the line. Perhaps this is why the GFS is showing a more active period in the Atlantic basin. Link to comment Share on other sites More sharing options...
wxtrackercody Posted September 2, 2014 Share Posted September 2, 2014 Link to comment Share on other sites More sharing options...
Eskimo Joe Posted September 2, 2014 Share Posted September 2, 2014 Care to elaborate on this? I have no idea what I'm looking at. Link to comment Share on other sites More sharing options...
icebreaker5221 Posted September 2, 2014 Share Posted September 2, 2014 Care to elaborate on this? I have no idea what I'm looking at. The red contours are positive VP200 anomalies (suppressed convection), the blue contours are negative VP200 anomalies (enhanced convection), and the VP is Kelvin-filtered to remove features propagating at other phase speeds. So basically there's a strong convectively-suppressed Kelvin wave about to cross the MDR right now (they always move from west to east). TC activity tends to be suppressed along and to the west of the center of the suppressed Kelvin wave, so all else equal, expect +/- 7 days of decreased TC activity in the MDR. Link to comment Share on other sites More sharing options...
billgwx Posted September 2, 2014 Share Posted September 2, 2014 Could we see another homebrew system off the Carolina/Mid Atlantic coasts early to mid next week per 02/12Z Euro? That's total wishcasting on my part this far out in time, but that said, that run of the Euro develops a surface low on the tail end of a frontal system, as a weak upper level low pinches off from the westerlies. The surface low would be in a high shear environment at first, but that shear could relax by the middle of next week as the upper low pinches off. Vaguely reminiscent of TS Danielle in 1992. Now back to reality Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Share Posted September 2, 2014 The red contours are positive VP200 anomalies (suppressed convection), the blue contours are negative VP200 anomalies (enhanced convection), and the VP is Kelvin-filtered to remove features propagating at other phase speeds. So basically there's a strong convectively-suppressed Kelvin wave about to cross the MDR right now (they always move from west to east). TC activity tends to be suppressed along and to the west of the center of the suppressed Kelvin wave, so all else equal, expect +/- 7 days of decreased TC activity in the MDR. Not that the MDR has been very active the last 1000 days. Link to comment Share on other sites More sharing options...
Kory Posted September 2, 2014 Share Posted September 2, 2014 What I make of the models runs is that the best chances for development in the coming days will be the Western Caribbean and Gulf. Link to comment Share on other sites More sharing options...
thewxmann Posted September 2, 2014 Share Posted September 2, 2014 And yet we got a NS out of this in the BOC. Pretty good, I'd say the ATL is still outperforming expectations. Link to comment Share on other sites More sharing options...
Srain Posted September 2, 2014 Share Posted September 2, 2014 As mentioned in post 1300, the pattern across North America as well as the unusually low pressure anomalies across the Western Caribbean and Western Gulf look rather interesting. The CPC Day 8+ Analogs dates are rather intriguing as well. Link to comment Share on other sites More sharing options...
Kory Posted September 2, 2014 Share Posted September 2, 2014 ^^^ September 2002 does come to mind. A slow moving system, such as Isidore, meandered around the Yucatan Peninsula before coming north due to a tough digging down to the Gulf Coast. Sent tremendous amounts of rain into the Gulf Coast. Link to comment Share on other sites More sharing options...
Ground Scouring Posted September 2, 2014 Share Posted September 2, 2014 The main issue is that the W Caribbean/Gulf have generally been hostile over the past few seasons--certainly in this year. The reliable models (ECMWF and its ensembles) show above-average shear over the W Caribbean and the Gulf through the entire forecast period, with a major TUTT remaining stuck in place over the central Atlantic…not a pattern favoring anything of significance, not even a homegrown hurricane. Even without WWBs, the warming of the EPAC and the recent Kelvin wave have made the global atmosphere (including the -SOI) finally start to behave in a Niño fashion, so even as the SAL has become less of a factor, shear has increased greatly in the MDR while remaining high in the W Caribbean/GOM. Link to comment Share on other sites More sharing options...
bluewave Posted September 3, 2014 Share Posted September 3, 2014 Driest 500 mb conditions on record this JJA over the Tropical Atlantic. This was the first time that there was no Cape Verde system declared east of 40W in the Tropical Atlantic by 9-3 since 1997. 10N-20N 0-20N Link to comment Share on other sites More sharing options...
Kory Posted September 3, 2014 Share Posted September 3, 2014 Just looking at some synoptic set up by the 0z Euro, it shows an anomalously deep trough in the Central U.S. digging down into the Gulf Coast States. Now, around this time, the GFS has been hinting at some monsoonal trough development in the Caribbean/Bay of Campeche around the same 7-10 day time frame. Such a deep trough would be able to pull anything out of the Gulf NW and N. But first, we must see if development come to fruition, because monsoonal trough developments are usually very large and slow to occur. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted September 3, 2014 Share Posted September 3, 2014 The red contours are positive VP200 anomalies (suppressed convection), the blue contours are negative VP200 anomalies (enhanced convection), and the VP is Kelvin-filtered to remove features propagating at other phase speeds. So basically there's a strong convectively-suppressed Kelvin wave about to cross the MDR right now (they always move from west to east). TC activity tends to be suppressed along and to the west of the center of the suppressed Kelvin wave, so all else equal, expect +/- 7 days of decreased TC activity in the MDR. Thanks! Link to comment Share on other sites More sharing options...
Kory Posted September 3, 2014 Share Posted September 3, 2014 Driest 500 mb conditions on record this JJA over the Tropical Atlantic. This was the first time that there was no Cape Verde system declared east of 40W in the Tropical Atlantic by 9-3 since 1997. It's obvious that any development will not occur in the MDR. Development will have to happen closer to the Lower 48 and Caribbean where it's more favorable...somewhat. Link to comment Share on other sites More sharing options...
IsentropicLift Posted September 3, 2014 Share Posted September 3, 2014 Two of the 00z GEFS ensemble members had major hurricanes in the Gulf in about 10 days. Several had a Dolly repeat a few days beforehand. Almost all of the individual members had at least heavy convection in that region. Link to comment Share on other sites More sharing options...
Superstorm93 Posted September 3, 2014 Share Posted September 3, 2014 12z ECMWF is pretty quiet over the next week or so. Has some weak systems in the EATL, but they struggle due to dry/stable air. Link to comment Share on other sites More sharing options...
AvantHiatus Posted September 4, 2014 Share Posted September 4, 2014 Long-range 06z GFS was probably the most interesting of the year. Looks like we could be tracking 3 simultaneous systems in the Atlantic. JB hinting at homebrew....interesting times ahead. Joe Bastardi @BigJoeBastardi · 1hForget the African waves cant get to US for 10 days. Innocuous area T storms off Fla on NC coast in 5 days, may be much more important Link to comment Share on other sites More sharing options...
Srain Posted September 4, 2014 Share Posted September 4, 2014 As has been mentioned over the last several days, the ensembles have been suggesting unusually low pressures developing across the Western Caribbean and the Western Gulf in the medium to long range. There is now growing indications that a cckw as well as a favorable MJO pattern moving E across the Pacific that tends to increase rising air in the Tropics allowing for potential enhanced tropical development. It is also noteworthy that a deep trough is expect across the Central United States later next week and that would suggest a stalled frontal boundary across Southern Plains into the Lower Mississippi Valley. It is a bit too soon to expect a strong Fall front to make it this far S in Mid September, but conditions may well develop for enhanced Tropical development from the SW Caribbean Sea into the Gulf of Mexico. It is too soon to know with any certainty exactly how things may develop in the Day 7+ Range, but the ensembles have remained very insistent that a pattern somewhat conducive for Tropical development may increase. Link to comment Share on other sites More sharing options...
Ground Scouring Posted September 4, 2014 Share Posted September 4, 2014 I'd dismiss the GFS out of hand because its forecasts (MJO and otherwise) have been atrocious this season. I would only rely on the ECMWF in the short range for MJO forecasts and in the medium range for TC genesis probabilities. The GFS has been completely wrong in forecasting so many spurious TC genesis events this season, and its MJO forecasts have been equivalent to dog dung. I don't see any reason to change my forecast re: low expectations for a pick-up in activity over the next week (about which, I must add, I have been right thus far). Link to comment Share on other sites More sharing options...
Kory Posted September 4, 2014 Share Posted September 4, 2014 I'd dismiss the GFS out of hand because its forecasts (MJO and otherwise) have been atrocious this season. I would only rely on the ECMWF in the short range for MJO forecasts and in the medium range for TC genesis probabilities. The GFS has been completely wrong in forecasting so many spurious TC genesis events this season, and its MJO forecasts have been equivalent to dog dung. I don't see any reason to change my forecast re: low expectations for a pick-up in activity over the next week (about which, I must add, I have been right thus far). You obviously don't follow the tropics world wide, because then you would see the Euro is not good to lean on for tropical cyclone genesis. Even in the Atlantic, it missed the formation of Dolly in the Bay of Campeche. Of course, it appears the Euro has done a decent job at genesis in the Atlantic, mainly because the Atlantic has has been quiet thus not much TC genesis. It often misses TC genesis, like several hurricanes in the Pacific. I will concede that the GFS doesn't handle the MJO very well. But to solely rely on only one model for TC genesis, especially one that isn't too good on genesis to begin with, is crazy and really hurts your argument. Link to comment Share on other sites More sharing options...
icebreaker5221 Posted September 4, 2014 Share Posted September 4, 2014 Sure 90L isn't the most beautiful easterly wave I've ever seen emerge from Africa, but at least it's maintaining some deep convection, which is a start. The 12Z ECMWF ensemble is perhaps slightly more optimistic with it than the deterministic, although that's not saying much. Let's see if it can survive the passage of that strong convectively-suppressed Kelvin wave first. Link to comment Share on other sites More sharing options...
Srain Posted September 4, 2014 Share Posted September 4, 2014 The 12Z Euro Ensemble mean also suggests lower pressures across the Western Caribbean and the Western Gulf as mentioned in post 1328. Link to comment Share on other sites More sharing options...
mackerel_sky Posted September 5, 2014 Share Posted September 5, 2014 I think the season is just starting! We will be at the "J" storm or deeper into the list by the time the seasons over, so hang on! Link to comment Share on other sites More sharing options...
Superstorm93 Posted September 5, 2014 Share Posted September 5, 2014 Getting back on topic.. There's an upper-level disturbance off the Florida coast that probably needs to be watched in my opinion. Once the front blows through the east coast this weekend and creates more of a temperature gradient (SE coast/Gulf Stream), this disturbance may become more convectively active. Fortunately, this has actually gained some support from the 12z ECMWF, CMC, and past runs of the UKMET. Even the NAM is starting to hint at a surface low developing off of SC. If something were to develop, proximity to land and time would probably be the huge limiting factors... Still, its better than watching a moisture starved low traverse the record stability of the MDR 12z ECMWF 850 vort @ 72 hours (looks better on the hi-res maps in 3-hour increments) Link to comment Share on other sites More sharing options...
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