Atlantic Tropical Action 2013 - Part 2

[AutoPenalti]

97L is getting better organized...at least it has convection over the area with the highest low level vorticity and is under a somewhat favorable upper level regime. Mid level vorticity is well displaced to the east still, so I wouldn't expect any sudden strengthening just yet. Next step would be a solid CDO which would rebuild/drag the mid level energy to stack it on top of the low level energy.

Slow and steady T, slow and steady.

[wxsmwhrms]

The 12Z GFS has come in much more developed with the 97L system.  Gets a low down to sub-1000 mb before making landfall near AQQ in 108 hours.

[GaWx]

 The 12Z Tue GFS is certainly an interesting run for the NE GOM with the most robust landfall yet, a 1007 mb symmetrical tropical surface low (it looks like a tropical storm to me) hitting the FL Big Bend Sat. night 10/5-6. Afterward, it stays pretty intact and leads to some strong winds and significant to very heavy/flooding rains in N FL, SE GA, E Carolinas, and E VA 10/6-7. Heaviest rains: ~10" Tallahassee Apalachicola area!

 

 Is this still another false alarm from the GFS? It already did that (TS hits on the US Gulf coast) in  Sep. and Aug. for two different Caribbean invests that ended up never even becoming a TD. What's different about this one is that the system does look more impressive now and the GFS has actually brought it back for a good number of runs now after having dropped it for a couple of days.

 

 As modeled, this would certainly be a significant/interesting weather maker for parts of the SE US. Moreover, there's no way to know whether or not it is actually being underdone, especially considering we're dealing with something over the very warm western Caribbean (~29C/84 F). This is a classic track for early to mid Oct. So, it is quite believable climowise. Maybe we finally have something exciting to watch for the US.

 

 

 

Edit: wxsmwhrms, I see ~1007 mb for the lowest pressure on the 12Z GFS and this is at landfall. It does look rather impressive and well organized though I don't see sub 1,000 mb pressures being modeled. Do you have access to a higher resolution run??

[Superstorm93]

97L doesn't look half bad. Seems to be organizing under the relatively light shear and warm SST's. There is quite a bit of dry air to its west, so I doubt that this will be in any hurry to wind up. Overall, it should be able to develop into a moderate tropical storm before interacting with the large system that will be located over the Central Plains this weekend. 

 

 

[IsentropicLift]

The 12Z GFS has come in much more developed with the 97L system.  Gets a low down to sub-1000 mb before making landfall near AQQ in 108 hours.

Yeah then runs it up the east coast along the stalled out frontal boundry bringing an enhanced rainfall threat.

[wxsmwhrms]

 The 12Z Tue GFS is certainly an interesting run for the NE GOM with the most robust landfall yet, a 1007 mb symmetrical tropical surface low (it looks like a tropical storm to me) hitting the FL Big Bend Sat. night 10/5-6. Afterward, it stays pretty intact and leads to some strong winds and significant rains in N FL, SE GA, E Carolinas, and E VA 10/6-7.

 

 Is this still another false alarm from the GFS? It already did that (TS hits on the US Gulf coast) in  Sep. and Aug. for two different Caribbean invests that ended up never even becoming a TD. What's different about this one is that the system does look more impressive now and the GFS has actually brought it back for a good number of runs now after having dropped it for a couple of days.

 

 As modeled, this would certainly be a significant/interesting weather maker for parts of the SE US. Moreover, there's no way to know whether or not it is actually being underdone, especially considering we're dealing with something over the very warm western Caribbean (~29C/84 F). This is a classic track for early to mid Oct. So, it is quite believable climowise. Maybe we finally have something exciting to watch for the US.

 

Edit: wxsmwhrms, I see ~1007 mb for the lowest pressure on the 12Z GFS and this is at landfall. It does look rather impressive and well organized though I don't see sub 1,000 mb pressures being modeled. Do you have access to a higher resolution run??

 

I am looking at it on weatherbell. Bottoms out at 999 mb at 84 hours, 1001 mb at landfall at 108 hours over AQQ.

 

Interestingly, Canadian is still very weak and farther west.

[jconsor]

Hi Larry,

 

The UKMET also trended toward a more favorable upper pattern and is significantly stronger w/ 97L than the prior run (and the past several runs have gradually showed a trend of increasing organization).  

 

If the upper trough over the western Gulf (not the big amplified trough over the Plains, but a narrow TUTT-like trough) can hold back a little more like the latest GFS and UKMET are showing, that would allow the upper flow near 97L to back to SSE vs. SSW, which would make a big difference in enhancing diffluence.  This could be a case where the diffluence counteracts moderate shear and allows 97L to intensify.

 

Here's the site for high-res GFS:  http://www.tropicaltidbits.com/analysis/models/gfsfull/

 

Here's a look at the system at peak intensity on GFS in the ne GOM:

 

 

 

 

 The 12Z Tue GFS is certainly an interesting run for the NE GOM with the most robust landfall yet, a 1007 mb symmetrical tropical surface low (it looks like a tropical storm to me) hitting the FL Big Bend Sat. night 10/5-6. Afterward, it stays pretty intact and leads to some strong winds and significant rains in N FL, SE GA, E Carolinas, and E VA 10/6-7.

 

 Is this still another false alarm from the GFS? It already did that (TS hits on the US Gulf coast) in  Sep. and Aug. for two different Caribbean invests that ended up never even becoming a TD. What's different about this one is that the system does look more impressive now and the GFS has actually brought it back for a good number of runs now after having dropped it for a couple of days.

 

 As modeled, this would certainly be a significant/interesting weather maker for parts of the SE US. However, there's no way to know whether or not it is actually being underdone, especially considering we're dealing with something over the very warm western Caribbean (~29C/84 F). This is a classic track for early to mid Oct. So, it is quite believable climowise. Maybe we finally have something exciting to watch for the US.

 

Edit: wxsmwhrms, I see ~1007 mb for the lowest pressure on the 12Z GFS and this is at landfall. It does look rather impressive and well organized though I don't see sub 1,000 mb pressures being modeled. Do you have access to a higher resolution run??

[Ed Lizard]

Just because it is wrong is no reason not to post it.

 

 

[Derecho!]

 

 

Interestingly, Canadian is still very weak and farther west.

 

 If so, then I'm going with a Cat 3 into Tampa.

 

Unfortunate the Canadian government never shuts down and the CMC still gets run.

[SunnyFL]

 If so, then I'm going with a Cat 3 into Tampa.

 

Unfortunate the Canadian government never shuts down and the CMC still gets run.

Not even funny. 

[Ed Lizard]

TCPOD for tomorrow mentioned only USAFR assets, and the following day also didn't mention a G-IV high altitude data mission.

 

 

Is this because this isn't expected to be a significant storm, or are NOAA flight ops restricted during the shut down?

[GaWx]

Hi Larry,

 

The UKMET also trended toward a more favorable upper pattern and is significantly stronger w/ 97L than the prior run (and the past several runs have gradually showed a trend of increasing organization).  

 

Do you happen to recall if the UKMET has been this strong with a Caribbean invest/gulf system since August?

[jconsor]

It was much stronger with 95L and Ingrid than this run is with 97L.  (It ended up overdoing 95L significantly in the nw/n-central Gulf).  However, IMHO the run-to-run trend is more important than how strong this run is vs. other systems.

 

Do you happen to recall if the UKMET has been this strong with a Caribbean invest/gulf system since August?

[bluewave]

The 12z Euro tries to close off a center before coming ashore in LA. It's an asymmetric storm with

most of the rain east of the low and dry air to the west.

[GaWx]

 The 12Z Euro remains much further west than the 12Z GFS (~350 miles) and strung out/much less interesting, similar to recent Euro runs. Fwiw, keep in mind that the Euro did much better than the GFS for two invests during Aug.-Sep. that were in the western Caribbean that never even became TDs. The Euro had stayed weak while the GFS had predicted a US Gulf coast TS hit on multiple runs. Will this be different? We are now much later in the season.

[Marion_NC_WX]

 The 12Z Euro remains much further west than the 12Z GFS (~350 miles) and strung out/much less interesting, similar to recent Euro runs. Fwiw, keep in mind that the Euro did much better than the GFS for two invests during Aug.-Sep. that were in the western Caribbean that never even became TDs. The Euro had stayed weak while the GFS had predicted a US Gulf coast TS hit on multiple runs. Will this be different? We are now much later in the season.

 

 

If the GFS continues its trend of slowing down the mid-latitude trough, we may get a track in between the current GFS and Euro. I think regardless, we could end up with something asymmetric coming northward.

[phil882]

The 12z Euro tries to close off a center before coming ashore in LA. It's an asymmetric storm with

most of the rain east of the low and dry air to the west.

 

This 12z ECMWF doesn't make clear sense... either the low-level vortex will be much closer to the mid-level vortex or the mid-level vortex won't exist. The recent ECMWF solution reminds me of a previous system it poorly handled in 2012 (Debby) in which is showed this incoherent vortex displacement which didn't exist in reality. 

 

The 12z GFS solution is more likely than the 12z ECMWF at this juncture, showing a moderately strong but sheared TC in the E GoM. 

[Ed Lizard]

12Z FIM-9 gets 97L up to a minimal tropical storm, before weakening it slightly back to probably just a tropical depression with landfall near Grand Isle/Port Fourchon.

 

Doesn't look like winds much over 30 knots ever experienced on land, but I'd think there could be TS Watches up for Louisiana and maybe Mississippi later Thursday evening if the FIM-9 verifies.  Also cool, at landfall FIM 6 hour precip says absolutely no rain over or to the West of the center.  All precip is East of the closed 1008 mb isobar. 

 

Yeah, 1008 isn't exciting.  I know...

[Roger Smith]

Just a rather late reminder to contest entrants that an October forecast is due (also Nov-Dec) and it's worth 20% of the monthly portion although you are now down about 15% of that (in other words 3%) due to late penalty. Sorry I failed to remember to drop by and remind people in a more timely way, I've been in my own personal vortex of doom for several weeks.

 

On a totally different note, don't forget the energy peak of Oct 20-23 ... what will it bring? Inquiring minds want to know.

[Lindsaywx]

Where can I find the early tropical cycle guidance

[wxmeddler]

Where can I find the early tropical cycle guidance

 

http://www.ral.ucar.edu/guidance/realtime/current/

[DopplerWx]

can i just get a cat 1 at least, something...anything...

 

EDIT: well looks like early cycle intensity has 97l getting to a moderate trop storm before landfall near the panhandle)

[DopplerWx]

gfs at 90 hr has a nice little ts making landfall in the eastern panhandle moving ne.  strongest the gfs has had it.

[hurricaneman]

The tropical wave WSW of the Cape Verde islands looks quite good, but the 0zGFS doesnt develop it until int he caribbean and has it east of Belize as a tropical storm at the end of the run, while its very unlikely to happen as modeled now it may need to be watched as it transverses the Atlantic.

 

as a side note the 6zGFS this morning had this feature becoming a significant hurricane in the Gulf moving out of the Caribbean but as with any long range model it needs to be taken with a grain of salt and until it shows a similar development closer to like 120hrs I'm not buying it

[bluewave]

This 12z ECMWF doesn't make clear sense... either the low-level vortex will be much closer to the mid-level vortex or the mid-level vortex won't exist. The recent ECMWF solution reminds me of a previous system it poorly handled in 2012 (Debby) in which is showed this incoherent vortex displacement which didn't exist in reality. 

 

The 12z GFS solution is more likely than the 12z ECMWF at this juncture, showing a moderately strong but sheared TC in the E GoM. 

 

They are both giving the same signal in their own way of an asymmetric system with most of the convection to

the east of the center. All the dry air wrapping in from the west looks like the brake on strengthening beyond

TD or TS status before landfall.

 

 

 

 

 

[Marion_NC_WX]

After several runs of a stronger system the 6z GFS went back to a weaker and strung out feature in the Gulf...that's been a trend on the models all hurricane season (and its been accurate) to spin up something significant Day 5 only to immediately lose it again inside of Day 4.

[GaWx]

After several runs of a stronger system the 6z GFS went back to a weaker and strung out feature in the Gulf...that's been a trend on the models all hurricane season (and its been accurate) to spin up something significant Day 5 only to immediately lose it again inside of Day 4.

Absolutely with regard to the gfs. Actually, the Euro hasn't really done this as it has hardly developed anything in the gulf that ended up not developing. I've been alluding to all of this. However, unlike the last two instances of an invest in the western Caribbean being way overdone in the Gulf by the gfs, this one appears to me to quite possibly already be developing into a TD. It seems like it may already have a rather concentrated and defined LLC there unlike the previous two. On satellite photos, it looks more impressive to me. Also, after having had 97L as a TS hitting the US gulf coast several runs a number of days ago, the gfs has since brought it back with several more runs hitting as a TS. Furthermore, we're now into the seasonal climo peak for western Caribbean disturbances that develop into TC's. For these reasons, I'm giving this one a decent shot. By the way, the TWO is now up to 40%/50% from 30%/50% at 2 AM.

Edit: I see Phil is currently here and he's been following 97L. I'd love to read his updated take on this if he's interested in giving it.

[Mike.Ventrice]

We are about two to three days after 97L was superimposed with an eastward propagating CCKW. Genesis typically is lagged from the day the active CCKW is over the system about 2 days. I'm favoring this system to spin up soon.

 

[GaWx]

From the words of "57", a well-respected and often conservative and nonhyping tropical met., just half hour ago: "Looks more impressive than Jerry, to me. Circulation is developing. Convection more circular and more depression-like looking. I think it'll make a weak TS by tomorrow. Sheared, weak TS making landfall near western FL panhandle Saturday afternoon. No TS winds over land, just over water. Rainfall will be main threat. Not much for FL Peninsula."

So, this is definitely getting more interesting. I think the LLC is near 17.9N and 85.3W. Any other opinions about the LLC location?

[DopplerWx]

yeah I can see it developing into a weak ts but it will be ugly and sheared.  best we can hope for at this point I guess.