Atlantic Tropical Action 2011 - Part IV

[Sleetfreak]

I have always preferred the longer tracks, but October sure packs a mean wallop if the conditions are right.

A friend of mine who works with emergency management in Florida says October scares him much more than September; hurricanes can come roaring up from Cuba or east of the Yucatan with much less lead time for evacuation (or media hype to get the public in an evacuation mood). He says his worst nightmare there in Sarasota would be an Opal type hurricane accelerating north-northeast towards Tampa Bay or Sarasota, going from cat-1 to cat-4 overnight, and so many residents who don't believe it can happen there because it hasn't during their lifetime.

[toad strangler]

I am really impressed with mid to long range modeling since what seems like a firm grip post Irene GOM and FL teases. This includes the difficult solutions in regards to Lee. Nate is another tough prospect at the moment. The buzz phrase "windshield wiping" all of the sudden went extinct. Fascinating!

[Srain]

There are indications that the Western Caribbean could become active in the longer range. The GFS (06Z) and the Euro ensembles suggest that area may need to be watched as we move further into the month of September...

[Ed Lizard]

12Z Euro ensembles still on the 0Z Euro ensemble SW Caribbean theme.

[gil888]

18z GFS supports the Caribbean possibility in the 6-10 day timeframe. Pretty big signal in the EC and its ensembles, so I'm hopeful of a decent Caribbean system finally around mid-month. The shear stays so low, we just need a decent wave to make it without trying to move north like the rest of them so far.

[HurricaneJosh]

18z GFS supports the Caribbean possibility in the 6-10 day timeframe. Pretty big signal in the EC and its ensembles, so I'm hopeful of a decent Caribbean system finally around mid-month. The shear stays so low, we just need a decent wave to make it without trying to move north like the rest of them so far.

That would be awesome after all the crap and fail we've been seeing-- a nice, red-meat Caribbean Cruiser. Could you imagine? I almost forgot what it's like to have a megacane with unlimited potential.

[Floydbuster]

That would be awesome after all the crap and fail we've been seeing-- a nice, red-meat Caribbean Cruiser. Could you imagine? I almost forgot what it's like to have a megacane with unlimited potential.

I look forward to a future CHASING RINA thread

[HurricaneJosh]

I look forward to a future CHASING RINA thread

Ha ha ha, thanks. I wouldn't mind that name, actually.

I can't believe that we might get to the W name again, and it might be early enough in the season (say, October) to be a real player. Weird.

[U_Thant]

**ROGUE STORM ALERT**

Both the 00Z GFS and ECM have strong signal of some sort of "rogue storm" developing along the SE seaboard in the day 8-10 range (9/17 - 9/19) as a result of a 500MB cutoff low over SC. The ECM is stronger with this feature because it ingests some low level vorticity coming out of the tropics, part of it from a decapitated Maria (it's much slower than the GFS in turning it northward east of the Bahamas).

[HurricaneJosh]

**ROGUE STORM ALERT**

Both the 00Z GFS and ECM have strong signal of some sort of "rogue storm" developing along the SE seaboard in the day 8-10 range (9/17 - 9/19) as a result of a 500MB cutoff low over SC. The ECM is stronger with this feature because it ingests some low level vorticity coming out of the tropics, part of it from a decapitated Maria (it's much slower than the GFS in turning it northward east of the Bahamas.

I think this is the feature that phlwx just mentioned in the Maria thread-- some kind of hybrid thing hitting OBX around Day 10?

[U_Thant]

I think this is the feature that phlwx just mentioned in the Maria thread-- some kind of hybrid thing hitting OBX around Day 10?

Yup, that be it.

[Ed Lizard]

Isn't "Rogue Storm" a term of the WeatherBoil met who shall not be named?

[U_Thant]

Isn't "Rogue Storm" a term of the WeatherBoil met who shall not be named?

Yup. Hence the

[Ed Lizard]

Only because the thread is slow, GFS at end of the run has a cyclone off New York headed Northwest...

Yes, I know about Hour 384 GFS, but that would save Hurricane Season 2011. So I'm glass 1/2048 optimistic. From the Caribbean, which Euro ensembles have been liking.

[Amped]

Only because the thread is slow, GFS at end of the run has a cyclone off New York headed Northwest...

Yes, I know about Hour 384 GFS, but that would save Hurricane Season 2011. So I'm glass 1/2048 optimistic. From the Caribbean, which Euro ensembles have been liking.

Sept 20-25 looks like an OKAY timeframe for the EC

Cental American coast looks good the first week in October.

[GaWx]

IF the model consensus of bringing down one big sfc high into the NE US and the 12Z GFS in bringing down a 2nd one were to verify, then the teleconnection would be for above avg. activity down below in the W. Caribbean. GOM, and/or off the east CONUS coast. Look at past seasons for proof of this. So, the 2nd half of SEP is liable to be very active in the western basin. Often times in mid to late Sep. and early to mid Oct., it is the strength of the surface highs that come into the NE US that determine how active it gets below them near the CONUS. That is because there foten is a tendency to balance out high pressure to the north with concentrated low pressure below that high pressure due to sfc convergence. JB has talked about this many times. 1947 is a very good example. Look at old surface wx maps from 9-10/1947 and you'll see the big highs over the NE US. Then check out how active it was in those areas below the highs from mid-Sep to mid-Oct.

[Eduardo]

Hard to believe we are on the 'N' storm, but have only had two hurricanes to watch to far. Has anything like this ever been observed since record-keeping began?

[Max]

What's that thing down in the Central Atlantic south of 10N?

[phil882]

[GaWx]

IF the model consensus of bringing down one big sfc high into the NE US and the 12Z GFS in bringing down a 2nd one were to verify, then the teleconnection would be for above avg. activity down below in the W. Caribbean. GOM, and/or off the east CONUS coast. Look at past seasons for proof of this. So, the 2nd half of SEP is liable to be very active in the western basin. Often times in mid to late Sep. and early to mid Oct., it is the strength of the surface highs that come into the NE US that determine how active it gets below them near the CONUS. That is because there foten is a tendency to balance out high pressure to the north with concentrated low pressure below that high pressure due to sfc convergence. JB has talked about this many times. 1947 is a very good example. Look at old surface wx maps from 9-10/1947 and you'll see the big highs over the NE US. Then check out how active it was in those areas below the highs from mid-Sep to mid-Oct.

Folks,

This is a followup to the post I made above prior to the 12Z Euro release. Since then, the 12Z Sat. Euro , 18Z Sat. gfs and 0Z sun. gfs are even more insistent on strong and persistent sfc high pressure over the NE US for the period ~9/17-9/23. When sfc high pressure does this, there is a good bit higher than average potential of a TC existing (either from a homegrown system or from one moving into that area) below it near the SE US/FL/E GOM due to a tendency for sfc pressures to fall and concentrate below persistent big highs aided by sfc convergence. Moreover, big persistent highs like this often act as blocks and normally prevent easy recurves/increase the chance for an existing TC to landfall over the SE US. History/analogs tell me all of this.

Stay tuned, folks. There are ominous signs that tell me that the season is likely going to get a good bit more interesting for the CONUS around the 9/18-24 period for the reason noted. IF the model consensus is close to being correct for 9/17-24, we're looking at about as strong and persistent a sfc high pressure pattern over the NE US as one would expect to see in Sep. I would be surprised to see the CONUS not get hit during or near this period. The 0Z GFS actually shows a 9/23 TC landfall over S FL fwiw (not at all surprising..I think we're going to see more runs like this in the days to come). This would be a totally different pattern from what has been experienced for much of the season to this point.

[gil888]

Decent agreement that the next cyclone will be forming SW of the Cape Verdes in about 5 days. That one is not a threat to anything probably. I've got my eye on the western Caribbean like a lot of other people. The ensembles and occasionally the operational models have been showing a large area of cyclonic flow with light wind shear. Kinda reminds me more of Oct than Sep. Overall that environment is ripe for a TC to form. Also it seems like another Kelvin wave will be in the area in the extended range, which should assist with formations.

Odd year so far. The ultimate quantity not quality one. Hard to even find a good analog at all.

[phil882]

Decent agreement that the next cyclone will be forming SW of the Cape Verdes in about 5 days. That one is not a threat to anything probably. I've got my eye on the western Caribbean like a lot of other people. The ensembles and occasionally the operational models have been showing a large area of cyclonic flow with light wind shear. Kinda reminds me more of Oct than Sep. Overall that environment is ripe for a TC to form. Also it seems like another Kelvin wave will be in the area in the extended range, which should assist with formations.

Odd year so far. The ultimate quantity not quality one. Hard to even find a good analog at all.

Let's try 2007 for an analog. 15 named storms, 2 major hurricanes with a couple of borderline cat 1's thrown in for good measure. That's as close to an analog as you are going to get, and it was a La Nina year as well.

[Amped]

I still think the pattern looks good in the Sept 22-26 timeframe for an East Coast Landfall. The ridging really builds over the Canadian Maratimes after the High Pressure moves offshore. All me need is an actual storm.

[phil882]

Boy those SST anomalies have taken a major hit in the last week.. Sure they will recover, but we are on the September Sun now and things are normally all downhill from here.

[Floydbuster]

Unless something else occurs, 2011 may go without a U.S. Major Hurricane landfall. That would mean 2006, 2007, 2008, 2009, 2010 and 2011 had not a single Category 3, 4 or 5 make U.S. landfall. That's insane.

[k***]

Unless something else occurs, 2011 may go without a U.S. Major Hurricane landfall. That would mean 2006, 2007, 2008, 2009, 2010 and 2011 had not a single Category 3, 4 or 5 make U.S. landfall. That's insane.

we are only at the midpoint of the season...what value do posts like this serve?

[Floydbuster]

we are only at the midpoint of the season...what value do posts like this serve?

Baring some kind of late season impact, I usually use September 18th as a major cut-off in my mind. There have been many exceptions, from Hazel to Hugo to Wilma...but Katrina, Andrew, Charley, Ivan, Great Miami, The '28 storm, all hit no later than September 18th.

[k***]

Baring some kind of late season impact, I usually use September 18th as a major cut-off in my mind. There have been many exceptions, from Hazel to Hugo to Wilma...but Katrina, Andrew, Charley, Ivan, Great Miami, The '28 storm, all hit no later than September 18th.

9/18 is a terrible cutoff, naso. rita, hugo, wilma, opal, hilda, gracie, hazel, king, 1949 #10, 1948 #8 etc etc etc i don't feel like going further back

the point is that your arbitrary cut off date is silly. yesterday was the climatological peak and there is plenty of time for big storms to form.

[phil882]

9/18 is a terrible cutoff, naso. rita, hugo, wilma, opal, hilda, gracie, hazel, king, 1949 #10, 1948 #8 etc etc etc i don't feel like going further back

the point is that your arbitrary cut off date is silly. yesterday was the climatological peak and there is plenty of time for big storms to form.

The one key thing that remains is that we still have a huge reservoir of warm waters in the Caribbean that's still averaging 1-2 degrees Celsius above average at this time. The problem is that we have had a hard time getting waves into the Caribbean due to the orientation of the ridge which has been further east than normal.

Also this might be partially to blame... vertical instability has been way below normal in the Caribbean this year. Basically it hasn't even approached close to normal in quite some time.

[k***]

It's no wonder SST's are anomalously high when instability has been low.