2017 Atlantic Hurricane Season

[geoffs]

could CONUS be at threat if a storm forms in the caribeann this october? sorry for asking but I am new to the tropics ???

[Windspeed]

could CONUS be at threat if a storm forms in the caribeann this october? sorry for asking but I am new to the tropics ???

 

Depends on location of development and timing of any dip in the jet stream. In an amplified trough pattern, a cyclone that develops is the Caribbean might lift into a position that could threaten the CONUS. Perhaps it would move into the Gulf of Mexico or phase into Florida.

 

Keep in mind, we're still in September, and we are not yet out of the woods for MDR development. MDR is an acronym for "Main Development Region" east of the Lesser Antilles. A strong western Altantic ridge could threaten the eastern seaboard well into October with this pattern.

 

[CheeselandSkies]

In other news, Lee has risen from the remnant swirl graveyard a la Harvey and is forecast to become a hurricane, although unlikely to be a threat to land.

[NJwx85]

4 hours ago, CheeselandSkies said:

In other news, Lee has risen from the remnant swirl graveyard a la Harvey and is forecast to become a hurricane, although unlikely to be a threat to land.

NHC mentioned the forecast is very uncertain for both track and intensity. Sometimes these microcanes can ramp up or die off very quickly.

[bluewave]

https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/09/22/category-5-hurricanes-have-hit-6-land-areas-dead-on-in-2017-more-than-ever-before/?tid=sm_tw&utm_term=.0516d2209576

Brenden Moses, a researcher at the National Hurricane Center, found that of all Category 5 landfalls on record in the Atlantic since 1851, one-quarter have occurred this season. This is a remarkable statistic.

However, it’s important to remember monitoring of hurricanes was much more difficult before the advent of weather satellites in the late 1960s and storms may have been missed. That said, there is no precedent in the last half century of Category 5 storms striking land so frequently in the same season.

 

[dan11295]

Some of that is just timing and bad luck. Irma returned to Category 5 status just before hitting Cuba, Maria became a Category 5 just before Dominica. Plus to get direct hits on many of the smaller islands requires a rather precise track. 20-30 miles either way, no landfall. A separate issue is the fact that before this year, there were no known Category 5 landfalls in the Caribbean east of Puerto Rico. Only a few other storms are known to have reached that intensity in that general area. (Hugo was the only one at the latitude of the islands, Carol and Isabel were further north). Much easier to get multiple landfalls over small landmasses which don't really disrupt the circulation.

[Windspeed]

Lee may be upgraded to a hurricane in the 5am advisory. It has a tiny core but you can see an eye trying to clear out.

[metagraphica]

Microcane Lee

 

[Amped]

Lee FTW may make major in the next few days.

[Amped]

Now that Lee's a hurricane,  that makes 8 consecutive storms that have reached hurricane status!!! 

[Windspeed]

50 minutes ago, Amped said:

Now that Lee's a hurricane,  that makes 8 consecutive storms that have reached hurricane status!!! 
 

Yep. We're on a role. Lee is such a tiny microcane and it may reach major status before possible restructuring. The visible satellite appearance is striking of a small Category 3. Of note, do not focus as much on Lee's lack of -70° to -80° C cloudtops on colorized IR. Above 30N latitude and in such a synoptic setup, the tropopause -60° to -70° C tops and cloud canopy structure show that Lee's convection is maximizing both convergence at the surface layer and heat potential. This is a tiny but intense vortex.

[Windspeed]

It doesn't look like the Atlantic basin is going to get a lull in tropical acitivity in the medium range. The ECMWF continues to hint at a dip is surface pressures in the Western Caribbean. The GFS also does this while closing off vorticity in several locations. Granted its too far out to be specific, but the trend is there.

[masomenos]

Microcanes must be an awesome sight from a distance. I'm guessing if you were on a ship, you'd be able to see the rotation and towering cloud tops of the storm while basking in sunshine?

[bluewave]

2 hours ago, Amped said:

Now that Lee's a hurricane,  that makes 8 consecutive storms that have reached hurricane status!!! 

New record for the satellite era.

Atlantic has had 8 consecutive named storms reach hurricane strength (Franklin-#Maria) - the most TCs in a row to reach hurricane since 1893pic.twitter.com/WoptBzyNcn

[SnowLover22]

On 8/10/2017 at 10:11 AM, ldub23 said:

99L explodes another Joe Bastardi myth. When the Euro went loopy and showed a cane off the se coast JB started harping about how an august  cool shot means atlantic tropical activity. all we got and we will get was  a  minimal cane in the one  place  in the tropics that  has been the only favorable  place for  years, BOC. Im baffled that NOAA upped their forecast slightly when the atlantic  is so dry and sheared. This also shows just  how  little SST's matter, at least above  normal SST's. They are above  normal over most  of the atlantic tropics yet the tropics are still choked  by  dry air, shear, and sinking  air. An oddball storm can always happen but  i will be stunned if we break the  non major streak that started after wilma struck FLA.

Wow you were so wrong.

[SnowLover22]

On 8/19/2017 at 3:11 PM, ldub23 said:

Wasnt  much of a  burst and Harvey dissipated as  i expected. Looks  like thru mid sept at least  it will be rather quiet.

I'm sorry it's just so tempting. Btw, last one.

[Windspeed]

Maria and Lee..

[Amped]

Lee was the first storm I've seen this season that global models totally missed 2 days out. Except for the CMC of course.   This is almost surely due to it's small size.

[Windspeed]

Thanks to Lee intensifying, combined with Maria, ACE jumped to 181.9 yesterday. Climatological mean is 74.8 through Sept. 24th.

[bluewave]

Yet another another first for the satellite era is this remarkable hurricane season.

September 2017 has generated the most major hurricane days (17.5) of any calendar month in the Atlantic on record. #Irma #Maria #Josepic.twitter.com/V3Cuft1Kb9

 

[Chinook]

Atlantic ACE is now what the NW Pacific seasonal ACE should be at this point.

credit: Ryan Maue's *new* ACE web page (not on Weatherbell's web site anymore.)

[Amped]

Looks like there is some pretty strong shear in the area from Cape Verde to the islands for about the next 10 days.   Watch the BOC and the Western Caribbean though.  

[wxmx]

26 minutes ago, Amped said:

Looks like there is some pretty strong shear in the area from Cape Verde to the islands for about the next 10 days.   Watch the BOC and the Western Caribbean though.  

Yes, those are the two areas to watch by the end of the first week of October. It looks like a monsoon gyre in the progs, with a big western trough and upstream ridging for 2/3 of the CONUS. Looks like a hot October start for most of the CONUS east of the Rockies and wet in MX, FL and W GoM.

[bluewave]

A new extreme between September inactivity and activity over the last 5 years.

 

The Atlantic has generated 35 hurricane days this September - the most in Atlantic calendar month on record. #Lee #Maria #Jose #Katia #Irmapic.twitter.com/zmXugVunXg

The Atlantic has now generated more Accum. Cyclone Energy in September 2017 than in any other calendar month on record. #Maria #Jose #Irmapic.twitter.com/Fyjf7Ui4dU

September 2017 has generated the most major hurricane days (17.5) of any calendar month in the Atlantic on record. #Irma #Maria #Josepic.twitter.com/V3Cuft1Kb9

And quite a contrast from past 4 Septembers (2013-2016) - which combined for the least 4-yr combined September ACE since 1911-1914.

7:52 AM - 25 Sep 2017

[NJwx85]

Lee is probably on the brink of becoming a major hurricane at this point. ADT estimates remain around 97kts. The IR appearance continues to improve and shear is forecasted to remain low through at least the next 36-48 hours. 

[SnoSki14]

1 hour ago, bluewave said:

A new extreme between September inactivity and activity over the last 5 years.

 

The Atlantic has generated 35 hurricane days this September - the most in Atlantic calendar month on record. #Lee #Maria #Jose #Katia #Irmapic.twitter.com/zmXugVunXg

The Atlantic has now generated more Accum. Cyclone Energy in September 2017 than in any other calendar month on record. #Maria #Jose #Irmapic.twitter.com/Fyjf7Ui4dU

September 2017 has generated the most major hurricane days (17.5) of any calendar month in the Atlantic on record. #Irma #Maria #Josepic.twitter.com/V3Cuft1Kb9

And quite a contrast from past 4 Septembers (2013-2016) - which combined for the least 4-yr combined September ACE since 1911-1914.

7:52 AM - 25 Sep 2017

That's incredible, the extremes just keep getting greater and greater. If the La Nina plays out into next season, then could 2018 be even worse.

In many ways 2017 is like 2004 ACE wise and we know what followed after. 

[NJwx85]

Lee is now forecasted to become a major hurricane tomorrow. NHC noted that the track has been shifted West in accordance with the latest ECMWF runs.

[Amped]

Most global models have a weak system developing over Florida and moving west across the gulf this week. 18z GFS has a 1010mb low hitting south TX day 7. You never really know if it will blow up on future runs the way this years going.

[NJwx85]

ADT estimates on Lee are up to ~100kts with final T#'s, ADJ T's & Raw T#'s all at 5.3.

Despite the estimates, Lee's overall IR appearance has deteriorated a bit the last few hours, it looks like some dry air may have wrapped into the circulation.

[Drz1111]

Lee is super interesting.  It appears to fit the satellite requirements to be classified as annular (no bands outside of CDO, eye very wide relative to width of CDO), but it's also tiny, verging on midget-sized.  I've never seen (nor did I know possible) to there to be a midget annular cyclone, but Lee's it.  That's what dryish air and marginal SSTs can do.