Atlantic Tropical Action 2013

[phil882]

Slightly stronger than average easterlies from 10-20 N throughout much of the month of July have spread slightly cooler waters across much of the basin, particularly the western N Atlantic.  At the same time, anomalous westerlies around 30 N have helped to advect much warmer than average surface waters to the sub-tropical N Atlantic, north of the MDR. 

 

current_anom_850wind.gif

 

 

If we can get a few persistent cutoff lows and/or PV breakoffs from the tails of stalled-out cold fronts, I suspect Aug (and possibly Sep if the pattern persists) will produce a greater than average number of tropical transition genesis events / high-latitude tropical storms a la 2012. 

 

atl_anom.gif

 

Another striking feature in addition to the enhanced easterlies between 10-20N is the enhanced low-level westerlies in the Atlantic basin south between the equator to 10N. This has probably played a factor in aiding the spinup of TCs in the MDR this July providing a broad source of enhanced cyclonic vorticity.

[icebreaker5221]

Another striking feature in addition to the enhanced easterlies between 10-20N is the enhanced low-level westerlies in the Atlantic basin south between the equator to 10N. This has probably played a factor in aiding the spinup of TCs in the MDR this July providing a broad source of enhanced cyclonic vorticity.

 

Good point Phil!  That would definitely generate some shear vorticity.

[Roger Smith]

Hello everyone, just a friendly reminder that the August forecasts and seasonal updates are due by the end of the month, if you're in the contest, don't forget to post in the thread by Thursday 06z to avoid any late penalties. Thanks ...

[TropicalAnalystwx13]

Slightly stronger than average easterlies from 10-20 N throughout much of the month of July have spread slightly cooler waters across much of the basin, particularly the western N Atlantic.  At the same time, anomalous westerlies around 30 N have helped to advect much warmer than average surface waters to the sub-tropical N Atlantic, north of the MDR. 

 

current_anom_850wind.gif

 

 

If we can get a few persistent cutoff lows and/or PV breakoffs from the tails of stalled-out cold fronts, I suspect Aug (and possibly Sep if the pattern persists) will produce a greater than average number of tropical transition genesis events / high-latitude tropical storms a la 2012. 

 

atl_anom.gif

Wouldn't the persistent ridge make surrounding atmospheric pressures too high to allow for development in the subtropics (assuming it remains)? That seems to be it's been so far this season.

[icebreaker5221]

Wouldn't the persistent ridge make surrounding atmospheric pressures too high to allow for development in the subtropics (assuming it remains)? That seems to be it's been so far this season.

 

The synoptic pattern can change very quickly, while the SSTs are slower to respond.  If just a small part of the ridge were to suddenly break down or the ridge were to split in two, this might allow some kind of PV tail or breakoff to sneak in.  Even if the pattern were to change entirely, it would still take a while for those positive anomalies to cool significantly. 

[Roger Smith]

Revised List of Storm Names for Each Year

_____________________________________

 

Atrocious

Bad

Cmon

Develop

Ecch

Fishgyre

Getacirculation

Heyitsacatone

Incredible

Justabout

Kouldthisone

Maybe...not

Namewaster

OMG

Pathetic

Questionable

Rapidshear

Sandy

Terrible

Ugly

Vortmax

Whenwillonespin

Xhumed

Yourekiddingme

ZZZZ

[HurricaneJosh]

Revised List of Storm Names for Each Year

_____________________________________

 

 

 

[Ground Scouring]

Isn't there a weak, low-amplitude CCKW near 135°W (enhanced convection and anomalous 850-mb westerlies) in the EPAC at this time? That could be what the GFS is showing in the MDR by 05 August. This meshes well with the ECMWF projection that the resuscitated, low-amplitude MJO signal will head toward Phase 2 in about one and a half week. This trend might, if I am reading the signs correctly, point to another Cape Verde TC genesis event on or shortly after--i.e., within five days of--05 August. Perhaps HM may feel free to chime in here.

[N. OF PIKE]

Invest 90 off carolina coast

[Superstorm93]

BEGIN
NHC_ATCF
invest_al902013.invest
FSTDA
R
U
040
010
0000
201307271810
NONE
NOTIFY=ATRP
END

 

 

Cute llittle non-tropical low that will be obliterated by 40+ knots of shear

[Ed Lizard]

I could be exactly backwards, but I think GFS briefly takes 90L warm core in the low levels.  Will have warm water for the next day or two.  Clear wind shift in there to its North, but the front doesn't seem to have that sharp a temp/dewpoint gradient.  1/32nd glass full on an STD.  The good kind of STD.

 

[Ed Lizard]

BEGIN

NHC_ATCF

invest_al902013.invest

 

 

 

Cute llittle non-tropical low that will be obliterated by 40+ knots of shear

20130727.1745.goes13.x.vis1km.90LINVEST.25kts-1013mb-335N-739W.100pc.jpg

 

 

The CIMSS analyzed shear isn't bad at all right where it is sitting, and I don't think anyone expects more than a minimal STS, best case.  And another named July system would ruin me in the contest.

[HurricaneJosh]

Just hatin' the tropics right now.

[Amped]

Just hatin' the tropics right now.

 

Agreed nothing, even on the GFS long range. Lots of shear over the Caribbean.

 

Lets hope the core of the season  Aug 15 - Oct 15 can produce. 

[HurricaneJosh]

Agreed nothing, even on the GFS long range. Lots of shear over the Caribbean.

 

Lets hope the core of the season  Aug 15 - Oct 15 can produce. 

 

Yep.  

 

P.S.  I view the core season the same as you-- maybe with an extra 5 days on either side: 10 Aug - 20 Oct, or even 25 Oct.  (It's hard for me to discount late Oct because of Wilma--  the strongest cyclone ever observed in the NATL and a major strike on MX and the USA-- and also events like Tampa Bay 1921 and Hattie 1961.)

[Ed Lizard]

Silver lining watch, maybe an uptick in the East Pac is a sign that things will get better in August.  Less happy, I see a couple of 1008 mb or below systems ever on the 12Z GEFS pertubations, not near each other and almost two full weeks out.   Only ray of hope is the 12Z Euro with what appears to be the tail end of a trough at 500 mb, with a remnant frontal boundary in the area, possibly pinching off over Florida.  I was working for the government  in August 1983 and wasn't aware of it at the time, but I know Steve remembers how the last major hurricane to landfall in the HGX CWA developed. 

 

But yeah, really, nothing obvious on the horizon.  But I always look out for the silver lining.

 

[metalicwx366]

Revised List of Storm Names for Each Year

_____________________________________

Atrocious

Bad

Cmon

Develop

Ecch

Fishgyre

Getacirculation

Heyitsacatone

Incredible

Justabout

Kouldthisone

Maybe...not

Namewaster

OMG

Pathetic

Questionable

Rapidshear

Sandy

Terrible

Ugly

Vortmax

Whenwillonespin

Xhumed

Yourekiddingme

ZZZZ

Lmao you forgot L.

[tmagan]

I am reading some of the public advisories from the NHC for Hurricane Allen in 1980, and the one from 18Z 9 August 1980 had maximum sustained winds of 170 mph when the center was 95 miles ESE of Brownsville, Texas. I knew it was very strong in the NW Caribbean, but I didn't know it was that strong that close to Brownsville.

[HurricaneJosh]

I am reading some of the public advisories from the NHC for Hurricane Allen in 1980, and the one from 18Z 9 August 1980 had maximum sustained winds of 170 mph when the center was 95 miles ESE of Brownsville, Texas. I knew it was very strong in the NW Caribbean, but I didn't know it was that strong that close to Brownsville.

 

Yeah, Allen bombed out and hit Cat 5 three times along its path-- with the final peak happening very close to the TX coast (as you saw).  it's kind of crazy thinking about how dire a situation it was. The cyclone was actually strengthening up until ~24 hr before landfall-- then it really unraveled. Estimated winds at landfall were 100 kt--  and since the center passed a tad N of BRO, they were on the weaker side and really didn't get it too badly at all. Max gust at the airport was 68 kt. Port Mansfield, just N of the landfall point, had 104 kt.

[tmagan]

Yeah, Allen bombed out and hit Cat 5 three times along its path-- with the final peak happening very close to the TX coast (as you saw).  It was actually strengthening up until ~24 hr before landfall-- then it really unraveled.  Estimated winds at landfall were 100 kt--  and since the center passed a tad N of BRO, they were on the weaker side and really didn't get it too badly at all.  Max gust at the airport was 68 kt.  Port Mansfield, just N of the landfall point, had 104 kt.

But when I saw that 170 mph advisory just ESE of Brownsville, I thought of the 130 mph Gloria advisory just to the east of Atlantic City, NJ.

[HurricaneJosh]

But when I saw that 170 mph advisory just ESE of Brownsville, I thought of the 130 mph Gloria advisory just to the east of Atlantic City, NJ.

 

Ha ha ha, totally!!    I remember when that thing was coming up the coast, heading straight for my town, hearing that advisory and just being like, "OMG!!!1! I can't believe something that intense is two hours away!"  Even the 12 noon advisory had the center at Fire Island with winds of 120 mph-- and that's when I knew something wasn't right.  On the North Shore, we were getting destructive winds by that point, but it was no Cat 3.

 

Of course, this was before they knew that a weakening cyclone at higher latitudes doesn't mix the really good sh*t down to the surface.  

[Ed Lizard]

Now that 2 Euro runs in a row try to pinch off a trough near Florida, I am going 1/32nds glass half full that a non-tropical feature will trigger a lemon in the NE Gulf Day 10-12

 

If that doesn't happen, GFS and ensembles suggest an incredibly boring two weeks.

 

[Superstorm93]

MDR is warming up rather quickly where it counts. The ECMWF and its ensembles are showing that the NAO should head towards a rather negative phase, which may induce further warming. This could set the stage for a nice August with a few decent MDR systems. 

 

But as always, we'll see what happens. 

 

[Ground Scouring]

MDR is warming up rather quickly where it counts. The ECMWF and its ensembles are showing that the NAO should head towards a rather negative phase, which may induce further warming. This could set the stage for a nice August with a few decent MDR systems. 

 

But as always, we'll see what happens. 

May you please provide the link (source) to that fantastic chart?

 

The bad news (for the Atlantic) is that the IOD looks to be moving more toward + territory, meaning instability--or lack thereof--could be a problem should rapid warming continue. Does anyone else know whether the current strength of the Antarctic Circumpolar Current favors the trend toward an +IOD in the S Hemisphere?

 

Slow warming trends in the equatorial Pacific (NINO 3, 3.4, and 4), on the other hand, look to favor a strong Bermuda High with an attendant high risk to FL and the C Gulf in August-September.

 

A little OT tease: Ex-Dorian has such an impressive mid-level vortex that it could almost be mistaken for, or imagined to be, a hefty hurricane--just add an eye and a CDO to the mix:

 

[Floydbuster]

Long range models look boring into the middle of August, but who knows that far out.

 

In 2010, 2011 and 2012 we had:

 

57 Named Storms
29 Hurricanes
10 Major Hurricanes

 

Two of the 29 hurricanes made U.S. landfall:

 

Hurricane Irene - Cat 1

Hurricane Isaac - Cat 1

A question for the pro-mets on here...

 

The last few hurricane seasons, things seem generally dull. I know we've had Karl and Igor and Sandy and Irene, but in general, since 2008, the level of convection seems weak outside of the Bay of Campeche and the Southwest Caribbean, waves seem dry as a bone and systems that do form seem to have troubles with tilted circulations and MLCs taking over with fast running away LLCs. My question is, why all the dry instability? I remember tracking hurricanes in the late 90s and early 00s and dealing with alot of wind shear occasionally, but the waves left Africa robust. It can't be something that terrible, after all, the last three Hurricane Seasons had 19 named storms, the same as 1995. But instead of Opal in the Gulf, it's Isaac or Tropical Storm Debby. Instead of Luis in the Central Atlantic, it's a dry-as-a-bone wave that may or may not have a circulation.

[bluewave]

The July 2013 tropical convective pattern looks more like 2006-2012 than 1995-2005.

A very similar pattern of enhanced West African Monsoon activity and suppressed Atlantic

MDR back to the Caribbean. The West PAC into the IO region also continues to

show more convection.

 

 

 

 

 

 

 

[Ed Lizard]

Now that the tropics are dead, I feel a little more free to throw out rampant weenie speculation.

 

3 runs in a row of the Euro moving an inverted trough at 500 mb and a corresponding surface trough (closing off at Day 10?), the remnants of an old front, Westward through the Northern Gulf from Florida Day 9 and 10.

 

 

Edit to add- Euro 200 mb winds (it is what they have for upper winds on PPV AccuWx) go from strongly shearing Easterly to rather light, with even a hint of anticyclonic flow near where the 850 mb vort max is...

[TropicalAnalystwx13]

Not sure if this has been posted anywhere on the forum, but in case it hasn't..

 

Nicknamed “Tide,” the supercomputer in Reston, Va., and its Orlando-based backup named “Gyre,” are operating with 213 teraflops (TF) — up from the 90 TF with the computers that preceded them. This higher processing power allows the National Weather Service to implement an enhanced Hurricane Weather Research and Forecasting (HWRF) model. 

"These forecasting advances can save lives,” said U.S. Sen. Bill Nelson, who helped get funding to add even more capacity to the supercomputer. “It's going to allow for better tracking of life-threatening storms and more accurately predict when and where they'll hit, and with what intensity."

With improved physics and a storm-tracking algorithm, the model has displayed up to a 15 percent improvement in both track and intensity forecasts, compared to last year's version of the model. The upgraded HWRF is also capable of processing real-time data collected from the inner core of a tropical system by the tail Doppler radar attached to NOAA’s P3 hurricane hunter aircraft, data which are expected to produce even greater forecast improvements.

 

See more here: http://www.noaanews.noaa.gov/stories2013/2013029_supercomputers.html

[Superstorm93]

Not sure if this has been posted anywhere on the forum, but in case it hasn't..

 

Nicknamed “Tide,” the supercomputer in Reston, Va., and its Orlando-based backup named “Gyre,” are operating with 213 teraflops (TF) — up from the 90 TF with the computers that preceded them. This higher processing power allows the National Weather Service to implement an enhanced Hurricane Weather Research and Forecasting (HWRF) model. 

"These forecasting advances can save lives,” said U.S. Sen. Bill Nelson, who helped get funding to add even more capacity to the supercomputer. “It's going to allow for better tracking of life-threatening storms and more accurately predict when and where they'll hit, and with what intensity."

With improved physics and a storm-tracking algorithm, the model has displayed up to a 15 percent improvement in both track and intensity forecasts, compared to last year's version of the model. The upgraded HWRF is also capable of processing real-time data collected from the inner core of a tropical system by the tail Doppler radar attached to NOAA’s P3 hurricane hunter aircraft, data which are expected to produce even greater forecast improvements.

 

See more here: http://www.noaanews.noaa.gov/stories2013/2013029_supercomputers.html

 

Interesting read. The FY2013 HWRF has been implemented, so I'm looking forward to it's performance with a red-meat topical cyclone. Also, the link has been in my signature for months  

 

 

The model has been extensively tested with a combination of all

the upgrades listed above for a 3-year sample of cases. The

results showed impressive and remarkable results. For Atlantic

basin track, the HWRF is improved by ~5-15% and now appears

competitive with the GFS. For intensity, the model reduces errors

by ~15%, has demonstrated skill greater than that of the NHC

official forecast and greater than that of the statistical

models. Similar improvements are noted for the Eastern North

Pacific basin as well

http://www.nws.noaa.gov/os/notification/tin13-13hwrf.htm

[TropicalAnalystwx13]

Interesting read, but the FY2013 HWRF has been implemented and the link has been in my signature for months 

 

 

http://www.nws.noaa.gov/os/notification/tin13-13hwrf.htm

Oh, yeah, I've known about it since then as well. Just wanted to post the news story from NOAA released today.

Should be interesting to see how it performs. Maybe we can actually view a run of the model without laughing at it.