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Atlantic Tropical Action 2011 - Part III


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I don't trust that map at all... last year everyone was going crazy over something similar and look what happened

We had a big number season and some good Mexico hits on video.

I doubt we get a big number season two years in a row, especially the look of that EuroSip, and Florida doesn't get something.

And a near miss, well, a not that near of a miss on SNE and an awesome local thread houseparty from Chatham.

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I don't trust that map at all... last year everyone was going crazy over something similar and look what happened

lol wut. The ECMWF seasonal and EUROSIP have been pretty dead on over the past 5 years or so. Look at the archived forecasts and compare with the seasonal activity.

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The lack of development so far this month is a bit perplexing to me, especially given the SSTAs. I know SSTAs aren't everything, but climatologically, warm SSTAs + neutral ENSO + favorable MJO = winning combination for July activity. Maybe the sample size is just too small to establish such rules, but in this case it at least supposedly makes sense.

Is it possible that ENSO is still a bit too La Niña-ish to promote the strong MJO waves needed to boost early activity? The May-June MEI was at -0.225, and the June-July MEI will probably be even lower.

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The lack of development so far this month is a bit perplexing to me, especially given the SSTAs. I know SSTAs aren't everything, but climatologically, warm SSTAs + neutral ENSO + favorable MJO = winning combination for July activity. Maybe the sample size is just too small to establish such rules, but in this case it at least supposedly makes sense.

Is it possible that ENSO is still a bit too La Niña-ish to promote the strong MJO waves needed to boost early activity? The May-June MEI was at -0.225, and the June-July MEI will probably be even lower.

Supercane,

With the first 15 days of July being about the climatologically least active of the entire cane

season (average well under half a storm) other than late Nov., I wouldn't ever see any significance with regard to the lack of development then. It is almost meaningless and has little bearing on ASO

imho. Things just don't "like to happen" then in the Atlantic basin no matter the ENSO although La Nina's may have a small edge.

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The lack of development so far this month is a bit perplexing to me, especially given the SSTAs. I know SSTAs aren't everything, but climatologically, warm SSTAs + neutral ENSO + favorable MJO = winning combination for July activity. Maybe the sample size is just too small to establish such rules, but in this case it at least supposedly makes sense.

Is it possible that ENSO is still a bit too La Niña-ish to promote the strong MJO waves needed to boost early activity? The May-June MEI was at -0.225, and the June-July MEI will probably be even lower.

The only legitimate MJO response since June 1st was late June into early July which prompted the environment for potential Arlene. The MJO hardly climbed out of the middle of the octant graph because the h85 winds and h2 winds were marginal while the OLR response was lame. As I expressed a month ago with the long range storm call: after potential Arlene (which verified in the forecast window), it may not be until late July before we get something again. Notice a well-defined convergent wave has developed and will have to propagate through. Harmonics of the MJO pattern will deliver the goods by the end of the month into August.

So I wouldn't call the MJO favorable by any means. However, next month it is predicted to be highly favorable. In combination with the extremely low shear, high TNA and climo ramp-up, it could potentially be an amazing August. Anyone know what the record amount of named storms for August is?

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Supercane,

With the first 15 days of July being about the climatologically least active of the entire cane

season (average well under half a storm) other than late Nov., I wouldn't ever see any significance with regard to the lack of development then. It is almost meaningless and has little bearing on ASO

imho. Things just don't "like to happen" then in the Atlantic basin no matter the ENSO although La Nina's may have a small edge.

Well, it looks unlikely that we'll see any development in the next 5 days, so that should bring us through 2/3 of the month with no development. Moreover, the busiest Julys in the Atlantic featured plenty of activity by the 20th -- 1966 (2/2/0), 1995 (2/0/0), 1996 (1/1/1), 2003 (2/2/0), 2005 (3/3/2), and 2008 (3/1/1). Given SSTAs warmer than several of those years plus what I had assumed was an ENSO conducive for strong MJO activity, logic would seem to have been on the side of a busy July. Unless we see an explosion in the last 10 days, that probably won't happen. Hence why I'm wondering about the cool-bias ENSO and its impact on the MJO -- La Niñas tend to correlate to reduced early season activity.

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The only legitimate MJO response since June 1st was late June into early July which prompted the environment for potential Arlene. The MJO hardly climbed out of the middle of the octant graph because the h85 winds and h2 winds were marginal while the OLR response was lame. As I expressed a month ago with the long range storm call: after potential Arlene (which verified in the forecast window), it may not be until late July before we get something again. Notice a well-defined convergent wave has developed and will have to propagate through. Harmonics of the MJO pattern will deliver the goods by the end of the month into August.

So I wouldn't call the MJO favorable by any means. However, next month it is predicted to be highly favorable. In combination with the extremely low shear, high TNA and climo ramp-up, it could potentially be an amazing August. Anyone know what the record amount of named storms for August is?

Yeah, it's clear now the MJO has not been so favorable, even though I thought it would be just based on a neutral ENSO. So do you think the cooler ENSO helps explain this lack of activity, or is it more something else?

Also, to answer the last question, the record is 8 named storms in August 2004.

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Well, it looks unlikely that we'll see any development in the next 5 days, so that should bring us through 2/3 of the month with no development. Moreover, the busiest Julys in the Atlantic featured plenty of activity by the 20th -- 1966 (2/2/0), 1995 (2/0/0), 1996 (1/1/1), 2003 (2/2/0), 2005 (3/3/2), and 2008 (3/1/1). Given SSTAs warmer than several of those years plus what I had assumed was an ENSO conducive for strong MJO activity, logic would seem to have been on the side of a busy July. Unless we see an explosion in the last 10 days, that probably won't happen. Hence why I'm wondering about the cool-bias ENSO and its impact on the MJO -- La Niñas tend to correlate to reduced early season activity.

1) OTOH, 2010 had nothing form in July until 7/22. (Alex was a June formation.) 2007 and 2004 had none form in July until 7/31. 2001, 2000, 1998, 1954, and 1953 had none in the entire month of July. 1969 had none in July until 7/25. July 1936 had none until 7/26. All of these seasons had at least 14 storms. Yes, 1933 had one form in July by 7/20 (and three for the entire month) and 1916 had two form in July by 7/20. 7/1887 had one form on 7/20. So, regarding seasons with 14+ storms, only 2008, 2005, 2003, 1995, 1933, 1916, and 1887 (seven seasons) had at least one form in July by 7/20. In contrast, ten seasons had no July formation by the 20th.

2) I am aware that La Nina's have averaged below the longterm avg. for June. However, the reverse was true for July during the period 1950-2008 (the period for which I had earlier done an analysis). **El Nino v. La Nina (1950-2008): # NS mo. by mo.

Month..............El Nino..................La Nina

May/Jun............1.1........................0.5

Jul....................0.6........................0.9

Aug..................2.3........................3.2

Sep..................3.4........................4.3

Oct...................1.3........................2.0

Nov..................0.3........................0.4

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1) OTOH, 2010 had nothing form in July until 7/22. (Alex was a June formation.) 2007 and 2004 had none form in July until 7/31. 2001, 2000, 1998, 1954, and 1953 had none in the entire month of July. 1969 had none in July until 7/25. July 1936 had none until 7/26. 7/1887 had none until 7/20. All of these seasons had at least 14 storms. Yes, 1933 had one form in July by 7/20 (and three for the entire month) and 1916 had two form in July by 7/20. So, regarding seasons with 14+ storms, only 2008, 2005, 2003, 1995, 1933, and 1916 (six seasons) had at least one form in July by 7/20. In contrast, eleven seasons had no July formation by the 20th.

2) I am aware that La Nina's have averaged below the longterm avg. for June. However, the reverse was true for July during the period 1950-2008 (the period for which I had earlier done an analysis). **El Nino v. La Nina (1950-2008): # NS mo. by mo.

Month..............El Nino..................La Nina

May/Jun............1.1........................0.5

Jul....................0.6........................0.9

Aug..................2.3........................3.2

Sep..................3.4........................4.3

Oct...................1.3........................2.0

Nov..................0.3........................0.4

1) Right, but I'm talking about July specifically, not making any broader point about the season as a whole. I fully expect a busy peak regardless of what happens in July.

2) Compared to an El Niño, sure. I don't have hard stats on hand, but I'm almost certain neutral ENSO averages more July activity than La Niña. In fact, of the years that had 3+ July named storms -- 1966, 1995, 1997, 2005, 2008 -- the lowest June-July MEI was -0.131, in 1966.

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The only legitimate MJO response since June 1st was late June into early July which prompted the environment for potential Arlene. The MJO hardly climbed out of the middle of the octant graph because the h85 winds and h2 winds were marginal while the OLR response was lame. As I expressed a month ago with the long range storm call: after potential Arlene (which verified in the forecast window), it may not be until late July before we get something again. Notice a well-defined convergent wave has developed and will have to propagate through. Harmonics of the MJO pattern will deliver the goods by the end of the month into August.

So I wouldn't call the MJO favorable by any means. However, next month it is predicted to be highly favorable. In combination with the extremely low shear, high TNA and climo ramp-up, it could potentially be an amazing August. Anyone know what the record amount of named storms for August is?

I was waiting for your hurricane season forecast.

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Well, as I've stated before...I'm guessing that our second storm, Bret, may be our first hurricane and our first August storm. Hell, it could even be our first major hurricane in August.

This off time does give us a chance to reflect on hurricane seasons. I remember following along until I began tracking them as I do today with Hurricane Debby in August 2000. I didn't start following storms online until around 2001/2002, and then began doing the hurricane coverage for IPR in 2004. Little did I know the amazing storms that would show up in 2004 and 2005.

In a way, 2004 and 2005 were the ultimate. 2006 and 2009 were complete snores except Hurricane John and Hurricane Lane in the East Pacific in 2006, along with some massive typhoons including Ioke, and 2009 had Hurricane Jimena and Hurricane Rick's record shattering intensities.

2007 and 2008 were interesting seasons. Dean and Felix really were astounding storms. 175 mph/906 mb landfall, and then two weeks later another 160 mph Category 5 landfall. I was told by NHC Forecaster Dr. Jack Beven back in 2008 that Hurricane Felix was very anomalous to Hurricane Andrew in 1992, and looking at satellite and data from recon, that's absolutely correct. 2008 was a blast. July had major long-tracked Bertha to keep us busy, nasty little Dolly, then August had crazy Fay and intense Gustav, Hanna could have easily been a monster up the East Coast, and Ike was at one time looking like the next Hurricane Andrew, but ended up leaving it's mark on Texas. Don't forecast our Cat 4 Omar in October and Cat 4 Paloma in November.

2010 was not as exciting considering the number of storms. Alex gave us some early June entertainment and could have been alot worse. If those winds would have responded to the 946 mb pressure, Hurricane Alex could have been a Category 4 hurricane...even worse...it could've coiled up next to South Texas. Hurricane Earl was strange because the models had a consistent northward bias, and yet here we had a strengthening 145 mph Ca 4 storm moving northwest towards the Carolinas...and it was kind of timid. Of course, had Earl gone over Hatteras, it would've been a different story. Gaston could have been a monster and it's dissapation surprised me. Hermine could have done the same but didn't have time. Karl was nasty but forgotten, especially since it avoided retirement. Richard and Paula couldn't get above Cat 2, and thankfully Hurricane Tomas was not the disaster it could've been. (I think we all began to envision a Mitch-like November storm named Tomas baring down on Haiti)

Overall, 2004 and 2005 take the cake. Katrina holds 1st place.

The storms forecast to be Cat 4 or Cat 5 U.S. landfalls the last 10 years:

- Lili

- Isabel (one time forecast to strike NC at 115 kt)

- Frances

- Ivan

- Dennis

- Katrina

- Rita

- Gustav

- Ike (one time forecast to strike FL at 115 kt)

The storms that made landfall at that strength:

- Charley

The biggies are rare, but they do come. I'll leave you with this as some food for thought and some Hurricane porn for Josh.

slp21.png

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A weak sfc low pressure appears to have formed offshore the N FL and GA coasts by ~100 miles and is nearly stationary with solid convection in a pretty tight area. This is the area to monitor just in case. It does appear that it MAY be slowly trying to organize. However, there seems to be NW shear with which to contend. Regardless, if this were to hold together, it could become Invest-worthy. Looking at qpf, the models seem to be severely underestimating the rainfall underneath the convection. There may be a problem getting a good handle on this because of its small size. It does appear that whatever forms from this will move westward to near the FL pen. on Monday. Will it still just be a very weak low by then or will it be more substantial?

Edit: There appears to be a good bit of NW shear, which would need to be overcome in order to allow more than only a fairly small level of development. I think the first vis. will show a somewhat sheared mess with most of convection to the E and SE of the LLC. Regardless, there does appear to be a somewhat decently defined LLC that even the 6z NAM doesn't seem to be modeling too well. Just compare the 6z NAM's sim. radar for hour six, which is real messy looking, and the more organized looking actual radar from Jax.

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A weak sfc low pressure appears to have formed offshore the N FL and GA coasts by ~100 miles and is nearly stationary with solid convection in a pretty tight area. This is the area to monitor just in case. It does appear that it MAY be slowly trying to organize. However, there seems to be NW shear with which to contend. Regardless, if this were to hold together, it could become Invest-worthy. Looking at qpf, the models seem to be severely underestimating the rainfall underneath the convection. There may be a problem getting a good handle on this because of its small size. It does appear that whatever forms from this will move westward to near the FL pen. on Monday. Will it still just be a very weak low by then or will it be more substantial?

Edit: There appears to be a good bit of NW shear, which would need to be overcome in order to allow more than only a fairly small level of development. I think the first vis. will show a somewhat sheared mess with most of convection to the E and SE of the LLC. Regardless, there does appear to be a somewhat decently defined LLC that even the 6z NAM doesn't seem to be modeling too well. Just compare the 6z NAM's sim. radar, which is real messy looking, and the more organized looking actual radar from Jax.

Certainly an interesting little feature this morning... won't be surprised if it gets lemonized at some point today. It does look like we have a circulation at around 14,000 feet based on radar that actually looks pretty well organized. There is a small window for this system to organize over the next 24-36 hours, as a weak anticyclone with plenty of divergence develops over the circulation as it drifts southward. However, beyond 36 hours the upper level anticyclone intensifies over the Eastern US, and northerly shear will pick up in intensity beyond this period. This storm won't be moving quickly anytime soon, as it is stuck between a strong upper level ridge to the west, and an upper level trough located over the West Atlantic.

e7gpwm.png

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KCHS thinks there is a weak sfc circ. although I'm not sure I follow the NAM comment:

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE CHARLESTON SC

1044 AM EDT SAT JUL 16 2011

A WEAK SURFACE LOW IS EVIDENT ON VISIBLE SATELLITE THIS MORNING OFF THE GA/FL COAST.

MODELS HAVE NOT INITIALIZED THIS FEATURE VERY WELL. THE NAM IS THE

ONLY MODEL THAT SHOWS A CLOSED LOW IN THE INITIAL CONDITIONS AND

IT TAKES THE LOW WEST INTO THE FLORIDA COAST TONIGHT.

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KCHS thinks there is a weak sfc circ. although I'm not sure I follow the NAM comment:

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE CHARLESTON SC

1044 AM EDT SAT JUL 16 2011

A WEAK SURFACE LOW IS EVIDENT ON VISIBLE SATELLITE THIS MORNING OFF THE GA/FL COAST.

MODELS HAVE NOT INITIALIZED THIS FEATURE VERY WELL. THE NAM IS THE

ONLY MODEL THAT SHOWS A CLOSED LOW IN THE INITIAL CONDITIONS AND

IT TAKES THE LOW WEST INTO THE FLORIDA COAST TONIGHT.

I can't tell for sure its at the surface, but there is rotation and even a suggestion of some outflow in the Northern part of the circulation

CIMSS shear looks a bit strong for development, near/over 20 knots, and low level convergence looks weak. OTOH, CIMSS vorticity suggests weak to nothing is there really at 500mb, 850 mb and 700 mb, and the vis satellite suggests otherwise to my eyes.

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The only legitimate MJO response since June 1st was late June into early July which prompted the environment for potential Arlene. The MJO hardly climbed out of the middle of the octant graph because the h85 winds and h2 winds were marginal while the OLR response was lame. As I expressed a month ago with the long range storm call: after potential Arlene (which verified in the forecast window), it may not be until late July before we get something again. Notice a well-defined convergent wave has developed and will have to propagate through. Harmonics of the MJO pattern will deliver the goods by the end of the month into August.

So I wouldn't call the MJO favorable by any means. However, next month it is predicted to be highly favorable. In combination with the extremely low shear, high TNA and climo ramp-up, it could potentially be an amazing August. Anyone know what the record amount of named storms for August is?

Interesting that that Roundy Probabilities experimental product is highlighting the Gulf of Mexico in a couple weeks. Bahama Bomber there after?

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Interesting that that Roundy Probabilities experimental product is highlighting the Gulf of Mexico in a couple weeks. Bahama Bomber there after?

Links? Now I have to Google 'Roundy Probabilities'...

Nothing free here... http://data.eol.ucar.edu/codiac/dss/id=110.033

This data set contains long-range (28 day) probabilistic forecasts of tropical cyclones that develop in association with convectively coupled atmospheric waves and intraseasonal oscillations. The products were developed by Paul Roundy of the University at Albany.

Do they have any previous success?

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