Atlantic Tropical Action 2011

[flwxwatcher45]

I know. I shouldn't do that-- I don't know what came over me. I apologized to those guys.

P.S. I hope all you Floridians get raked by a good one this year.

LOL.. No need for apologies, I got a good laugh from it.

Now though , I will earn that weenie tag. Just for you Josh, some early season porn.

[Srain]

^

The GFS has been sniffing out lowering pressures across the Western Basin and the EPAC in la la land range for a while now. Sort of fits with what one would expect for the first part of June.

[bluewave]

It may be the case that the possible development keeps getting pushed back due to the dry air showing up on the water vapor hanging around the Western Caribbean.

[Riptide]

It may be the case that the possible development keeps getting pushed back due to the dry air showing up on the water vapor hanging around the Western Caribbean.

Ugly. Eastern Caribbean looks prime though when the shear goes away.

[k***]

It's May...

[Scorpion]

I'm gonna be chasing this year.

[Srain]

Looking E, convection/wave activity showing signs of life. Always a good indication that season is nearing...

[Eyewall2005]

Yea. And from 1966-1991 there were none in S. Florida. . 27 years between Betsy and Andrew. 1965/1992.

Mother Nature delivered Andrew about 20 years late.

Also, the odds in any given year (based on statistics) of a hurricane making landfall in S. Florida are around one in 7. This implies that your hurricane is not "due" until 2012.

Actually it has a very definite statistical bearing; but limited to that. Statistical studies study what did happen in the past; and is one indicator of what might happen, on average, in the future. What it doesn't have is a bearing in reality; until maybe after the fact.

Just wanted to add futher to this...TPC uses a 100-year period and then see how many hurricanes of various categories affect a specific location. In the case of Miami/Ft. Lauderdale, FL, the Cat 3 return frequency is one every 9 years.

However, this area went 27 years between Cat 3 Betsy in 1965 and Cat 5 Andrew in 1992. So how do we get a 9-year Cat 3 return period from that? We don't. But going back during the mid 1920's to the mid-1960's, miami was affected by Cat 3 and higher hurricanes about every 4 years or so.It is just an average of extremes over a 100-year period. Hurricane tend to come -- and not come -- in clusters, not with any regularity like the return frequency might suggest.

.

[HurricaneJosh]

Just wanted to add futher to this...TPC uses a 100-year period and then see how many hurricanes of various categories affect a specific location. In the case of Miami/Ft. Lauderdale, FL, the Cat 3 return frequency is one every 9 years.

However, this area went 27 years between Cat 3 Betsy in 1965 and Cat 5 Andrew in 1992. So how do we get a 9-year Cat 3 return period from that? We don't. But going back during the mid 1920's to the mid-1960's, miami was affected by Cat 3 and higher hurricanes about every 4 years or so.It is just an average of extremes over a 100-year period. Hurricane tend to come -- and not come -- in clusters, not with any regularity like the return frequency might suggest.

.

Yes, as per my post above-- that they come in clusters, not regular intervals (see Post 735).

As I mentioned, SE FL had an extremely active period, with one major per year (including a a few apparent Cat4s) from 1945-1950. That one burst of activity alone comoensated for the very long dry period that followed.

[rainstorm]

LC:

WEATHERAmerica Newsletter, Saturday, May 21, 2011 at 6:45 P.M. - Houston Weather | Examiner.com http://www.examiner.com/weather-in-houston/weatheramerica-newsletter-saturday-may-21-2011-at-6-45-p-m-1#ixzz1N2PiUA7O

[matthewweatherwatcher]

LC:

WEATHERAmerica Newsletter, Saturday, May 21, 2011 at 6:45 P.M. - Houston Weather | Examiner.com http://www.examiner....1#ixzz1N2PiUA7O

Right time being around the first week of June and within the western Caribbean/Gulf of Mexico. Typical! The models are starting to hint at something that could be our first cyclone. I've seen this happen quite a few times with Alberto, Arlene, Arthur 2008.

[flwxwatcher45]

Right time being around the first week of June and within the western Caribbean/Gulf of Mexico. Typical! The models are starting to hint at something that could be our first cyclone. I've seen this happen quite a few times with Alberto, Arlene, Arthur 2008.

Yep, the GFS has been hinting off and on about something brewing in the Caribbean for about 2 weeks.

[icebreaker5221]

Yep, the GFS has been hinting off and on about something brewing in the Caribbean for about 2 weeks.

And it's always 2 weeks away.

[k***]

And it's always 2 weeks away.

exactly....eventually it'll be right and a ton of people will then worship the GFS for sniffing it out

[bronxx]

Just wanted to add futher to this...TPC uses a 100-year period and then see how many hurricanes of various categories affect a specific location. In the case of Miami/Ft. Lauderdale, FL, the Cat 3 return frequency is one every 9 years.

However, this area went 27 years between Cat 3 Betsy in 1965 and Cat 5 Andrew in 1992. So how do we get a 9-year Cat 3 return period from that? We don't. But going back during the mid 1920's to the mid-1960's, miami was affected by Cat 3 and higher hurricanes about every 4 years or so.It is just an average of extremes over a 100-year period. Hurricane tend to come -- and not come -- in clusters, not with any regularity like the return frequency might suggest.

.

The map you used above (for cat 3+ hur) , and the other in that same series that gives all hurricanes (cat 1 +), lists Miami has a return period of once every 4-6 yrs. (as you earlier noted). The main reason those maps and the one I posted (that gives return rates for cat 1 for the Miami area as once every 9 years) is that the series you posted uses hurricane center positions that passed with 75 miles, and the one I posted uses hurricanes that passed within 50 miles.

I can add that I have studied many hurricane landfalls, and there are many,many cases, where hurricane winds did NOT extend out 75 miles from the center. In fact, many hurricanes do not have sustained hurricane winds extending out even 50 miles; especially in all quadrants. This would eliminate a good bunch of those canes that passed within 75 from Miami, as actually bringing hurricane winds at each given point. Hurricane seas maybe, but not winds in many cases.

I would say the study that uses 50 miles gives a more accurate idea of the actual return period of sustained hurricane winds at each given point. Having now looked at both sets of statistical maps, I would say that any point in S. Florida receives hurricane winds every 7 years, or so, on average.

----

Andrew was very small, but also very intense; yet in the advisory as he made landfall in S. Florida, hurricane winds extended out only 45 miles. I don't believe hurricane winds occurred in Ft. Lauderdale, which is 50 miles from where the center of the eye came ashore near Naranja, Florida.

<<

5 am, august 24, 1992

MAXIMUM SUSTAINED WINDS ARE NEAR 140 MPH AND SOME WEAKENING IS LIKELY AS THE CENTER OF ANDREW PASSES OVER THE FLORIDA PENINSULA. DURING THE PAST HOUR...A SUSTAINED WIND OF 115 MPH WITH A GUST TO 138 MPH OCCURRED AT THE NATIONAL HURRICANE CENTER. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 45 MILES FROM THE CENTER ...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140 MILES FROM THE CENTER. THE CENTRAL PRESSURE REPORTED FROM AN AIR FORCE RESERVE UNIT AIRCRAFT IS 932 MB...27.52 INCHES.>>

[Srain]

It will be difficult to get an early June storm in the Gulf with the pattern depicted with the Euro/GFS. Shear would likely shread anything that would come out of the Western Caribbean. My hunch is later in June into July/August before that region will see something worth watching, but you never know with stalled boundaries and convective activity that can fester long enough.

[Srain]

New Euro Seasonal outlook is out and looking only at July, August and September, areas from the Western Gulf, Florida and parts the EC do suggest lower pressures and higher rainfall amounts. Looking out a bit further into October, the MDR looks primed for long tracking systems with lower pressures across the Atlantic...

[rainstorm]

http://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2011052212&field=Sea+Level+Pressure&hour=168hr

great pattern. please lock in.

[Ed Lizard]

To give LC some credit, he does recognize the GFS tends to be too aggressive.

A TC in the Gulf in early/mid June would be a happy thing for Texas if it would happen, maybe the only way South Texas sees much rain, and the heat content would be too low for anything too damaging wind wise, and as long as something didn't go Allison, it would be all positives and no negatives.

[Mencken_Fan]

The return periods reflect the frequency with which the eye of a storm passes through a particular coastline segment. The storm eye is easy to track but is only one aspect of a storm that must be considered when determining its impact. The storm (and storm surge) may extend 50 or more miles from the center. . The correlation of occurrence and hurricane category is not a design tool but should be used as an indicator of the frequency with which one may expect the potential damage, flooding, and wind conditions in an area of interest. he number in parentheses is the landfall occurrences of hurricane eye for each 50 nautical mile segment during the 113-year period from 1886 to 1999 . The number in parentheses is the landfall occurrences of hurricane eye for each 50 nautical mile segment during the 113-year period from 1886 to 1999

Figure C.1. Return period of Category 1 or greater hurricanes along the Atlantic coast.

Thank you bronxx for the graphic. What I would really like to see (and believe would be much more useful,) is a pair of charts; one reflecting the active Atlantic phase and one for the inactive phase. It's quite clear that 1 in 14 for southeast N.C. is nonsense when the Atlantic is active; it's been a freight train of hurricanes here since the 1990s - which leads me to suspect this area is rarely visited by storms during the inactive phase (to get such a strange number as 1 in 14.)

Being the Atlantic has two phases, a single chart cannot reveal true context. A dual chart would be an excellent homework assignment for someone!

Thanks again though.

Cape Fear FTW.

[OSUmetstud]

http://moe.met.fsu.e...sure&hour=168hr

great pattern. please lock in.

bad weakness at 60W

[flwxwatcher45]

bad weakness at 60W

Party Pooper

[Ed Lizard]

Posting a one week surface pressure forecast map valid late May sort of deserves to be pooped on. OSU and Amy for dual mods!

[flwxwatcher45]

Posting a one week surface pressure forecast map valid late May sort of deserves to be pooped on. OSU and Amy for dual mods!

My post was said in jest.

[matthewweatherwatcher]

Posting a one week surface pressure forecast map valid late May sort of deserves to be pooped on. OSU and Amy for dual mods!

That is what rainstorm likes to do and it kind of shows the general pattern of things. Anyways that weakness is still "weaker" then what we had to deal with much of last season. I expect that this season will have more western Atlantic ridging and a much more east coast centered trough as the 500 millibar pattern shows in early June on the last page...That is why this season will more likely be like 1996, 1999 with track of the cyclones. It. doesn't deserve crapped on, but explained to rainstorm why a storm might not make it across on the short scale, but the large scale of things is far better then last season.

[Ivanhater]

Well consistency isn't a problem.

[bronxx]

Thank you bronxx for the graphic. What I would really like to see (and believe would be much more useful,) is a pair of charts; one reflecting the active Atlantic phase and one for the inactive phase. It's quite clear that 1 in 14 for southeast N.C. is nonsense when the Atlantic is active; it's been a freight train of hurricanes here since the 1990s - which leads me to suspect this area is rarely visited by storms during the inactive phase (to get such a strange number as 1 in 14.)

Being the Atlantic has two phases, a single chart cannot reveal true context. A dual chart would be an excellent homework assignment for someone!

Thanks again though.

Cape Fear FTW.

Here's the track book: enjoy yourself. Let us know what numbers you come up with.

Atl Hur. tracks 1851-2009

Also, you never know when the "period" you are in is going to end.

The numbers will vary if you even further categorize what period of the period this year is.

In inactive "periods" there are years that are very active.

In inactive years, one gets an Andrew, Donna, Betsy.

In active periods, there are slow years mixed in.

In busy years, sometimes there are no landfalls.

Some active periods last many more years than other active periods. Same for inactive periods.

Variable

Variable

Variable

Personally, I think flipping a coin is as reliable a method as any in determining whether you will experience a hurricane in the coming year.

There are not enough years of record to really make any reliable landfall prognostications for any given year coming. If there were 500+ yrs of records, maybe.

There are so few storms each year (the sample is 6 to 17 that covers probably 98% of years) that CHANCE is the most likely predictor of outcome. As the NHC seasonal forecast states: "NOAA’s seasonal hurricane outlook does not predict where and when any of these storms may hit. Landfall is dictated by weather patterns in place at the time the storm approaches." And this is where scientific knowledge has us at this point in time.

There are two "statistics" one can slightly rely upon:

A. The more storms there are in a yr. the more likely your house will experience a hurricane

B. There are long term averages that one can use to state which coastline areas have a greater likelihood of landfall.

[toad strangler]

I know. I shouldn't do that-- I don't know what came over me. I apologized to those guys.

P.S. I hope all you Floridians get raked by a good one this year.

Josh,

sassy = funny. I mean, its YOUR forum coined word bro! That is what I was getting at ....

[phil882]

The current subtitle for the thread kinda made me think of this. Apologies in advance

Also when is it socially acceptable for a mod to ban rainstorm again? I mean I could post why showing a 168 hour surface pressure map doesn't really explain anything, but others have already done that how many times now?

[Ed Lizard]

The current subtitle for the thread kinda made me think of this. Apologies in advance

Also when is it socially acceptable for a mod to ban rainstorm again? I mean I could post why showing a 168 hour surface pressure map doesn't really explain anything, but others have already done that how many times now?

Matthew explained it shows the general pattern...