But here comes the MJO, just in time for the heart of the season.

Is this the year that at least one major hurricane affects the east coast from Hatteras north? Or how about four such storms in a month a la 1954, during the last maturing phase of the AMO? Imagine what the Gang would make of that? Hurricane Carol did to Providence, Rhode Island what Katrina did to New Orleans. The center of Hazel, in October, passed 80 miles west of New York City, but produced a sustained wind at the Battery of 115 mph, still the official record for the city.

Or how about Hurricane Donna in September of 1960, the only storm on record to produce hurricane conditions onshore in every state from Florida (both coasts) to Maine?

Deja vu? ‘We have all been there before.’

“What I’ve noticed is that NOAA is naming any cluster of thunder storms and calling it a ‘tropical’ storm even though it forms well above the tropics. for a time they used the term ’sub-tropical’ now they just tack the next alphabetical name …”

The terms tropical, subtropical, and extratropical refer to a storm’s structure, not to any location along its track. Subtropical storms tend to start as a broad area of thunderstorms linked by a large low pressure area. The Weather Underground has a very good writeup at http://www.wunderground.com/hurricane/subtropical.asp . Subtropical storms can “grow up” into tropical storms, but they can be named before that.

Subtropical storms that eat up names and never become tropical storms are a bit awkward for the longterm tropical storm forecasts, since the count of named storms no longer matches the count of tropical storms, Gray and co. have groused about that a bit and claim that the NHC has been too quick and inconsistant about assigning names to subtropical storms.

http://www.sciencenews.org/view/generic/id/35023/title/Forecast_Gullywashers says in part:

Models not accurately predicting intense rains of warmer climate

Climate simulations are underestimating how often intense rainstorms occur at warm temperatures, new analyses of weather data suggest. If true, the findings indicate that episodes of extremely strong precipitation, usually accompanied by flooding, will strike more often if the global average temperature continues to rise.

…

Statistical analyses of the satellite data, to be reported in an upcoming Science, indicate that “very heavy” precipitation episodes — those within the top 10 percent of rainfall totals for each patch of ocean — occurred between two and three times more often than an ensemble of climate simulations suggest.

Their comment system doesn’t like me today, I tried to add:

The real world observations are certainly no surprise to weather watchers, especially this summer in New Hampshire! If the models are underestimating rainfall, that implies they overestimate water vapor, the most important greenhouse gas, which then implies their temperature projections are too high.

My guess is that if the modelers fix that, they’ll increase the CO2 feedback factor since that was set to make the projections match the temperature rise over the last few decades. Or however it is that they set it. At any rate, the result may be a wash for recent temperatures, perhaps a bit of reduction in their projections forward.

“I’ve wondered about the inhibiting effect of previous activity relative to later storms. If storm convection effectively sucks the energy out of the sea surface, could early storms … be used as predictors for late season storms?”

I don’t think they’re used as such, but a storm’s passage does leave cooler water in its wake. Both evaporation and mixing of the ocean column are culprits. In the short term, a storm that stalls will be forecasted to weaken due to SST cooling.

The empirical and analog forecasting Gray & associates use does take that into account indirectly – if the current season looks similar to a previous season, then expectations are that the two will be similar. So any suppression due to activity in the previous system is carried forward into the current season.

This is not an exercise in taking quantitative data and adjusting it for local and temporal conditions, it’s more a matter of taking uncertain data and determining what would have been measured if it could have been measured. Except for one detour, they started with 1851 and have worked forward. The exception was to review Hurricane Andrew, then the most costly storm in history, to refine track, landfall, windspeed at landfall, etc. The result was to upgrade landfall from Cat 4 to Cat 5. It’s interesting that even now we don’t have enough equipment or the density to answer some simple questions. Just like the USHCN surface stations, except that the anemometers blow away, especially the ones best sited for the storm at hand.

All in all, it looks like a big project with a lot of manual labor on a lot of data points.
http://www.aoml.noaa.gov/hrd/data_sub/re_anal.html

http://davidsmith1.files.wordpress.com/2008/07/07290812.jpg

NOAA may be right about the rest of the season, and I think they indeed are, but it’s not due to the large number of early-season storms.

Something has always puzzled me, how did they every know how many hurricanes were out in the Atlantic before satellites? Sure an occasional ship my have found one but it may have sunk.

Apparently there have been a lot of ships, but yeah, missed storms are a significant issue in looking at longterm trends. Perhaps even bigger is the uncertainty in knowing the complete track or having a good record of the intensity. Hurricane hunter flights began in the 1940s, but even with them hurricanes far from land weren’t checked, especially those in the eastern Pacific, so the decent history of hurricane intensity is less than 50 years old.

It’s another one of the big reasons Bill Gray refuses to put any faith in any claims about global warming and hurricane intensity or energy release.

Even trying to extrapolate from landfalling storms is problematic as some years favor landfalls, some years don’t. That’s one aspect of hurricane prediction people are working on, but it has a ways to go.

If you really want to go out on a limb, check out http://theweatherwiz.com/Hurricane-FUTURE.htm – it’s a site run by Joe D’Aleo’s high school teacher and is trying to forecast the weather from past analogs. Not a new idea, but an interesting implementation. I haven’t checked out any of the forecasts, but have put it on my list of stuff I’ll don’t expect to get to.