NOAA 2007 Atlantic Hurricane season forecast...

[summer blizzard]

http://www.cpc.ncep.noaa.gov/products/outl...hurricane.shtml

13-17 named storms...

[johnholmes]

that is some increase and must be bad news for many living in the se States.

[WhiteFox]

that is some increase and must be bad news for many living in the se States.

At the moment the SE states would absolutely love a tropical depression to cross the area. The displaced Bermuda high has left areas of Florida North of Fort Lauderdale, through to South Carolina and across to Tennessee absolutely parched. Nobody would be wanting a hurricance, but a couple of rainmaker systems would be more than welcome I suspect. Fires continue to burn in Southern Georgie and Florida and believe it or not, some of the smoke from the fires has made it all of the way around the high pressure system to New York!

[kold weather]

Indeed WF, i remember quite a few people out there wanting Andrea to hit o it could throw its eastern band storms across.

anyway not really surprising that they've gone for a decently active season, about the same as most seasons from 1998 onwards. Many of the factors do look very good for tropical cyclone development. ACE (Accumulated Cyclone Energy) 125% to 210% is interesting, my forecast was for about 190% above normal, on the upper end of the expected scale but just outside the top 10 and also about average for 1995-2006 period which has averaged a stunning 15 tropical storms every season!

[Anti-Mild]

Wasn't last years hurricane season prediction way off the mark?

I seem to remember a prediction that involved a fair few named storms and it ended up being average.

Or am I misremembering?

Edit: Just checked, the NOAA predicted between 13 and 16 named storms on the 22nd of May last year and there was 10.

[kold weather]

to be fair to them though last forecast was messed big time by that El nino. According to Dr.Gray last years El nino was the fastest developing El nino of all time to develop when it did, for the summer months no other El nino formed as quickly according to him and to be fair the models didn't predict either, the only signs was a drop in the SOI index in April/May which normally occurs at the start of El Nino

[crimsone]

I seem to recall from the NASA widget on my google homepage that they are using some sort of new technology this year?

[johnholmes]

KW

not sure how you quote

anyway not really surprising that they've gone for a decently active season, about the same as most seasons from 1998 onwards.

when NOAA quote

indicates a very high 75% chance of an above-normal hurricane season, a 20% chance

I'm no expert in this field but

you say

my reading suggests that 75% is above normal

so are you saying that 1998 has seen above this figure each year?

[kold weather]

Hi John, what I meant is its about the same in terms of numbers of tropical storms as we have seen since 1998, with the average over the last few years being 15 tropical storms, directly in between the range of numbers.

Only 2 years since 1998 have come out below average in terms of the ACE index (which is far better measure of Atlantic activity then number of storms) and they were the El nino years of 2002 and 2006, though even 2006 weren't that far away from average.

[Gray-Wolf]

Thanks K.W. (and Dr Gray) I was sure that the El-Nino last year was so fast in establishing that the initial forcast (Hurricane) was out before the El-Nino impact was amalgamated into the model.

It would appear thar La-Nina may be as rapid in it's development and impact on the season this year (I don't think they'll need to bump down the numbers this time around!)

Nearly June first and the official start of things, we should run a sweep for date of first 'Cane of the season........

[johnholmes]

ta for that mate

[kold weather]

Interesting you mention La Nina, its really having a hard time to establish itself and the models seem to have over-done the strength of it as well, it probably will form weakly some time during summer/Autumn but right now while the east Pacific is fairly cool the west is still seeing subsurface profiles which are above average, not a sign of a strongly developing La Nina.

I'll bet the hurricane season overall will average neutral values in the Pacific in terms of the ENSO.

[summer blizzard]

I must disagree Kold Weather, i think that while the models did over egg La Nina calling a moderate to strong event, we are still on track for an overall weak La Nina season, having looked at the data and reports, May will have lowered the MEI value by 0.1 to 0.3, so a May value of 0 to -0.2 seems the best bet, and so a peak between -0.6 and -1.2 in November seems the best bet considering La Nina generally peaks around November.

[Gray-Wolf]

I still believe my eyes and some of the 'cold water upwelling' was sourced from the Ross sea (as meltwater outflow) and ,as such, I don't think the models are primed (yet) to include this input. As it is a late southern summer event and fininshes with the onset of the southern winter freeze up an initial 'strong signal' of cold water upwelling would fade and die as the meltwater pulse influence fades. In all probability the 'neutral state' may well swing positive as the equitorial/northern heat builds in the oceans (not by the normal ENSO drivers). Time will tell all!

[kold weather]

That may play a small part but if you see the sub-surface charts you can clearly see the cold anomalies drift up from below the surface, its pretty clear it can't be meltwater thats the main driver, because the cold is coming up from about 200M below the surface of the water.

As for La nina, we are just going to have to wait and see I suppose!

[Gray-Wolf]

That may play a small part but if you see the sub-surface charts you can clearly see the cold anomalies drift up from below the surface, its pretty clear it can't be meltwater thats the main driver, because the cold is coming up from about 200M below the surface of the water.

As for La Nina, we are just going to have to wait and see I suppose!

I was of the understanding that meltwater headed straight for the bottom (bottom freshening) and as such would displace the waters there already. The tracing out of the 'pulses' progress was via surface SST anomalies but only where submarine ridges/plateaus forced the kind of displacement to the surface (as I would expect).

I may have been a little misleading in my description and should have said 'bottom waters displaced by meltwater freshening at the oceans base'.