WSI revises 2007 forecast

[HURAKAN]

Always the same thing. Big predictions before the season, then the season starts quiet, as normal, and they start going down with their predictions. If the season starts really active, aka 2005, then their predictions go up.

By the way, with 2 named storms 2007 didn't start quiet, but Andrea and Barry were nuisance for the most part.

An easy example for an accurate prediction:

Normal season: ~10 named storms
Since 95: ~15 named storms

Forecast for this season:

Expect between 10-15 named storms!!!

[caneman]

Philnyc,

Excellent analysis. In fact, one of the better ones I've seen. Thanks.

[Windsurfer_NYC]

Philnyc,

Excellent analysis. In fact, one of the better ones I've seen. Thanks.

Yes, excellent post -- just use caution when viewing the maps, as the scale is not consistent from map to map. For example, white signifies different pressures:

Climo: 1016 - 1017 mb
2004: 1017 - 1019 mb
2007: 1018 - 1020 mb
2006: 1018 - 1020 mb

[DanKellFla]

Let them keep trying with the seasonal forecasts. With time, they will learn from the past and get better.

[Emmett_Brown]

BTW, I'm ALMOST willing to bet the rent that Jeff Masters is about to back off of his last forecast, since the global models (particularly the GFS which he quoted in his last forecast) have backed off of the Bermuda high nosing further westward into the southeast and/or east. The latest GFS ensembles show troughing in the eastern U.S. to continue, i.e. they have backed off of their mid-July predictions. All I can say is persistence is hard to beat in the middle of a season. Here it is:

http://www.meteo.psu.edu/rtwx/ewall/ENSHGTAVGNH_18z/ensloopmref.html

Now it's saying the BH will extend further westward later in August. When a model forcasts a major pattern change, and it doesn't happen, and then it keeps moving the pattern change further into the future, that's not a sign of high confidence...

And this is probably why WSI decided to get a jump on Masters and forecast more tropical cyclones in the eastern Gulf rather than central or western Gulf. i.e. they are hedging their bets because the GFS is starting to back off of its mid-July Bermuda high forecast.

This GFS forecast still shows that the BH is pretty well established, at least at the surface, during the first week of August:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_384s.gif

[wxmann_91]

BTW, I'm ALMOST willing to bet the rent that Jeff Masters is about to back off of his last forecast, since the global models (particularly the GFS which he quoted in his last forecast) have backed off of the Bermuda high nosing further westward into the southeast and/or east. The latest GFS ensembles show troughing in the eastern U.S. to continue, i.e. they have backed off of their mid-July predictions. All I can say is persistence is hard to beat in the middle of a season. Here it is:

http://www.meteo.psu.edu/rtwx/ewall/ENSHGTAVGNH_18z/ensloopmref.html

Now it's saying the BH will extend further westward later in August. When a model forcasts a major pattern change, and it doesn't happen, and then it keeps moving the pattern change further into the future, that's not a sign of high confidence...

And this is probably why WSI decided to get a jump on Masters and forecast more tropical cyclones in the eastern Gulf rather than central or western Gulf. i.e. they are hedging their bets because the GFS is starting to back off of its mid-July Bermuda high forecast.

This GFS forecast still shows that the BH is pretty well established, at least at the surface, during the first week of August:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_384s.gif

I'd take Ensembles over 384 hr GFS any day. Phil is right. That east coast trough has been there for a long, long time, and it doesn't look to be leaving any time soon. If that holds, that could be good news for the Gulf Coast.

[philnyc]

Philnyc,

Excellent analysis. In fact, one of the better ones I've seen. Thanks.

Yes, excellent post -- just use caution when viewing the maps, as the scale is not consistent from map to map. For example, white signifies different pressures:

Climo: 1016 - 1017 mb
2004: 1017 - 1019 mb
2007: 1018 - 1020 mb
2006: 1018 - 1020 mb

Thanks, caneman and windsurfer.
BTW windsurfer, yes, I knew about the inconsistencies on the map keys. Sorry, I should have noted that, because it's obviously critical to the proper analysis. That's the one thing that bugs me about ESRL. If you don't specify the scale it jumps all over the place. And very cool that you caught that. Thanks. I'll go back and add the adviso.

[vacanechaser]

I made the same editorial mistake myself, call it "weather dyslexia", by calling La Nina "El Nino" in my origianl May outlook...could've just been an oversight.

But the lessened threat to the Western GOM...I don't see where he's getting that from...

maybe the lesened threat is due in part to this....july 23, 2007



look at the cooler than normal temps due to the rain run off in the western gulf... not saying it is what they mean, but possible... and yest that can turn around quickly and warm... but those temps dropped off from earlier...

Example: july 1, 2007




Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[cycloneye]

And Jesse,to comment further about what you posted,two things stick out that are important.First the cool waters in the Pacific haved mantained so nothing really new there in terms of being Neutral now.Second in the Atlantic side the MDR area looks a little below average due to the sal events that haved cooled a tad those waters.Let's see how those anomalies do in the next 2-4 weeks as we enter the meat of the season.

[vacanechaser]

:uarrow: And Jesse,to comment further about what you posted,two things stick out that are important.First the cool waters in the Pacific haved mantained so nothing really new there in terms of being Neutral now.Second in the Atlantic side the MDR area looks a little below average due to the sal events that haved cooled a tad those waters.Let's see how those anomalies do in the next 2-4 weeks as we enter the meat of the season.

true.. but how much is sal???? lets remember the azores high has been strong recently.. that may have a bigger effect on it than sal... remember, offshore winds are up welling winds.. the stronger and longer those winds blow offshore, the cooler the water will become... but yes the mdr is below normal and that has dropped since the even the 1st of the month... but it can recover quickly too...


Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[Downdraft]

I don't think anyone at anytime should ever lessen the threat in the Gulf of Mexico. That particular body of water is always ready and more than willing to surprise everyone. Conditions can change so quickly in the Gulf it's never totally out of the running threat wise. Considering the Gulf's reputation for blowing up in every month of the year tropical and non-tropical I respect it more than the Atlantic or the Caribbean on a consistent basis.

[philnyc]

I don't think anyone at anytime should ever lessen the threat in the Gulf of Mexico. That particular body of water is always ready and more than willing to surprise everyone. Conditions can change so quickly in the Gulf it's never totally out of the running threat wise. Considering the Gulf's reputation for blowing up in every month of the year tropical and non-tropical I respect it more than the Atlantic or the Caribbean on a consistent basis.

You're so right! For all of the talk and attention to the Cape Verde types, we can get cat 4 or 5's from non CV types in the GOM at any month in the warm season, like Audrey in 1957 or Opal in 1995. There are many other ways to initiate tropical cyclone development besides easterly waves from Africa.

[StormWarning1]

Here is the reason WSI is reducing the threat to the western GOM.

"Finally, our seasonal temperature forecast is now less bullish on late-summer heat in the Southeast, with the subtropical ridge migrating farther to the north than originally expected. Because of this, we feel that the general threat to the western Gulf is reduced slightly, with a corresponding increase in the threat to the eastern Gulf and Florida.”

[philnyc]

:uarrow: And Jesse,to comment further about what you posted,two things stick out that are important.First the cool waters in the Pacific haved mantained so nothing really new there in terms of being Neutral now.Second in the Atlantic side the MDR area looks a little below average due to the sal events that haved cooled a tad those waters.Let's see how those anomalies do in the next 2-4 weeks as we enter the meat of the season.

true.. but how much is sal???? lets remember the azores high has been strong recently.. that may have a bigger effect on it than sal... remember, offshore winds are up welling winds.. the stronger and longer those winds blow offshore, the cooler the water will become... but yes the mdr is below normal and that has dropped since the even the 1st of the month... but it can recover quickly too...

Good point, Jesse. We all know that SAL generally and usually decreases after July. This of course will allow SSTs to rise. And even though offshore winds will cause more upwelling, or at least sustain it, there is a normal value for SSTs out there that is quite high to begin with. If SSTs are 1C below the normal of 27.7, that means they are 26.7C which is 80F.

[StormWarning1]

Some more news on the WSI news release of less activity for this year.

http://www.investors.com/editorial/edit ... 6634686203

[caneman]

Some more news on the WSI news release of less activity for this year.

http://www.investors.com/editorial/edit ... 6634686203

Fascinating article. Thanks. You should also post in Global Weather forum.

[Derek Ortt]

Please explain to me why revising a forecast after new data becomes available gives it less credibility. These forecasts are not guessing games so that enthusiasts on a message board can be entertained, nor are they for bragging rights. There is a lot of money riding on these forecasts especially when a private company issues them. Not changing the forecast would make the institution less credible

IMO, comments attacking the credibility of a forecast merely because it is revised are out of line. Now, question whether the science is advanced enough, that is another storm all together

[cpdaman]

i am criticizing (not attacking) the reliability of a forecast for the tropics in general .

the history of forecasts made regarding an upcoming season are poor

i give these forecast's ZERO credibility before they are updated so theoretically they can't lose something they don't have

maybe the money riding on these forecasts, has inflluenced some forecasters to forecast high, so that the insurance company's can justify raising there premiums even further. And when they are revised down or miss completely , people say :phewww less storms i'm glad they were off, and if they are right , the forecasters's gain credibility seems like a win-win to the forecaster. I mean there are so many ingredients the forecasters can add more weight too if they were so inclined in order to justify a higher forecast than normal.

[DanKellFla]

Seasonal Forecasts need to start somewhere, just like storm track forecasting started. In both cases, the beginning was rough. It took a few decades to get storm track prediction to the place it is now, seasonal forecasting needs the same chance. It may be years before enough data is collected until seasonal forecasting becomes reliable. It may be never. But it is worth trying. This is how the scientific process works.

[flwxwatcher]

Looks like Tropical Storm Risk plans to lower their numbers further in the August update.

http://www.heraldtribune.com/article/20 ... /707270506