Roger Edson
Hi,

The following is reflective of my own opinion (and not directed at any
particular forecast agency---THERE are MANY in this area):

The attached image 'should' speak for itself.....

All types of 'reconaissance' data are included (in addition, several synoptic wind reports in the area were in excess of 35kts) for approximately
the same time period.

So, why isn't this system classified the same by all forecast agencies?

-10 minute vs 1 minute?

- "Forecastability" versus 'analysis'?

- Interpretation of Dvorak technique?

- Forecast agency policy/criteria on 'weak' systems?

- Experience or knowledge of other reconnaissance tools?

- Other????

Bottom-line: A ship passing through this region will feel the same wind and seas. I'm not sure that I would like to be in this area with a
'rowboat'--how about you?

With due respect to all concerned (especially any wayward ship that was expecting fair skies and following seas),

Roger
Roger Edson
University of Guam (WERI)

H. Wang

Hi

Roger has made a very good point. This has been an ongoing problem in the issues of TS warning. There are
discrepencies at times in terms of TS intensity, position and forecast track/trend from differenct
agencies. Seamen out there receive conflicting reports sometimes, which I think would be quite confusing.

I happened to be on shift from 07/1800 GMT, and told our clients 07W has apparently reached TS intensity
based on Dvorak analysis of 1800 GMT IR imagery. At the same time HK still called TD, and the latest JTWC
warning available was a TD warning from 1500 GMT. JTWC didn't issue a TS warning until 2100 GMT.

In most cases, regional offices tend to follow JTWC warnings. Therefore, it is important for JTWC to
constantly monitor any systems and update its warning in a more timely manner, besides the standard 6-hrly
issues.

To solve the problems of inconsistencies in the warnings, JTWC, as its name suggests, should take the
initiative to discuss any systems which have potential to develop with other regional offices, so some sort
of agreement can be reached before everyone issues its own warning and the recipients will have to make their
own decision on which one to trust.

Hong Wang
Marine Forecaster
WNI Weathernews
Melbourne, Australia

 "Schaudt, Kenneth J." <KJSchaudt@MarathonOil.com>
To: tropical-storms@tstorms.org
Subject: RE: [Tropical-storms] Consistency of Forecast Agencies (editorial)

>Bottom-line: A ship passing through this region will feel the same wind and seas. I'm not sure that I would like to be in this
area with a
>'rowboat'--how about you?

Even in the Atlantic and more or less within a single organization (ie. NOAA), I've see arguments about whether or not a tropical
system with 35 kt winds is a "tropical storm".  Was it a warm-core, cold-core, monsoonal or did it fit a textbooks definition?  The
new remote sensing products have only allowed those in the lab to split hair even finer than before.

As an operational/engineering hand,  my concern is the hands on the ships so so my bottom line is the same as yours.  Since the
mariners expect the forecasters to follow the WMO guidance, I tend to say forget the splitting of hairs and call a a 35kt tropical
low pressure system a tropical storm.

Ken

Johnny Chan

>In most cases, regional offices tend to follow JTWC
>warnings. Therefore, it is important for JTWC to
>constantly monitor any systems and update its warning
>in a more timely manner, besides the standard 6-hrly
>issues.
>
>To solve the problems of inconsistencies in the
>warnings, JTWC, as its name suggests, should take the
>initiative to discuss any systems which have potential
>to develop with other regional offices, so some sort
>of agreement can be reached before everyone issues its
>own warning and the recipients will have to make their
>own decision on which one to trust.
>
>
I'll have to disagree with the first statement in the first paragraph.  In fact, the large discrepancies exist because the regional offices don't
follow JTWC warnings.  When JTWC was in Guam, the forecasters (or may be only Frank Wells) would call up Hong Kong to find out whether any passing
ship would report any significant wind before JTWC would issue a warning on a system over the South China Sea.  But apparently they don't do it now.
So what was said in the second paragraph is important and you wonder why this has not been resolved in the annual meeting of the Typhoon Committee.

Johnny Chan
**************************************************************
* Prof. Johnny C. L. Chan
* Laboratory for Atmospheric Research
* Dept. of Physics & Mat. Sci., City University of Hong Kong