Hazel invest

[Ed Schoenborn]

Were tropical invests recorded in 1954 and if there were any, what invest number was Hurricane Hazel? Ed

[Jim Leonard]

Invests is a satellite estimate of a tropical system that has potential for further development. Hurricane Hazel was in 1954, long before satellites.

[Ed Schoenborn]

Thanks, Jim. Until Stu first mentioned invests in a post on the SLT forum a year or two ago I had never heard of invests and have been trying to learn as much as I can about them ever since. Even at the Central North Carolina chapter of the AMS no one there seemed to have even heard of invests. I would sure like to print a copy of that first post by Stu. Ed

[Pat Lawrence]

As far as I know the number doesn't really mean much... the letter gives the basin location. And everything is satellite based so we couldn't have had an Invest before April 1960. And no, I don't know when using satellites to track potential developers actually started.. might have been a long time after the first weather satellite for all I know.

Pat

[Jack Beven]

Thanks, Jim. Until Stu first mentioned invests in a post on the SLT forum a year or two ago I had never heard of invests and have been trying to learn as much as I can about them ever since. Even at the Central North Carolina chapter of the AMS no one there seemed to have even heard of invests. I would sure like to print a copy of that first post by Stu. Ed

Ed, I think you might be reading a little too much into the significance of the invests. The numbers we assign are more for internal tracking and data sorting purposes for disturbances than anything else. If you watch the numbers on the NRL Tropical Cyclone page, you'll see that we re-use the numbers from 90-99 over and over again.

I think the use of the invest designation started at the Joint Typhoon Warning Center when they got the Automated Tropical Cyclone Forecasting system (ATCF) back in the late 1980's. We started using them in the Atlantic and Eastern Pacific when we got the ATCF in 1989. The public didn't really see them until the invest identifiers were used to collect microwave satellite data on the NRL and FNMOC tropical cyclone pages starting in the late 1990's.

Jack Beven
Tropical Prediction Center

[Pat Lawrence]

Ed, I think you might be reading a little too much into the significance of the invests. The numbers we assign are more for internal tracking and data sorting purposes for disturbances than anything else. If you watch the numbers on the NRL Tropical Cyclone page, you'll see that we re-use the numbers from 90-99 over and over again.

I think the use of the invest designation started at the Joint Typhoon Warning Center when they got the Automated Tropical Cyclone Forecasting system (ATCF) back in the late 1980's. We started using them in the Atlantic and Eastern Pacific when we got the ATCF in 1989. The public didn't really see them until the invest identifiers were used to collect microwave satellite data on the NRL and FNMOC tropical cyclone pages starting in the late 1990's.

Jack Beven
Tropical Prediction Center

Thanks for the detailed information!

Pat

[Ed Schoenborn]

What books should I read in order to study tropical waves and invests? BTW as a trivial matter so far this year four invests numbered 90 L became named storms. They are Alberto, Chris, Ernesto, and Florence.