Definition of "Invest" by NHC meteorologist

[southerngale]

With the disturbed weather in the GOM in recent days, and the possible recon mission that was scheduled, I saw some people asking if it qualified the area for an Invest and someone asking what actually determines designating an area an Invest, so I emailed the NHC early Friday afternoon when development, although unlikely, was still possible. My original email and his response are pasted below. I then asked if he minded if I post his response on here and he said sure and thanked me for asking.

Hi,

I see that there's a possible recon mission for tomorrow for the disturbed weather in the GOM. I understand that it could be canceled if you don't think a low center is forming and that's it's scheduled ahead of time just in case. My question is since there's a possible recon mission, might that qualify this area of potential development as an Invest? What are the criteria for an Invest?

Thank you,
Kelly ******

Kelly,

An "invest" is defined as the following:

A weather system for which a tropical cyclone forecast center (NHC, CPHC, or JTWC) is interested in collecting specialized data sets (e.g., microwave imagery) and/or running model guidance. Once a system has been designated as an invest, data collection and processing is initiated on a number of government and academic web sites, including the Naval Research Laboratory (NRL) and the University of Wisconsin Cooperative Institute for Meteorological Satellite Studies (UW-CIMSS). The designation of a system as an invest does not correspond to any particular likelihood of development of the system into a tropical cyclone; operational products such as the Tropical Weather Outlook or the JTWC/TCFA should be consulted for this purpose.

If the forecasters have reason to believe that an area of disturbed weather might develop into an organized tropical system (environmental conditions favorable, forecast models show development, observations show some organization, etc) then an invest is usually declared.

In the case over the weekend, I don't believe any of the above were noted for the Gulf of Mexico system.

Best wishes,

Christopher Juckins
Meteorologist / Webmaster
National Hurricane Center
Web: http://www.hurricanes.gov
Mobile web: http://www.hurricanes.gov/mobile
Email: nhcwebmaster@noaa.gov

[jasons2k]

Southerngale, thanks for posting that.

I have read at another time, I think on this forum and maybe it was Air force Met who posted it (maybe, could be wrong).

Anyway, there was a set of criteria, such as an area of sustained low pressure with convection for at least 24 hours, etc. I cannot remember them specifically but it was something like that.