djones65 wrote:An invest is ONLY declared when there is sufficient evidence of a "closed low," or low pressure are. Not necessarily a well defined closed circulation, but does require a low pressure area with surface rotation. There is not a low pressure area at this time and not forecast to develop for another day or so. I suspect if models are close to accurate that more robust turning or closing off from wave to a low will occur in about 30-36 hours. So invest designation will probably occur early Tuesday in my humble opinion.
From the Glossary of NHC Terms: http://www.nhc.noaa.gov/aboutgloss.shtml
"Invest:
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."
Sounds to me like an invest is simply a 'weather system' the NHC would like to investigate for any number of reasons. Not seeing anything regarding a "closed low" or "low pressure area."
