Background
Focus on the Highest Threat
Never Split Existing Hazard
Additional Resources

 

Background

Over the last few months, customers have complained about warning products containing a "split" event tracking number (ETN). A split is defined as one segment which contains at least 2 lines of VTEC for the same ETN. The action codes can be the same, such as EXT, or different, like an EXP and CON. Normally, the customers would expect the later VTEC line to have an incremented ETN.

These segments with multiple action codes for the same ETN cause dissemination problems for our customers and could delay the transmission of warning products by these vendors. A software adjustment to GHG is being planned, but will likely not be ready until late spring due to development and testing time.

In the meantime, many of these instances can be avoided by following certain guidelines, outlined below. If you have questions or concerns about these guidelines, please contact your regional public focal point.

Focus on Highest Threat

1. If multiple hazards are in effect, advisory and warning combinations, keep the focus on the highest threat hazard (i.e. the warning).

2. If an advisory is in effect for a long period of time and it appears that the middle may actually reach warning criteria (e.g. SC.Y and GL.W), remove the advisory hazard that would have remained after adding the warning. This may also occur when a warning is expanded into an adjacent advisory for a short time.

3.Once it is clear when the lesser conditions will prevail, add it back into the hazard grid.

4. Bottom line: Do not insert another hazard into the middle of an existing hazard. It will cause a split ETN.

 

Never Split an Existing Hazard

1. If a hazard is in effect for a long period and it appears there may be a break in conitions, do not simply remove the hours that may be below criteria.

2. Either leave the hazard as-is or remove the hazard completely after the time of the lull. A new hazard can be added once it is clear the conditions will resume. This will allow the ETN to advance.

3. Bottom line: Do not remove hours from the middle of an existing hazard. It will cause a split ETN.

Additional Resources

On the GHG training CD at each WFO (from Oct. 2005):

If your office cannot locate the GHG training CD, please contact Shannon White for a replacement.