|All Affected Offices|
|FROM:||W/OS3 Glenn Austin, <signed>
HSD Chief:, NWS Office of Climate, Water, and Weather Services
|THROUGH:||Regional Hydrologic Services Managers|
|SUBJECT:||VTEC in FFW/FFS and Temporary Work-Arounds for Non-Convective Situations|
Today is the implementation day for VTEC in flash flood warnings (FFW) and flash flood statements (FFS). There are a few important pieces of information that need to be provided to the WFOs with regard to WarnGen and the capabilities of upcoming Builds to produce FFW and FFS products.
OB 8.1 Version - During recent static testing, a problem was uncovered with regard to follow-ups to initially issued "non-convective" FFWs - e.g., products for dam failures, ice jams, and upstream reservoir releases. In the rare instance of events of this type occurring, the initial product is generated with correct VTEC and product content. However, when the forecaster wants to issue a follow-up FFS, the product can't be found under WarnGen's "non convective" menu. The product can be found under the convective menu, but when it is generated and displayed, the immediate cause is changed from DM, IJ, RS, etc. to ER and the text of the FFS is formatted as if it were for a standard "excessive precipitation" situation. The WFOs need to be aware of this, and should they need to issue a FFW/FFS for a non-convective situation during the next week or two, they will have to know where to find follow-up FFS in the WarnGen menu and will have to make some edits before issuing any follow-up FFS products.
Note: For those WFOs that use a single template for all "convective" and "non convective" FFW/FFS, the above problem does not occur.
OB 8.1.1 Version - A maintenance release should be available by the end of this week (Sept 29) or sometime next week (by Oct 6) which partially fixes the previously described problem. The forecaster will still have to find follow-up FFS products for "non-convective" FFWs under the "convective" menu, but the product will be formatted with the correct immediate cause in the H-VTEC string. This is good because we strongly discourage doing any edits to VTEC information. However, the text of the formatted product will still suggest a standard "excessive precipitation" situation and the forecaster will have to make edits before issuing the FFS.
AWIPS DR - An AWIPS Discrepancy Report (DR) has been written to document this defect. The DR is being given significant attention. However, at this time, we are not aware of an implementation date for the fix to this problem. We will share that information with you as it becomes available.
OB 8.2 Version - The capability developed in Central Region for automated insertion of dam failure data into FFW/FFS products becomes available with this build. The dam data isn't extracted out of DamCat or some kind of hydrologic database, but it will be possible for a WFO to set up special pre-formatted files with failure scenario data for a specific dam (e.g., from an emergency action plan). The issue WFOs need to be aware of here is that those that lumped multiple kinds of flash flood situations into a single template will have to start using the nationally-provided set of templates (or locally customized versions of those) for the various types of "convective" and "non convective" flash flood situations. WarnGen focal points need to be aware - using a single template for all "convective" and "non convective" FFW/FFS will no longer be an option. OB 8.2 is currently in alpha testing, and beta deployments are scheduled to begin next month. National implementation of OB8.2 is scheduled to begin after the first of the year and run through March 2008.