H-VTEC in Hydro Products Jason Elliott NWS Huntsville

H-VTEC in Hydro ProductsJason ElliottNWS Huntsville

What is H-VTEC?• Standardized coding that will appear in all

watch/warning/advisory products• NWS is testing this code in point-based river

flood warnings and statements now.

• In the TVA area, the following WFOs are participating in the test:– MRX (Morristown, TN)– HUN (Huntsville, AL)– PAH (Paducah, KY)

• All other offices are scheduled to begin using the code in the summer of 2007

The H-VTEC Line• AstC001-002-ddhhmm-

/k.aaa.cccc.pp.s.####.yymmddThhnnZB-yymmddThhnnZE+6/

/nwsli.s.ic.yymmddThhnnZB.yymmddThhnnZC.yymmddThhnnZE.fr/

hhmm am/pm time_zone day mon dd yyyy

stC001-002-ddhhmm-/k.aaa.cccc.pp.s.####.yymmddThhnnZB-yymmddThhnnZE+6/



nwsli .......................NWS Location Identifiernwsli .......................NWS Location Identifiers ..............................Flood Severity Codes ..............................Flood Severity Codeic .............................Immediate Causeic .............................Immediate CauseyymmddThhnnZyymmddThhnnZBB ..Flood Beginning Date/Time ..Flood Beginning Date/TimeyymmddThhnnZyymmddThhnnZCC ..Flood Crest Date/Time ..Flood Crest Date/TimeyymmddThhnnZyymmddThhnnZEE ..Flood Ending Date/Time ..Flood Ending Date/Time

• yymmdd - Year, Month, and Dayyymmdd - Year, Month, and Day• hhnn - Hour and Minute in UTChhnn - Hour and Minute in UTC• ““T” & “Z” - non-numeric characters T” & “Z” - non-numeric characters

(FIPS/ANSI)(FIPS/ANSI)

fr .............................Flood Record Statusfr .............................Flood Record Status

The Forecast is Important!

The forecasts issued by the RFCs and TVA will directly drive the times put in the code.

Crest forecasts (when issued) will also directly populate the crest time in the code.







Calculations of Code Times Flood Stage

Action Stage

Observed Data

24 hr Forecast

/TEST1.1.ER.061019T0320Z.061019T0600Z.061019T2230Z.NO/

Calculations of Code Times

Flood Stage

Action Stage

Observed Data

6 hr Forecast Crest Forecast

/TEST1.1.ER.061019T0331Z.061019T1400Z.061020T0320Z.NO/

The Biggest Pitfall?

NWS software recommendations always assume that the forecast is correct!

This means you (TVA) may be hearing from us (NWS) more during flood situations…especially as the “fall below flood stage” time approaches or occurs.

Because of the coding, we must make a “call” on flood warnings within six hours of the time when the point is forecast to fall below flood stage.







Documents

H-VTEC in Hydro Products Jason Elliott NWS Huntsville