NOUS41 KWBC 271340

PNSWSH

 

Public Information Statement 18-07

National Weather Service Headquarters Silver Spring MD

940 AM EDT Fri Apr 27 2018

 

To:        Subscribers:

           -NOAA Weather Wire Service

           -Emergency Managers Weather Information Network

           -NOAAPort

           Other NWS Partners and NWS Employees

 

From:      Allison Allen

           Chief, Marine, Tropical and Tsunami Services Branch

       

Subject:   Changes to Section E of the Post Tropical Cyclone        

           Report (PSH) Noted in the 2018 Version of NWSI 10-601

           Will Be Delayed Until Further Notice

 

Until further notice, software implementation delays will

prevent National Weather Service (NWS) Weather Forecast Offices

(WFOs) from having the capability to issue Section E of the PSH

product using the format and content described in the 2018

version of NWSI 10-601: Weather Forecast Office Tropical Cyclone

Products. 

 

The PSH is the primary WFO tropical cyclone product issued to

the public to report and document local tropical cyclone

impacts.  For the foreseeable future, Section E of the PSH will

continue to provide maximum storm surge and storm tide

information, and the following guidelines will apply:

 

"Section e - Maximum storm surge and storm tide: The preferred

reference levels for reporting storm tide (total water level)

are the North American Vertical Datum of 1988 (NAVD-88) vertical

datum and Above Ground Level (AGL). For NOS tide stations or

other tide reporting systems, Mean Higher High Water (MHHW)

should be used to approximate inundation along the immediate

coast. For USGS high water marks (HWMs), AGL measurements are

typically provided, and no conversion is required. For U.S.

Geological Survey (USGS) pressure sensors and HWMs, report only

NAVD-88 if AGL values are missing. Do not include HMWs based on

debris lines found on the ground in a PSH, as debris lines are

often influenced by waves and may not accurately represent the

surge. As such, they may not accurately represent the surge.

Report storm surge in feet above the normal predicted

(astronomical) tide level. Identify location and date / time

(UTC) of peak occurrence where possible. Report storm surge /

tide greater than 1 foot, with tides of less than 1 foot

reported as needed or as requested. Report extent of beach

erosion as appropriate.

 

The NOS Center for Operational Oceanographic Products and

Services (NOS CO-OPS) will provide a final report of storm surge

and storm tide information from NOS tide gauges to NWS Regional

offices within 4 days following the issuance of the final HLS.

The PSH will reflect the data and appropriate reference datums

provided in the NOS report."

 

The following is an example of the PSH product that will be

valid for the foreseeable future:

 

https://www.nhc.noaa.gov/productexamples/PSH_example.txt

 

The changes reflected in the 2018 version of NWSI 10-601, but

not yet implemented, will be made to standardize how maximum

water level is reported by including only one peak overall

height for each location during the event. Peak surge will be

removed because it only represents the departure from normal

tide levels and often does not coincide with maximum overall

water level (when surge related inundation is greatest).

Furthermore, the inclusion of the data source and reference

datum removes ambiguity in the peak water level measurements,

allowing for easier comparison of water levels collected by

different agencies and across different WFOs.

 

Once implemented, these changes will ensure consistency of

information provided across all WFOs required to issue the PSH

product following tropical cyclones.

 

An example of the upcoming change to PSH Section E can be found

at:

 

https://www.nhc.noaa.gov/productexamples/PSH_example2.txt

 

A Service Change Notice will be issued within 30 days of the

expected implementation of the changes to the PSH Section E

described above.

 

For more information, please contact:

 

  Jessica Schauer

  NWS Tropical Services Program Leader

  NWS Marine, Tropical, and Tsunami Branch

  Miami, FL 33165

  Telephone: 305-229-4476

  Email: Tropical.Program@noaa.gov

 

National Public Information Statements are online at:

 

  http://www.weather.gov/os/notif.htm

 

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