Sample Message - 1 when coastal tsunami with heights of 0.3 m or more are expected
Sample Message - 2 when coastal tsunami with heights of 0.3 m or more are not expected
Sample Message - 3 when Mjma is judged as underestimated and Mw is unavailable in a timely manner
Sample Message - 4 when the depth is 100 km or more
Sample Message - 5 based on real-time simulation and added with tsunami observations

Italic parts (DDhhmm, etc.) indicate that numbers or sentences are described in accordance with the following explanation.
Braces ({NORTH/SOUTH}, etc.) indicate that one of the words divided by slashes is described.
Brackets ([(MJMA)/(MW)], etc.) indicate that the word (or one of the words divided by slashes) is optional.


(1) Heading
The heading of messages on the GTS circuit (WEPA40 RJTD) appears at the top. DDhhmm represents the day, hour and minute of issuance in UTC.


(2) Bulletin Number
NNN is the number of the bulletin, and increases with each issuance.
hhmm, DD, MMM and YYYY represent the hour, minute, day, month and year of issuance in UTC. Overly long NWPTA messages may be issued in separate parts.
nn is the number of the part, and NN is the total number of parts. For non-separated messages, nn and NN are both 01.


(3) Earthquake Parameters
hhmm, DD, MMM and YYYY represent the hour, minute, day, month and year of the earthquake’s origin in UTC. LL.L and LLL.L represent the latitude and longitude of the epicenter, respectively. NORTH or SOUTH is added for latitude, while the longitude is always EAST. Geographical Area is the epicenter region based on Flinn-Engdahl regionalization. M.M is the magnitude of the earthquake. (MJMA) is added for Mjma values and (MW) is added for Moment Magnitude values. FOCAL DEAPTH is included only for depths of 100 km or more. When parameters are revised in a subsequent message, (REVISION) appears on the first line of this part.
To ensure consistency and minimize confusion among users, NWPTAC, SCSTAC and PTWC coordinate their earthquake parameters prior to official bulletin issuance using agreed-upon arrangements, and use identical earthquake parameters in their first text products to the maximum extent possible.

(4) Tsunamigenic Potential
Tsunamigenic potential evaluation is based on earthquake magnitude.


(5) Coastal Blocks
If a tsunami with an amplitude of 0.3 m or more is expected for any FP, the Coastal Blocks containing the relevant FPs are shown in this part (See Figure and Table). If no tsunami of this scale is expected at any FP, the report states, ESTIMATION AT FORECAST POINTS - NO TSUNAMI WAVES WITH AN AMPLITUDE OF 0.3 METERS OR MORE ARE EXPECTED AT ANY FORECAST POINT.. (Addition) or (Cancellation) is specified as described below (6) in subsequent information issued due to earthquake parameter updates.


(6) Forecast Amplitude and Arrival Time
Tsunami amplitude and arrival time are estimated for each coastal FP. The estimated amplitudes AMPL and arrival times (hhmm DD MMM in UTC) are listed with the names (FP-1, etc.) for each FP along with its latitude and longitude (LL.L{N/S} LLL.LE to the nearest 0.1 degrees) in Coastal Block groups.
Amplitude here is defined as the maximum distance between the crests of tsunami waves and the undisturbed sea level. It is estimated in categories of 0.3-1M, 1-3M, 3-5M, 5-10M and OVER10M, and shown only for FPs expected to experience tsunami with heights of 0.3 m or more. If no tsunami of this scale is expected at any FP, this part does not appear in the message.
If new FPs need to be added or the expected arrival time/amplitude of tsunami need to be changed in a revised issue due to earthquake parameter updates, (Addition) or (REVISION) is specified in the line for the relevant FPs. For FPs that appeared in the previous NWPTA message but need to be removed due to revision, (Cancellation) is stated in the revised issuance.


(7) Tsunami Observation
Information on tsunami waves recorded at sea level stations with telemetric links to NWPTAC is provided as necessary. The amplitude OBS of the largest wave to the nearest 0.1 m and the arrival time (hhmm DD MMM in UTC) are listed along with the station name (STATION-1, etc.) and its latitude and longitude (LL.L{N/S} LLL.LE to the nearest 0.1 degrees).
To minimize confusion among user countries/organizations, NWPTAC generally adopts values of Maximum Tsunami Amplitude in PTWC products in correspondence to those in NWPTAC products.


(8) Qualitative Expressions for Huge Earthquakes
In the event of a huge earthquake close to Japan, the qualitative forecast amplitude expression Huge, High or ---- and the magnitude expression OVER 8 and THIS INFORMATION IS BASED ON THE PREDEFINED MAGNITUDE may be used in NWPTAs. Such expressions can be shown when the earthquake is so massive that JMA magnitude is unavailable, and moment magnitude is undetermined within around 15 minutes as well. In such cases, tsunami scale estimation is based on a predefined possible maximum magnitude.