how to issue sigmet - world meteorological · pdf filejapan meteorological agency 1 how to...

Japan Meteorological Agency 1

How to issue How to issue SIGMET SIGMET

Shikembaru, Toru志堅原透

Japan Meteorological Agency (JMA)日本気象庁

SIGMET Seminar for Asia/Pacific Region

Bangkok, Thailand, 11-13 July 2007


Contents of lectureContents of lecture

I. Outline of SIGMETII. How to issue SIGMET


I. Outline of SIGMETI. Outline of SIGMET


Definition of SIGMET informationDefinition of SIGMET information

Information issued by a meteorological watch office concerning the occurrence or expected occurrence of specified en-route weather phenomena which may affect the safety of aircraft operations.

Excerpt from WMO Technical Regulations [C.3.1.] 1.1


Importance of SIGMET informationImportance of SIGMET information

SIGMET information is the highest priority among other types ofmeteorological information provided to the aviation users.

SIGMET information is used for flight planning of the airlines globally.


Principal operation as a Meteorological watch office (MWO) Principal operation as a Meteorological watch office (MWO) for issuing SIGMET informationfor issuing SIGMET information

To prepare SIGMET and other information relating to its area ofresponsibility.

To supply SIGMET information and, as required, other meteorological information to associated air traffic services units.

To disseminate SIGMET information.


Dissemination of SIGMETDissemination of SIGMET

SIGMET messages shall be disseminated toMWOs,WAFCsother meteorological offices

SIGMET messages for volcanic ash shall be disseminated to VAACs.


Note to issue SIGMETNote to issue SIGMET

Although SIGMET information is required to be issued for cruising level, there is no stated lower limit regarding the height.

MWOs should not issue SIGMET for weather phenomena of lower intensity, transient nature, or smaller scale, which do not affect significantly the flight safety.


Type of SIGMET at subsonic cruising levelsType of SIGMET at subsonic cruising levels

OBSC TS EMBD TSFRQ TSSQL TSOBSC TSGREMBD TSGRFRQ TSGRSQL TSGR

TC (+ cyclone name) where the criterion of 10-minute

mean surface wind speed is 63km/h(34kt) or more.

SEV TURB

SEV ICESEV ICE(FZRA)

SEV MTW

HVY DS

HVY SS

VA (+ volcano name, if known)

ThunderstormThunderstorm Tropical cycloneTropical cycloneTurbulenceTurbulence

IcingIcing

Mountain waveMountain wave

DuststormDuststorm

SandstormSandstorm

Volcanic ashVolcanic ash


Type of SIGMET Type of SIGMET at transonic and supersonic cruising levelsat transonic and supersonic cruising levels

ISOL CB OCNL CBFRQ CB

MOD TURBSEV TURB

VA (+ volcano name, if known)CumulonimbusCumulonimbus TurbulenceTurbulence Volcanic ashVolcanic ash

GR HailHail

Note :

Only one of the weather phenomena should be selected and included in each SIGMET.


Period of validity of SIGMETPeriod of validity of SIGMET

Up to 6 TC, VAUp to 4TURB, TS, ICE, MTW, DS, SS, CB, GRHoursPhenomena


Update and cancellation of SIGMETUpdate and cancellation of SIGMET

When the Sig-WX phenomena (which is on SIGMET) is growing, MWO should issue a new updated SIGMET.

When the phenomena is no longer occurring nor expected to occur, MWO should cancel the SIGMET speedily.


Principal components of SIGMET message of Principal components of SIGMET message of ICAO Amendment 74 to Annex 3ICAO Amendment 74 to Annex 3

Direction of the requirement of SIGMET for transonic and supersonic cruising level.

Elimination of OTLK from SIGMET messages related to VA and TC.

See the ICAO Working Paper “APPROVAL OF DRAFT REPORT TO COUNCIL ONAMENDMENT 74 TO ANNEX 3 - METEOROLOGICAL SERVICEFOR INTERNATIONAL AIR NAVIGATION ”.


II. How to issue SIGMETII. How to issue SIGMET


Example of SIGMET for phenomena excluded TC and VAExample of SIGMET for phenomena excluded TC and VA

RJJJ SIGMET 4 VALID 260725/261125 RJTD-RJJJ FUKUOKA FIR SEV TURB OBS AT 0715Z S OF N3450 E13950 FL280/320 MOV NE 20KT INTSF

(This SIGMET is fictitious)

ICAO Location indicator of FIR or CTA

Message indicator Validity period Location indicator of MWO and hyphen

ICAO Location indicator and name of the FIR(/UIR) or CTA

Phenomenon Indication of observed and expected to

continue, or forecast

Expected changes in intensity

Movement or expected movement

Location

Daily sequence number Validity indicator

Vertical extent or level


Types of satellite imageTypes of satellite image

Visible image Infrared image Water-vapour image

The Visible image or infrared image is useful for judging occurrences or expected occurrences phenomena to SIGMET information. But the water-vapour image is more useful for expected occurrences TURB. (To know occurrences of air turbulences, we need to get pilot reports.) It is because that occurring TURB, especially CAT, is connected with pattern of Jet Streams. If estimated position of Jet Streams can be understood with a water-vapour image, it will be possible to issue SIGMET information for turbulence.


NWP data over the satellite imageNWP data over the satellite image

Relationship between position of Jet Streams, trough and ridge, value of wind shears and cloud can be understood with NWP data over the satellite image.

The left image is that the NWP data of 300hPa winds and 300hPa parallel of altitude lap over the infrared image.

(at 26 Feb. 2007 00UTC)


AerologicAerologic observation and NWP data over the satellite observation and NWP data over the satellite imageimage

Additionally, three dimensional meso-scale phenomena can be understood using aerologic observation and NWP data over the satellite image.

The left image is that the aerologic observation wind data at 300hPa, light blue pennants, the NWP data of 300hPa winds and 300hPa parallel of altitude lap over the infrared image.

(at 26 Feb. 2007 00UTC)

T Td


How to make SIGMET information for TSHow to make SIGMET information for TS

RJJJ FUKUOKA FIR FRQ TS FCST WI N40E148 - N40E158 -N45E156 - N45E150 - N43E148 MOV NE 15KT INTSF

The moving direction and moving velocity will be estimated with the animated satellite images.

This red area is described in SIGMET information.

Area except at a stationary area may be widened in consideration of validity period and moving direction and velocity.

mov

ing d

irect

ion

This blue area is estimated the area of frequent TS on this image.

The following SIGMET main body is determined in this situation. Where the name of the FIR is Fukuoka FIR, the moving direction is northeastward, the moving velocity is 15kt and the phenomenon’s intensity is intensifying.

how to issue sigmet - world meteorological · pdf filejapan meteorological agency 1 how to...

Documents