Općenito o GAFOR-u

GAFOR (General Aviation FORecast) je prognoza otvorenosti prethodno definiranih ruta za generalnu avijaciju u ovisnosti o horizontalnoj vidljivosti i podnici BKN/OVC naoblake.

Radi se o karti na kojoj su nacrtane rute i nad svakom rutom je nacrtana info-kućica u kojoj se nalazi prognoza otvorenosti te rute u razdoblju od šest sati, te eventualno pojave koja smanjuje kategoriju otvorenosti rute.

Slika 1: primjer GAFOR-a

 

Otvorenost ruta

Otvorenost ruta iskazuje se pomoću slova O (Open), D (Difficult), M (Marginal) i X (Closed), a određuje se prema kriterijima horizontalne vidljivosti i baze niske BKN ili OVC naoblake.

 

Slika 2: Grafički prikazana ovisnost otvorenosti ruta o horizontalnoj vidljivosti i bazi BKN/OVC naoblake.

 

Pojave koje se prognoziraju u GAFOR-u:

 

Tabela 1: Prognozirane pojave u GAFOR-u poredane po prvenstvu izdavanja

 

Vrijeme izdavanja i period važenja

GAFOR se izdaje tri puta dnevno u zimskom razdoblju i 5 puta u ljetnom, a važi 6 sati. Period važenja dijeli se na tri dvosatna intervala. Svakom dvosatnom intervalu u GAFOR se pridružuje simbol (slovo) otvorenosti koja će prevladavati tijekom tog intervala. Intervali koji padaju prije izlaska i poslije zalaska sunce ne prognoziraju se, već se označavaju s "/".

 

                     Izdano u:

 

Mjesec

u godini:

02:30

 

(vrijedi 03-09)

05:30 UTC

 

(vrijedi 06-12)

08:30 UTC

 

(vrijedi 09-15)

11:30 UTC

 

(vrijedi12-18)

14:30 UTC

 

(vrijedi 15-21)

11, 12, 01, 02

 

06-08, 08-10, 10-12

09-11,11-13, 13-15

 

12-14, 14-16, /

 

03, 04

/, 05-07, 07-09

 

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, 16-18

15-17, 17-19, /

05, 06, 07, 08

03-05, 05-07, 07-09

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, 16-18

15-17, 17-19, 19-21

09, 10

/, 05-07, 07-09

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, 16-18

15-17, 17-19, /

Tabela 2: termini izdavanja GAFOR-a i periodi važenja
 

Info-kućica

Info-kućica nad rutom sadrži prognozu otvorenosti rute u svakom dvosatnom intervalu i pripadajući ID (broj) rute.

Slika 3: Objasnjenje primjera info kućice: na ruti 12 u prva dva sata prognoze kriterij otvorenosti bit će "otvoreno". U druga dva sata kriterij će biti "rubno" radi sumaglice na ruti, a zadnja dva sata "zatvoreno" zbog magle.

 

Rute

Rute su pruge širine 1200m. Svaka ruta ima svoju referentnu visinu, odnosno nadmorsku visinu najviše geografske prepreke. Referentne visine su zaokružene na 100ft na gornju vrijednost (npr. ako je RV=802 ft AMSL, zaokružena je na 900 ft AMSL).

Neke rute završavaju na ulaznim točkama u CTR, koje je meteorološki je pokriveno METAR i TAF izvješćima.

Tabela 3: Popis novih i starih ruta, promjena i pripadajućih referentnih visina.

 

GAFOR-a bilteni

Zaglavlje biltena s kategorijama otvorenosti je FB, dok FR bilten sadržava prognozirane pojave.

Kratice pojava u biltenu FR su sljedeće:

FG = magla

BR = sumaglica

RA = kiša

SN = snijeg

SHRA = pljusak

LC = niska naoblaka

Primjer FR biltena:

FRRH41 LDZM 211130

LDZO 1218 01// 02// 03// 04// 05// 06// 07// 08// 09// 10// 11// 12LC/LC/LC13BR/BR/BR 14FG/FG/FG 15RA/RA/RA 16SHRA/SHRA/SHRA 17SN/SN/SN 18// 19//20// 21// 22// 23// 24//=

 

Primjer FB biltena:

FBRH41 LDZM 211130

LDZO 1218 01OOO 02OOO 03OOO 04OOO 05OOO 06OOO 07OOO 08OOO 09OOO 10OOO 11OOO 12DDD 13MMM 14XXX 15MMM 16DDD 17MMM 18OOO 19OOO 20OOO 21OOO22OOO 23OOO 24OOO=

 

Dodatna objašnjenja i informacije

Dodatna objašnjenja i informacije mogu se dobiti kod:

 

Stjepko Jančijev, stjepko.jancijev@crocontrol.hr , tel. 01/6259360

About GAFOR

GAFOR (General Aviation FORecast) is a forecast of the state of previously defined routes for general aviation depending on horizontal visibility and low BKN/OVC cloud base.

GAFOR is a chart with drawn routes. Above each route there is an info-box with a forecast of the state of the route, and possibly weather phenomen which caused degradation of the state of the route.

Figure 1: GAFOR example

 

State of the routes

The state of the routes is presented with the letters O (Open), D (Difficult), M (Marginal) and X (Closed). It is determined by the horizontal visibility and low BKN/OVC cloud base criteria.

The dependence of the state of the routes on horizontal visibility and BKN/OVC cloud base is shown graphically:

Figure 2. A graphical presentation of the state of the routes criteria

 

Weather phenomena forecasted in GAFOR

Table 1: Weather phenomena forecasted in GAFOR listed by issuance priority

 

Time of issuance and validity

GAFOR is issued three times a day in winter period and five times a day in the summer period with a validity of 6 hours. The period of validity is divided into three two-hour intervals. Each two-hour interval has its forecast of the prevailing state of the route. Intervals before sunrise and after sunset are not forecasted but marked as "/".

                     Issued at:

 

Month

of the year:

02:30

 

(valid 03-09)

05:30 UTC

 

(valid 06-12)

08:30 UTC

 

(valid 09-15)

11:30 UTC

 

(valid 12-18)

14:30 UTC

 

(valid 15-21)

11, 12, 01, 02

 

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, /

 

03, 04

/, 05-07, 07-09

 

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, 16-18

15-17, 17-19, /

05, 06, 07, 08

03-05, 05-07, 07-09

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, 16-18

15-17, 17-19, 19-21

09, 10

/, 05-07, 07-09

06-08, 08-10, 10-12

09-11,11-13, 13-15

12-14, 14-16, 16-18

15-17, 17-19,  /

Table 2: Time of issuance and period of validity

 

Info-box

The Info-box above the route contains the route ID (number) and the forecast for each two-hour interval.

Figure 3. Info-box explanation: On route 12 in the first two hours the route status will be "Open". In the following two hours the status will be "Marginal" due to mist on the route, and in the last two hours the status will be "Closed" due to to fog.

 

Routes

Routes are defined as stripes 1200m wide. Each route has its reference height, i.e. the altitude of the highest geographical obstacle. Referent Altitudes are rounded-up to 100ft (eg. If RA=802 ft AMSL, then it is rounded up to 900 ft AMSL). Some routes end at entry points in CTRs. The area inside CTRs is meteorologically covered with METAR and TAF reports.

Table 3. List of new and old routes, changes and reference heights.

 

GAFOR Bulletin Change

The GAFOR Bulletin is FB and FR Bulletin contains weather phenomena.

Weather phenomena in FR Bulletin:

FG = fog

BR = mist

RA = rain

SN = snow

SHRA = shower

LC = low clouds

 

FR Bulletin example:

FRRH41 LDZM 211130
LDZO 1218 01// 02// 03// 04// 05// 06// 07// 08// 09// 10// 11// 12LC/LC/LC13BR/BR/BR 14FG/FG/FG 15RA/RA/RA 16SHRA/SHRA/SHRA 17SN/SN/SN 18// 19//20// 21// 22// 23// 24//=
 

FB Bulletin example:

FBRH41 LDZM 211130
LDZO 1218 01OOO 02OOO 03OOO 04OOO 05OOO 06OOO 07OOO 08OOO 09OOO 10OOO 11OOO 12DDD 13MMM 14XXX 15MMM 16DDD 17MMM 18OOO 19OOO 20OOO 21OOO22OOO 23OOO 24OOO=

 

 

Additional explanation and information

For additional explanation and information please contact:

Stjepko Jančijev, stjepko.jancijev@crocontrol.hr , tel. +385 1 6259 360