Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-13 HOUSTON OCEANIC FIR… NO SGFNT ICE EXP OUTSIDE CNVTV ACT.
GLFMEX MIAMI OCEANIC FIR…NO SGFNT ICE EXP OUTSIDE CNVTV ACT.
FRZLVL…140 THRUT.
.
04 TURB...
CSTL WATERS…SEE AIRMETS TANGO WAUS44 KKCI AND WAUS42 KKCI.
HOUSTON OCEANIC FIR… NO SGFNT TURB EXP OUTSIDE CNVTV ACT.
GLFMEX MIAMI OCEANIC FIR…NO SGFNT TURB EXP OUTSIDE CNVTV ACT.
7.1.8 Area Forecast Format – Caribbean (FACA) Area forecasts issued for the Caribbean (FACA) cover the airspace between the surface and 24,000 feet AMSL and include the following elements. Each geographical section will have an entry even if it is negative.
Synopsis: brief discussion of the synoptic weather affecting the FACA area during the 24-hour valid period.
Significant Clouds and Weather: description of the significant clouds and weather for the first 12 hours including the following elements.
o Cloud amount (SCT, BKN or OVC) for cloud bases below FL180 o Cloud bases and tops associated with the above bullet o Precipitation and thunderstorms o Visibility below 7 SM and obstruction(s) to visibility o Sustained surface winds greater than or equal to 20 knots o 12- to 24-hour categorical outlook (IFR, MVFR or VFR)
Icing and Freezing Level: moderate or greater icing and freezing level
Turbulence: moderate or greater turbulence
7.1.8.1 Area Forecast – Caribbean (FACA) Example
FACA20 KKCI 121530 (ICAO product header) OFAMKC (NWS AWIPS Communication header)
INTERNATIONAL OPERATIONS BRANCH
AVIATION WEATHER CENTER KANSAS CITY MISSOURI VALID 121600-130400 OUTLOOK...130400-131600 .
ATLANTIC S OF 32N W OF 57W...CARIBBEAN...GULF OF MEXICO BTN 22N AND 24N.
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TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND IFR CONDS. SFC TO 400 MB.
.
SYNOPSIS...WK CDFNT EXTDS FM NR 28N60W TO 23N63W TO THE MONA PASSAGE. CDFNT WL MOV EWD AND WKN TODAY. EXP NARROW BAND OF CLDS WITH ISOL SHRA INVOF CDFNT.
.
SIGNIFICANT CLD/WX...
ERN MONTERREY FIR...NRN MERIDA FIR
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-14 SCT025 SCT060. OTLK...VFR.
.
ATLC SWRN NEW YORK FIR...SAN JUAN FIR NW OF CDFNT...SCT025 SCT060. LYR OCNL BKN. TOP 120. ISOL SHRA.
OTLK...VFR.
VCNTY CDFNT...SCT025 BKN060. OCNL BKN025. TOP 120. WDLY SCT SHRA. ISOL TSRA TIL 20Z. OTLK...VFR SHRA.
SE OF CDFNT...SCT025 SCT060. ISOL SHRA. OTLK...VFR.
.
ATLC MIAMI FIR SCT025 SCT060. LYR OCNL BKN. TOP 120. ISOL SHRA. OTLK...VFR.
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WRN PIARCO FIR...NRN MAIQUETIA FIR...CURACAO FIR BTN 61W-63W...SCT025 BKN060. OCNL BKN025. TOP 120. WDLY SCT SHRA. OTLK...VFR SHRA.
RMNDR...SCT025 SCT060. ISOL SHRA. OTLK...VFR.
.
SANTO DOMINGO FIR...PORT-AU-PRINCE FIR SCT025 SCT060. LYR OCNL BKN. TOP 120. ISOL SHRA. OTLK...VFR.
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NRN BARRANQUILLA FIR...NRN PANAMA FIR SCT025 SCT060. ISOL SHRA. SFC WND NE 20-25KT. OTLK...VFR.
.
KINGSTON FIR...NERN CNTRL AMERICAN FIR...HABANA FIR SCT025 SCT060. ISOL SHRA. OTLK...VFR.
.
ICE AND FRZLVL...
NO SGFNT ICE EXP OUTSIDE CNVTV ACT.
FRZLVL... 145-170.
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TURB...
NO SGFNT TURB EXP OUTSIDE CNVTV ACT.
7.1.9 Area Forecast Format - Hawaii Area forecasts issued for Hawaii cover the airspace between the surface and 45,000 feet AMSL and include the following elements.
Synopsis: brief discussion of the significant synoptic weather affecting the FA area during the 18-hour valid period.
Clouds and Weather: description of the clouds and weather for the first 12-hour period including the following elements.
o Cloud amount (SCT, BKN or OVC) with bases and tops o Visibilities of 6 SM or less with obstruction(s) to visibility o Precipitation and thunderstorms o Sustained surface winds 20 knots or greater
12- to 18-hour categorical outlook: IFR, marginal MVFR, or VFR, including expected precipitation and/or obstructions to visibility
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-15
7.1.9.1 Area Forecast – Hawaii Example
FAHW31 PHFO 080940 (ICAO product header) FA0HI (NWS AWIPS Communication header) .
HNLC FA 080940 (Area forecast region, product type, issuance date/time)
SYNOPSIS AND VFR CLD/WX SYNOPSIS VALID UNTIL 090400 CLD/WX VALID UNTIL 082200...OUTLOOK VALID 082200-090400 .
SEE AIRMET SIERRA FOR IFR CLD AND MT OBSC.
TS IMPLY SEV OR GREATER TURB SEV ICE LOW LEVEL WS AND IFR COND.
NON MSL HGT DENOTED BY AGL OR CIG.
.
SYNOPSIS...SFC HIGH FAR N PHNL NEARLY STNR.
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BIG ISLAND ABOVE 060.
SKC. 20Z SCT090. OUTLOOK...VFR.
.
BIG ISLAND LOWER SLOPES...COAST AND ADJ WATERS FROM UPOLU POINT TO CAPE KUMUKAHI TO APUA POINT.
SCT030 BKN050 TOPS 080 ISOL BKN030 VIS 3-5SM -SHRA BR. 21Z SCT030 SCT- BKN050 TOPS 080 ISOL BKN030 5SM -SHRA. OUTLOOK...VFR.
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BIG ISLAND LOWER SLOPES…COAST AND ADJ WATERS FROM APUA POINT TO SOUTH CAPE TO UPOLU POINT. SKC. 21Z SCT-BKN060 TOPS 080. 23Z SCT030 SCT- BKN060 TOPS 080 ISOL BKN030 -SHRA. OUTLOOK...VFR.
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BIG ISLAND LOWER SLOPES…COAST AND ADJ WATERS FROM SOUTH CAPE TO PHKO TO UPOLU POINT.
SCT050 ISOL BKN050 TOPS 080. 18Z FEW050. 23Z SCT-BKN050 TOPS 080.
OUTLOOK...VFR.
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N AND E FACING SLOPES...COAST AND ADJ WATERS OF THE REMAINING ISLANDS.
SCT020 BKN045 TOPS 070 TEMPO BKN020 VIS 3-5SM -SHRA...FM OAHU EASTWARD ISOL CIG BLW 010 AND VIS BLW 3SM SHRA BR WITH TOPS 120. 22Z SCT025 SCT-BKN050 TOPS 070 ISOL BKN025 3-5SM -SHRA. OUTLOOK...VFR.
.
REST OF AREA.
SCT035 SCT-BKN050 TOPS 070 ISOL BKN030 -SHRA. 20Z SCT050 ISOL SCT030 BKN045 TOPS 070 -SHRA. OUTLOOK...VFR.
7.1.10 Area Forecast Format - Alaska Area forecasts issued for Alaska cover the airspace between the surface and 45,000 feet AMSL and include the following elements. Clouds and weather, turbulence and icing information is included in each geographical zone.
Synopsis: a brief description of the significant synoptic weather affecting the FA area during the first 18 hours of the forecast period.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-16 Clouds and Weather: a description of the clouds and weather for each geographical zone during the first 12 hours of the forecast period including the following elements:
o SIGMET information for thunderstorms and volcanic ash o AIRMET information for IFR ceiling and visibility, mountain obscuration, and strong surface winds o Cloud amount (SCT, BKN or OVC) with bases and tops o Visibilities of 6 SM or less with obstruction(s) to visibility o Precipitation and thunderstorms o Surface wind greater than 20 knots o Mountain pass conditions using categorical terms (for selected zones only) o 12- to 30-hour categorical outlook (VFR, MVFR, and IFR)
Turbulence: a description of expected turbulence conditions including the following elements.
o SIGMET information for turbulence o AIRMET information for turbulence or low level wind shear o Turbulence not meeting SIGMET or AIRMET criteria during the 6- to 12-hour period o If no significant turbulence is forecast, NIL SIG will be entered.
Icing and freezing level: a description of expected icing conditions including the following elements.
o SIGMET information for icing o AIRMET information for icing and freezing precipitation o Icing not meeting SIGMET or AIRMET criteria during the 6- to 12-hour period o Freezing level o If no significant icing is forecast, NIL SIG will be entered followed by the freezing level.
7.1.10.1 Area Forecast – Alaska Example
FAAK48 PAWU 251345 (ICAO product header) FA8H (NWS AWIPS Communication header) ANCH FA 251345 (Area forecast region, product type, issuance date/time) AK SRN HLF EXC SE AK...
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AIRMETS VALID UNTIL 252000 TS IMPLY POSSIBLE SEV OR GREATER TURB SEV ICE LLWS AND IFR CONDS.
NON MSL HEIGHTS NOTED BY AGL OR CIG.
.
SYNOPSIS VALID UNTIL 260800 972 MB BRISTOL BAY LOW WL MOV N TO 50 S PAOM AT 987 MB BY END OF PD.
ASSOCIATED OCCLUDED FRONT FM PALJ..KENNEDY ENTRANCE..SE WL MOV NE TO PAMH..PACV..SE BY 08Z.
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COOK INLET AND SUSITNA VALLEY AB...VALID UNTIL 260200 ...CLOUDS/WX...
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-17 ***AIRMET IFR/MT OBSC***AK RANGE/W SIDE COOK INLET..OCNL CIGS BLW 10 VIS BLW 3SM -RA BR. NC...
OTHERWISE..AK RANGE/W SIDE INLET..SCT005 OVC020 VIS 3-5SM -RA BR.
ELSEWHERE..SCT025 BKN045 OVC080 LYR ABV TO FL250. OCNL BKN025 OVC045 - RA.
COOK INLET..SFC WND NE 20G30 KTS. THRU TERRAIN GAPS..ERN MTS/AK RANGE..SFC WND E 30G60 KTS.
OTLK VALID 260200-262000...MVFR CIG RA WND.
PASSES...LAKE CLARK..MERRILL..RAINY..IFR CIG RA WND. WINDY..MVFR CIG RA. PORTAGE..IFR CIG RA WND.
...TURB...
***SIGMET***KILO 1 VALID 251607/252000 PANC- OCNL SEV TURB FCST BLW 080 WI AN AREA FM TKA-JOH-MDO-AKN-SQA-TKA.
THIS IS THE AREA S OF A PAHZ-PATK LN.
***AIRMET TURB/LLWS***OCNL MOD TURB BLW 120. LLWS. NC...
...ICE AND FZLVL...
***AIRMET ICE***OCNL MOD RIME/MX ICEIC 050-160. FZLVL 050. NC...
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COPPER RIVER BASIN AC...VALID UNTIL 260200 ...CLOUDS/WX...
FEW045 SCT090 BKN-OVC180 TOP FL250.
SFC WND SE G 25 KTS.
WRN MTS..ISOL BKN025 OVC045 4SM -SHRA.
OTLK VALID 260200-262000...VFR.
PASS...TAHNETA..MVFR CIG.
...TURB...
NIL SIG.
...ICE AND FZLVL...
NIL SIG. FZLVL 050.
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CNTRL GLF CST AD...VALID UNTIL 260200 ...CLOUDS/WX...
***AIRMET MT OBSC***MTS OBSCD IN CLDS/PRECIPITATION. NC...
SCT020 OVC040 LYRD ABV TO FL250 -RA.
OCNL SCT005 OVC020 VIS 3-5SM -RA BR.
SFC WND E 20G35 KTS. THRU TRRN GAPS WND E-NE 25G50 KTS.
ALONG KENAI PENINSULA..ISOL CIGS BLW 10 VIS BLW 3SM RA BR.
OTLK VALID 260200-260200..MVFR CIG RA WND.
...TURB...
***SIGMET***KILO 1 VALID 251607/252000 PANC- OCNL SEV TURB FCST BLW 080 WI AN AREA FM TKA-JOH-MDO-AKN-SQA-TKA.
THIS IS THE AREA E OF A JOH-PAMD LN.
***AIRMET TURB/LLWS***OCNL MOD TURB BLW 120. LLWS NR TRRN. NC...
...ICE AND FZLVL...
***AIRMET ICE***OCNL MOD RIME ICEIC 050-160. FZLVL 050. NC...
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KODIAK ISLAND AE...VALID UNTIL 260200 ...CLOUDS/WX...
***AIRMET MT OBSC***MTS OBSCD IN CLDS/PRECIPITATION. NC...
SCT020 OVC040 LYRD ABV TO FL250 -RA.
OCNL SCT005 OVC020 VIS 3-5SM -RA BR.
E SIDE..ISOL CIGS BLW 10 VIS BLW 3SM RA BR.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-18 SFC WND SE G 25 KT.
OTLK VALID 260200-262000...MVFR CIG SHRA WND. AFT 06Z..VFR.
...TURB...
NIL SIG.
...ICE AND FZ LVL...
ISOL MOD RIME ICEIC 030-120. FZLVL 030.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-19
7.2 Terminal Aerodrome Forecast (TAF) A Terminal Aerodrome Forecast (TAF) is a concise statement of the expected meteorological conditions significant to aviation for a specified time period within five statute miles (SM) of the center of the airport’s runway complex (terminal). The TAFs use the same weather codes found in METAR weather reports (Section 2) and can be viewed on the National Weather Service (NWS) Aviation Digital Data Service (ADDS) web site at:
http://adds.aviationweather.noaa.gov/tafs/.
7.2.1 Responsibility TAFs are issued by NWS Weather Forecast Offices (WFOs). A map of U.S. TAF locations is located on Figures 7-8, 7-9, and 7-10.
Figure 7-8. TAF Locations – Western Contiguous United States
Aviation Weather Services, Advisory Circular 00-45F, Revision 1
NWS TAF LOCATIONS KCAR KEUF KELM_ GNV KD&B KMLB ORDI O KFLL Puerto Rico and Virgin Islands
NATIONAL WEATHER SERVICE TIST INCM JANUARY 2006 MIRS GIS GROUP Figure 7-9. TAF Locations - Eastern Contiguous U.S., Puerto Rico and Virgin Islands AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-20
Aviation Weather Services, Advisory Circular 00-45F, Revision 1
NWS TAF LOCATIONS
PAOTOZ FASC
• PAFA
•FAOR PHNY DO PHOE
IN PAGY PHTO PADO
ALASKA HAWAII
WESTERN PACIFIC FAEY International Date Line PLON POEN PGWT PGUM PHIA Equator *S NSTU
NATIONAL WEATHER SERVICE JULY 2004 MIRS GIS GROUP Figure 7-10. TAF Locations - Alaska, Hawaii and Western Pacific AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-21
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-22
7.2.2 Generic Format of the Forecast Text of a NWS-Prepared TAF
TAF or
TAF AMD Type of report
CCCC YYGGggZ YlY1G1G1G2G2 DddffGfmfmKT Location identifier Date/time of forecast origin group Valid period Wind group
VVVV w'w' or NSW NsNsNshshshs or VVhshshs or SKC WShwshwshws/dddftKT Visibility group Significant weather group Cloud and vertical obscuration groups Non-convective low-level wind shear (LLWS) group
TTGGgg Forecast change indicator groups
FMGG GGGeGe TEMPO GGGeGe PROB40GGGeGe “From” group “Temporary” group Probability Forecast
7.2.2.1 Type of Report (TAF or TAF AMD) The report-type header always appears as the first element in the TAF and is produced in two forms: a routine forecast, TAF, and an amended forecast, TAF AMD.
TAFs are amended whenever they become, in the forecaster's judgment, unrepresentative of existing or expected conditions, particularly regarding those elements and events significant to aircraft and airports. An amended forecast is identified by TAF AMD (in place of TAF) on the first line of the forecast text.
7.2.2.2 Location Identifier (CCCC) After the line containing either TAF or TAF AMD, each TAF begins with its four-letter International Civil Aviation Organization (ICAO) location identifier. Figures 7-8, 7-9 and 7-10 contains the locations of NWS issued TAFs.
Examples:
KDFW – Dallas-Fort Worth PANC – Anchorage, Alaska PHNL – Honolulu, Hawaii
7.2.2.3 Date/Time of Forecast Origin Group (YYGGggZ) The date/time of forecast origin group (YYGGggZ) follows the terminal's location identifier. It contains the day of the month in two (2) digits (YY) and time in four (4) digits (GGgg in hours
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-23 and minutes) the forecast is completed and ready for transmission, with a Z appended to denote UTC. This time is entered by the forecaster.
Examples 061737Z The TAF was issued on the 6th day of the month at 1737 UTC.
121123Z The TAF was issued on the 12th day of the month at 1123 UTC.
7.2.2.4 Valid Period (Y1Y1G1G1G2G2) The TAF valid period (Y1Y1G1G1G2G2) is the next group. Scheduled 24-hour TAFs are issued four (4) times per day, at 0000, 0600, 1200, and 1800Z. The first two digits (Y1Y1) are the day of the month for the start of the TAF. The next two digits (G1G1) are the starting hour, and the last two digits (G2G2) are the ending hour of the valid period. A forecast period beginning at midnight UTC is annotated as 00. If the end time of a valid period is at midnight UTC, it is annotated as 24. For example, a 00Z TAF issued on the 9th of the month would have a valid period of 090024.
Examples:
151212 The TAF is valid from 1200 UTC on the 15th of the month until 1200 UTC on the 16th.
230606 The TAF is valid from 0600 UTC on the 23rd of the month until 0600 UTC on the 24th of the month.
011818 The TAF is valid from 1800 UTC on the 1st of the month until 1800 UTC on the 2nd of the month.
060024 The TAF is valid from 0000 UTC on the 6th of the month until 0000 UTC on the 7th of the month.
7.2.2.5 Valid Period of Amended TAFs An amended TAF (TAF AMD) covers all of the remaining valid period of the original scheduled forecast. Expired portions of the amended forecast or references to weather occurring before the issuance time are omitted from the amendment.
In an amended forecast, the date and time of the forecast origin group (YYGGggZ) reflects the time the amended forecast was prepared. In the forecast valid period group (Y1Y1G1G1G2G2), the first four digits (Y1Y1G1G1) reflect the UTC date and time of the beginning of the valid period of the amended TAF.
With an issuance time (YYGGggZ) in the first half hour of any given hour (:00 to :29), the current hour (based on UTC) is used to denote the beginning valid time. For example, an amended TAF issued at 1416Z would be valid from 1400 UTC until the standard ending time of the TAF. For the second half of any given hour (:30 to :59), the next hour (based on UTC) is used for the beginning valid time. For example, an amended TAF issued at 1639Z would be valid from 1700 UTC until the standard ending time of the TAF.
Example:
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-24
Original Amended
TAF TAF AMD PAEN 030540Z 030606... PAEN 031012Z 031006...
The scheduled forecast was sent, and 4 ½ hours later, the forecaster prepared an amendment to the forecast, at 1012Z on the 3rd day of the month.
7.2.2.6 Wind Group (dddffGfmfmKT) The initial time period and any subsequent FM (section 7.1.12.12.1) groups begin with a mean surface wind forecast (dddffGfmfmKT) for the period. Wind forecasts are expressed as the mean three-digit direction (ddd - relative to true north) rounded to the nearest ten degrees and the mean wind speed in knots (ff) for the time period. If wind gusts are forecast (gusts are defined as rapid fluctuations in wind speeds with a variation of 10 knots or more between peaks and lulls), they are indicated immediately after the mean wind speed by the letter G, followed by the peak gust speed expected. KT is appended to the end of the wind forecast group. Any wind speed of 100 knots or more will be encoded in three digits. Calm winds are encoded as 00000KT.
The prevailing wind direction is forecast for any speed greater than or equal to seven (7) knots.
When the prevailing surface wind direction is variable (variations in wind direction of 30 degrees or more), the forecast wind direction is encoded as VRBffKT. Two conditions where this can occur are very light winds and convective activity. Variable wind direction for very light winds must have a wind speed of one (1) through six (6) knots inclusive. For convective activity, the wind group may be encoded as VRBffGfmfmKT, where Gfmfm is the maximum expected wind gusts. VRB is not used in the non-convective LLWS group.
Squalls are forecast in the wind group as gusts (G), but must be identified in the significant weather group (Section 7.2.2.8) with the code SQ.
Examples:
23010KT Wind from 230 degrees “true” (southwest) at 10 knots.
28020G35KT Wind from 280 degrees “true” (west) at 20 knots gusting to 35 knots.
VRB05KT Wind variable at 5 knots. This example depicts a forecast for light winds that are expected to variable in direction.
VRB15G30KT Wind variable at 15 knots gusting to 30 knots. This example depicts winds that are forecast to be variable with convective activity.
00000KT Wind calm
090105KT Wind from 90 degrees at 105 knots