AC 00-45F

Change 1Historical

Advisory circular · Aviation Weather Services

Approved
July 1, 2008
Last reviewed
September 13, 2024
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This entire document series, all through the H Revision, is canceled.
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AC00-45F
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AC00-45F CHG 2
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AC 00-45 · 10 versions
Revision
F, change 1
14 CFR parts
1

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 21, 2025.

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Page 232Open in PDF

Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-1 7 FORECAST TEXT PRODUCTS

7.1 Area Forecasts (FA) An Area Forecast (FA) is a forecast in an abbreviated plain language of specified weather phenomena covering a flight information region or other area designated by the meteorological authority. The Area Forecast in conjunction with the AIRMETs and SIGMETs are used to determine forecast enroute weather and to interpolate conditions at airports which do not have a Terminal Aerodrome Forecast (TAF).

Note…Hazardous weather (e.g., IFR, icing, turbulence, etc.) meeting AIRMET or SIGMET criteria are not forecast in the CONUS or Hawaii FAs. Valid AIRMETs and SIGMETs must be used in conjunction with the FA to determine hazardous weather information for the flight.

All Area Forecasts are available on the Aviation Weather Center (AWC) web site at:

http://aviationweather.gov/products/fa/.

Alaska Area Forecasts can also be found on the Alaska Aviation Weather Unit (AAWU) web site at: http://aawu.arh.noaa.gov/areaforecasts.php

7.1.1 Area Forecast Issuance Area forecasts are issued by the following offices for the following areas:

The Aviation Weather Center (AWC)

o Conterminous U.S (CONUS) - Six (6) FAs covering separate geographical areas of the CONUS, excluding the Gulf of Mexico coastal waters west of 85W (Figure 7-1).

o Gulf of Mexico: The northern Gulf of Mexico, including the Houston Oceanic FIR, the Gulf of Mexico portion of the Miami Oceanic FIR, and the coastal waters west of 85W longitude (Figure 7-1 and 7-2).

o Caribbean Sea: Portions of the Gulf of Mexico (south of the Houston Oceanic FIR to approximately 22N latitude), the Caribbean Sea and adjacent portions of the North Atlantic (Figure 7-3).

The Alaskan Aviation Weather Unit (AAWU)

o Alaska: Seven (7) FAs covering separate geographical areas of Alaska and the adjacent coastal waters, including the Pribilof Islands and Southeast Bering Sea (Figure 7-5).

WFO Honolulu, Hawaii

o Hawaii: The main Hawaiian Islands and adjacent coastal waters extending out 40 nautical miles from the coastlines (Figure 7-4).

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 SFO San Francisco

CHI BOS Salt Lake City NSLC Chicago Boston

•DFW MIA® Dallas/Fort Worth Miami GULF of Mexico Figure 7-1. AWC Area Forecast Regions- Contiguous U.S.

Coastal Waters FAGX20 Gulf of Mexico Houston Miami Oceanic FIR Oceanic FIR Figure 7-2. AWC Area Forecast Region and WMO Header - Gulf of Mexico AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-2

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-3

Figure 7-3. AWC Area Forecast Region and WMO Header - Caribbean

Figure 7-4. WFO Honolulu Area Forecast Region and WMO header - Hawaii

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-4

Figure 7-5. AAWU Flight Advisory and Area Forecast Zones - Alaska

Table 7-1. AAWU Area Forecast Zones – Alaska 1 Arctic Coast Coastal 14 Southern Southeast Alaska 2 North Slopes of the Brooks Range 15 Coastal Southeast Alaska 3 Upper Yukon Valley 16 Eastern Gulf Coast 4 Koyukuk and Upper Kobuk Valley 17 Copper River Basin 5 Northern Seward Peninsula-Lower Kobuk Valley 18 Cook Inlet-Susitna Valley 6 Southern Seward Peninsula-Eastern Norton Sound 19 Central Gulf Coast 7 Tanana Valley 20 Kodiak Island 8 Lower Yukon Valley 21 Alaska Peninsula-Port Heiden to Unimak Pass 9 Kuskowim Valley 22 Unimak Pass to Adak 10 Yukon-Kuskowim Delta 23 St. Lawrence Island-Bering Sea Coast 11 Bristol Bay 24 Adak to Attu 12 Lynn Canal and Glacier Bay 25 Pribilof Islands and Southeast Bering Sea 13 Central Southeast Alaska

7.1.2 Area Forecast Standardization All Area Forecasts follow these standards:

All heights or altitudes are referenced to above mean sea level (AMSL), unless otherwise noted (i.e., prefaced by AGL or CIG), and annotated using the height in hundreds of feet, consisting of three digits (e.g., 040). For heights at or above 18,000

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-5 feet, the level is preceded by FL to represent flight levels (e.g., FL180). Tops are always referenced to AMSL.

References to latitude and longitude are in whole degrees and minutes following the model: Nnn[nn] or Snn[nn], Wnnn[nn] or Ennn[nn] with a space between latitude and longitude and a hyphen between successive points. Example: N3106 W07118 – N3011 W7209

Messages are prepared in abbreviated plain language using contractions from the Federal Aviation Administration (FAA) Order 7340.1Z for domestic products and International Civil Aviation Organization (ICAO) document 8400for international products issued for Oceanic FIRs. A limited number of non-abbreviated words, geographical names and numerical values of a self-explanatory nature may also be used.

Weather and obstructions to visibility are described using the weather abbreviations for surface weather observations (METAR/SPECI). See the Federal Meteorological Handbook (FMH) No. 1 – Surface Observations or Section 3.1 of this document.

Heights are identified as follows:

o For heights below 3,000 feet, increments are in 100’s of feet o For heights from 3,000 to 5,000 feet, increments are in 500’s of feet o For heights greater than 5,000 feet, increments are in 1,000’s of feet.

7.1.3 Area Forecast Issuance Schedule Area forecasts are scheduled products issued at the following times.

Table 7-2. Area Forecast (FA) Issuance Schedule Boston and Miami (UTC) Chicago and Fort Worth (UTC) San Francisco and Salt Lake City (UTC) Gulf of Mexico (UTC) Caribbean (UTC) Hawaii (UTC) Alaska (UTC) 1st Issuance 0845 DT 0945 ST 0945 DT 1045 ST 1045 DT 1145 ST 0130 0330 0340 0145 DT 0245 ST 2nd Issuance 1745 DT 1845 ST 1845 DT 1945 ST 1945 DT 2045 ST 1030 0930 0940 0745 DT 0845 ST 3rd Issuance 0045 DT 0145 ST 0145 DT 0245 ST 0245 DT 0345 ST 1830 1530 1540 0145 DT 1445 ST 4th Issuance N/A N/A N/A N/A 2130 2140 1945 DT 2045 ST Note: DT - Daylight Time, ST - Standard Time

7.1.4 Area Forecast Amendments Area Forecasts are under continuous review and amended at the discretion of the forecaster.

“AMD” is included after the date/time group on the FAA product line. The date/time group on the WMO and FAA lines is updated to indicate the time of the correction. The ending valid time remains unchanged.

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-6

7.1.5 Area Forecast Corrections Area Forecasts containing errors are corrected. “COR” is included after the date/time group on the FAA product line. The date/time group on the WMO and FAA lines is updated to indicate the time of the correction. The ending valid time remains unchanged.

7.1.6 Area Forecast Format – Conterminous U.S. (CONUS) Area forecasts issued for the conterminous U.S. (CONUS) cover the airspace between the surface and 45,000 feet AMSL and include the following elements.

Synopsis: brief discussion of the 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 for each state or group of states including the following elements.

o Cloud amount (SCT, BKN or OVC) for clouds with bases higher than or equal to 1,000 feet AGL and below FL180 o Cloud bases and tops (AMSL) associated with the above bullet o Precipitation o Visibilities between 3 and 6 statute miles (SM) and obstruction(s) to visibility o Sustained surface winds 20 knots or greater

12 to 18-hour categorical outlook: IFR, marginal VFR (MVFR), or VFR, including expected precipitation and/or obstruction(s) to visibility

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-7

Figure 7-6. Area Forecast – CONUS Communication and Product Header Example

Table 7-3. Decoding a CONUS Area Forecast Communication and Product Header Line Content Description 1 DFW Area Forecast region identifier C Indicates VFR clouds and weather forecast FA Product type 120945 Issuance and beginning of valid date/time (UTC) 2 SYNOPSIS AND VFR CLDS/WX Statement of weather information contained in this forecast message 3 SYNOPSIS VALID UNTIL 130400 Synopsis valid date and time 4 CLDS/WX VALID UNTIL 122200…OTLK VALID 122200-130400 The clouds and weather section valid time. The valid date and time of the outlook.

5 OK TX AR TN MS AL AND CSTL WTRS Description of the area for which the FA is valid.

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-8

Figure 7-7. Area Forecast - Clouds and Weather Element Example

The “Clouds and Weather” element above is decoded as follows:

South central and southeast Texas:

Scattered to broken bases at 1,000 feet above ground level (AGL). Tops at 3,000 feet above mean sea level (MSL). Visibility 3 to 5 statute miles in mist. Between 1400 and 1600 UTC…clouds bases becoming scattered at 3,000 feet AGL. 1900 UTC…scattered bases at 5,000 feet AGL. 12 to 18 hour categorical outlook…VFR.

Oklahoma:

Panhandle and northwest…scattered bases at 3,000 feet AGL, scattered to broken bases at 10,000 feet AGL. Tops at flight level 20,000 feet MSL. 1500 UTC…scattered bases at 4,000 feet AGL, scattered bases at 10,000 feet AGL. After 2000 UTC…scattered thunderstorms with rain showers developing..a few possible severe. Cumulonimbus tops to flight level 45,000 feet MSL. Outlook…VFR.

Remainder of the state…Ceilings broken at 2,000 feet AGL. Tops at 5,000 feet MSL.

Visibilities 3 to 5 statute miles in mist. 1400 UTC…scattered to broken bases at 4,000 feet AGL.

Tops at 10,000 feet MSL. 1800 UTC…ceilings broken 6,000 feet AGL. Tops to flight level 18,000 feet MSL. 2200 UTC…scattered thunderstorm with rain showers developing…a few possibly severe. Cumulonimbus tops above flight level 45,000 feet MSL. 12-18 hour categorical outlook…VFR.

7.1.6.1 Area Forecast – Conterminous U.S. (CONUS) Examples

7.1.6.1.1 Area Forecast – BOS Example

FAUS41 KKCI 150845 (ICAO product header) FA1W (NWS AWIPS Communication header) BOSC FA 150845 (Area forecast region, product type, issuance date/time)

SYNOPSIS AND VFR CLDS/WX SYNOPSIS VALID UNTIL 160300

Page 240Open in PDF

Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-9 CLDS/WX VALID UNTIL 152100...OTLK VALID 152100-160300

ME NH VT MA RI CT NY LO NJ PA OH LE WV MD DC DE VA AND CSTL WTRS

SEE AIRMET SIERRA FOR IFR CONDS AND MTN OBSCN.

TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND IFR CONDS.

NON MSL HGTS DENOTED BY AGL OR CIG.

SYNOPSIS...CDFNT EXTDD FROM CSTL SXNS OF ME SWWD THRU LOW OVR WRN MA...THEN CONTD SWWD ACRS SERN PA AND NERN WV INTO A LOW OVR SWRN KY. FNT WILL SAG SLOLY SWD DURG PD. BY 03Z...CDFNT WILL EXTD FROM

SRN NEW ENG CSTL WTRS ACRS THE DELMARVA PENINSULA AND ALG THE NC/TN BDR INTO A LOW PRES SYS OVR NWRN AL.

.

ME NH VT CIG BKN-OVC020 LYR FL240. OCNL -RA BR. BECMG 1518 OCNL -SN BR OVR NRN PTNS AREA. OTLK...MVFR CIG.

.

MA RI CT SCT050 BKN080-100 LYR FL240. OCNL VIS 3SM BR. BECMG 1215 WRN MA/CT ISOL -TSRA CB TOP FL310. BECMG 1518 CIG OVC 010-020. OCNL -RA BR.

OTLK...MVFR CIG RA BR.

.

NY LO SERN NY...SCT050 BKN080-100 LYR FL240. OCNL VIS 3SM BR. BECMG 0912 WDLY SCT -TSRA CB TOPS FL310. BECMG 1518 CIG OVC 010-020. OCNL -RA BR.

OTLK...MVFR CIGS RA BR.

NRN AND WRN NY/LO...SCT-BKN015-025 BKN-OVC030-050 LYR FL240. OCNL -RA BR. BECMG 1215 OCNL -SN BR. BECMG 1821 SCT 030-050 BKN100 TOP 150.

OTLK...VFR.

.

PA NJ NRN AND WRN PA...CIG OVC010-020 LYR FL240. OCNL –RA BR. BECMG 1821 BKN-SCT015-025 OVC-BKN050 TOP 150. OTLK...MVFR CIG BR.

SERN PA/NJ...BKN050 BKN-OVC080-100 LYR FL240. WDLY SCT –TSRA CB TOP FL330. BECMG 1518 CIG OVC010-020. OCNL –RA BR. OTLK...MVFR CIG RA BR.

.

OH LE CIG OVC020 LYR FL240. OCNL -RA BR. BECMG 1518 NRN OH/LE PTNS...OCNL -RASN BR. BECMG 1821 CIGS BKN-SCT015-025 OVC-BKN050 TOP 150.

OTLK...MVFR CIG BR.

.

WV SCT-BKN060 BKN-OVC100-120 LYR FL240. OCNL VIS 3SM BR. BECMG 1518 WDLY SCT -SHRA/ISOL –TSRA CB TOPS FL330. BECMG 1821 CIG OVC010-020. OCNL - RA BR. OTLK...MVFR CIG RA BR.

.

VA MD DC DE SCT-BKN060 BKN-OVC100-120 LYR FL240. OCNL VIS 3SM BR. BECMG 1518 WDLY SCT -SHRA/ISOL –TSRA CB TOP FL330. BECMG 1821 CIG OVC010-020. OCNL -RA BR. OTLK...MVFR CIG RA BR.

.

CSTL WTRS

Page 241Open in PDF

Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-10 NEW ENG CSTL WTRS...SCT050 BKN080-100 LYR TO FL240. OCNL VIS 3SM BR.

SCT AREAS OF ST AND BR/FG. BECMG 1518 ISOL -TSRA CB TOP FL310. BECMG 1821 CIG OVC 010-020. OCNL -RA BR. OTLK...MVFR CIGS RA BR.

RMNDR CSTL WTRS...SCT050 SCT-BKN080-100 LYR TO FL240. BECMG 1821 WDLY SCT -SHRA/ISOL –TSRA CB TOP FL310. OTLK...MVFR CIG SHRA BR.

7.1.6.1.2 Area Forecast – DFW Amendment Example

FAUS44 KKCI 121115 (ICAO product header) FA4W (NWS AWIPS Communication header) DFWC FA 121115 AMD (Area forecast region, product type, issuance date/time)

SYNOPSIS AND VFR CLDS/WX SYNOPSIS VALID UNTIL 130400 CLDS/WX VALID UNTIL 122200...OTLK VALID 122200-130400

OK TX AR TN LA MS AL

SEE AIRMET SIERRA FOR IFR CONDS AND MTN OBSCN.

TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND IFR CONDS.

NON MSL HGTS DENOTED BY AGL OR CIG.

SYNOPSIS...10Z LOW S PLAINS OF TX WITH CDFNT TO NR BIG BEND..STNR FNT FM LOW-NRN LA. BY 04Z LOW NR JCTN WITH STNR FNT TO NRN LA-SRN AL..CDFNT EXTDG SWD FM LOW. HIGH OVR NERN GULF MEX.

.

OK…UPDT PNHDL...CIG OVC010 TOP 100. TIL 16Z VIS 3-4SM BR. BECMG 1618 CIG OVC020. OTLK...VFR.

RMNDR WRN HLF...CIG OVC010 TOP TO 080. TIL 16Z VIS 3-5SM BR. 18Z CIG BKN025. WDLY SCT -SHRA. OTLK...MVFR CIG SHRA.

ERN HLF...CIG BKN-OVC015 TOP 060. TIL 15Z VIS 3-5SM BR. BECMG 1518 CIG BKN050 BKN100 TOP 150. OTLK...VFR.

.

NWRN TX PNHDL...CIG OVC010 TOP 100. VIS 3-5SM BR. BECMG 1618 CIG OVC015.

OTLK...MVFR CIG.

S PLAINS...CIG OVC010-020 LYR FL250. N PTN SCT VIS 3-5SM -SHRA. S PTN OCNL 3-5SM BR. BECMG THRUT 1618 CIG BKN-OVC025 TOP 100. OTLK...MVFR CIG.

.

SWRN TX EXTRM W TX/BIG BEND...SCT-BKN100 LYR FL250. 20Z SCT080 BKN140. WDLY SCT -TSRA. CB TOP FL400. OTLK...VFR TSRA.

RMNDR...SCT100. 18Z AGL SCT050 SCT100. WDLY SCT -TSRA. CB TOP FL400.

OTLK...VFR TSRA.

.

N CNTRL TX WRN HLF...CIG OVC010 TOP 100 LYR FL250. TIL 16Z VIS OCNL 3-5SM BR.

BECMG 1820 CIG BKN-OVC030. WDLY SCT -SHRA/-TSRA. CB TOP FL400.

OTLK...MVFR CIG SHRA TSRA.

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-11 ERN HLF...CIG OVC010 TOP 080 BKN150 LYR FL250. VIS 4-5SM SHRA BR.

BECMG 1518 CIG OVC020 TOP 080. OTLK...VFR.

NERN TX CIG OVC010-020 BKN100 LYR FL250. VIS 4-5SM -RA BR. OTLK...MVFR CIG.

.

SERN TX CSTL PLAINS...CIG OVC010 TOP 040. VIS 3-4SM BR. SCT TSRA POSS SEV. CB TOP FL400. OTLK...MVFR CIG TSRA.

INLAND...CIG OVC010 LYR FL250. VIS 3-5SM SHRA BR. SCT TSRA POSS SEV.

CB TOP FL400. OTLK...MVFR CIG SHRA TSRA.

.

S CNTRL TX LWR RIO GRANDE VLY...CIG OVC-BKN010 TOP 025. 16Z AGL SCT030 BKN050 TOP

100. AFT 18Z WDLY SCT -TSRA CB TOP FL400. OTLK...VFR TSRA.

CSTL PLAINS...CIG OVC010 TOP 100 LYR FL250. SCT TSRA POSS SEV. CB TOP FL400. 18Z CIG BKN-OVC025 TOP 100. SCT –TSRA CB TOP FL350. OTLK...MVFR CIG TSRA.

HILL COUNTRY/RMNDR...CIG OVC010 LYR FL250. BECMG 1618 CIG OVC020.

OTLK...MVFR CIG TSRA.

.

AR NRN HLF...AGL SCT050 SCT-BKN100 BKN LYR FL250. OTLK...VFR.

SRN HLF...SCT-BKN120 LYR FL250. BECMG 1618 CIG BKN-OVC030 TOP 100.

WDLY SCT -SHRA. OTLK...VFR SHRA TSRA.

.

LA NRN/CNTRL/SWRN...AGL SCT020. BECMG 1215 CIG BKN-OVC025 TOP100. VIS OCNL 5SM -SHRA. AFT 14Z WDLY SCT TSRA. CB TOP FL400. OTLK...MVFR CIG SHRA TSRA.

SERN...AGL SCT010. TIL 15Z VIS 3-5SM BR. 18Z AGL SCT030 BKN080 LYR FL250. OTLK...VFR.

.

TN WRN...SKC. BECMG 1820 SCT050. OTLK...VFR.

MID...SKC. OTLK...VFR.

ERN...SKC. OTLK...VFR.

.

MS SKC BLW FL180. 14Z EXTRM S VIS 3-5SM BR. 18Z AGL SCT040. OTLK...VFR SHRA.

.

AL NRN HLF...SKC BLW FL180. OTLK...VFR.

SRN HLF...SCT-BKN090 TOP150. CSTL PLAINS VIS 3-5SM BR. 15Z AGL SCT030.

OTLK...VFR.

7.1.7 Area Forecast Format – Gulf of Mexico (FAGX) Area Forecasts issued for the Gulf of Mexico (FAGX) cover the airspace between the surface and 45,000 feet AMSL (Above Mean Sea Level) and include the following elements with each geographical section having an entry even if it is negative.

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Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 7: Forecast Text Products Page 7-12

Synopsis: This is a brief discussion of the significant synoptic weather affecting the FAGX area during the entire 24-hour valid period.

Significant Clouds and Weather: This is a description of the significant clouds and weather for the first 12-hours including the following elements.

o Cloud amount (SCT, BKN or OVC) for clouds with 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 (LIFR, IFR, MVFR or VFR)

Icing and Freezing Level: Moderate or severe icing and freezing level. For the coastal waters portion of the FAGX, users will be referred to the appropriate CONUS AIRMET.

Turbulence: Moderate or greater turbulence. For the coastal waters portion of the FAGX, users will be referred to the appropriate CONUS AIRMET.

7.1.7.1 Area Forecast – Gulf of Mexico (FAGX) Example

FAGX20 KKCI 091812 (ICAO product header) OFAGX (NWS AWIPS Communication header) SYNOPSIS VALID TIL 101900Z FCST...091900Z-100700Z OTLK...100700Z-101900Z

INTERNATIONAL OPERATIONS BRANCH

AVIATION WEATHER CENTER KANSAS CITY MISSOURI .

CSTL WATERS FROM COASTLINE OUT TO HOUSTON OCEANIC FIR AND GLFMEX MIAMI OCEANIC FIR AND W OF 85W. HOUSTON OCEANIC FIR AND GLFMEX MIAMI OCEANIC FIR.

.

TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND IFR CONDS. HGTS MSL.

.

01 SYNOPSIS...HIGH PRES OVR NRN GLFMEX.

.

02 SIGNIFICANT CLD/WX...

.

CSTL WATERS...

SCT020. OTLK...VFR.

.

HOUSTON OCEANIC FIR… SCT020. OTLK...VFR.

.

GLFMEX MIAMI OCEANIC FIR...

SCT020. OTLK...VFR.

.

03 ICE AND FRZLVL...

CSTL WATERS…SEE AIRMETS ZULU WAUS44 KKCI AND WAUS42 KKCI.