 SUMMARY
OF TROPICAL CYCLONE PRODUCTS
(36kb)
Regardless
of how accurate NHC forecasts of tropical cyclone activity are, they are useless
unless reliable and timely methods are available to get this information to
the mariner. There are many ways that tropical cyclone information is made available
to the mariner. However, knowing which products are available via which source
is often the difficult part in obtaining tropical cyclone information.
Internet
Although internet access at sea can often be an expensive and technically challenging
alternative to obtaining tropical cyclone information, use of this method while
in port is becoming more popular as access costs decrease and personal computer
use among mariners increases.
A
majority of NWS forecasts and warnings are now available on-line from NWS web
servers. Specifically, all tropical cyclone products are available in this format
directly from TPC/NHC. Additionally, these products can also be found via other
National Weather Service and government web servers. Although the Internet is
not part of the National Weather Service's operational data stream and should
never be relied upon as the primary method of obtaining the latest forecast
and warning data, web servers maintained by the National Weather Service are
usually reliable and can serve as a valuable source of information for the Mariner.
TABLE 1 indicates current web sites available for Atlantic tropical cyclone
information. Finally, any active marine warning, including tropical cyclone
related warnings can also be found on the Interactive Weather Information Network
(IWIN) of the Emergency Mangers Weather Information Network (EMWIN) at the following
internet address. http://iwin.nws.noaa.gov/iwin/textversion/nationalwarnings.html
BACK
TO THE TOP
E-mail
TPC/NHC text files & graphic charts are available via email through a NWS
FTPMAIL server. This server allows Mariner's who do not have direct access to
the World Wide Web but who are equipped with an email system to receive NWS
products at sea or in port. Using this service, users can request files from
the NWS and have them automatically e-mailed back to the user. Turnaround is
generally less than three hours, however, performance may vary widely and receipt
cannot be guaranteed. However, this service can be a valuable tool to the Mariner
in obtaining tropical cyclone information as well as other weather information
over open water areas.
To
start using this service, obtain the FTPMAIL help file by:
1.
Sending an email to: ftpmail@ftpmail.nws.noaa.gov
2. Subject Line: Anything that you like
3. Body: help
The
help file that you receive via email will discuss procedures and methods of
obtaining tropical cyclone information along with a listing of available products
using this method. In order to get further information on tropical cyclone specific
data available via this service:
1.
Send an email to: ftpmail@weather.noaa.gov
2. Subject Line: Anything that you like
3. Body of message (case and line sensitive):
open
cd fax
get marine2.txt
quit
This
will generate an email response with a description of tropical cyclone products
and file names along with further instructions on obtaining this particular
information via the FTPMAIL server.
BACK
TO THE TOP
HF
Fax
The HF Fax, also known as the radiofax or WEFAX, for years has been the mainstay
of weather information for the mariner. During the tropical cyclone season in
the Atlantic, information on current tropical systems in text or graphical formats
can be acquired via this method. Additionally, satellite imagery is made available
throughout the year via this circuit. Transmitters located in Boston and New
Orleans continuously transmit weather information for the Atlantic Basin available
to anyone at sea with the proper receiving equipment.
TABLE
2 lists the frequencies assigned to the Boston and New Orleans sites in addition
to broadcast times for each site's current HF Fax schedule. Users should occasionally
review the fax schedules at each site for changes in available products and
transmission times.
Typical
dedicated radiofax receivers use assigned frequencies, while receivers or transceivers,
connected to external recorders or personal computers, are operated in the upper
sideband (USB) mode using the carrier frequencies. From the HF Fax assigned
frequencies in TABLE 3 subtract 1.9 kHz for carrier frequency. All radiofax
broadcasts of NWS products use a radiofax signal of 120 lines-per-minute (LPM)
and an Index-of-Cooperation (IOC) of 576. Although radio reception in the high-frequency
band varies greatly with a multitude of factors, generally, frequencies above
10 MHz work best during the day, while lower frequencies work best at night.
|
Transmitter
|
Frequencies
(in kHz)
|
Broadcast
Times
|
Broadcast
Schedule Transmitted (in UTC)
|
|
New
Orleans
|
4317.9
8503.9
12789.9
|
Continuous
Continuous
Continuous
|
0630
& 1830
0630
& 1830
0630
& 1830
|
|
Boston
|
4235
6340.5
9110
12750
|
0230-1015
UTC
Continuous
Continuous
1430-2215
UTC
|
0243
0243
& 1905
0243
& 1905
1905
|
BACK
TO THE TOP
WWV
HF Voice (Time Tick)
The National Institute of Standards and Technology (NIST) broadcasts a time
and frequency service from station WWV in Fort Collins, Colorado. The "Time
Tick" is normally used as an aid to celestial navigation but hourly voice broadcasts
of Atlantic High Seas Warnings are transmitted at 8 & 9 minutes past the
hour on the frequency signals: 2.5, 5, 10, 15, and 20 MHz.
U.S.
Coast Guard HF SITOR (SImplex Teletype Over Radio)
Broadcasts of high seas forecasts and storm warnings are transmitted from the
United States Coast Guard's Boston high seas communications station in the SITOR
mode. These text broadcasts are performed in mode B, FEC, with broadcast times
& frequencies listed in TABLE 3. Information included in these broadcasts
range from weather to navigational safety text information. Transmission range
of these broadcasts, as with all HF signals, is dependent on operating frequency,
time of day, and multiple environmental factors.
|
Transmitter
|
Frequencies
(in kHz)
|
Broadcast
Times
|
|
BOSTON
|
6314
8416.5
12579
16806.5
|
0000-0200
UTC
Continuous
Continuous
1200-1700 UTC
|
BACK
TO THE TOP
U.S.
Coast Guard HF Voice
Effective Jan 01, 2005 U.S. Coast Guard long range communications stations NMF, NMN, NMA, NMG, NMC, NMO, NOJ and NRV changed their single sideband voice radio guard to the following simplex frequencies: 4125, 6215, 8291, and 12290 kHz. These frequencies are intended for initial voice contact and distress alerts and working only. Follow-on working frequencies if necessary shall be by mutual agreement after initial contact. Previously the ship/shore guard duplex frequencies of 4134/4426, 6200/6501, 8240/8764, 12242/13089, and 16432/17314 kHz were routinely shared with the broadcasts of maritime safety information, including weather. These duplex frequency pairs may still be used, however, for traffic handling purposes after initial contact is established on the distress and initial contact frequencies.
Chesapeake(NMN)
HF Voice Broadcast Schedule |
| 4426, 6501, 8764 kHz (USB) |
0330Z1 |
0515Z2 |
0930Z1 |
|
|
|
|
| 6501, 8764, 13089 kHz (USB) |
|
|
1115Z2 |
1530Z1 |
2130Z1 |
2315Z2 |
| 8764, 13089, 17314 kHz (USB) |
|
|
|
1715Z2 |
|
|
1 Offshore Forecasts, hurricane information
2 Highseas Forecast, hurricane information
Broadcast of hurricane and other weather broadcasts from this station may on occasion be preempted, as the frequencies are shared with other USCG stations.
|
New Orleans(NMG)
HF Voice Broadcast Schedule |
| 4316, 8502, 12788 kHz (USB)
|
0330Z1 |
0515Z2 |
0930Z1 |
1115Z2 |
1530Z1 |
1715Z2 |
2130Z1 |
2315Z2 |
1 Offshore Forecasts, hurricane information
2 Highseas Forecast, hurricane information
Broadcast of hurricane and other weather broadcasts from this station may on occasion be preempted, as the transmitters are shared with the radiofax broadcast.
|
Pt. Reyes(NMC)
HF Voice Broadcast Schedule |
| 4426, 8764, 13089 kHz (USB) |
0430Z |
1030Z |
|
|
| 8764, 13089, 17314 kHz (USB) |
|
|
1630Z |
2230Z |
Broadcast of hurricane and other weather broadcasts from this station may on occasion be preempted, as the frequencies are shared with other USCG stations, and the transmitters are shared with the radiofax broadcast.
|
Kodiak(NOJ)
HF Voice Broadcast Schedule |
| 6501 kHz (USB) |
0203Z |
|
1645Z |
Honolulu(NMO)
HF Voice Broadcast Schedule |
| 6501, 8764 kHz (USB) |
|
0600Z |
1200Z |
|
| 8764, 13089 kHz (USB) |
0005Z |
|
|
1800Z |
Guam(NRV)
HF Voice Broadcast Schedule |
| 6501 kHz (USB) |
|
0930Z |
1530Z |
|
| 13089 kHz (USB) |
0330Z |
|
|
2130Z |
HF voice broadcasts may be terminated if longer than the available broadcast period. This will most likely occur during the hurricane season when supplementary advisories are broadcast in addition to the routine forecasts.
Carrier frequencies shown. HF voice broadcasts use a synthesized
voice "Iron Mike".
ITU channel numbers as follows:
4426(#424), 6501(#601), 8764(#816), 13089(#1205), 17314(#1625)
Note that stations share common frequencies.
BACK
TO THE TOP
U.S.
Coast Guard MF Voice
Medium frequency broadcasts of NWS offshore waters forecasts and storm warnings
are conducted on 2670 kHz after an initial announcement on 2182 kHz (will become
2187.5 kHz sometime in the future although exact date is unavailable at time
of publication). These broadcasts originate from various Coast Guard Groups
located along the Atlantic & Gulf coasts of the United States with a typical
range of 50-150 NM during the day to about 150-300 NM at night. TABLE 5 lists
the location and transmission times of products sent via MF voice broadcast
in the Atlantic Basin.
NWS
offshore waters forecast products valid for the regions where the broadcasts
originate are disseminated throughout the year. The tropical weather outlook
and any active tropical cyclone forecast/advisories are broadcast from some
of these transmitters during the Atlantic Hurricane season of 1 June through
30 November. Additionally, Group New Orleans and Group Corpus Christi broadcast
various other coastal forecasts and marine or severe weather statements when
applicable throughout the year.
|
Coast
Guard Group
|
Broadcast
Time (UTC)
|
Coast
Guard Group
|
Broadcast
Time (UTC)
|
Coast
Guard Group
|
Broadcast
Time (UTC)
|
|
Southwest
Harbor
|
1135,
2335
|
Hampton
Roads
|
0203,
1333
|
St.
Petersburg
|
0320,
1420
|
|
Portland
|
1105,
2305
|
Cape
Hatteras
|
0133,
1303
|
Mobile
|
1020,
1220, 1620, 2220
|
|
Boston
|
1035,
2235
|
Fort
Macon
|
0103,
1233
|
New
Orleans
|
0550,
1035, 1235, 1635
|
|
Woods
Hole
|
0440,
1640
|
Charleston
|
0420,
1620
|
New
Orleans
|
2235
|
|
Moriches
|
0010,
1210
|
Mayport
|
0620,
1820
|
Galveston
|
1050,
1250, 1650, 2250
|
|
Atlantic
City
|
1103,
2203
|
Miami
|
0350,
1550
|
Corpus
Christi
|
1040,
1240, 1640, 2240
|
|
Eastern
Shore
|
0233,
1403
|
Greater
Antilles
|
0305,
1505
|
|
|
MF
Voice broadcast transmitter sites and transmission times for offshore forecasts
and tropical cyclone information during the hurricane season in the Atlantic Basin.
Frequency for all USCG MF transmitters is 2670 kHz after an initial announcement
on 2182 kHz (to become 2187.5 kHz some time in the future).
BACK
TO THE TOP
U.S.
Coast Guard VHF Voice
Coastal water forecasts and storm warnings of interest to mariners are broadcast
by the Coast Guard on VHF channel 22A (156.8 MHz VHF FM) after an initial announcement
on VHF channel 16 (157.1 MHz VHF FM). The Coast Guard VHF network provides nearly
continuous coverage of all coastal areas of the United States East and Gulf
coasts to a range of approximately 20 NM from shore. In regions where NOAA weather
radio broadcasts provide complete coverage of the USCG VHF network, the Coast
Guard may elect to only broadcast storm warnings and not any NWS marine weather
information. TABLE 6 lists Coast Guard stations that transmit over VHF voice
along with transmission times.
|
Coastal
Area
|
Broadcast
Time (UTC)
|
Coastal
Area
|
Broadcast
Time (UTC)
|
Coastal
Area
|
Broadcast
Time (UTC)
|
|
Southwest
Harbor
|
1135,
2335
|
Eastern
Shore
|
0200,
1145
|
St.
Petersburg
|
1300,
2300
|
|
Portland
|
1105,
2305
|
Hampton
Roads
|
0230,
1120
|
Mobile
|
Broadcast
Warnings Only
|
|
Boston
|
1035,
2235
|
Cape
Hatteras
|
0100,
1055
|
New
Orleans
|
1035,
1235, 1635, 2235
|
|
Woods
Hole
|
1005,
2205
|
Fort
Macon
|
0103,
1233
|
Galveston
|
1050,
1250, 1650, 2250
|
|
Moriches
|
0010,
1210
|
Charleston
|
1200,
2200
|
Corpus
Christi
|
1040,
1240, 1640, 2240
|
|
Long
Island Sound
|
1120,
2320
|
Mayport
|
1215,
2215
|
|
|
|
New
York
|
1050,
2250
|
Miami
Beach
|
1230,
2230
|
|
|
|
Atlantic
City
|
1103,
2303
|
Key
West
|
1200,
2200
|
|
|
|
Baltimore
|
0130,
1205
|
Greater
Antilles
|
1210,
2210
|
|
|
USCG
VHF Voice broadcast transmitter sites and transmission times for coastal forecast
and marine warning information. Frequency for all USCG VHF transmitters is 156.8
MHz VHF FM (VHF Channel 22A) after an initial announcement on 157.1 MHz VHF FM
(VHF Channel 16).
BACK
TO THE TOP
NOAA
Weather Radio - visit the NOAA weather
radio web site.
Local and coastal marine forecasts & warnings are broadcast across the NOAA
weather radio network on a constant basis. This network provides near continuous
coverage of the coastal waters in the Atlantic and Gulf of Mexico. Additionally,
NOAA weather radio transmitters are located in the Caribbean region transmitting
over the coastal waters of Puerto Rico & the U.S. Virgin Islands. Reception
ranges of 25 NM from the coast are typical, however coverage may be more or
less depending on location of vessel and transmitter.
Most
VHF radios have the ability to receive NOAA weather radio over the frequencies
listed in TABLE 7. However, it is recommended that a separate NOAA Weather Radio
receiver be used to copy this broadcast so that the marine VHF channels can
remain clear in order to copy other important information at sea.
During
severe weather situations, an automated 1050 Hz tone is transmitted to automatically
turn on compatible NOAA weather radio receivers. Most, but not all, NOAA weather
radios possess this feature. However, an active NOAA Weather Radio channel must
be selected in order for the mariner to be alerted. Additionally, newer NOAA
weather radios utilize SAME (Specific Area Message Encoding) technology. This
feature allows weather radios to alert only for specific weather conditions
or certain geographic areas. It is recommended that SAME technology weather
radios operated by mariners making coastal transits be set to the `All County
Code Option' in order to avoid the need for continual reprogramming of the radio
during transit. This also reduces the likelihood of missing any important weather
warning information while underway.
|
Broadcast
Channel
|
Broadcast
Frequency in MHz
|
|
WX
1
|
162.550
|
|
WX
2
|
162.400
|
|
WX
3
|
162.475
|
|
WX
4
|
162.425
|
|
WX
5
|
162.450
|
|
WX
6
|
162.500
|
|
WX
7
|
162.525
|
BACK
TO THE TOP
NAVTEX
Element of the Global Maritime Distress & Safety System
NAVTEX is a low-cost, simple, and automated means of receiving important marine
information aboard ships. It is an internationally accepted medium frequency
(518 kHz) direct-printing service for delivery of navigational information and
meteorological warnings/forecasts to ships. NAVTEX is similar to SITOR in many
aspects, however SITOR does not offer the same degree of functionality that
NAVTEX does, such as avoiding repeated messages. The NAVTEX system possesses
typical operating ranges of approximately 200 NM from the coast.
All
NAVTEX stations in the United States are operated by the Coast Guard and provide
offshore forecasts of weather conditions for the region in which the transmitter
is located. TABLE 9 is a listing of NAVTEX transmitter sites and scheduled broadcast
times for locations along the Atlantic & Gulf coasts along with some offshore
waters in the vicinity of Puerto Rico in the Caribbean region. TABLE 8 also
lists the required station identifiers needed by the NAVTEX receivers in order
to obtain broadcasts.
It
is recommended that all mariners in U. S. waters program their NAVTEX receivers
to include subject indicator "E" in order to receive both warnings & routine
weather forecasts via NAVTEX. This will decrease the possibility of missing
important tropical weather information at sea.
|
NAVTEX
STATION
|
STATION
IDENTIFIER
|
WEATHER
BROADCAST SCHEDULE (In UTC)
|
|
BOSTON
|
F
|
0045,
0445, 0845, 1245, 1645, 2045
|
|
PORTSMOUTH
|
N
|
0130,
0530, 0930, 1330, 1730, 2130
|
|
SAVANNAH
|
E
|
0040,
0440, 0840, 1240, 1640, 2040
|
|
MIAMI
|
A
|
0000,
0400, 0800, 1200, 1600, 2000
|
|
SAN
JUAN
|
R
|
0200,
0600, 1000, 1400, 1800, 2200
|
|
NEW
ORLEANS
|
G
|
0300,
0700, 1100, 1500, 1900, 2300
|
BACK
TO THE TOP
INMARSAT-C
SafetyNET
Inmarsat-C SafetyNET is an internationally adopted, automated satellite system
for promulgating weather forecasts/warnings, marine navigational warnings, and
other safety related information to all types of vessels and is part of the
Global Maritime Distress and Safety System (GMDSS).
National
Weather Service high seas forecasts, warnings, and tropical cyclone information
(when applicable) for SafetyNET Area IV, the Atlantic Basin west of 35W Longitude
and north of 7N latitude, are broadcast four times per day at 0430, 1030, 1630,
and 2230 UTC.
This
information is sent over the INMARSAT system of geostationary satellites with
each satellite in the system transmitting on a designated channel at 1.5 GHz.
Any ship sailing within the coverage area of an Inmarsat satellite is able to
receive all SafetyNET messages broadcast over the appropriate channel of that
satellite, so long as Inmarsat-C GMDSS equipment is programmed to the proper
Metarea/Navarea (Area IV for the Western Atlantic). Additionally, Inmarsat-C
equipment must also be interconnected with a GPS receiver or updated with a
manually entered position at least every 12 hours or SafetyNET broadcasts for
several Metareas/Navareas will be received unintentionally. Finally, the broadcast
transfer technology of this system is extremely reliable ensuring a high probability
of receiving messages correctly during first transmission, irrespective of the
atmospheric conditions or the ship's position within the satellite coverage.
NWS
Telephone Support
Many National Weather Service forecast offices offer recorded marine & local
weather forecasts similar to those found on NOAA Weather Radio. Numbers to these
recorded forecasts can usually be found by contacting the nearest coastal National
Weather Service Forecast Office (NWSFO). Some recorded tropical cyclone forecast/advisories
can be obtained by contacting TPC/NHC directly at (305)229-4483.
|
