A Practical Guide

Select your Island: Antigua Aruba Bahamas: Abaco Bahamas: Bimini Bahamas: Exuma Bahamas: Grand Bahama Bahamas: Inagua Bahamas: Nassau Bahamas: San Salvador Barbados Barbuda Belize: Ambergris Caye Bermuda Bonaire Cayman Islands: Grand Cayman Cuba: Guantanamo Bay Cuba: Habana Culebra Curacao Dominica Dominican Republic: Puerta Plata I. Dominican Republic: Punta Cana Dominican Republic: Santa Domingo Grenada Guadeloupe Haiti: Port au Prince Honduras: Guanaja Honduras: Roatan Jamaica: Kingston Jamaica: Montego Bay Martinique Mexico: Cancun Mexico: Cozumel Montserrat Nevis Puerto Rico: Mayaguez Puerto Rico: San Juan Saba St.Barths St.Croix St.Eustatius St.John St.Kitts St.Lucia St.Maarten/St.Martin St.Thomas St.Vincent Tobago Tortola Trinidad Turks & Caicos: Grand Turk Turks & Caicos: Provo Turks & Caicos: South Caicos Vieques Enter Hurricane Specifics: The eye is located at: NS EW It is moving near mph kt km/h TS winds extend from the center about mi nm km Or enter your Coordinates: Lat: NS Lon: EW

Help? The latitude/longitude location of the center of the storm and the speed at which it is moving can be found in the Public Advisories. A 72 hour forecast of the wind radii are listed in the Marine Advisories. Often it might be better to take the 72 hour value for wind radius to account for changes in hurricane strength. Both products are issued by the National Hurricane Center and linked directly from the Quick Hurricane Web Resource Navigator (QHWRN). Note that the units in the Public Advisories are normally in miles and mph (miles per hour), and in the Marine Advisories in nm (nautical mile) and kt (nautical mile per hour). Lat/Lon should be entered in decimal degrees, not in the dd:mm:ss-format, so: 18.5, not: 18:30:00. Valid range: latitude 0-90 degrees, longitude: 0-180 degrees. When numbers are entered in the 'Or enter your Coordinates' box, the island selection is ignored. The coordinates for the islands are based on the corresponding National Weather Service weather stations. The algorithm and code for the distance calculation was provided by the National Geodetic Survey.

one kilometer (km):

0.62 mile

0.54 nautical mile

one mile (m):

1.61 kilometer

0.87 nautical mile

one nautical mile (nm):

1/60 degree latitude

1.85 kilometer

1.15 mile

one knot (kt):

one nautical mile per hour

1.85 km per hour

1.15 mile per hour (mph)

Use the following table for a quick estimate of travel time of a tropical system to the Leeward islands.

Example: Suppose that the center of a tropical storm is located at 15° N, 40° W, moving at 18 mph.
Most easterly Leeward islands located at around 61° W. This is a distance of 61-40=21° longitude. At 15° N this equals to 21x66.8= 1403 miles. So it will take around 1403/18= 78 hours or a 3 days and 6 hours to reach the islands. This is a rough estimate because the center of the storm has to stay on the same latitude and keep travelling at the same speed. You can also use the above form to calculate the distance and ETA.

WTNT32.KNHC, MIASPFAT3, etc., what do they mean? Which is which?

There are two different formats of NHC-advisories titles in use: (1) WTNT##.KNHC and (2) something like MIATCPAT#.

(1) WTNT##.KNHC: the first number (#) indicates the kind of advisory, the second the storm number. Marine Advisories have number 2, Public Advisories 3, Tropical Cyclone Discussions 4, Strike Probabilities 7. At times Tropical Cyclone Special Updates are released, numbered 6.

The storm numbers are as follows: Edouard has number 5, Fran 1 and Gustav 2.

Example: WTNT75.KNHC are the strike probablilites for Edouard.

(2) MIA*-format: Marine Advisories are titled MIATCMAT, Public Advisories MIATCPAT, Tropical Cyclone Discussions MIATCDAT, and the Strike Probabilities MIASPFAT. These are all followed by the number of the storm (see above).

Example: MIATCMAT2 (MIAmi Tropical Cyclone Marine Advisory Tropical Storm 2?) is the Marine Advisory for Gustav.

Most advisories have the time in the local timezone of where the storm is, this can be AST, EDT,... Then on other advisories is just says something like 18:00 Z. That means 'Zulu' time, which is the same as Coordinated Universal Time (UTC), formerly known as Greenwich Mean Time (GMT). Below a quick reference table of some of the most common timezones used in the Caribbean and USA. Most islands are in the Atlantic Standard Timezone (AST) and do not observe daylight saving time (for a island-specific timezone list see: sizes.com).

Timezones relative to UTC (Current UTC Date/Time: Sat Dec 21 17:12:01 UTC 2024 ):

Daylight Saving Time:
     ADT (Atlantic Daylight Time): subtract 3 hours from UTC --> 14:12
     EDT (Eastern Daylight Time):  subtract 4 hours from UTC --> 13:12
     CDT (Central Daylight Time):  subtract 5 hours from UTC --> 12:12
     MDT (Mountain Daylight Time): subtract 6 hours from UTC --> 11:12
     PDT (Pacific Daylight Time):  subtract 7 hours from UTC --> 10:12
 
Standard Time:
     AST (Atlantic Standard Time): subtract 4 hours from UTC --> 13:12
     EST (Eastern Standard Time):  subtract 5 hours from UTC --> 12:12
     CST (Central Standard Time):  subtract 6 hours from UTC --> 11:12
     MST (Mountain Standard Time): subtract 7 hours from UTC --> 10:12
     PST (Pacific Standard Time):  subtract 8 hours from UTC --> 09:12

The Marine Advisories give information about the current and forecasted windfield and sea conditions around the center of the storm. Important to check is that if a Hurricane does not make landfall to see how close it passes by.

An example of a small piece taken out of the Marine Advisory of Hortense of 11PM/Sep 11:

     EYE DIAMETER  16 NM
     MAX SUSTAINED WINDS  85 KT WITH GUSTS TO 105 KT
     64 KT....... 50NE  25SE  25SW  25NW
     50 KT.......100NE  50SE  30SW  60NW
     34 KT.......175NE 150SE  50SW 120NW
     12 FT SEAS..175NE 150SE  50SW 120NW
     ALL QUADRANT RADII IN NAUTICAL MILES

All numbers are in nautical miles (nm). One nm equals 1.15 mile. In the above example the diameter of the eye is 16 nm (18 miles). Maximum sustained winds near the center are 85 kts (98mph) with gusts to 121 mph (105kt). Now comes the interesting part. Up to 50 nm to the North East of the center 64 kt winds (hurricane force) occur, and up to 25 nm to the SE, SW and NW. Connecting those points will make a kind of 'crooked' circle around the center. The same goes for the 50 kt, 34 kt (tropical storm) and 12 ft seas. So you can see from these data that the storm is a-symmetrical and that the 'grunt' of the storm is on the North-Eastern side.

At the time of this advisory Turks Island was 35 miles (30 nm) to the West of the center, so they are just outside the range of (sustained) hurricane force winds. If they would have been to the North West of the center they would be in the range of 64 kt winds. Since there are gusts to 105 kt (121 mph) they will experience hurricane force winds from time to time.

From time to time the National Hurricane Center sends out reconnaisance airplanes to the eye of the storm. If you are a serious 'hurricane tracker' you must check out those Reconnaisance Reports. This document tells you exactly how to decode it. It was written by Chris Sells and forwarded to me by Chris Novy.

Weather Station Identifiers for most of the Caribbean Islands as reported in the NHC Strike Probabilities Advisories. A complete list of all weather stations around the world can be found on the National Weather Service website. You can also click on the station identifier to get the current weather conditions (if available) from the Internet Weather Source (NWS).

Tropical disturbance, tropical wave:

Unorganized mass of thunderstorms, very little, if any, organized wind circulation.

Tropical depression:

Evidence of closed wind circulation around a center with sustained winds of 33 knots (38 mph) or less.

Tropical storm:

Maximum sustained winds are from 34-63 knots (39-73 mph). The storm is named once it reaches tropical storm strength.

Hurricane:

Maximum sustained winds exceed 64 knots (74 mph).

Category One - A Minimal Hurricane

Winds: 74-95 mph, 64-82 kts, 119-153 km/h

Minimum surface pressure: higher than 980 mbar

Storm surge: 3-5 ft, 1.0-1.7 m

Damage primarily to shrubbery, trees, foliage, and unanchored homes. No real damage to other structures. Some damage to poorly constructed signs. Low-lying coastal roads inundated, minor pier damage, some small craft in exposed anchorage torn from moorings. Example: Hurricane Jerry (1989)

Category Two - A Moderate Hurricane

Winds: 96-110 mph, 83-95 kts, 154-177 km/h

Minimum surface pressure: 979-965 mbar

Storm surge: 6-8 ft, 1.8-2.6 m

Considerable damage to shrubbery and tree foliage; some trees blown down. Major damage to exposed mobile homes. Extensive damage to poorly constructed signs. Some damage to roofing materials of buildings; some window and door damage. No major damage to buildings. Coast roads and low-lying escape routes inland cut by rising water 2 to 4 hours before arrival of hurricane center. Considerable damage to piers. Marinas flooded. Small craft in unprotected anchorages torn from moorings. Evacuation of some shoreline residences and low-lying areas required. Example: Hurricane Bob (1991)

Category Three - An Extensive Hurricane

Winds: 111-129 mph, 96-112 kts, 178-208 km/h

Minimum surface pressure: 964-945 mbar

Storm surge: 9-12 ft, 2.7-3.8 m

Foliage torn from trees; large trees blown down. Practically all poorly constructed signs blown down. Some damage to roofing materials of buildings; some wind and door damage. Some structural damage to small buildings. Mobile homes destroyed. Serious flooding at coast and many smaller structures near coast destroyed; larger structures near coast damaged by battering waves and floating debris. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane center arrives. Flat terrain 5 feet of less above sea level flooded inland 8 miles or more. Evacuation of lowlying residences within several blocks of shoreline possibly required. Example: Hurricane Gloria (1985)

Category Four - An Extreme Hurricane

Winds 130-156 mph, 113-136 kts, 209-251 km/h

Minimum surface pressure: 944-920 mbar

Storm surge: 13-18 ft, 3.9-5.6 m

Shrubs and trees blown down; all signs down. Extensive damage to roofing materials, windows and doors. Complete failures of roofs on many small residences. Complete destruction of mobile homes. Flat terrain 10 feet of less above sea level flooded inland as far as 6 miles. Major damage to lower floors of structures near shore due to flooding and battering by waves and floating debris. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane center arrives. Major erosion of beaches. Massive evacuation of all residences within 500 yards of shore possibly required, and of singlestory residences within 2 miles of shore. Example: Hurricane Andrew (1992)

Category Five - A Catastrophic Hurricane

Winds: equal or greater than 157 mph, 137 kts, 252 km/h

Minimum surface pressure: lower than 920 mbar

Storm surge: higher than 18 ft, 5.6 m

Shrubs and trees blown down; considerable damage to roofs of buildings; all signs down. Very severe and extensive damage to windows and doors. Complete failure of roofs on many residences and industrial buildings. Extensive shattering of glass in windows and doors. Some complete building failures. Small buildings overturned or blown away. Complete destruction of mobile homes. Major damage to lower floors of all structures less than 15 feet above sea level within 500 yards of shore. Low-lying escape routes inland cut by rising water 3 to 5 hours before hurricane center arrives. Massive evacuation of residential areas on low ground within 5 to 10 miles of shore possibly required. Example: Hurricane Camille (1969)

In the event of a disaster -God forbid-, one can obtain information from Amateur Radio Operators in the West Indies on the following frequencies:

• HF Frequencies
  • 14.303 MHz - The International Assistance and Traffic Net (IATN). This is the International Extension of the National Traffic System of the American Radio Relay League (ARRL)
  • 3.815 MHz - The Antilles Emergency and Weather Net. The Amateur radio operators will handle emergency messages out of the affected areas during the first 48 to 60 hours after a Disaster.
  • These Nets will operate on a 24 hour basis. Health and welfare messages will be handled when Public Facilities are restored.
    Operators in affected areas will most probable be operating with battery power and stations outside of the disaster areas should cooperate and do not jam the system with calls. Please listen.
    These persons should direct their calls to one of the Net Control stations.
• VHF Frequencies
  • 147.80 MHz -600 Repeater. This is the local National Emergency Management Agency Repeater.
  • 147.93 MHz -600 Repeater. The Trinidad and Tobago Amateur Radio Society Repeater.
  • 146.94 MHz -600 Repeater. do. do.. do..
  • These frequencies will be used if they are operational after a hurricane. If these repeaters fail to function after a hurricane, operators will use the output frequencies as simplex frequencies to communicate.
    In addition to the above frequencies 147.500 MHz will also be used as a simplex frequency.

Because of modern technology e.g. satellite pictures, one can tell in advance when a hurricane is likely to strike. In this situation, amateur radio operators will secure antennas and may shut down their stations about 1 hour before the hurricane strikes. During this period there will be lightning and strong winds until the hurricane passes. This period can be 2 to 3 hours.

Only those stations that took the necessary precaution and preparation in time will be heard on the air.

I hope you find this information useful and informative so that people can be aware of what is likely to happen in the event of a National Disaster and will be more enlightened and cooperate when the real situation occurs -God forbid-.

Irvine B. Niffikeer -9Y4IBN-.
i9y4ibn@carib-link.net
http://www.angelfire.com/nf/9y4ibn/

Other Hurricane HAM info:
• Hurricane Frequencies
• The Hurricane Watch Net - 14.325 MHz

National Hurricane Center Advisories are released at 03:00, 09:00, 15:00 and 21:00 GMT. Intermediate advisories are released at 00:00, 06:00, 12:00 and 18:00 GMT. GMT is 4 hours ahead of Eastern Daylight Time.

It is now: Saturday, 21-Dec-2024 17:12:01 GMT

National Hurricane Center Advisories:

• Try our 'framed' Quick Hurricane Web Resource Navigator to find the least overloaded webserver for NHC advisories or look at our own weather discussions and local reports which are focused on the Caribbean
• The National Hurricane Center, at peak of storms often difficult to get through.
• Alternate: Ohio State University
• Eric Blake's Atlantic Tropical Weather Center has links to the above 2 sources and to the University of North Carolina-Charlotte.
• Tropical Cyclone Special Update
• If getting 'busy', 'time-out' or 'unreachable' messages check out some of the websites as found in the FAQ2: HURRICANES, TYPHOONS, AND TROPICAL CYCLONES (an excellent source of links):
  • gopher://geograf1.sbs.ohio-state.edu:70/1/Tropical (good source)
  • http://cirrus.sprl.umich.edu/wxnet/tropical.html (most info available)
  • http://iwin.nws.noaa.gov/iwin/us/hurricane.html (full advisory list)
  • http://lumahai.soest.hawaii.edu/Tropical_Weather/tropical.shtml (map)
  • http://www.atms.unca.edu/%7Efarr/hurricane96.html (simple & excellent)
  • http://www.ih2000.net/ira/bmt-wth.htm (strike probs & track maps)
  • http://www.typhoon.org.hk/ (all basins)

Hurricane Forecasts & Models:

• Which hurricane models should you trust in 2024?
• Experimental forecast Tropical Cyclone Genesis Potential Fields: FSU.edu - and PSU.edu - model animations used by forecasters
• Colorado State University - Dr. Gray et al.
• Maximum Hurricane Potential Intensity - Kerry Emanuel
• 1998 Seasonal Forecast - Gary Gray, see also his TRANTECH model
• GFDL & NOGAPS model runs - Penn State U.

Satellite and other images:

• Try our 'framed' Quick Hurricane Web Resource Navigator
• My Satellite - High resolution imagery centered at your island
• NRL Monterey Tropical Images & Movies, best source for the latest GOES and METEOSAT images when there is a storm or 'invest'
• NOAA/NESDIS - Very nice IR loop, with nice overlays, like wind direction
• NOAA's GOES 8 Hurricane Sector Page
• hurricane.terrapin.com - Hurricane Tracking - original content!
• WeatherMan911 - good links to Caribbean and other satellite images
• Ti'Bleu Images Satellite - links to nice satellite images. In French.
• WebPoint's Weatherpoint: Latest image of the Tropical Atlantic and Caribbean Sea, updated every 3 hours; and latest image (updated every 30 minutes) and satellite loop of the Caribbean Sea.
• The Weather Channel, CARIBSAT
• WeatherNet's Tropical Weather Page, lot of links to satellite imagery
• Intellicast, Atlantic Tropical IR Sector
• Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin-Madison complete with satellite derived wind vectors.
• GOES Weather Satellite, compiled by PCWP, the makers of HurrTrak
• University of Hawaii: Current track and forecast
• Purdue University, sat. images and other info
• Ohio State University: Current track and 72 hour forecast
• Eric Blake's Weather Pages contain multiple links as well, esp. to strike probabilities in image format.
• Bermuda Biological Station for Research Weatherpage: satellite imagery and other tropical weather info.
• Dundee Satellite Receiving Station. Free registration
• Fancy images (but not the latest):
  - ZAMG - Very nicely done animated satellite loops of past storms (in German, but easy to follow)
  - NASA Earth Observatory - Severe Storms - Spectacular satellite imagery of hurricanes

Hurricane Plotting Software and Tracking Charts:

• JStrack - Freeware. Tcl/Tk-based Hurricane Tracking Program. Basic, just what you need, without all the frills! A great program! Developed by Jim Graham. It also includes filters to automatically process NHC advisories. Highly recommended.
• Weather Defender - Desktop weather software. Weather Defender provides real-time weather with street-level accuracy. Free demo available.
• Tracking the Eye, an excellent hurricane tracking program, awarded 'Best of the Net' by PC Computing, shareware
• HURRTRAK professional software for Windows. Examples of output can be found at the Hurrtrak homepage and the WRAL website.
• Other software packages can be found in the WeatherNet Software Archive
• Profesional Tracking Charts: Grid Track and Kornor Enterprises.
• Track info of past hurricanes since 1851: unisys and HURDAT. See also the climatology section on this website for island specific maps.
• HURSAT View historical hurricane satellite imagery and track info in Google Earth, by NOAA/NCDC
• Add any historical track to your own map with Google maps: stormadvisory.org. Very nicely done!
• Hurricane - Fast, full featured hurricane tracking app for the iPhone and iPod Touch by Kitty Code.
• MyHurricane.net - Hurricane tracking with model runs embedded in Google Maps. You can also click through the archived advisories of storms to see how well the forecast agreed with the actual track. Nice and clean interface.

Other:

• Current Weather Conditions on the Islands - see above
• Jeff Master's WunderBlog - Excellent discussion of current conditions with great tracking maps and satellite images on the Weather Underground website.
• caribbeanweather.org: Fast and easy access to satellite and weather information for the Caribbean
• El Tiempo en Puerto Rico Weather - Hurricane info for Puerto Rico and surroundings, in English and Spanish
• Caribbean Disaster Emergency Response Agency (CDERA)
• Hurricane Havens Handbook for the North Atlantic Ocean - Hurricane Holes and the always intriguing 'leave/stay' decision.
• ouragan-guadeloupe - Hurricane updates from Guadeloupe (in French)
• DR1.com - Dominican Republic hurricane information, also includes a question and answer forum.
• St.Barths Online - Local Hurricane Information from the island of St.Barths
• Caribbean Weather Center - Discussions and images by where2stay.com
• StormVI.com - Doug's hurricane page from St.Thomas.
• www.weatherincayman.com - Weather monitoring network in the Cayman Islands.
• eleuthera-map.com/weather.php: Weather information for Eleuthera, Bahamas
• Ti'Bleu - Cyclones des antilles francaise
• Orrin's Caribbean Index - Very complete list of links to 'current weather & forecasts' for many of the Caribbean islands
• Caribbean Guide: Caribbean Weather Info
• Hurricane City - features the city being threatened.
• Megatropic's Hurricane Page, St.Maarten's only ISP.
• Antigua and Barbuda Hurricane Information, provided by Cable and Wireless, Antigua
• Tropical Atlantic & Caribbean Weather Watch - Sara Sommers' BVI weather page.
• CaribbeanNewspapers.com
• CARDIN - Caribbean Disaster Information Network, University of the West Indies, Jamaica
• TropicalWeather.net - Run by former Weather Channel meteorologist. Also has a hurricane forecasts message board.
• Yahoo Full Hurricane Coverage - news stories from several sources, incl. AP, Reuters, CNN, etc.
• suncam.tv, 9 live weather cams in Florida
• Palm Beach Post, a lot to offer, like the latest hurricane related news. (Excellent site but why didn't they cut down on the large number of graphics and un-necessary java applets which really slows down browsing)
• Disaster Message Service - stay in touch - before, during and after a disaster...
• ExploreZone - Hurricane related news updats
• Sun-Sentinel, South Florida, with 'shockwave' tracking maps
• Central Atlantic Storm Investigators Tropical Season 1998 - Excellent Site! Tropical Atlantic Weather Information
• Johns Hopkins University Applied Physics Laboratory - Ocean Remote Sensing Group. Excellent satellite imagery, well organized TS info.
• News & Observer Hurricane Watch at Nando Net
• Scott's Hurricane Discussion
• MAWS Hurricane & Tropics Page - (see also Herb's weather updates and hurricane news)
• Mike Bryson's 'no-nonsense' page - Fast access to actual hurricane info
• hurricaneville.com - hurricane commentary and lots of info by Greg Machos
• USA Today - Weather
• CNN - Storm Center
• Nick Zelinsky's Hurricane Page
• The MSNBC Site for News
• Dr. Gray's Atlantic Hurricane Forecast
• Florida State University, current and historical data.
• Purdue University, Historical Hurricane/Tropical Data
• FEMA, Tropical Storm Watch
• NOAA Hurricane and Natural Disaster Brochures
• The Risk Prediction Initiative - Hurricane Prediction info
• How far is it...? Just punch in the lat/lon pairs (e.g. 18.2N 64.1W) for both eye and target. When you divide it by the current speed to get a rough estimate of the time of arrival.
• WindGuru.com - Interesting website presenting model data (incl. wind direction/speed, wave height) in nice format for some of the islands
• Our own Practical Guide to Hurricane Tracking

GoBeach Vacations
- Your source for the best Caribbean vacation you've ever had! -
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