TPC/TAFB Product Descriptions

High Seas Forecasts

The TAFB issues High Seas Forecast for the tropical and subtropical Atlantic, eastern Pacific, and south Pacific Oceans. These products are now-casts through 36 hr forecasts of winds, waves, and convection updated every six hours. The products include marine warnings for gale, storm, and tropical cyclone conditions. The products can also include information on reduced visibility and other marine hazards.

The TAFB has three areas of responsibility (8.5K GIF): The Atlantic Ocean from 7°N to 31°N west of 35°W, including the Caribbean Sea and Gulf of Mexico; the Northeast Pacific Ocean from the Equator to 30°N east of 140°W; and the Southeast Pacific Ocean from the Equator to 18.5°S east of 120°W.

The most current High Seas Forecasts are found on the Forecast Products page. Products are transmitted under a variety of World Meteorological Organization (WMO) and AWIPS headers:

Alternate headers for the Atlantic and Northeast Pacific Forecasts are where TAFB forecasts are appended to High Seas Forecasts of the Marine Prediction Center. In addition, Atlantic high seas products are transmitted by radiofax.

Offshore Waters Forecasts

The TAFB issues Offshore Waters Forecasts for the southwest north Atlantic, Caribbean Sea, and Gulf of Mexico. These products are now-casts through 36 hr forecasts of winds, waves, and convection updated every six hours. The products include marine warnings for gale, storm, and tropical cyclone conditions. The products can also include information on reduced visibility and other marine hazards.

The TAFB has three areas of responsibility: The Atlantic Ocean south of 31°N west of 65°W; the entire Caribbean Sea and the Gulf of Mexico beyond the Coastal Waters Forecast.

The most current Offshore Waters Forecasts are found on the Forecast Products page. Products are transmitted under a variety of World Meteorological Organization (WMO) and AWIPS headers:

The TAFB provides satellite rainfall estimates for tropical cyclones or other significant convective systems when these systems threaten land. These estimates employ infrared satellite imagery and satellite observed motion estimates. Results are given in ranges of potential rainfall in 1 degree wide semicircles to the left and right of the observed system motion.

The TAFB issues estimates when tropical cyclones or convective systems threaten the Caribbean region or the southeastern United States. They are also issued when eastern Pacific tropical cyclones threaten the west coast of Mexico.

TAFB satellite rainfall estimates are on the Forecast Products page. They are transmitted under the following WMO and AWIPS headers:

The TAFB provides the National Hurricane Center with position estimates of tropical cyclones every three hours and intensity estimates every six hours. Intensity estimates use the Dvorak technique, which is a statistical system using observed satellite cloud pattern and a set of rules to produce a current estimate of a cyclone's strength. Estimates can be made from both visible and infrared satellite imagery. The Dvorak technique is the main tool for determining tropical cyclone strength when it is out of range of reconnaissance aircraft.

The TAFB also provides NHC with position and intensity estimates for subtropical cyclones (a hybrid between tropical cyclones and frontal or extratropical cyclones) using the Herbert-Poteat technique.

TAFB's position and intensity estimates are not currently available to the public. However, the intensity estimates (called T numbers, CI numbers, and ST numbers), are often referred to in NHC's Tropical Cyclone Discussions and Preliminary Reports. The following table (taken from the reports mentioned below) gives the approximate wind and pressure values for the CI and ST numbers.

NHC uses the Atlantic pressure table for eastern Pacific tropical cyclones. Note that these are intensity estimates and may be superceded by reconnaissance and/or surface observations.

More information on the Dvorak technique is found in NOAA Technical Report NESDIS 11 - Tropical Cyclone Intensity Analysis Using Satellite Data - by Vernon F. Dvorak. More infomation on the Herbert-Poteat technique is found in NOAA Technical Memorandum NWS SR-83 - A Satellite Classification Technique for Subtropical Cyclones - by Paul J. Herbert and K.O. Poteat.

The TAFB is currently testing an objective version of the Dvorak technique. This could provide intensity estimates every 30 minutes. More information can be obtained from Ray Zehr at the Cooperative Institute for Research in the Atmosphere, Colorado St. University, or from Chris Velden or Tim Olander at the Cooperative Insititute for Meteorological Satellite Studies, University of Wisconsin.

Gulf of Mexico, Atlantic, and Caribbean Wind/Wave Nowcast/Forecast

The TAFB produces a graphical marine forecast of wind and waves for selected points in our Gulf of Mexico, Atlantic, and Caribbean forecast area south of 31°N west of 55°W, as well as forecast positions of significant weather systems. It also includes any marine warning areas. The product comes in two varieties: A short term two panel product with a nowcast and a 24 hour forecast (issued four times a day), and a two panel product with 48 and 72 hour forecasts (issued twice a day).

The most current Gulf/Atlantic Wind/Wave Forecasts are found on the Forecast Products page. They are also transmitted by radiofax.

The Atlantic Tropical Weather Discussion (or TWD) is a narrative of significant surface or upper level weather features in the TAFB area of responsiblilty, including fronts, troughs, cyclones, and anticyclones. It includes special feature discussions for systems such as tropical cyclones or tropical disturbances. It also includes satellite-based descriptions of significant weather across the discussion area. The Pacific TWD is similar but less detailed. It concentrates on surface weather systems and satellite-based descriptions of significant weather.

The TAFB issues TWDs for the Atlantic from the Equator to 32°N between Africa and roughly 100°W, including the Caribbean and Gulf of Mexico. It also issues them for the northeastern Pacific from the Equator to 32°N east of 140°W. Both products are issued every six hours.

The most current TWDs are found on the TAFB Forecast Products page. The Atlantic TWD is transmitted under the WMO header AXNT20 KNHC and the AWIPS header MIATWDAT. The Pacific TWD is transmitted under the WMO header AXPZ20 KNHC and the AWIPS header MIATWDEP.

Tropical Surface Analysis

The TAFB produces wide-area surface analyses at the 4 synoptic times. Analyses cover the region from 20°S to 40°N (except to 50°N over the continental United States) between the Greenwich Meridian westward to 160°W. It is a standard surface analysis for synoptic-scale systems with isobars every 4 millibars (2 millibars in the tropics). Analysis and subsections described below are produced on TAFB's NMAP system.

The most current Tropical Surface Analysis is found on the TAFB Forecast Products page. It is transmitted graphically under AWIPS header NMCGPHTSA. A subsection of the 0000 UTC analysis is transmitted over the DIFAX circuit. It covers the region from 18S to 40N east of 100W.

Atlantic Tropical Surface Analysis

The Atlantic Tropical Surface Analysis is a subsection of the Tropical Surface Analysis covering the region from 5°S to 35°N east of 120°W. It is transmitted four times a day at 0000, 0600, 1200, and 1800 UTC.

The most current Atlantic Tropical Surface Analysis is found on the TAFB Forecast Products page. It is also transmitted by radiofax.

North American Surface Analysis

The North American Surface Analysis is a subsection of the Tropical Surface Analysis covering the region from 15°N to 50°N between 65°W and 125°W. It is transmitted four times a day at 0000, 0600, 1200 and 1800 UTC.

The most current North American Surface Analysis is found on the TAFB Forecast Products page. It is also transmitted by radiofax.

Eastern Pacific Wind/Wave Analysis

The TAFB produces a graphical marine forecast of wind and waves for selected points in the eastern and south Pacific forecast area from 20°S to 30°N east of 145°W, as well as forecast positions of significant weather systems. It also includes any marine warning areas. The product comes in two varieties: A short term two panel product with a nowcast and a 24 hour forecast (issued four times a day), and a two panel product with 48 and 72 hour forecasts (issued twice a day).

The most current East and South Pacific Wind/Wave Forecasts are found on the Forecast Products page. It is also transmitted by radiofax from Pt. Reyes, California and Honolulu, Hawaii.

The TAFB produces a table summarizing the weather, temperatures, and rainfall for the Caribbean and Central American countries. It is issued twice daily from 0000 UTC and 1200 UTC data.

The most current Pan American Temperature and Precipitation Table is found on the Forecast Products page.