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Tabular State | Point Forecast Matrix | Marine Forecast Matrix

Tabular State Forecast ( Tabular State Forecast   )

Provides a quick overview of the forecasted daytime weather and chance of rain along with the high and low temperatures for selected locations across Hawaii for the next 7 days. The product is generally issued twice a day around 4am and 4pm. Information or headlines concerning any watches or warnings is not included.

POP = Probability of Precipitation, or the chance of rain (or snow), for the daytime (6am-6pm) only and ranges from 0% to 100%.

Weather Codes: This is a forecast for the prevailing daytime (6am-6pm) weather.

Point Forecast Matrix ( Point Forecast Matrices   )

Provides a very detailed overview of the 7-day forecast, at a resolution of up to every 3 hours for a variety of locations across Hawaii. The format is also designed for those that wish to write/use computer programs to decode the product. Information or headlines concerning any watches or warnings is not included.

For each location, there are two parts to the forecast. The first being the 3 hourly forecast for the next 3 days. The second part being a 6 to 12 hourly forecast for the next 4 days.

Elements in the detailed 3 day portion of the forecast

UTC 3 HRLY - Time the forecast is valid for in UTC or Greenwich Mean Time, a 24-hour clock. 10 UTC = 1000 (10:00am) UTC. Hawaii is 10 hours behind UTC, so 10 UTC = 12:00am Midnight HST

HST 3 HRLY - Local time using a 24-hour clock. 09 = 9:00am HST. 18 = 6:00 pm HST.

MAX/MIN - High and Low temperature forecasts

TEMP - Forecast temperature for that hour.

DEWPT - Forecast dewpoint temperature for that hour.

RH - Relative Humidity (in %) forecast for that hour.

WIND DIR - The prevailing direction from which the wind is blowing from for that hour. A “00” means “calm”

WIND SPD - The average wind speed (in mph).

WIND GUST - Forecast wind gust (in mph). This line is included if significant gusts are forecast.

CLOUDS - Average Sky cover for that period

POP 12 HR - Chance of Rain for the 12 hour period ending at 6am or 6pm HST. Values range from 0 to 100%

QPF 12 HR - Amount of Rainfall forecast in inches for the 12 hour period ending at 6am or 6pm HST.

SNOW 12 HR - Amount of snow forecast in inches for the 12 hour period ending at 6am or 6pm HST.

Various Precipitation Type Forecasts - These codes will only show up if at some point during the time of the forecast they are expected to occur. If they do show up, a letter code will provide information about the forecast likelihood of that precipitation type.

Probability of occurrence codes

Elements in the less-detailed 4-7 day portion of the forecast

Many of the element names are identical to those listed above. These are the differences

PWIND DIR - Prevailing wind direction for the 12 hour period ending at 6am or 6pm HST.

WIND CHAR - Wind “characteristic”. Rather than a specific wind speed, letter codes will provide information about the range of wind speeds on average over the 12 hour period.

AVG CLOUDS - same as the “CLOUDS” as listed above, but now for the average cloud condition over a 6 hour period.

Graphic Forecasts (link to product)

HIGH/LOW TEMPERATURE- Expected daytime high or nighttime low temperature expected.

WEATHER -  In the legend bar at the top of the image, you will see abbreviations for the various weather scenarios being forecast. Many times these will use "abbreviations". Some of the more common abbreviations in the legend bar will be:

In the actual graphic, the colored areas will denote both the type and "amount" of weather that is being forecast.

Type of weather is governed by the colors

Coverage/Chance of weather is governed by the amount of color fill

POP - Probability of Precipitation (rain or snow). Ranges from 0-100%.

SKY - Cloud coverage, expressed in percentage of the sky covered by clouds. Ranges from 0% (totally clear) to 100% (totally cloudy)

WIND - Values plotted indicate the direction the wind is blowing from (E = East, SW= Southwest) and the wind speed in knots. 1 knot = 1.15 mph. The “flag” plotted shows the wind speed and direction using standard weather chart plotting rules. Refer to: https://tgftp.nws.noaa.gov/fax/PLBZ08.gif for additional examples.

SWELL - Values plotted indicate the direction the swell is coming from and the height. First two digits are the direction of the swell in of degrees. The last two digits are the swell height in feet.

Examples:
3107 = Swell direction from 310 degrees (or Northwest). Height = 7 feet
0311 = Swell direction from 30 degrees (North-northeast). Height = 11 feet

The arrows also indicate the direction the swell is moving toward.

Marine Forecast Matrix ( Marine Forecast Matrix   )

The product provides a detailed overview of the short range (3 day) marine forecast, at a resolution of every 3 hours, for specific locations in the adjacent waters across the state. Locations include many Hawaii Fishing Aggregate Device (FAD) Buoys along with mid-points for several of the channels. The location description along with the latitude and longitude of the point is provided before each forecast section.

The format is also designed for those that wish to write/use computer programs to decode the product.

Information or headlines concerning any watches or warnings are not included.

Forecast Elements

UTC 3 HRLY - Time the forecast is valid for in UTC or Greenwich Mean Time, a 24-hour clock. 10 UTC = 1000 (10:00am) UTC. Hawaii is 10 hours behind UTC, so 10 UTC = 12:00am Midnight HST

HST 3 HRLY - Local time using a 24-hour clock. 09 = 9:00am HST. 18 = 6:00 pm HST.

WIND DIR - The prevailing direction from which the wind is forecast to blow from for that hour. A "00" means "calm". "E" means winds from the East.

WIND SPD (KT) - The average wind speed (in knots).

WIND GUST - Forecast wind gust (in knots). This line is included if significant gusts are forecast.

SWELL DIR - Forecast swell direction from which the swell is coming from. A "S" means a swell from the south.

SWELL HGT - Forecast swell height in feet.

WIND WAVE HT - Forecast height of the waves that are locally generated by the winds.

SIG WAVE HT - Forecast of the significant wave height, which is a combination of the wind waves and swell. This should generally represent the height of the highest one-third waves. The maximum wave height could be up to twice this value.

CLOUDS - Average Sky cover for that period

POP 12 HR - Chance of Rain for the 12 hour period ending at 6am or 6pm HST. Values range from 0 to 100%

Various Precipitation Type Forecasts - These codes will only show up if at some point during the time of the forecast they are expected to occur. If they do show up, a letter code will provide information about the forecast likelihood of that precipitation type.

Probability of occurrence codes