NBM v4.2 Weather Elements by Category

These are the weather elements available in NBM v4.2, the regions they are available, and their definitions. Weather elements new to NBM v4.2 are marked with an * . Regions available are marked by x in a the region column. The regions are: CONUS (CO), Alaska (AK), Puerto Rico (PR), Hawaii (HI), Guam (GU) and Oceanic (OC). The elements are separated into six tables, each with a category of data: surface, aviation (includes 10m winds), fire weather, winter weather, marine, and upper air.

You can use the Page Contents menu to skip to a given category, and click on the up-arrow next to a category label to return to the top of this page.

NBM V4.2 SURFACE WEATHER ELEMENTS

Available surface weather elements weather elements and regions available (x in column) for: CONUS (CO), Alaska (AK), Puerto Rico (PR), Hawaii (HI), Guam (GU) and Oceanic (OC)
Surface Weather Elements CO AK PR HI GU OC Definition
TEMPERATURE
x x x x x   Maximum Temperature; Time Window: 12z to 06z except 18z to 12z in Guam
x x x x x   Minimum Temperature; Time Window: 00z to 18z except 06z to 00z in Guam
x x x x     Standard Deviation (SD) of Maximum Temperature; Time Window: 12z to 06z except 18z to 12z in Guam
x x x x     Standard Deviation (SD) of Minimum Temperature; Time Window: 00z to 18z except 06z to 00z in Guam
x x         Percentiles from 1-99 of Maximum Temperature; derived from the QMD inputs; Time Window: 12z to 06z except 18z to 12z in Guam
x x         Percentiles from 1-99 of Minimum Temperature; derived from the QMD inputs; Time Window: 00z to 18z except 06z to 00z in Guam
x x         Arithmetic mean of Maximum Temperature QMD inputs; Time Window: 12z to 06z except 18z to 12z in Guam
x x         Arithmetic mean of Minimum Temperature QMD inputs; Time Window: 00z to 18z except 06z to 00z in Guam
x x         Standard Deviation (SD) of Maximum Temperature QMD inputs; Time Window: 12z to 06z except 18z to 12z in Guam
x x         Standard Deviation (SD) of Minimum Temperature QMD inputs; Time Window: 00z to 18z except 06z to 00z in Guam
x x x x x x Top of hour value of temperature; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
x x x x x   Top of the hour value Temperature Standard Deviation (SD)
x x x x     Apparent Temperature; derived parameter from Temp, Td, and wind speed
x   x x x   Wet Bulb Globe Temperature; measure of heat stress using NBM Temp, Td, Sky, Wspd, and MSLP
PRECIPITATION
x x x x x   Quantitative Precipitation Forecast; hourly rainfall or melted liquid equivalent of frozen/freezing precipitation to 264 hours
x x x x x   Quantitative Precipitation Forecast; 6-hour forecast
x x x x   x Percentile Quantitative Precipitation Forecast; derived from the QMD inputs; 6-hour percentiles from 1-99
x x x x   x Percentile Quantitative Precipitation Forecast; derived from the QMD inputs; 12-hour percentiles from 1-99
x x x x   x Percentile Quantitative Precipitation Forecast; derived from the QMD inputs; 24-hour percentiles from 1-99
x x x x   x Percentile Quantitative Precipitation Forecast; derived from the QMD inputs; 48-hour percentiles from 1-99
x x x x   x Percentile Quantitative Precipitation Forecast; derived from the QMD inputs; 72-hour percentiles from 1-99
x x x x   x Quantitative Precipitation Forecast; 6-hour mean value
x x x x   x Percentile Quantitative Precipitation Forecast; derived from the QMD inputs; 12-hour mean value
x x x x   x Quantitative Precipitation Forecast; derived from the QMD inputs; 24-hour mean value
x x x x   x Quantitative Precipitation Forecast; derived from the QMD inputs; 48-hour mean value
x x x x   x Quantitative Precipitation Forecast; derived from the QMD inputs; 72-hour mean value
x x x x x   1-hour Probability of Precipitation; through 36 hours
x x x x x   6-hour Probability of Precipitation
x x x x x   12-hour Probability of Precipitation
x x x x   x 6-hour Probability of Precipitation; derived from the QMD inputs
x x x x   x 12-hour Probability of Precipitation; derived from the QMD inputs
x x x x   x 24-hour Probability of Precipitation; derived from the QMD inputs
x x         Predominant Weather derived field
x x x x     Number of hours within a 12 hour period that at least 0.01 in of QPF is forecast
PROBABILITIES OF SPECIFIC AMOUNTS
x x         Threshold probabilities of Maximum Temperature valid 12z to 06z; derived from the QMD inputs
x x         Threshold probabilities of Minimum Temperature valid 00z to 18z; derived from the QMD inputs
x x x x   x 6-hour Quantitative Precipitation Forecast threshold probabilities; derived from the QMD inputs
x x x x   x 12-hour Quantitative Precipitation Forecast threshold probabilities; derived from the QMD inputs
x x x x   x 24-hour Quantitative Precipitation Forecast threshold probabilities; derived from the QMD inputs
x x x x   x 48-hour Quantitative Precipitation Forecast threshold probabilities; derived from the QMD inputs
x x x x   x 72-hour Quantitative Precipitation Forecast threshold probabilities; derived from the QMD inputs
HUMIDITY
x x x x x   Top of hour Dewpoint value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
x x x x x   Dewpoint Standard Deviation (SD)
x x x x x   Relative Humidity; derived from Temp and Td
x x x x     Maximum Relative Humidity; derived from highest hourly/3 hourly/6 hourly value
x x x x     Minimum Relative Humidity; derived from lowest hourly/3 hourly/6 hourly value
PRESSURE
          x Mean Sea Level Pressure; 10th, 25th, 50th, 75th, and 90th percentiles
          x Mean Sea Level Pressure; Spread between the 10th and 90th percentiles

NBM V4.2 AVIATION WEATHER ELEMENTS

Available aviation weather elements weather elements and regions available (x in column) for: CONUS (CO), Alaska (AK), Puerto Rico (PR), Hawaii (HI), Guam (GU) and Oceanic (OC)
Aviation Weather Elements CO AK PR HI GU OC Definition
WIND
x x x x x x Top of hour sustained Wind Speed value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
x         x Top of hour sustained Wind Speed QMD percentile values; percentiles from 1-99
x           Top of the hour sustained Wind Speed QMD mean; derived from the QMD inputs
x           Top of the hour sustained Wind Speed QMD Standard Deviation (SD); derived from the QMD inputs
x x x x x x Top of hour sustained Wind Speed value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
x x x x x x Top of hour sustained Wind Speed value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
x x x x x x Top of the hour Wind Gust value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
x           Top of hour Wind Gust QMD percentile values; percentiles from 1-99
x           Top of the hour Wind Gust QMD mean; derived from QMD inputs
x           Top of the hour Wind Gust QMD Standard Deviation (SD); derived from QMD inputs
x x x x x x Top of the hour Wind Direction value
x x x x x   Wind Speed Standard Deviation (SD)
x x x x x   Wind Gust Standard Deviation (SD)
          x Top of the hour Wind Direction value
          x Top of the hour Wind Direction value
x           24-hour Maximum Wind Speed percentile values; QMD percentiles from 1-99
x           24-hour Maximum Wind Gust percentile values; QMD percentiles from 1-99
x           24-hour Maximum Wind Speed QMD mean; derived from the QMD inputs
x           24-hour Maximum Wind Gust QMD mean; derived from the QMD inputs
x           24-hour Maximum Wind Speed Standard Deviation (SD); derived from the QMD inputs
x           24-hour Maximum Wind Gust Standard Deviation (SD); derived from the QMD inputs
x x x x     Intended to provide Low Level Wind Shear Height guidance (up to 2,000 feet AGL) for WFO TAFs
x x x x     Intended to provide Low Level Wind Shear Speed guidance (up to 2,000 feet AGL) for WFO TAFs
x x x x x   Intended to provide Low Level Wind Shear Direction guidance (up to 2,000 feet AGL) for WFO TAFs
x x x x x   Low level and mountain wave induced turbulence guidance
x x x x     High level turbulence guidance for roughly the 300-200 mb layer
CLOUDS AND OBSTRUCTIONS
x x x x x   Mean Sky Cover 0-100%
x x x x x   Sky Cover Standard Deviation (SD)
x x x x x   The lowest broken or overcast cloud deck
x x x x x x The greatest horizontal distance objects can be seen and identified
x x x x x   Lowest cloud base whether or not a ceiling is present (could be FEW or SCT layer)
x           Height of cloud base, top, and coverage of digital aviation service's primary cloud layer
x           Height of cloud base, top, and coverage of digital aviation service's secondary cloud layer
x           Height of cloud base, top, and coverage of digital aviation service's tertiary cloud layer
x           Height of cloud base, top, and coverage of AWC's cirrus cloud layer
PROBABILITIES OF SPECIFIC AMOUNTS
x           Threshold Probability of VLIFR (0 or 100), LIFR (200-400), IFR (500-900), and MVFR (1,000-3,000) ceilings
x           Threshold Probability of VLIFR (0), LIFR (1/4-3/4), IFR (1-3), and MVFR (3-5) visibilities
x Probability of exceedence for various thresholds of QMD 10-m Wind Speeds at the top of the hour; derived from the QMD inputs
x Probability of exceedence for various thresholds of QMD 10-m Wind Gusts at the top of the hour; derived from the QMD inputs
x           Probability of exceedence for various thresholds of QMD 10-m Maximum Wind Speeds over a 24-hour period; derived from the QMD inputs
x           Probability of exceedence for various thresholds of QMD 10-m Maximum Wind Gusts over a 24-hour period; derived from the QMD inputs
x           Probability of 50-64 (Marginal), 65-69 (Slight), 70-74 (Enhanced), 75-84 (Moderate), or 85-100 (High) Values of Craven Wiedenefeld Aggregate Severe Parameter: designed to detect environments favorable for significant hail and significant tornadoes
CONVECTION
x x x x x   Top of the hour height above mean sea level of highest light precipitation echoes (hourly 1-36 hours)
x x x x   x 1 hour probability of thunder through 36 hours
x x x x   x 3 hour probability of thunder through 192 hours
x x x x   x 6 hour probability of thunder through 192 hours
x x x x   x 12 hour probability of thunder through 192 hours
x x x x x   Maximum reflectivity in the column over the past hour in dBZ (hourly 1-36 hours)
x           Expert weighted mean of Craven Wiedenfeld Aggregate Severe Parameter (75% of EF2+ tornadoes have CWASP of 65+)
x x x x   x A product closely follows AWC's three defined probabilistic categories of thunderstorm coverage: Isolated (10-20%), Scattered (30-50%), and Numerous (60-100%)
x x x x x   Top of the hour vertically integrated liquid (hourly 1-36 hours)
x x x x x   Surface based Convectively Available Potential Energy
x x x x x   Surface Based Convectively Available Potential Energy Standard Deviation
x           5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile of CWASP
x           SPC-POST calibrated HREF 4hr probability of severe hazards (wind/hail/tornado)
x           SPC-POST calibrated HREF 24hr probability of severe hazards (wind/hail/tornado)

NBM V4.2 FIRE WEATHER ELEMENTS

Available fire weather elements weather elements and regions available (x in column) for: CONUS (CO), Alaska (AK), Puerto Rico (PR), Hawaii (HI), Guam (GU) and Oceanic (OC)
Fire Weather Elements CO AK PR HI GU OC Definition
POTENTIAL
x x x x     Calculation of six hour maximum value of Haines Index based on NBM unified terrain elevation (Low Haines up to 999 feet MSL, Mid Haines 1,000-2,999 MSL, and High Haines 3,000+ MSL)
x x x x     6-Hour maximum Fosberg Fire Weather Index using 2-m temperature, 10-m wind speeds, and 2-m dew point/relative humidity
x x x x     Combination of PBL height and modified Stull Method using 0.5K warm bubble (height above ground level)
x x x x     Incoming solar radiation
x           The joint probability in the SREF of one or more CG flashes within 20 km over the previous 3-h period in an environment favorable for dry thunderstorms [as defined by P(precip) <0.10 in x P(2-m RH) <30% x P(PW) <1 in]
WIND
x x x x     Mean Wind Speed in the layer defined by mixing height
x x x x     Mean Wind Direction in the layer defined by mixing height
x x x x     The product of the Mixing Height and the Transport Wind Speed

NBM V4.2 WINTER WEATHER ELEMENTS

Available winter weather elements weather elements and regions available (x in column) for: CONUS (CO), Alaska (AK), Puerto Rico (PR), Hawaii (HI), Guam (GU) and Oceanic (OC)
Winter Weather Elements CO AK PR HI GU OC Definition
EXPECTED AMOUNT
x x         1-hour Snow Accumulation through 36 hours
x x         6-hour Snow Accumulation through 264 hours
x x         24-hour Snow Accumulation through 264 hours
x x         48-hour Snow Accumulation through 264 hours
x x         72-hour Snow Accumulation through 264 hours
x x         1-hour Flat Ice Accumulation using FRAM technique through 36 hours
x x         6-hour Flat Ice Accumulation using FRAM technique through 264 hours
x x         24-hour Flat Ice Accumulation using FRAM technique through 264 hours
x x         48-hour Flat Ice Accumulation using FRAM technique through 264 hours
x x         72-hour Flat Ice Accumulation using FRAM technique through 264 hours
ACCUMULATION PERCENTILES (INCHES)
x x         1-hour Snow Accumulation percentiles
x x         6-hour Snow Accumulation percentiles
x x         24-hour Snow Accumulation percentiles
x x         48-hour Snow Accumulation percentiles
x x         72-hour Snow Accumulation percentiles
x x         6-hour Flat Ice Accumulation (FRAM) percentiles
x x         24-hour Flat Ice Accumulation (FRAM) percentiles
x x         48-hour Flat Ice Accumulation (FRAM) percentiles
x x         72-hour Flat Ice Accumulation (FRAM) percentiles
PROBABILITIES OF SPECIFIC AMOUNTS (>1 in, >12 in etc)
x x         1-hour threshold probability of exceedance for Snow Accumulation
x x         6-hour threshold probability of exceedance for Snow Accumulation
x x         24-hour threshold probability of exceedance for Snow Accumulation
x x         48-hour threshold probability of exceedance for Snow Accumulation
x x         72-hour threshold probability of exceedance for Snow Accumulation
x x         6-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
x x         24-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
x x         48-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
x x         72-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
x           24-hour probability of liquid equivalent of melted snow and sleet exceeding 0.25 in
PRECIPIATION TYPE (PTYPE)
x x         Probability of Snow, Rain, Sleet, or Freezing Rain (instantaneous top of hour)
x x         Snow to Liquid Ratio (using combination of Cobb, Roebber, MaxTaloft, thickness)
x x x x     Elevation where the wet bulb temperature reaches 0.5 degrees C
x x         Snow to Liquid Ratio there is a given percent chance of being at or below (ex: p75 = 75% chance the SLR is the given number or less)
x x x       Snow Level elevation there is a given percent chance of being at or below (ex: p75 = 75% chance the Snow Level is the given elevation or less)

NBM V4.2 MARINE WEATHER ELEMENTS

Available marine weather elements weather elements and regions available (x in column) for: CONUS (CO), Alaska (AK), Puerto Rico (PR), Hawaii (HI), Guam (GU) and Oceanic (OC)
Marine Weather Elements CO AK PR HI GU OC Definition
WATER
x x x x x x Significant Wave Height
x x x x x x Significant Wave Height Standard Deviation (SD)
x x x x x x 10/50/90 percentile of Significant Wave Height
x x       x Top of the hour Sea Surface Temperature
x x       x Categorical Freezing Spray potential
  x         Percent Sea Ice Coverage inside gridbox
  x         Sea Ice Thickness
WIND
x x x x x x Tropical Cyclone Wind Speed forecast feature matched over NBM wind speed background
x x x x x x Tropical Cyclone Wind Direction forecast feature matched over NBM wind speed background

NBM V4.2 UPPER AIR WEATHER ELEMENTS

Available upper air weather elements weather elements and pressure levels.
Upper Air Elements 250mb 500mb 700mb 850mb 925mb Definition
x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
  x x     Standard deviation (SD) at 500mb and 700mb heights. 00Z & 12Z forecasts. 6-hourly through 384