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
MaxT x x x x x   Maximum Temperature; Time Window: 12z to 06z except 18z to 12z in Guam
MinT x x x x x   Minimum Temperature; Time Window: 00z to 18z except 06z to 00z in Guam
MaxT SD x x x x     Standard Deviation (SD) of Maximum Temperature; Time Window: 12z to 06z except 18z to 12z in Guam
MinT SD x x x x     Standard Deviation (SD) of Minimum Temperature; Time Window: 00z to 18z except 06z to 00z in Guam
PMaxT x x         Percentiles from 1-99 of Maximum Temperature; Time Window: 12z to 06z except 18z to 12z in Guam
PMinT x x         Percentiles from 1-99 of Minimum Temperature; Time Window: 00z to 18z except 06z to 00z in Guam
PMaxT Mean x x         Arithmetic mean of Maximum Temperature percentiles; Time Window: 12z to 06z except 18z to 12z in Guam
PMinT Mean x x         Arithmetic mean of Minimum Temperature percentiles; Time Window: 00z to 18z except 06z to 00z in Guam
PMaxT SD x x         Standard Deviation (SD) of Maximum Temperature percentiles; Time Window: 12z to 06z except 18z to 12z in Guam
PMinT SD x x         Standard Deviation (SD) of Minimum Temperature percentiles; Time Window: 00z to 18z except 06z to 00z in Guam
Temp 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.
Temp SD x x x x x   Top of the hour value Temperature Standard Deviation (SD)
AppT x x x x     Apparent Temperature; derived parameter from Temp, Td, and wind speed
WBGT x   x x x   Wet Bulb Globe Temperature; measure of heat stress using NBM Temp, Td, Sky, Wspd, and MSLP
PRECIPITATION
QPF01 x x x x x   Quantitative Precipitation Forecast; hourly rainfall or melted liquid equivalent of frozen/freezing precipitation to 264 hours
QPF06 x x x x x   Quantitative Precipitation Forecast; 6-hour forecast
PQPF06 x x x x   x Quantitative Precipitation Forecast; derived from Quantile Mapping and Dressing; 6-hour percentiles from 1-99
PQPF12 x x x x   x Quantitative Precipitation Forecast; derived from Quantile Mapping and Dressing; 12-hour percentiles from 1-99
PQPF24 x x x x   x Quantitative Precipitation Forecast; derived from Quantile Mapping and Dressing; 24-hour percentiles from 1-99
PQPF48 x x x x   x Quantitative Precipitation Forecast; derived from Quantile Mapping and Dressing; 48-hour percentiles from 1-99
PQPF72 x x x x   x Quantitative Precipitation Forecast; derived from Quantile Mapping and Dressing; 72-hour percentiles from 1-99
PQPF06 Mean x x x x   x Quantitative Precipitation Forecast; 6-hour mean value
PQPF12 Mean x x x x   x Quantitative Precipitation Forecast; 12-hour mean value
PQPF24 Mean x x x x   x Quantitative Precipitation Forecast; 24-hour mean value
PQPF48 Mean x x x x   x Quantitative Precipitation Forecast; 48-hour mean value
PQPF72 Mean x x x x   x Quantitative Precipitation Forecast; 72-hour mean value
PoP01 x x x x x   1-hour Probability of Precipitation; through 36 hours
PoP06 x x x x x   6-hour Probability of Precipitation
PoP12 x x x x x   12-hour Probability of Precipitation
QMD PoP06 x x x x   x 6-hour Probability of Precipitation; output from Quantile Mapping and Dressing
QMD PoP12 x x x x   x 12-hour Probability of Precipitation; output from Quantile Mapping and Dressing
QMD PoP24 x x x x   x 24-hour Probability of Precipitation; output from Quantile Mapping and Dressing
Wx x x         Predominant Weather derived field
Duration 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
ProbMaxT x x         Threshold probabilities of Maximum Temperature valid 12z to 06z
ProbMinT x x         Threshold probabilities of Minimum Temperature valid 00z to 18z
ProbQPF06 x x x x   x 6-hour Quantitative Precipitation Forecast threshold probabilities
ProbQPF12 x x x x   x 12-hour Quantitative Precipitation Forecast threshold probabilities
ProbQPF24 x x x x   x 24-hour Quantitative Precipitation Forecast threshold probabilities
ProbQPF48 x x x x   x 48-hour Quantitative Precipitation Forecast threshold probabilities
ProbQPF72 x x x x   x 72-hour Quantitative Precipitation Forecast threshold probabilities
HUMIDITY
Td 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.
Td SD x x x x x   Dewpoint Standard Deviation (SD)
RH x x x x x   Relative Humidity; derived from Temp and Td
MaxRH x x x x     Maximum Relative Humidity; derived from highest hourly/3 hourly/6 hourly value
MinRH x x x x     Minimum Relative Humidity; derived from lowest hourly/3 hourly/6 hourly value
PRESSURE
PMSLP           x Mean Sea Level Pressure; 10th, 25th, 50th, 75th, and 90th percentiles
PMSLP Spread           x Mean Sea Level Pressure; Standard Deviation (SD)

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
10-m Speed x x x x x x Top of hour Wind Speed sustained value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
P10-m Speed x         x Top of hour Wind Speed sustained value percentiles
P10-m Speed Mean* x           Top of the hour Wind Speed sustained value percentile mean
P10-m Speed SD* x           Top of the hour Wind Speed sustained value percentile Standard Deviation (SD)
30-m Speed x x x x x x Top of hour Wind Speed sustained value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
80-m Speed x x x x x x Top of hour Wind Speed sustained value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
10-m Gust 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.
P10-m Gust* x           Top of hour Wind Gust value percentiles
P10-m Gust Mean* x           Top of the hour Wind Gust value percentile mean
P10-m Gust SD* x           Top of the hour Wind Gust value percentile Standard Deviation (SD)
10-m Direction x x x x x x Top of the hour Wind Direction value
10-m Speed SD x x x x x   Wind Speed Standard Deviation (SD)
10-m Gust SD x x x x x   Wind Gust Standard Deviation (SD)
30-m Direction           x Top of the hour Wind Direction value
80-m Direction           x Top of the hour Wind Direction value
PMaxSpeed24 x           Maximum Wind Speed in 24-hour period percentiles from 1-99
PMaxGust24 x           Maximum Wind Gust speed in 24-hour period percentiles from 1-99
PMaxSpeed24 Mean x           Mean of PMaxSpeed24
PMaxGust24 Mean x           Mean of PMaxGust24
PMaxSpeed24 SD x           Standard Deviation (SD) of PMaxSpeed24
PMaxGust24 SD x           Standard Deviation (SD) of PMaxGust24
LLWS Height x x x x     Intended to provide Low Level Wind Shear Height guidance (up to 2,000 feet AGL) for WFO TAFs
LLWS Speed x x x x     Intended to provide Low Level Wind Shear Speed guidance (up to 2,000 feet AGL) for WFO TAFs
LLWS Direction x x x x x   Intended to provide Low Level Wind Shear Direction guidance (up to 2,000 feet AGL) for WFO TAFs
Low-Level Turbulence x x x x x   Low level and mountain wave induced turbulence guidance
Ellrod Index x x x x     High level turbulence guidance for roughly the 300-200 mb layer
CLOUDS AND OBSTRUCTIONS
Cover x x x x x   Mean Sky Cover 0-100%
Cover SD x x x x x   Sky Cover Standard Deviation (SD)
Cig x x x x x   The lowest broken or overcast cloud deck
Vis x x x x x x The greatest horizontal distance objects can be seen and identified
Base Height x x x x x   Lowest cloud base whether or not a ceiling is present (could be FEW or SCT layer)
AWC Primary x           Height of cloud base, top, and coverage of digital aviation service's primary cloud layer
AWC Secondary x           Height of cloud base, top, and coverage of digital aviation service's secondary cloud layer
AWC Teritary x           Height of cloud base, top, and coverage of digital aviation service's tertiary cloud layer
AWC High Level x           Height of cloud base, top, and coverage of AWC's cirrus cloud layer
PROBABILITIES OF SPECIFIC AMOUNTS
ProbCig x           Threshold Probability of VLIFR (0 or 100), LIFR (200-400), IFR (500-900), and MVFR (1,000-3,000) ceilings
ProbVis x           Threshold Probability of VLIFR (0), LIFR (1/4-3/4), IFR (1-3), and MVFR (3-5) visibilities
ProbSpeed* x Threshold probability of exceedence for 10-m Wind Speed.
ProbGust* x Threshold probability of exceedence for 10-m Wind Gust.
ProbMaxSpeed24 Thresholds x           Probability of maximum wind speed exceeding threshold in 24-hour period
ProbMaxGust24 Thresholds x           Probability of maximum wind gust speed exceeding threshold in 24-hour period
ProbCWASP 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
18 dbZ Echo Tops x x x x x   Top of the hour height above mean sea level of highest light precipitation echoes (hourly 1-36 hours)
PoT01 x x x x   x 1 hour probability of thunder through 36 hours
PoT03 x x x x   x 3 hour probability of thunder through 192 hours
PoT06 x x x x   x 6 hour probability of thunder through 192 hours
PoT12 x x x x   x 12 hour probability of thunder through 192 hours
Max Reflectivity x x x x x   Maximum reflectivity in the column over the past hour in dBZ (hourly 1-36 hours)
CWASP x           Expert weighted mean of Craven Wiedenfeld Aggregate Severe Parameter (75% of EF2+ tornadoes have CWASP of 65+)
T-storm Coverage 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%)
VIL x x x x x   Top of the hour vertically integrated liquid (hourly 1-36 hours)
SBCAPE x x x x x   Surface based Convectively Available Potential Energy
SBCAPE SD x x x x x   Surface Based Convectively Available Potential Energy Standard Deviation
Percentile CWASP x           5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile of CWASP
SPC ProbSevere 4 hour x           SPC-POST calibrated HREF 4hr probability of severe hazards (wind/hail/tornado)
SPC ProbSevere 24 hour 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
Haines Index 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)
Fosberg Index 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
Mixing Height x x x x     Combination of PBL height and modified Stull Method using 0.5K warm bubble (height above ground level)
Solar Radiation x x x x     Incoming solar radiation
Prob DryThunder 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
Transport WindSpd x x x x     Mean Wind Speed in the layer defined by mixing height
Transport WindDir x x x x     Mean Wind Direction in the layer defined by mixing height
Ventilation Rate 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
SnowAmt01 x x         1-hour Snow Accumulation through 36 hours
SnowAmt06 x x         6-hour Snow Accumulation through 264 hours
SnowAmt24 x x         24-hour Snow Accumulation through 264 hours
SnowAmt48 x x         48-hour Snow Accumulation through 264 hours
SnowAmt72 x x         72-hour Snow Accumulation through 264 hours
IceAccum01 x x         1-hour Flat Ice Accumulation using FRAM technique through 36 hours
IceAccum06 x x         6-hour Flat Ice Accumulation using FRAM technique through 264 hours
IceAccum24 x x         24-hour Flat Ice Accumulation using FRAM technique through 264 hours
IceAccum48 x x         48-hour Flat Ice Accumulation using FRAM technique through 264 hours
IceAccum72 x x         72-hour Flat Ice Accumulation using FRAM technique through 264 hours
ACCUMULATION PERCENTILES (INCHES)
SnowP01 x x         1-hour Snow Accumulation percentiles
SnowP06 x x         6-hour Snow Accumulation percentiles
SnowP24 x x         24-hour Snow Accumulation percentiles
SnowP48 x x         48-hour Snow Accumulation percentiles
SnowP72 x x         72-hour Snow Accumulation percentiles
IceP06 x x         6-hour Flat Ice Accumulation (FRAM) percentiles
IceP24 x x         24-hour Flat Ice Accumulation (FRAM) percentiles
IceP48 x x         48-hour Flat Ice Accumulation (FRAM) percentiles
IceP72 x x         72-hour Flat Ice Accumulation (FRAM) percentiles
PROBABILITIES OF SPECIFIC AMOUNTS (>1 in, >12 in etc)
ProbSnow01 x x         1-hour threshold probability of exceedance for Snow Accumulation
ProbSnow06 x x         6-hour threshold probability of exceedance for Snow Accumulation
ProbSnow24 x x         24-hour threshold probability of exceedance for Snow Accumulation
ProbSnow48 x x         48-hour threshold probability of exceedance for Snow Accumulation
ProbSnow72 x x         72-hour threshold probability of exceedance for Snow Accumulation
ProbIce06 x x         6-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
ProbIce24 x x         24-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
ProbIce48 x x         48-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
ProbIce72 x x         72-hour threshold probability of exceedance for Flat Ice Accumulation (FRAM)
Snow or Sleet > 0.25 in Liquid Equiv x           24-hour probability of liquid equivalent of melted snow and sleet exceeding 0.25 in
PRECIPIATION TYPE (PTYPE)
PType x x         Probability of Snow, Rain, Sleet, or Freezing Rain (instantaneous top of hour)
Snow Ratio x x         Snow to Liquid Ratio (using combination of Cobb, Roebber, MaxTaloft, thickness)
Snow Level x x x x     Elevation where the wet bulb temperature reaches 0.5 degrees C
PSnow Ratio 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)
PSnow Level 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
WaveHgt x x x x x x Significant Wave Height
WaveHgtSD x x x x x x Significant Wave Height Standard Deviation (SD)
PWaveHgt x x x x x x 10/50/90 percentile of Significant Wave Height
SST x x       x Top of the hour Sea Surface Temperature
Frzg Spray x x       x Categorical Freezing Spray potential
Ice Coverage   x         Percent Sea Ice Coverage inside gridbox
Ice Thickness   x         Sea Ice Thickness
WIND
Tropical Speed x x x x x x Tropical Cyclone Wind Speed forecast feature matched over NBM wind speed background
Tropical Direction 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
Temperature x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
Pressure Height x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
Rel Humidity x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
Wind Speed x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
Wind Direction x x x x x 00Z & 12Z forecasts. 6-hourly through 384.
Height Standard Deviation   x x     Standard deviation (SD) at 500mb and 700mb heights. 00Z & 12Z forecasts. 6-hourly through 384