NBM V4.0 SURFACE WEATHER ELEMENTS

Available surface weather elements and regions available 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     12z to 06z except in Guam 18z to 12z; dynamically weighted mean
MinT x x x x     00z to 18z except in Guam 06z to 00z; dynamically weighted mean
MaxT SD x x x x     12z to 06z except in Guam 18z to 12z; SD from a subset of about 25 inputs
MinT SD x x x x     00z to 18z except in Guam 06z to 00z; SD from a subset of about 25 inputs
PMaxT x           12z to 06z except in Guam 18z to 12z; percentiles from 1-99 with up to 171 members
PMinT x           00z to 18z except in Guam 06z to 00z; percentiles from 1-99 with up to 171 members
PMaxT Mean x           12z to 06z except in Guam 18z to 12z; true mean from up to 171 members
PMinT Mean x           00z to 18z except in Guam 06z to 00z; true mean from up to 171 members
PMaxT SD x           12z to 06z except in Guam 18z to 12z; SD from up to 171 members
PMinT SD x           00z to 18z except in Guam06z to 00z; SD from up to 171 members
Temp x x x x x x Top of hour value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
Temp SD x x x x x   SD from subset of about 25 inputs
AppT x x x x     Derived parameter from Temp, Td, and wind speed
PRECIPITATION
QPF01 x x x x x   Hourly rainfall or melted liquid equivalent to 264 hours
QPF06 x x x x x   Expert weighted mean
PQPF06 x x x     x Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members
PQPF12 x x x     x Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members
PQPF24 x x x     x Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members
PQPF06 Mean x x x     x Mean value from up to 171 members
PQPF12 Mean x x x     x Mean value from up to 171 members
PQPF24 Mean x x x     x Mean value from up to 171 members
PoP01 x x x x x   Expert weighted mean to 36 hours
PoP06 x x x x x   Expert weighted mean
PoP12 x x x x x   Expert weighted mean through 36 hours
QMD PoP06 x x x     x Output from Quantile Mapping and Dressing without expert weights in short term
QMD PoP12 x x x     x Output from Quantile Mapping and Dressing without expert weights in short term
Wx x x         Predominant Weather derived field
Duration x x   x     Number of hours within a 12 hour period that at least 0.01" of QPF is forecast
PROBABILITIES OF SPECIFIC AMOUNTS
ProbMaxT (<0F, >100F, etc) x           Threshold probabilities from 171 member ensemble valid 12z to 06z
ProbMinT x           Threshold probabilities from 171 member ensemble valid 00z to 18z
ProbQPF24 (>0.10, >1.00", etc) x x x     x Threshold probabilities from 171 member ensemble
HUMIDITY
Td x x x x x   Top of hour value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
Td SD x x x x x   SD from subset of about 25 inputs
RH x x x x x   Derived from Temp and Td
MaxRH x x x x     Derived from highest hourly/3 hourly/6 hourly value
MinRH x x x x     Derived from lowest hourly/3 hourly/6 hourly value
PRESSURE
PMSLP           x 10th, 25th, 50th, 75th, and 90th percentiles
PMSLP Spread           x Standard Deviation from ~100 member multi-model ensemble

NBM V4.0 AVIATION WEATHER ELEMENTS

Available aviation weather elements and regions available 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 sustained value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
P10m-Speed           x Top of hour sustained value 10th, 25th, 50th, 75th, and 90th percentiles; 3 hourly temporal resolution
30-m Speed x x x x x x Top of hour 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 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 gust value; hourly through 36 hours, then 3 hourly to 192 hours, then 6 hourly to 264.
10-m Direction x x x x x x Top of the hour value
10-m Speed SD x x x x x   Standard Deviation of ~100 member multi-model ensemble
10-m Gust SD x x   x x   Standard Deviation of ~100 member multi-model ensemble
30-m Directon           x Top of the hour value
80-m Direction           x Top of the hour value
LLWS Height x x x x     Intended to provide Low Level Wind Shear guidance (up to 2,000 feet AGL) for WFO TAFs
LLWS Speed x x x x     Intended to provide Low Level Wind Shear guidance (up to 2,000 feet AGL) for WFO TAFs
LLWS Direction x x x x     Intended to provide Low Level Wind Shear guidance (up to 2,000 feet AGL) for WFO TAFs
Low-Level Turbulence 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   SD from subset of about 25 inputs
Cig x x x x x   Ceiling from GLMP through 36 hours, then blend of NAM MOS and GFS MOS 39-78 hours
Vis x x x x x x Visibility from GLMP through 36 hours, then blend of NAM MOS and GFS MOS 39-78 hours
Lowest Base Height x x x x x   Lowest cloud base regardless of ceiling height (could be FEW or SCT 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
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     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 expert weighted probability of thunder through 36 hours
PoT03 x x x x   x 3 hour expert weighted probability of thunder through 192 hours
PoT06 x x x x   x 6 hour expert weighted probability of thunder through 192 hours
PoT12 x x x x   x 12 hour expert weighted probability of thunder through 192 hours
Max Reflectivity x x x x     Maximum reflectivity in the column over the past hour in dBZ (hourly 1-36 hours)
VIL x x x x     Top of the hour vertically integrated liquid (hourly 1-36 hours)
SBCAPE x x x x     Expert weighted mean surface based convectively available potential energy
SBCAPE SD x x x x     SD from subset of about 25 inputs
CWASP x           Expert weighted mean of Craven Wiedenfeld Aggregate Severe Parameter (75% of EF2+ tornadoes have CWASP of 65+)
PCWASP x           5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile of CWASP using roughly 25 inputs

NBM V4.0 FIRE WEATHER ELEMENTS

Available fire weather elements and regions available 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 maximum temperature, maximum wind speeds, and minimum 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
MaxRH         x   Maximum Relative Humidity from 0000 to 1800 UTC
MinRH         x   Minimum Relative Humidity from 1200 to 0600 UTC
WIND
Transport WindSpd x x   x     Mean wind speed in the layer defined by mixing height
Transport WindDir x x   x     Mean wind direction in the layer defined by mixing height
Ventilation Rate x x   x     The product of the mixing height and the transport wind speed

NBM V4.0 WINTER WEATHER ELEMENTS

Available winter weather elements and regions available 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
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
ACCUMULATION PRECENTILES (INCHES)
SnowP24 (5th, 10th, 25th, etc) x x         24 hour snow accumulation percentiles
SnowP48 x x         48 hour snow accumulation percentiles
SnowP72 x x         72 hour snow accumulation 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", >12" etc)
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
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" Liquid Equiv x           24 hour probability of liquid equivalent of melted snow and sleet exceeding 0.25"
PRECIPIATION TYPE (PTYPE)
CPType x x         Conditional Probability of Snow, Rain, Sleet, or Freezing rain (instantaneous top of hour)
ProbZZ x x         Conditional Probability of sleet refreezing in the near surface cold layer
Cloud Ice x x         Probability of cloud ice present in the vertical column (for snow versus freezing drizzle)
Frzg Spray x x       x Categorical freezing spray potential
Snow Ratio x x         Snow to Liquid Ratio (using combination of Cobb, Roebber, MaxTaloft, and thickness)
Snow Level x x   x     Elevation where the wet bulb temperature reaches 0.5 degrees C
BOURGOUIN ENERGY
Negative Energy Near Surface Cold Layer x x         Total area under the curve of near surface cold layer (for winter precipitation type)
Positive Warm Nose Aloft x x         Total area under the curve of the elevated warm layer aloft (for winter precipitation type)

NBM V4.0 MARINE WEATHER ELEMENTS

Available marine weather elements and regions available 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 Expert weighted mean of significant wave height
WaveHgtSD x x x x x x SD calculated from roughly 10 inputs
SST x x       x Mean top of the hour sea surface temperature
Frzg Spray x x       x Categorical freezing spray potential