NBM v4.1 Weather Elements - MDL
NBM v4.1 Weather Elements by Category
These are the weather elements available in NBM v4.1, the regions they are available, and their definitions. Weather elements new to NBM v4.1 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 V4.1 SURFACE WEATHER ELEMENTS
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 | x | 12z to 06z except in Guam 18z to 12z; percentiles from 1-99 with up to 171 members | ||||
PMinT | x | x | 00z to 18z except in Guam 06z to 00z; percentiles from 1-99 with up to 171 members | ||||
PMaxT Mean | x | x | 12z to 06z except in Guam 18z to 12z; true mean from up to 171 members | ||||
PMinT Mean | x | x | 00z to 18z except in Guam 06z to 00z; true mean from up to 171 members | ||||
PMaxT SD | x | x | 12z to 06z except in Guam 18z to 12z; SD from up to 171 members | ||||
PMinT SD | x | 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 | ||
WBGT * | x | x | x | x | Measure of heat stress using NBM Temp, Td, Sky, Wspd, and MSLP | ||
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 | x | Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members | |
PQPF12 | x | x | x | x | x | Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members | |
PQPF24 | x | x | x | x | x | Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members | |
PQPF48 * | x | x | x | x | x | Derived from Quantile Mapping and Dressing; percentiles from 1-99 with up to 171 members | |
PQPF72 * | x | 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 | x | Mean value from up to 171 members | |
PQPF12 Mean | x | x | x | x | x | Mean value from up to 171 members | |
PQPF24 Mean | x | x | x | x | x | Mean value from up to 171 members | |
PQPF48 Mean * | x | x | x | x | x | Mean value from up to 171 members | |
PQPF72 Mean * | x | 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 | x | Output from Quantile Mapping and Dressing without expert weights in short term | |
QMD PoP12 | x | x | x | x | x | Output from Quantile Mapping and Dressing without expert weights in short term | |
QMD PoP24 * | x | 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 | 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 | x | Threshold probabilities from 171 member ensemble valid 12z to 06z | ||||
ProbMinT | x | x | Threshold probabilities from 171 member ensemble valid 00z to 18z | ||||
ProbQPF06 * | x | x | x | x | x | Threshold probabilities from 171 member ensemble | |
ProbQPF12 * | x | x | x | x | x | Threshold probabilities from 171 member ensemble | |
ProbQPF24 | x | x | x | x | x | Threshold probabilities from 171 member ensemble | |
ProbQPF48 * | x | x | x | x | x | Threshold probabilities from 171 member ensemble | |
ProbQPF72 * | x | 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 V4.1 AVIATION WEATHER ELEMENTS
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 | 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 | |||||
PMaxSpeed24 * | x | Maximum wind speed in 24-hour period percentiles from 1-99; Derived from ~200 model members | |||||
PMaxGust24 * | x | Maximum wind gust speed in 24-hour period percentiles from 1-99; Derived from ~200 model members | |||||
PMaxSpeed24 Mean * | x | Mean of PMaxSpeed24 | |||||
PMaxGust24 Mean * | x | Mean of PMaxGust24 | |||||
PMaxSpeed24 SD * | x | Standard deviation of PMaxSpeed24 | |||||
PMaxGust24 SD * | x | Standard deviation of PMaxGust24 | |||||
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 |
Base Height | x | x | x | x | x | Lowest cloud base regardless of ceiling height (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 | |||||
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 | |||||
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 | |||||
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 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 | x | Maximum reflectivity in the column over the past hour in dBZ (hourly 1-36 hours) | |
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 | Expert weighted mean surface based convectively available potential energy | |
SBCAPE SD | x | 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+) | |||||
Percentile CWASP | x | 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile of CWASP using roughly 25 inputs | |||||
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 V4.1 FIRE WEATHER ELEMENTS
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" x P(2-m RH) <30% x P(PW) <1"] | |||||
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 | 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 V4.1 WINTER WEATHER ELEMENTS
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 PRECENTILES (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", >12" 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" Liquid Equiv | x | 24 hour probability of liquid equivalent of melted snow and sleet exceeding 0.25" | |||||
PRECIPIATION TYPE (PTYPE) | |||||||
PType | x | x | Probability of Snow, Rain, Sleet, or Freezing rain (instantaneous top of hour) | ||||
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 | 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 V4.1 MARINE WEATHER ELEMENTS
Marine Weather Elements | CO | AK | PR | HI | GU | OC | Definition |
---|---|---|---|---|---|---|---|
WATER | |||||||
WaveHgt | x | x | x | x | x | x | MAE weighted mean of significant wave height |
WaveHgtSD | x | x | x | x | x | x | SD calculated from roughly 10 inputs |
PWaveHgt * | x | x | x | x | x | x | 10/50/90 percentile of significant wave height |
SST | x | x | x | Mean top of the hour sea surface temperature | |||
Frzg Spray | x | x | x | Categorical freezing spray potential | |||
Ice Coverage * | x | Expert-weighted precent sea ice coverage inside gridbox | |||||
Ice Thickness * | x | Expert-weighted mean sea ice thickness | |||||
WIND | |||||||
Tropical Speed * | x | x | x | x | x | x | Expert-weighted tropical cyclone wind speed forecast placed over NBM wind speed background |
Tropical Direction * | x | x | x | x | x | x | Expert-weighted tropical cyclone wind direction forecast placed over NBM wind speed background |
NBM V4.1 UPPER AIR WEATHER ELEMENTS
Upper Air (Global) | 250mb | 500mb | 700mb | 850mb | 925mb | Definition |
---|---|---|---|---|---|---|
Temperature | x | x | x | x | x | 00Z & 12Z forecasts. 6-hourly through 384. Expert-weighted, bias corected forecasts for 100 members. |
Pressure height | x | x | x | x | x | 00Z & 12Z forecasts. 6-hourly through 384. Expert-weighted, bias corected forecasts for 100 members. |
RH | x | x | x | x | x | 00Z & 12Z forecasts. 6-hourly through 384. Expert-weighted, bias corected forecasts for 100 members. |
Wind Speed | x | x | x | x | x | 00Z & 12Z forecasts. 6-hourly through 384. Expert-weighted, bias corected forecasts for 100 members. |
Wind Directon | x | x | x | x | x | 00Z & 12Z forecasts. 6-hourly through 384. Expert-weighted, bias corected forecasts for 100 members. |
Height Standard Deviation | x | x | Standard deviations at 500mb and 700mb heights. 00Z & 12Z forecasts. 6-hourly through 384 |