DeGRIB NDFD WWA Hazards - MDL
How NDFD Treats wwaHazards
wwaHazards(Watch, Warning, Advisory Hazards) in NDFD is handled by including a wwaHazard string table in the local use section of the GRIB2 message. The grid cell values in the data part of the GRIB2 message are numbers(Codes) which refer to that entry in the wwaHazard string table. The entries consist of ASCII wwaHazard strings which have up to 5 wwaHazards separated by '^'. Simple wwaHazards are of the form "AA.B^CC.D" where AA and CC are a two letter descriptor unique to each Hazard, and B and D are either a "W" for Warning, an "A" for Watch, a "Y" for Advisory or a "S" for statement.
Simple Hazard code
In order to create graphical images of wwaHazards, NDFD needed a way to combine the various possibilities of wwaHazards into a discrete number of colors. So they came up with NDFD simple wwaHazards codes. degrib currently (as of 3/2017) recognizes four iterations of simple wwaHazards codes, as follows:
1 = initial version of NDFD Simple Hazard(WWA) Code 2 = 9/2008 version of NDFD Simple Hazard(WWA) Code 3 = 7/2009 version of NDFD Simple Hazard(WWA) Code 4 = 3/2017 version of NDFD Simple Hazard(WWA) Code(default)
Note: If there are more than one wwaHazards at a certain grid point, degrib will always pick up on the lowest Code value of a wwaHazard. The lower the Code the higher the priority. For example, what if we have a wwaHazard of "TO.W^EH.W"? See the Simple Hazard(WWA) Code Table below. Tornado Warning has a Code of "2", and Excessive Heat Warning has a Code of "44", so degrib will pick up on the TO.W and ignore the EH.W.
Please see Handling wwaHazard in Degrib(below), or our man page, for instructions on how to work with wwaHazards in degrib.
Current(version 4) Simple Hazard(WWA) Code Table:
wwaHazard | Code | Label 1 |
---|---|---|
None | 0 | None |
TS.W | 1 | Tsunami Warning |
TO.W | 2 | Tornado Warning |
EW.W | 3 | Extreme Wind Warning |
SV.W | 4 | Severe Thunderstorm Warning |
FF.W | 5 | Flash Flood Warning |
- | 6 | Shelter In Place Warning |
- | 7 | Evacuation - Immediate |
- | 8 | Civil Danger Warning |
- | 9 | Nuclear Power Plant Warning |
- | 10 | Radiological Hazard Warning |
- | 11 | Hazardous Materials Warning |
- | 12 | Fire Warning |
- | 13 | Civil Emergency Message |
- | 14 | Law Enforcement Warning |
HF.W | 15 | Hurricane Force Wind Warning |
HI.W | 16 | Hurricane Wind Warning |
SS.W | 17 | Storm Surge Warning |
HU.W | 18 | Hurricane Warning |
HU.W | 19 | Hurricane Warning |
TY.W | 20 | Typhoon Warning |
TY.W | 21 | Typhoon Warning |
MA.W | 22 | Special Marine Warning |
MA.W | 23 | Marine Weather Statement (follow up to SMW) |
BZ.W | 24 | Blizzard Warning |
IS.W | 25 | Ice Storm Warning |
TI.W | 26 | Tropical Storm Wind Warning |
HS.W | 27 | Heavy Snow Warning |
WS.W | 28 | Winter Storm Warning |
HW.W | 29 | High Wind Warning |
TR.W | 30 | Tropical Storm Warning |
TR.W | 31 | Tropical Storm Warning |
SR.W | 32 | Storm Warning |
TS.A | 33 | Tsunami Watch |
- | 34 | Avalanche Warning |
- | 35 | Earthquake Warning |
AF.W | 36 | Ashfall Warning |
CF.W | 37 | Coastal Flood Warning |
LS.W | 38 | Lakeshore Flood Warning |
FA.W | 39 | Flood Warning (areal) |
FL.W | 40 | Flood Warning (for forecast points) |
SU.W | 41 | High Surf Warning |
IP.W | 42 | Sleet Warning |
LE.W | 43 | Lake Effect Snow Warning |
EH.W | 44 | Excessive Heat Warning |
DS.W | 45 | Dust Storm Warning |
TO.A | 46 | PDS - Tornado Watch |
TO.A | 47 | Tornado Watch |
SV.A | 48 | PDS - Severe Thunderstorm Watch |
SV.A | 49 | Severe Thunderstorm Watch |
FF.A | 50 | Flash Flood Watch |
TO.W | 51 | Severe Weather Statement |
SV.W | 52 | Severe Weather Statement |
FF.W | 53 | Flash Flood Statement |
GL.W | 54 | Gale Warning |
FA.W | 55 | Flood Statement (follow-up to areal Flood Warning) |
FL.W | 56 | Flood Statement (follow-up to point Flood Warning) |
TS.Y | 57 | Tsunami Advisory |
WC.W | 58 | Wind Chill Warning |
EC.W | 59 | Extreme Cold Warning |
HZ.W | 60 | Hard Freeze Warning |
FZ.W | 61 | Freeze Warning |
FW.W | 62 | Red Flag Warning |
SS.A | 63 | Storm Surge Watch |
HU.A | 64 | Hurricane Watch |
HU.A | 65 | Hurricane Watch |
TY.A | 66 | Typhoon Watch |
TY.A | 67 | Typhoon Watch |
HU.S | 68 | Hurricane Local Statement |
TY.S | 69 | Typhoon Local Statement |
SB.Y | 70 | Snow and Blowing Snow Advisory |
ZR.Y | 71 | Freezing Rain Advisory |
- | 72 | Freezing Drizzle Advisory |
IP.Y | 73 | Sleet Advisory |
WW.Y | 74 | Winter Weather Advisory |
LB.Y | 75 | Lake Effect Snow and Blowing Snow Advisory |
LE.Y | 76 | Lake Effect Snow Advisory |
WC.Y | 77 | Wind Chill Advisory |
HT.Y | 78 | Heat Advisory |
FA.Y | 79 | Urban and Small Stream Flood Advisory |
FA.Y | 80 | Small Stream Flood Advisory |
FA.Y | 81 | Arroyo and Small Stream Flood Advisory |
FA.Y | 82 | Flood Advisory |
FL.Y | 83 | Flood Advisory (for forecast points) |
FA.Y | 84 | Hydrologic Advisory |
LS.Y | 85 | Lakeshore Flood Advisory |
CF.Y | 86 | Coastal Flood Advisory |
SU.Y | 87 | High Surf Advisory |
BS.Y | 88 | Blowing Snow Advisory |
SN.Y | 89 | Snow Advisory |
UP.W | 90 | Heavy Freezing Spray Warning |
SM.Y | 91 | Dense Smoke Advisory |
MS.Y | 92 | Dense Smoke Advisory |
SW.Y | 93 | Small Craft Advisory For Hazadous Seas |
RB.Y | 94 | Small Craft Advisory for Rough Bar |
SI.Y | 95 | Small Craft Advisory for Winds |
SC.Y | 96 | Small Craft Advisory |
BW.Y | 97 | Brisk Wind Advisory |
SE.W | 98 | Hazardous Seas Warning |
FG.Y | 99 | Dense Fog Advisory |
MF.Y | 100 | Dense Fog Advisory |
LW.Y | 101 | Lake Wind Advisory |
WI.Y | 102 | Wind Advisory |
DU.Y | 103 | Blowing Dust Advisory |
FR.Y | 104 | Frost Advisory |
AF.Y | 105 | Ashfall Advisory |
MH.Y | 106 | Ashfall Advisory |
ZF.Y | 107 | Freezing Fog Advisory |
UP.Y | 108 | Freezing Spray Advisory |
AS.Y | 109 | Air Stagnation Advisory |
LO.Y | 110 | Low Water Advisory |
- | 111 | Local Area Emergency |
- | 112 | Avalanche Watch |
BZ.A | 113 | Blizzard Watch |
RP.S | 114 | Rip Current Statement |
BH.S | 115 | Beach Hazard Statement |
TI.A | 116 | Tropical Storm Wind Watch |
HF.A0 | 117 | Hurricane Force Wind Watch |
HI.A | 118 | Hurricane Wind Watch |
TR.A | 119 | Tropical Storm Watch |
TR.A | 120 | Tropical Storm Watch |
SR.A | 121 | Storm Watch |
GL.A | 122 | Gale Watch |
WS.A | 123 | Winter Storm Watch |
SE.A | 124 | Hazardous Seas Watch |
UP.A | 125 | Heavy Freezing Spray Watch |
CF.A | 126 | Coastal Flood Watch |
LS.A | 127 | Lakeshore Flood Watch |
FA.A | 128 | Flood Watch (areal) |
HW.A | 129 | High Wind Watch |
EH.A | 130 | Excessive Heat Watch |
EC.A | 131 | Extreme Cold Watch |
WC.A | 132 | Wind Chill Watch |
LE.A | 133 | Lake Effect Snow Watch |
HZ.A | 134 | Hard Freeze Watch |
FZ.A | 135 | Freeze Watch |
FW.A | 136 | Fire Weather Watch |
- | 137 | Extreme Fire Danger |
- | 138 | Child Abduction Emergency |
- | 139 | 911 Telephone Outage |
CF.S | 140 | Coastal Flood Statement |
LS.S | 141 | Lakeshore Flood Statement |
MA.S | 142 | Marine Weather Statement |
- | 143 | Special Weather Statement |
- | 144 | Hazardous Weather Outlook |
- | 145 | Short Term Forecast |
- | 146 | Administrative Message |
TR.S | 147 | Tropical Storm Local Statement |
- | 148 | Test |
Handling wwaHazards in Degrib
Handing wwaHazards: Degrib -P Option
Degrib has several different ways of handling wwaHazards. Starting with the "degrib -P" option, it can:
- Output the wwaHazards string:
degrib ds.wwa.bin -P -pnt 35,-76 -WxParse 0 - Convert the wwaHazards string to english:
degrib ds.wwa.bin -P -pnt 35,-76 -WxParse 1 - Convert the wwaHazards string to an NDFD simple wwaHazards code:
degrib ds.wwa.bin -P -pnt 35,-76 -WxParse 2
Handling wwaHazards: Degrib -C Option
Continuing to the "degrib -C" option, it is limited in some respects by the file formats that it writes to.
The -C -Flt option
- degrib ds.wwa.bin -C -Flt -Met -msg 1 => convert the message to a NxM 4 byte float file where each cell contains the number in the wwaHazards string lookup table contained in the .txt file (created with the default -Met option)
- degrib ds.wwa.bin -C -Flt -nMet -msg 1 -SimpleWWA 4=> convert the message to a NxM 4 byte float file using simple wwaHazards scheme 4 (see Table above).
The -C -Csv option
- degrib ds.wwa.bin -C -Csv -msg 1 => convert the message to an ASCII comma delimited file with a x, y, lat, lon, and wwaHazards value for each cell. In this case the wwaHazards value is the wwaHazards string.
- degrib ds.wwa.bin -C -Csv -msg 1 -WxParse 1 => convert the message to an ASCII comma delimited file with a x, y, lat, lon, and wwaHazards value for each cell. In this case the wwaHazards value is the wwaHazards string converted to english.
- degrib ds.wwa.bin -C -Csv -msg 1 -WxParse 2 => convert the message to an ASCII comma delimited file with a x, y, lat, lon, and wwaHazards value for each cell. In this case the wwaHazards value is the wwaHazards string converted to an NDFD simple wwaHazards code (see Table above).