National Weather Service United States Department of Commerce
Decoding the Valid Time Event Coding

 

Valid Time Event Coding (VTEC) is a new code string which will be used in many NWS event-driven text products (and in routine marine forecasts) to describe the parameters of Watch/Warning/Advisory (W/W/A) events explicitly. This new code form was requested by NWS partners and customers with whom the development, testing, and implementation have been coordinated.

Customers say they desire VTEC code because it contains all necessary W/W/A information in an easy-to-decode, uniform format. This NWS-wide consistency allows our partners to develop dissemination software to relay the information contained in the VTEC code. Therefore, VTEC will automate the delivery of NWS W/W/A information to our customers and partners, allowing them to relay it more quickly to their customers (i.e., the public).

P-VTEC String:

/k.aaa.cccc.pp.s.####.yymmddThhnnZB-yymmddThhnnZE/

See if you can decode this line:

/O.NEW.KBMX.SV.A.0002.051013T1424Z-051013T1700Z/

or this one:

/O.CAN.KBMX.TO.A.0002.000000T0000Z-051013T1700Z/

P-VTEC

 String

 Event Group

 k - Product Class (O, T, E, X)

 aaa - Action (NEW, CON, EXT, EXA, EXB, UPG, CAN, EXP, COR, ROU)

 cccc - Office ID

 pp - Phenomena (e.g., FL, FF - see table)

 s - Significance (W, A, Y, S)

 #### - Event Tracking Number (ETN)

 Date/Time Group

 yymmddThhnnZB - Event Beginning Date/Time

 yymmddThhnnZE - Event Ending Date/Time

 yy - year

 mm - month

 dd - day

 T - fixed time indicator

 hh - hour

 nn - minute

 Z - fixed UTC indicator

 

Product (k)

class

O  Operational product

 

T   Test product

E  Experimental product

X  Experimental VTEC in Operational product

Phenomena

  (pp)            

 

BZ   Blizzard

WS  Winter Storm

WW Winter Weather

SN   Snow

HS   Heavy Snow

LE    Lake Effect Snow

LB   Lake Effect Snow & Blowing Snow

BS   Blowing/Drifting Snow

SB   Snow & Blowing Snow

IP     Sleet

HP    Heavy Sleet

ZR   Freezing Rain

IS     Ice Storm

FZ    Freeze

ZF    Freezing Fog

FR    Frost

WC  Wind Chill

EC    Extreme Cold

WI    Wind

HW  High Wind

LW   Lake Wind

FG   Dense Fog

SM   Dense Smoke

HT    Heat

EH    Excessive Heat

DU   Blowing Dust

DS   Dust Storm

FL    Flood

FF    Flash Flood

SV   Severe Thunderstorm

TO   Tornado

FW   Fire Weather

RH   Radiological Hazard

VO   Volcano

AF   Volcanic Ashfall

AS   Air Stagnation

AV   Avalanche

TS    Tsunami

MA   Marine

SC   Small Craft

GL   Gale

SR   Storm

HF    Hurricane Force Wind

TR    Tropical Storm

HU   Hurricane

TY   Typhoon

TI     Inland Tropical Storm Wind

HI     Inland Hurricane Wind

LS    Lakeshore Flood

CF    Coastal Flood

UP    Ice Accretion

LO   Low Water

SU   High Surf

Actions (aaa)  

NEW  New event

CON  Event continued

EXT   Event extended (time)

EXA   Event extended (area)

EXB   Event extended (both time and area)

UPG     Event upgraded

CAN     Event cancelled

EXP      Event expired

COR     Correction

ROU     Routine

Significance

  (s)

 

W         Warning

A          Watch

Y    Advisory

S    Statement

 

H-VTEC String:

/s.ic.yymmddThhnnZB.yymmddThhnnZC.yymmddThhnnZE.fr/ 

H-VTEC

 String

 Event Group

 s - Flood Severity (0, N, 1, 2, 3, U)

 ic - Immediate Cause (ER, SM, RS, DM, GO, IJ, IC, UU)

 fr - Flood Record (NO, NR, UU, OO)

 Date/Time Group

 yymmddThhnnZB - Flood Begin Date/Time

 yymmddThhnnZC - Flood Crest Date/Time

 yymmddThhnnZE - Flood End Date/Time

 

Flood Severity (s)

 

0

 

N

1

For areal flood warnings or areal flash flood products

None

Minor

 

2

3

U

Moderate

major

Unknown

Flood Timing

yymmddThhnnZB

yymmddThhnnZC

yymmddThhnnZE

Begin - time flood stage/level is exceeded

Crest - time of maximum stage/flow

End - time for fall below flood stage/level

Immediate Cause

(ic)

ER

SM

RS

DM

IJ

Excessive Rainfall

Snowmelt

Rain and Snowmelt

Dam or Levee Failure

Ice Jam

GO

 

IC

 

UU

Glacier-Dammed

Lake Outburst

Rain and/or Snowmelt and/or Ice Jam

Unknown

Flood Record

Status (fr)

 

NO

NR

UU

OO

A record flood is not expected

Near record or record flood expected

Flood without a period of record to compare

For areal flood warnings or areal flash flood products

 

Examples of VTEC in Products
For Alabama county codes click here - look for the last 3 numbers in the SAME# column. (example: 021 is Chilton County)

 

Example code