This nowCOAST™ time-enabled map service provides maps depicting the geographic coverage of the latest NOAA/National Weather Service (NWS) WATCHES, WARNINGS, ADVISORIES, and STATEMENTS for long-duration hazardous weather, marine weather, hydrological, oceanographic, wildfire, air quality, and ecological conditions which may or are presently affecting inland, coastal, and maritime areas. A few examples include Gale Watch, Gale Warning, High Surf Advisory, High Wind Watch, Areal Flood Warning, Coastal Flood Watch, Winter Storm Warning, Wind Chill Advisory, Frost Advisory, Tropical Storm Watch, Red Flag Warning, Air Stagnation Warning, and Beach Hazards Statement. (A complete list is given in the Background Information section below.) The coverage areas of these products are usually defined by county or sub-county boundaries. The colors used to identify the different watches, advisories, warnings, and statements are the same colors used by the NWS on their map at weather.gov. The NWS products for long-duration hazardous conditions are updated in the nowCOAST map service approximately every 10 minutes. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule.
The coverage areas of these products are usually defined by county or
sub-county boundaries, but for simplicity and performance reasons, adjacent
WWAs of the same type, issuance, and expiration are depicted in this service as
unified (merged/dissolved) polygons in the layers indicated with the suffix
"(Dissolved Polygons)". However, a set of equivalent layers containing the
original individual zone geometries are also included for querying purposes,
and are indicated with the suffix "(Zone Polygons)". Corresponding zone polygon
and dissolved polygon layers are matched together in group layers for each WWA
category. The zone polygon layers are included in this service only to support
query/identify operations (e.g., in order to retrieve the original zone
geometry or other attributes such as a URL to the warning text bulletin) and
thus will not be drawn when included in a normal map image request. Thus, the
dissolved polygon layers should be used when requesting a map image (e.g. WMS
GetMap or ArcGIS REST export operations), while the zone polygon layers should
be used when performing a query (e.g. WMS GetFeatureInfo or ArcGIS REST query
or identify operations).
The colors used to identify the different watches, advisories, warnings, and
statements are the same colors used by the NWS on their map at
http://www.weather.gov.
The NWS products for long-duration hazardous conditions are updated in the
nowCOAST™ map service approximately every 10 minutes.
For more detailed information about layer update frequency and timing, please reference the
nowCOAST™ Dataset Update Schedule.
Background Information
NWS watches depict the geographic areas where the risk of hazardous weather or
hydrologic events has increased significantly, but their occurrence, location,
and/or timing is still uncertain. A warning depicts where a hazardous weather
or hydrologic event is occurring, is imminent, or has a very high probability
of occurring. A warning is used for conditions posing a threat to life or
property. Advisories indicate where special weather conditions are occurring,
imminent, or have a very high probability of occurring but are less serious
than a warning. They are for events that may cause significant inconvenience,
and if caution is not exercised, could lead to situations that may threaten
life and/or property. Statements usually contain updated information on a
warning and are used to let the public know when a warning is no longer in
effect. NWS issues over 75 different types of watches, warnings, and advisories
(WWAs). WWAs are issued by the NWS regional Weather Forecast Offices (WFOs) and
also the NWS Ocean Prediction Center, National Hurricane Center, Central
Pacific Hurricane Center, and Storm Prediction Center.
The NWS WWAs are organized on the nowCOAST™ map viewer and within this
map service by hazardous condition/threat layer groups and then by the
geographic area (i.e. coastal & inland, immediate coast or maritime) for
which the WWA product is targeted. This was done to allow users to select WWAs
for hazardous conditions that are important to their operations or activities.
Please note that the Tropical Storm and Hurricane Warnings are provided in both
the High Wind Hazards: Maritime Areas and Coastal & Inland Areas layer
groups and the Flooding Hazards: Coastal Areas layer group. These warnings are
included in the Flooding Hazards/Coastal Areas layer group because the NWS uses
those warnings to inform the public that tropical storm or hurricane winds may
be accompanied by significant coastal flooding but below the thresholds
required for the issuance of a storm surge warning. In addition, a tropical
storm or hurricane warning may remain in effect when dangerously high water or
a combination of dangerously high water and waves continue, even though the
winds may be less than hurricane or tropical storm force. The NWS does not
issue a Coastal Flood Warning or Advisory when a tropical storm or hurricane
warning is in effect; however that does not mean that there is not a
significant coastal flooding threat.
High Wind Hazards (Associated with Non-Tropical & Tropical Cyclones)
Maritime Areas
Brisk Wind Advisory
Small Craft Advisory
Small Craft Advisory for Winds
Gale Watch
Gale Warning
Storm Watch
Storm Warning
Hurricane Force Wind Watch
Hurricane Force Wind Warning
Tropical Storm Watch
Tropical Storm Warning
Hurricane Watch
Hurricane Warning
Coastal & Inland Areas
High Wind Watch
Wind Advisory
Lake Wind Advisory
High Wind Warning
Tropical Storm Watch
Tropical Storm Warning
Hurricane Watch
Hurricane Warning
Hazardous Seas, Surf, and Beach Conditions
Maritime Areas
Small Craft Advisory for Hazardous Seas
Small Craft Advisory for Rough Bar
Hazardous Seas Watch
Hazardous Seas Warning
Immediate Coast
Beach Hazards Statement
High Surf Advisory
High Surf Warning
Low Water Advisory
Rip Current Statement
Flooding Hazards
Coastal Areas
Coastal Flood Statement
Coastal Flood Watch
Coastal Flood Advisory
Coastal Flood Warning
Lakeshore Flood Watch
Lakeshore Flood Advisory
Lakeshore Flood Warning
Lakeshore Flood Statement
Storm Surge Watch
Storm Surge Warning
Tsunami Watch
Tsunami Warning
Tropical Storm Warning
Hurricane Warning
Inland Areas
Flood Watch (Point) (also called River Flood Watch)
Flood Watch (Areal)
Flood Advisory (Point) (also called River Flood Advisory)
Flood Advisory (Areal)
Flood Warning (Point) (also called River Flood Warning)
Flood Warning (Areal)
Hydrologic Outlook
Hydrologic Statement
Reduced Visibility Hazards
Maritime Areas
Dense Fog Advisory
Coastal & Inland Areas
Ashfall Advisory
Ashfall Warning
Blowing Dust Advisory
Blowing Dust Warning
Dense Fog Advisory
Dense Smoke Advisory
Freezing Spray Hazards
Maritime Areas
Heavy Freezing Spray Watch
Freezing Spray Advisory
Heavy Freezing Spray Advisory
Snow, Sleet, Freezing Rain, and Freezing Fog Hazards
Coastal & Inland Areas
Blizzard Watch
Blizzard Warning
Freezing Fog Advisory
Freezing Rain Advisory
Ice Storm Warning
Lake-Effect Snow Watch
Lake-Effect Snow Advisory
Lake-Effect Snow Warning
Winter Storm Watch
Winter Weather Advisory
Winter Storm Warning
Cold and Heat Hazards
Coastal & Inland Areas
Excessive Cold Watch
Excessive Cold Warning
Excessive Heat Watch
Heat Advisory
Excessive Heat Warning
Frost Advisory
Freeze Watch
Freeze Warning
Wind Chill Advisory
Wind Chill Warning
Critical Wildfire Conditions
Coastal & Inland Areas
Fire Weather Watch
Red Flag Warning
Unhealthy Air Quality
Coastal & Inland Areas
Air Stagnation Advisory
Air Quality Alerts from states are NOT available
For descriptions of individual NWS watches, warnings, and advisories please see
Section 2 of the NWS Reference Guide available at
http://www.nws.noaa.gov/om/guide/Section2.pdf.
Time Information
This map service is time-enabled, meaning that each individual layer contains
time-varying data and can be utilized by clients capable of making map requests
that include a time component.
In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is
also provided by this service.
This particular service can be queried with or without the use of a time
component. If the time parameter is specified in a request, the data or imagery
most relevant to the provided time value, if any, will be returned. If the time
parameter is not specified in a request, the latest data or imagery valid for
the present system time will be returned to the client. If the time parameter
is not specified and no data or imagery is available for the present time, no
data will be returned.
This service is configured with time coverage support, meaning that the service
will always return the most relevant available data, if any, to the specified
time value. For example, if the service contains data valid today at 12:00 and
12:10 UTC, but a map request specifies a time value of today at 12:07 UTC, the
data valid at 12:10 UTC will be returned to the user. This behavior allows more
flexibility for users, especially when displaying multiple time-enabled layers
together despite slight differences in temporal resolution or update frequency.
When interacting with this time-enabled service, only a single instantaneous
time value should be specified in each request. If instead a time range is
specified in a request (i.e. separate start time and end time values are
given), the data returned may be different than what was intended.
Care must be taken to ensure the time value specified in each request falls
within the current time coverage of the service. Because this service is
frequently updated as new data becomes available, the user must periodically
determine the service's time extent. However, due to software limitations, the
time extent of the service and map layers as advertised by ArcGIS Server does
not always provide the most up-to-date start and end times of available data.
Instead, users have three options for determining the latest time extent of the
service:
Issue a returnUpdates=true request (ArcGIS REST protocol only)
for an individual layer or for the service itself, which will return
the current start and end times of available data, in epoch time format
(milliseconds since 00:00 January 1, 1970). To see an example, click on
the "Return Updates" link at the bottom of the REST Service page under
"Supported Operations". Refer to the
ArcGIS REST API Map Service Documentation
for more information.
Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against
the proper layer corresponding with the target dataset. For raster
data, this would be the "Image Footprints with Time Attributes" layer
in the same group as the target "Image" layer being displayed. For
vector (point, line, or polygon) data, the target layer can be queried
directly. In either case, the attributes returned for the matching
raster(s) or vector feature(s) will include the following:
validtime: Valid timestamp.
starttime: Display start time.
endtime: Display end time.
reftime: Reference time (sometimes referred to as
issuance time, cycle time, or initialization time).
projmins: Number of minutes from reference time to valid
time.
desigreftime: Designated reference time; used as a
common reference time for all items when individual reference
times do not match.
desigprojmins: Number of minutes from designated
reference time to valid time.
Query the nowCOAST™ LayerInfo web service, which has been created to
provide additional information about each data layer in a service,
including a list of all available "time stops" (i.e. "valid times"),
individual timestamps, or the valid time of a layer's latest available
data (i.e. "Product Time"). For more information about the LayerInfo
web service, including examples of various types of requests, refer to
the
nowCOAST™ LayerInfo Help Documentation
References
NWS, 2006: NWS Instructions 10-313, WFO Severe Weather Products Specification, NWS, Silver Spring, MD.
NWS, 2007: NWS Instructions 10-320, Coastal/Lakeshore Hazard Services, NWS, Silver Spring, MD.
NWS, 2007: NWS Instructions 10-922, Weather Forecast Office Hydrologic Products Specification, NWS, Silver Spring, MD.
NWS, 2008: NWS Instructions 10-301, Marine and Coastal Services Abbreviations and Definitions, NWS, Silver Spring, MD.
NWS, 2010: NWS Instructions 10-519, WFO Air Quality Products Specification, NWS, Silver Spring, MD.
NWS, 2011: NWS Products and Services Reference Guidebook, NWS/Office of Climate, Water, and Weather Services, Silver Spring, MD.
NWS, 2012: NWS Policy Directive 10-3, Marine and Coastal Weather Services, NWS, Silver Spring, MD.
NWS, 2012: NWS Instructions 10-701, Tsunami Warning Center Operations, NWS, Silver Spring, MD.
NWS, 2013: NWS Instructions 10-601, Tropical Cyclone Products, NWS, Silver Spring, MD.
NWS, 2012: NWS Instructions 10-701, Tsunami Warning Center Operations, NWS, Silver Spring, MD.
NWS Instructions and other directives are available at http://www.nws.noaa.gov/directives/.
