Weather Map

The weather map provides a comprehensive, real-time view focused on current meteorological conditions across Vermont by integrating multiple data sources to support emergency operations.

The weather map (named Weather - Current) is accessible here. It contains both grouped and ungrouped layers from internal and external sources.

Purpose

This map provides detailed weather information for:

• Pre-event planning and preparation
• Storm tracking and monitoring
• Historical weather analysis
• Forecast verification

Data Layers

Layer Visibility

Many layers are only turned on (visible by Default) seasonally or during SEOC activation. For example, NWS Ice Accumulation would only be turned on with sufficient warning of an impending ice storm.

Group	Layer Name	Symbology	Source
	NWS Weather Stations	Classified by Wind Speed (km/h)	NWS
	Road Weather Information Stations (RWIS)	ESRI basic point	VTrans
	RAWS Weather Stations	ESRI basic point	NIFC
	USGS Live Stream Gauges	Classified by Status	USGS
	Red Cross Trailer Locations	ESRI basic point	Red Cross
Weather	USA Storm Reports	Classified by INCIDENT_TYPE	NOAA
Weather	NOAA Hail Storm Reports	ESRI basic point	NOAA
Weather	NOAA Wind Storm Reports	ESRI basic point	NOAA
Weather	Current NWS Events	Classified by Subject Type	NOAA
Weather	NOAA Severe Thunderstorm Warnings	ESRI basic polygon	NOAA
Weather	NOAA Tornado Warnings	ESRI basic polygon	NOAA
Weather	NOAA Flash Flood Warnings	ESRI basic polygon	NOAA
Weather	NOAA Special Marine Warnings	ESRI basic polygon	NOAA
Weather	Active Hurricanes, Cyclones, & Typhoons	Multiple layers	NOAA
Weather	Wind Gust Projections	Classified by Speed Class	NWS
Weather	NWS Radar	Classified by conus_bref_qcd	NWS
Weather	NWS River Gauges	Classified by Flood Status	NWS
Winter Weather	Ice Accumulation Forecast	Multiple layers	NWS
Winter Weather	Snowfall Forecast	Multiple layers	NWS
Drought	Public Reports CMOR	ESRI basic point	CMOR
Drought	US Drought Monitor -Current	Classified by DM	USDM

Reference Layers

The reference layers group is at the top of the table of contents to create a visual mask so that data within Vermont is highlighted, but the user can still data in surrounding states.

Group	Layer Name	Type	Source
Boundaries	U.S. States and Territories	Polygon	NOAA
Boundaries	Vermont Counties	Polygon	VCGI
Boundaries	Vermont Towns	Polygon	VCGI
Boundaries	NA Political Divisions Polygons (mask)	Polygon	NAEA

Layer Details

External Sources

The following layers are consumed from external, authoritative sources. These sources include Vermont agencies and departments and external partners like the NWS, USGS, FEMA, etc.

NWS Weather Stations

Source: NWS
Geometry Type: Point
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Automatically updated by NWS

Pop-Up Attributes:

• STATION_NAME: Unique weather station name
• OBS_DATETIME: Date and time of reported observation
• WIND_DIRECT: Wind direction recorded by weather station (in degrees)
• WIND_SPEED: Wind speed recorded by weather station (in km/h)
• TEMP: Temperature recorded by the weather station (in fahrenheit)
• SKY_CONDTN: Description of sky conditions
• VISIBILITY: A measure of the horizontal distance at which a person can clearly see and identify a prominent dark object against the horizon sky (during the day) or a moderately intense light source (at night)

Symbology:

Color-coded by WIND_SPEED
Icon: Geometric symbols imported from ESRI basic polygons

Filter:

Filtered by Country Name

NWS Weather Stations Updates

NWS weather data is "near real-time. The data displayed in the weather map is typically 5 to 20 minutes old and the standard update cycle is only once per hour unless something of importance happens.

Road Weather Information Stations - (RWIS)

Source: VTrans
Geometry Type: Point Coordinate System: Vermont State Plane (EPSG:32145)
Update Method: Automatically updated by VTrans

Pop-Up Attributes:

• Name: Unique weather station name
• Status: This field is strictly reporting the health of the communication link
• roadway: Roadway adjacent to the weather station
• AirTemp: Standard ambient air temperature (in fahrenheit)
• DewPoint: A value derived from the air temperature and relative humidity sensors (in fahrenheit)
• WindSpeed: Wind direction recorded by weather station (in mph)
• WindDir: Wind direction recorded by weather station (in degrees)
• Direction: Wind speed recorded by weather station (in km/h)
• PavementTemp: The actual temperature of the road pavement
• PrecipRate: Intensity of rainfall or snowfall (in/hr)
• RoadSurfaceCond: The condition of the roadway. Values typically include: dry, wet, chemically wet, ice, snow, slush
• SubsurfaceTemp: The temperature of the soil ~18 inches below the road
• SurfaceFriction: WA calculated value (often 0.0 to 1.0) representing how slippery the surface is
• Visibility: Distance one can see (in miles)
• Timestamp: Date and time of reported observation

Symbology:

ESRI basic point
Icon: Geometric symbols imported from ESRI basic polygons

Road Weather Information Stations Updates

RWIS weather data is "near real-time. The stations are programmed to report a new observation every 10 minutes. During active winter storms, VTrans can remotely command stations to switch to "polling mode" or increase their reporting frequency (~5 minutes)

RAWS Weather Stations

Source: NIFC
Geometry Type: Point Coordinate System: WGS1984 (EPSG:4326) Update Method: Automatically updated by NIFC

Pop-Up Attributes:

• Agency: Agency that owns the stations (e.g., USFS, BLM, etc.).
• StationName: Unique weather station name
• Status: Weather station status (A = Active, I = Inactive, M = Maintenance)
• Ob Time: The time the sensor actually took the reading
• Elevation: Ground elevation of the weather station (in feet)
• Air Temperature, Standard Placement: Standard ambient air temperature (in fahrenheit)
• Relative Humidity: The percentage of water vapor present in the air compared to the maximum amount the air can hold at the same temperature (in %)
• Rain Accumulation: Cumulative rainfall at the site, relative to a start date on October 1st (rainfall = 0) and accumulate until September 30th of the following year
• Wind Speed MPH: Wind speed recorded by weather station (in mph)
• Wind Direction: Wind direction recorded by weather station (in degrees)
• Solar Radiation: The intensity of sunlight hitting the ground (in W/m²)
• Fuel Moisture: The moisture content of dead vegetation (specifically "10-hour" fuels, which are sticks 1/4" to 1" in diameter) - (in %)
• Fuel Temperature: The temperature of the fuel stick
• MesoWest Detailed Weather Link: A website run by the University of Utah that aggregates all US weather data
• NOAA Detailed Weather Link: The National Weather Service observations page

Symbology:

ESRI basic point
Icon: Geometric symbols imported from ESRI basic polygons

Filtered by State

RAWS Weather Stations Updates

RAWS weather data is "near real-time. The stations are programmed to report a new observation every hour.

USGS Stream Gauges

Source: USGS Geometry Type: Point Coordinate System: Web Mercator (EPSG:3857) Update Method: Automatically updated by USGS

Pop-Up Attributes:

• stationid: The unique 8-to-15 digit identifier assigned by the USGS
• org: The agency managing the data feed. Usually USGS, but can sometimes include partners like USACE or local water districts
• name: Location description (river + town + state)
• status: The current flood condition relative to NWS flood thresholds
• height: Refers to gauge height; the vertical distance of the water surface above the station's reference datum (in ft)
• flow: Refers to discharge; the volume of water moving down the river (in cfs)
• governing_location: Describes the general location of the gauge (State, USA)
• lastupdate: The timestamp of the most recent data received from the gauge

Symbology:

ESRI basic point
Icon: Geometric symbols imported from ESRI basic polygons

Filtered by State

USGS Stream Gauges Updates

USGS gauges typically update every 15 to 60 minutes.

USA Storm Reports (past 24 hours)

Source: NOAA
Geometry Type: Point
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• INCIDENT_TYPE: Type of storm incident (e.g., Heavy Snow, Snow, Sleet, Hail, etc.)
• LOCATION: Description of location
• INCIDENT_DATETIME: Timestamp for storm report
• COUNTY: County name
• STATE: State name
• COMMENTS: Relevant comments

Symbology:

Color-coded by report_type
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by HOURS_OLD and location

Data Limitations

Weather alert data may be delayed during severe weather events when NWS systems experience heavy load.

NOAA Hail Storm Reports (past 24 hours)

Source: NOAA
Geometry Type: Point
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• LOCATION: Description of location
• UTC_DATETIME: Timestamp for hail report
• COUNTY: County name
• STATE: State name
• COMMENTS: Relevant comments

Symbology:

ESRI basic point
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by STATE

NOAA Wind Storm Reports (past 24 hours)

Source: NOAA
Geometry Type: Point
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• LOCATION: Description of location
• UTC_DATETIME: Timestamp for hail report
• COUNTY: County name
• STATE: State name
• COMMENTS: Relevant comments

Symbology:

ESRI basic point
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by STATE

Current NWS Events

Source: NOAA
Geometry Type: Polygon Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• Event: NWS event type (e.g., Flash Flood Watch, Fire Warning, Winter Weather Advisory, etc.)
  
• Affected: Geographic areas affected
• Summary: Concatenated summary of event, time period of event, and issuing NWS office.
• Updated: Time/date last updated
• Start: Start time of event notice
• End: End time of event notice
• Description: Detailed description of the NWS event
• Instruction: Authoritative instructions for how to prepare/respond to NWS event

Symbology:

Color-coded by Subject Type
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by Summary Overview

Data Limitations

Weather alert data may be delayed during severe weather events when NWS systems experience heavy load. Polygons represent alert zones, not exact impact areas.

NOAA Severe Thunderstorm Warnings

Source: NOAA
Geometry Type: Polygon
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• UTC_ISSUE: Date/time warning was issued
• UTC_EXPIRE: Date/time warning expires

Symbology:

ESRI basic polygon
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by Weather Forecast Office = BTV OR Weather Forecast Office = ALY

NOAA Tornado Warnings

Source: NOAA
Geometry Type: Polygon
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• UTC_ISSUE: Date/time warning was issued
• UTC_EXPIRE: Date/time warning expires

Symbology:

ESRI basic polygon
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by Weather Forecast Office = BTV OR Weather Forecast Office = ALY

NOAA Flash Flood Warnings

Source: NOAA
Geometry Type: Polygon
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• UTC_ISSUE: Date/time warning was issued
• UTC_EXPIRE: Date/time warning expires

Symbology:

ESRI basic polygon
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by Weather Forecast Office = BTV OR Weather Forecast Office = ALY

NOAA Special Marine Warnings

Source: NOAA
Geometry Type: Polygon
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Pop-Up Attributes:

• UTC_ISSUE: Date/time warning was issued
• UTC_EXPIRE: Date/time warning expires

Symbology:

ESRI basic polygon
Icon: Pre-defined symbology by NOAA

Filter:

Filtered by Weather Forecast Office = BTV OR Weather Forecast Office = ALY

Active Hurricanes, Cyclones, and Typhoons

Source: NOAA
Geometry Type: Points, Lines, Polygons Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NOAA/NWS

Grouped Feature Layer
This grouped service contains the following layers, which depict active hurricanes and associated storm characteristics.

• Forecast Position
• Observied Position
• Forecast Track
• Observed Track
• Forecast Error Cone and Danger Area
• Watches and Warnings
• Tropical Storm Force (34kts)
• Tropical Storm Force (50kts)
• Tropical Storm Force (64kts+)
• Raw 1 10th Degree Data (All)
• Observed Wind Swath

Symbology:

Point, Polyline, Polygon
Icon: Pre-defined symbology by NOAA

Wind Gust Projections

Source: NWS Geometry Type: Polygon Coordinate System: Web Mercator (EPSG:3857)
Update Method: Automatically updated by NWS

Pop-Up Attributes:

• label: The forecasted gust speed Range (in mph and km/h)
• Speed Class (Beaufort Scale): The Beaufort wind force scale category description (e.g., Gentle Breeze, Strong Breeze, Violent Storm, etc.)
• Description: The Beaufort scale description combined with label
• From Date: The beginning of the valid forecast period
• To Date: The end of the valid forecast period

Symbology:

Color-coded by Speed Class (Beaufort Scale)
Icon: Geometric symbols imported from ESRI basic polygons

Wind Gust Projections

NWS forecasts are often broken into 1-hour, 3-hour, or 6-hour blocks. A polygon on the map represents the maximum gust expected between the From Date and To Date.

NWS River Gauges

Source: NWS Geometry Type: Point Coordinate System: NAD83(NSRS2007) (EPSG:4759) Update Method: Automatically updated by NWS

Pop-Up Attributes:

• Gauge ID: A unique 5-character alphanumeric identifier assigned by the National Weather Service (e.g., BTVV1 for Burlington).
• Flood Hazard Value: The current water level measurement relative to the highest NWS flood category reached (Action, Minor, Moderate, or Major).
• Flood Status: A text description of the current severity (e.g., "No Flooding," "Minor Flooding," or "Major Flooding") based on the latest observation.
• Gauge Location: The descriptive name of the station, typically including the river name and the nearest town or city (e.g., "WINOOSKI RIVER AT ESSEX JUNCTION").
• Hydrograph: A dynamic URL that links to the official NWS hydrograph image, showing the last few days of observations and the next few days of predicted water levels.
• Major Flood Danger Value: The specific water level (stage) at which "Major" flooding begins; this is the threshold where extensive inundation of structures and roads is expected.
• Observation Time: The exact date and time (usually in UTC) when the most recent physical measurement was recorded at the gauge site.
• Observed: The numerical value of the most recent water level measurement (Stage in feet or Flow in cubic feet per second).
• Units: The unit of measurement for the Observed value, typically "ft" (feet) for stage height or "kcfs" (kilo-cubic feet per second) for discharge.
• Water Body: The name of the river, stream, creek, or lake where the gauge is physically located.
• Water Level In Need of Action: Also known as "Action Stage"; the water level where the NWS or local officials need to begin taking preparatory mitigation actions before actual flooding begins.

Symbology:

ESRI basic point
Icon: Geometric symbols imported from ESRI basic polygons

Filtered by State

NWS River Gauges Updates

NWS river gauge data typically update every 15 to 60 minutes.

NWS Radar

Source: NWS
Geometry Type: n/a (Image Service)
Coordinate System: WGS1984 (EPSG:4326)
Update Method: Automatically updated by ESRI

This image service displays the NWS CONUS_BREF_QCD radar product. CONUS = Continental United States, BREF = Base Reflectivity, which is the "raw" echo intensity from the lowest tilt of the radar (0.5°), which shows what is happening closest to the ground, and QCD = Quality Controlled Data. This means the NWS has run an algorithm to remove "non-meteorological" noise, such as ground clutter (buildings/mountains) or sun spikes, to clean up the image. Units are dBZ (Decibels of Z), which is a logarithmic scale representing the energy reflected back to the radar dish.

Symbology:

ESRI Image Service
Color Ramp: Pre-defined symbology by NWS

dBZ Range Interpretation:

This table outlines the standard relationship between radar reflectivity values (measured in dBZ) and precipitation intensity. Note that the same dBZ value indicates different conditions depending on whether the precipitation is liquid (rain) or frozen (snow/hail). While high values (>50 dBZ) typically indicate heavy rain in summer, even moderate values (30–40 dBZ) can signify dangerous whiteout conditions during winter storms.

dBZ Range	Intensity Category	Summer Interpretation	Winter Interpretation
< 10	Non Precipitation	Clouds, fog, smoke, or dust	Very light snow flurries or ice crystals
10 - 20	Very Light	Light mist or drizzle	Winter Light snow (trace accumulation)
20 - 30	Light	Light steady rain	Moderate snow accumulation
30 - 40	Moderate	Moderate rain	Heavy snow (whiteout conditions)
40 - 50	Heavy	Heavy rain	Extremely heavy snow or sleet mix
50 - 60	Intense	Very heavy rain / thunderstorms	Hail is likely forming
60 - 70	Extreme	Flash flood producing rain	Severe hail (golf ball+ size)
> 70	Catastrophic	Extreme storm core	Giant hail (baseball+ size or debris)

NWS Ice Accumulation Forecast

Source: NWS
Geometry Type: Points, Lines, Polygons Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NWS

Grouped Feature Layer
This grouped service contains the following layers, which depict variations on ice accumulation forecasts from the NWS:

• Amount by Time
• Accumulation by Time
• Cumulative Total

Pop-Up Attributes:
The attributes below is the same for all three layers.

• label: Summarizes forecasted accumulation range (in inches)
• fromdate: The beginning of the valid forecast period
• todate: The beginning of the valid forecast period

Symbology:
The symbology below is the same for all three layers.

ESRI basic polygon
Icon: Pre-defined symbology by NWS

NWS Snowfall Forecast

Source: NWS)
Geometry Type: Points, Lines, Polygons Coordinate System: Web Mercator (EPSG:3857)
Update Method: Updated daily by NWS

Grouped Feature Layer
This grouped service contains the following layers, which depict variations on snowfall forecasts from the NWS:

• Amount by Time
• Accumulation by Time
• Cumulative Total

Pop-Up Attributes:
The attributes below is the same for all three layers.

• label: Summarizes forecasted accumulation range (in inches)
• fromdate: The beginning of the valid forecast period
• todate: The beginning of the valid forecast period

Symbology:
The symbology below is the same for all three layers.

ESRI basic polygon
Icon: Pre-defined symbology by NWS

Public Reports - CMOR

Source: CMOR
Geometry Type: Point
Coordinate System: WGS1984 (EPSG:4326)
Update Method: Automatically updated by the CMOR via public submissions

Pop-Up Attributes:

• Description and/or caption information: User submitted observations
• Select a county: County of submission/observation
• What is the date?: Date of submission

Symbology:

ESRI basic point
Icon: Pre-defined symbology by CMOR

Filter:

Filtered by Select a state/territory

CMOR Updates

CMOR submissions are provided via public submission and should be verified prior to mobilizing resources.

US Drought Monitor - Current

Source: USDM
Geometry Type: Polygon
Coordinate System: Web Mercator (EPSG:3857)
Update Method: Manually updated (weekly) by the National Drought Mitigation Center

Pop-Up Attributes:

• DM: Drought Monitor Category (e.g., Abnormally Dry, Severe Drought, etc.)
• DMArea_Units: The raw area of the drought polygon in square miles (mi²)
• CatagoricalPerct: The percentage of the area exclusively in each specific drought category
• CumulativePerct: This is the "or worse" statistic. It represents the percentage of the area in the specific drought category plus all more severe categories
• ReleaseDate: The release date of the updated feature layer
• ValidStart: The start date of the observation week
• ValidEnd: The end date of the observation week

Attribute Expressions (Arcade):

The original DMArea field was rounded and units were added for easier interpretation using the DMArea_Units field.

    Text($feature.DMArea, '#,###') + " mi²"

Symbology:

ESRI basic polygon
Icon: Pre-defined symbology by USDM

Basemap

Default: Topographic for visualizing data relative to Vermont's variable topography

Performance Notes

For optimal performance with this map:

• Recommended to keep 4-5 layers active simultaneously
• Turn off reference layers when not needed
• Use time filters to limit historical data queries

Related Documentation

• Situational Awareness Map
• Fire Risk Map