National Weather Service United States Department of Commerce

Tropical Storm Warnings for Guam; Fire Weather Concerns in the Northeast U.S.

Tropical Storm Man-Yi in the Western Pacific is forecast to pass near or over Guam Wednesday CHST as a tropical storm. Tropical Storm Warnings have been issued for Guam, Rota, Tinian and Saipan. Red Flag Warnings have been issued today for southern New England due to critical fire weather from gusty winds and dry fuels. Read More >

Snow Amount Potential
Experimental -
 
Expected Snowfall - Official NWS Forecast
Expected Snowfall - Official NWS Forecast
What's this?
High End Amount
1 in 10 Chance (10%) of Higher Snowfall

Maximum Potential Snow Accumulation
What's this?
Low End Amount
9 in 10 Chance (90%) of Higher Snowfall

Minimum Potential Snow Accumulation
What's this?

Low End Amount – 9 in 10 Chance (90%) of Higher Snowfall

 

This map depicts a reasonable lower-end snowfall amount for the time period shown on the graphic, based on many computer model simulations of possible snowfall totals. This lower amount is an unlikely scenario with a 9 in 10, or 90% chance that more snow will fall, and only a 1 in 10, or 10% chance that less snow will fall. This number can help serve as a lower-end scenario for planning purposes.

Expected Snowfall - Official NWS Forecast

 

This map is the official NWS snowfall forecast in inches during the time period shown on the graphic. This snowfall amount is determined by NWS forecasters to be the most likely outcome based on evaluation of data from computer models, satellite, radar, and other observations.

High End Amount – Only a 1 in 10 Chance (10%) of Higher Snowfall

 

This map depicts a reasonable upper-end snowfall amount for the time period shown on the graphic, based on many computer model simulations of possible snowfall totals. This higher amount is an unlikely scenario, with only a 1 in 10, or 10% chance that more snow will fall, and a 9 in 10, or 90% chance that less snow will fall. This number can help serve as an upper-end scenario for planning purposes.

 
The purpose of these experimental probabilistic snowfall products is to provide customers and partners a range of snowfall possibilities, in complement to existing NWS deterministic snowfall graphics, to better communicate forecast uncertainties during winter weather events. For more information visit this project's Product/Service Description Document, and please provide us your feedback here.
Percent Chance That Snow Amounts Will Be Greater Than...
Experimental -
 
What's this?

Percent Chance That Snow Amounts Will Be Greater Than

 

This series of maps shows the probability (that is, the likelihood) that snowfall will equal or exceed specific amounts during the time period shown on the graphic. These forecasts are based on many computer model simulations of possible snowfall totals.

Hover over thumbnails below to view larger image.
>=0.1"
>=0.1"
>=1"
>=1"
>=2"
>=2"
>=4"
>=4"
>=6"
>=6"
>=8"
>=8"
>=12"
>=12"
>=18"
>=18"

Snowfall Totals by Location
Experimental -
 
What's this?

Snowfall Totals by Location

 

These tables show the snowfall forecast for individual locations, and provide the same information as the graphics on this web page, just shown in a different way. All of these values are valid for the same time period as depicted on the graphics.

County:

Box Plots   Bar Plots

 
Snow Amount Potential
Experimental -
 
Expected Snowfall - Official NWS Forecast
Expected Snowfall - Official NWS Forecast
What's this?
High End Amount
1 in 10 Chance (10%) of Higher Snowfall

Maximum Potential Snow Accumulation
What's this?
Low End Amount
9 in 10 Chance (90%) of Higher Snowfall

Minimum Potential Snow Accumulation
What's this?

Low End Amount – 9 in 10 Chance (90%) of Higher Snowfall

 

This map depicts a reasonable lower-end snowfall amount for the time period shown on the graphic, based on many computer model simulations of possible snowfall totals. This lower amount is an unlikely scenario with a 9 in 10, or 90% chance that more snow will fall, and only a 1 in 10, or 10% chance that less snow will fall. This number can help serve as a lower-end scenario for planning purposes.

Expected Snowfall - Official NWS Forecast

 

This map is the official NWS snowfall forecast in inches during the time period shown on the graphic. This snowfall amount is determined by NWS forecasters to be the most likely outcome based on evaluation of data from computer models, satellite, radar, and other observations.

High End Amount – Only a 1 in 10 Chance (10%) of Higher Snowfall

 

This map depicts a reasonable upper-end snowfall amount for the time period shown on the graphic, based on many computer model simulations of possible snowfall totals. This higher amount is an unlikely scenario, with only a 1 in 10, or 10% chance that more snow will fall, and a 9 in 10, or 90% chance that less snow will fall. This number can help serve as an upper-end scenario for planning purposes.

 
The purpose of these experimental probabilistic snowfall products is to provide customers and partners a range of snowfall possibilities, in complement to existing NWS deterministic snowfall graphics, to better communicate forecast uncertainties during winter weather events. For more information visit this project's Product/Service Description Document, and please provide us your feedback here.
Percent Chance That Snow Amounts Will Be Greater Than...
Experimental -
 
What's this?

Percent Chance That Snow Amounts Will Be Greater Than

 

This series of maps shows the probability (that is, the likelihood) that snowfall will equal or exceed specific amounts during the time period shown on the graphic. These forecasts are based on many computer model simulations of possible snowfall totals.

Hover over thumbnails below to view larger image.
>=0.1"
>=0.1"
>=1"
>=1"
>=2"
>=2"
>=4"
>=4"
>=6"
>=6"
>=8"
>=8"
>=12"
>=12"
>=18"
>=18"
Ice Accumulation Potential
 

Expected Ice Accumulation - Official NWS Forecast

This is the elevated flat surface ice accumulation. It is not radial/line ice. Radial/line ice is typically 39% of the elevated flat surface ice. For more information on this, see this module.

Most Likely Ice Accumulation

What's this?

Most Likely Ice Accumulation

Represents our official ice forecast in inches within the next one to three days. The ice accumulation amounts are provided in ranges.

Ice Accumulation Potential
 

Expected Ice Accumulation - Official NWS Forecast

This is the elevated flat surface ice accumulation. It is not radial/line ice. Radial/line ice is typically 39% of the elevated flat surface ice. For more information on this, see this module.

Most Likely Ice Accumulation

What's this?

Most Likely Ice Accumulation

Represents our official ice forecast in inches within the next one to three days. The ice accumulation amounts are provided in ranges.


 

 
**Prototype Under Development - not to be relied on for operational decision making**

 

 

Detailed information on the Weather Type Graphic can be located here.

 

**Prototype Under Development - not to be relied on for operational decision making**
The snowfall character is categorized based on the forecasted snow-to-liquid ratio. If no snow is forecasted, the snow character is not shown.

 
**Prototype Under Development - not to be relied on for operational decision making**
The snowfall character is categorized based on the forecasted snow-to-liquid ratio. If no snow is forecasted, the snow character is not shown.

 
Winter Storm Severity Index (WSSI) Winter Storm Outlook (WSO)
Winter Storm Severity Index
Winter Storm Outlook
National Snow Reports National Snowfall Analysis
National Snow Reports
National Snowfall Analysis
 
Local Snow Reports
Days 4-7 Winter Weather Outlook
 
Day 4 Winter Weather Outlook Day 5 Winter Weather Outlook
Day 4 Winter Weather Outlook Day 5 Winter Weather Outlook
 
Day 6 Winter Weather Outlook Day 7 Winter Weather Outlook
Day 6 Winter Weather Outlook Day 7 Winter Weather Outlook


Click here for an interactive map

 
CPC Week-2 Experimental Heavy Snow Risk
 
CPC Week-2 Experimental Heavy Snow Risk
 
CPC Temperature & Precipitation Maps
 

Days 6-10

Temperature  Precipitation
6-10 day temperature 6-10 day precipitation
 
 

Days 8-14

TEMPERATURE  PRECIPITATION
8-14 day temperature 8-14 day precipitation
 
 

Week 3-4

TEMPERATURE

PRECIPITATION

Week 3-4 Temperature Week 3-4 precipitation
Other Snow/Ice Information
NDFD Graphic Forecast Displays Zoomable Snowfall Analysis
NDFD Graphical Forecast Viewer
What's this?

Precipitation Onset

Most likely time of winter precipitation onset (snow, sleet, freezing rain). Rain is not included here. This information is provided when we issue a Warning or Advisory for expected snow or ice accumulation; typically six to 24 hours in advance. Times are only given for places that are under a Warning or Advisory. They will be blank in areas outside Warnings or Advisories.

Precipitation End Time

Most likely time of winter precipitation ending (snow, sleet, freezing rain). Rain is not included here. This information is provided when we issue a Warning or Advisory for expected snow or ice accumulation; typically six to 24 hours in advance. Times are only given for places that are under a Warning or Advisory. They will be blank in areas outside Warnings or Advisories.

Winter Storm Severity

The purpose of the Winter Storm Severity Index (WSSI) is to provide NWS partners and the general public with an indication of the level of winter precipitation (snow and ice) severity and its potential related societal impacts. The WSSI does not depict official warnings, and should always be used in context with official NWS forecasts and warnings. Because this is a prototype, it may not update in a timely fashion. Always check the creation and valid times.

NDFD Graphic Forecast Displays

The NWS’s NDFD graphic products are derived from a prescribed set of data contained within the NDFD. These graphics are representations of the official NWS digital forecast. The graphics are created on national and regional scales and will follow a standardized format prescribed by the NWS to best meet the needs of its users

Low Tracks Graphic

The graphic depicts the forecast location of significant surface lows impacting the 48 contiguous United States in 12 hour increments out to 72 hours into the future.

The low position and track forecast by NCEP WPC meteorologist is in white. Each low position is accompanied by a lead time (Eastern Time). The circles around each low represents a 75% probability the observed low will be located with the circle. Note: The probability is derived using previous season's verification data. For reference, existing surface lows are depicted with a red marker without yellow circles.

Reported

As snow and/or ice reports come into the NWS (you can email reports to w-abr.webmaster@noaa.gov or Tweet to @NWSAberdeen), we will pass them on here. With the map linked here, and the supporting reports below it, you can keep tabs on how much has fallen.

 

Aberdeen, SD Products
HAZARDOUS WEATHER OUTLOOK FORECAST DISCUSSION WINTER WEATHER WATCH/WARNING/ADVISORY SPECIAL WEATHER STATEMENT PUBLIC INFORMATION STATEMENT
Additional Winter Weather Information
EM Briefing Page SD EOC Page SD Road Conditions Winter Preparedness