National Weather Service United States Department of Commerce

Moderate Risk Severe Thunderstorms in the Tennessee Valley on Thursday

Severe weather is expected to shift slightly east into the Tennessee and lower Ohio Valleys Thursday. The greatest risk of severe thunderstorms is forecast for northern Alabama, western Tennessee, and the far southwestern portions of Kentucky. Very large hail, damaging winds, and tornadoes can be expected. Read More >

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.

 

 

 

 

Snow Accumulation Potential
Experimental -
 
EXPECT AT LEAST THIS MUCH MOST LIKELY SNOWFALL POTENTIAL FOR THIS MUCH
   
Minimum Potential Snow Accumulation
Most Likely Snow Accumulation (Point)Most Likely Snow Accumulation (Range)
Maximum Potential Snow Accumulation
What's this? What's this? What's this?

Minimum Potential Accumulation

Expect at least this much. This is what we see as the least amount of snow the storm can produce.

This information is for advance planning ahead of the storm. It is provided out as far as three days. However, when the snow starts to fall, this will be discontinued to focus on the forecast snow amount.
 

Most Likely Snow Accumulation

Represents our official snow forecast in inches within the next one to three days. The snowfall amounts are provided in point (single number) and ranges (1-2", 2-4", etc.). You can toggle between the two by hovering over the "Point" and "Range" text above the image. The point amount is our forecast but the range for the "most likely" represents the forecast uncertainty in predefined ranges.

Maximum Potential Accumulation

What you should be prepared for. This is what we see as the storm's maximum potential snowfall accumulation.

This information is for advance planning ahead of the storm. It is provided out as far as three days. However, when the snow starts to fall, this will be discontinued to focus on the forecast snow amount.

 

Ice Accumulation Potential
 
  MOST LIKELY ICE GLAZE  
  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.

 

Percent Chance That Snow Accumulation Will Be Greater Than...
Experimental -
 
What's this?

Exceedance Probabilities

Represents the likelihood of exceeding a specific snowfall amount. Thresholds are 0.1", 1", 2", 4", 6", 8", 12", and 18". This product is designed to indicate high or low confidence in the official snowfall forecast.

Example: An 80% chance of exceeding 2" means that we have a high confidence that it will snow at least 2". Conversely, a 10% chance of exceeding 18" means that we have high confidence that it will snow less than 18".

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"

 

Chance of Snow Accumulation
Experimental -
 
What's this?

Snow Accumulation

Ranges

Represents the likelihood of various snowfall ranges. Amounts ranges are 0", 1-2", 2-4", 4-6", 6-8", 8-12", 12-18" and 18" +. This product is designed to indicate high or low confidence in the official snowfall forecast.

Exceedance

Represents the likelihood of exceeding a specific snowfall amount. Thresholds are 0.1", 1", 2", 4", 6", 8", 12", and 18". This product is designed to indicate high or low confidence in the official snowfall forecast.

County:
 

 

Other Snow/Ice Information
Storm Track Reported Snow/Ice Totals Experimental Winter Storm Severity Index (WSSI)
Storm Total Ice Graphic
Latest snow report
Winter Storm Severity Index
What's this? What's this? What's this?

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 send us reports at http://www.weather.gov/phi/stormreport or Tweet to @NWSMountHolly), 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.

WSSI

The purpose of this experimental 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 an experimental product, it may not update in a timely fashion. Always check the creation and valid times.

For more information, please refer to the following links: Product/Service Description Document, WSSI Users Guide. Please provide us your feedback here.

 

Long-Range Forecast
 
Days 4-5 Forecast Precipitation Days 6-7 Forecast Precipitation
Days 4-5 Precip Days 6-7 Precip
   

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

 

Philadelphia-Mount Holly Products
HAZARDOUS WEATHER OUTLOOK FORECAST DISCUSSION SHORT TERM FORECAST SPECIAL WEATHER STATEMENT PUBLIC INFORMATION STATEMENT