Philadelphia/Mt Holly

Weather Forecast Office

Winter Weather Snow and Ice Probability Accumulation

Minimum	MOST LIKELY SNOWFALL	Maximum
Snow Accumulation Potential Experimental - Leave feedback
Expect at least this much:	Point / Range	Potential for this much:

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. Close 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. Close 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. Close

Ice Accumulation Potential

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MOST LIKELY ICE GLAZE

Impacts

Amount Forecast

Icy Spots Expected
Beware driving or walking on pavement. Some areas will be icy, some not.

Up to a Tenth

Widespread Icing
Limit unnecessary travel. Any untreated paved surface will likely be glazed with ice. Scattered power outages possible.

Tenth to a Quarter Inch

Ice Storm Expected
More widespread power outages. Downed trees. Extremely dangerous to walk or drive on untreated paved surfaces that will be ice covered.

Quarter Inch to a Half Inch

Severe Ice Storm
Widespread power outages, possibly for an extended time. Many downed trees, and impassable roads expected.

Half Inch to an Inch

Devastating Ice Storm
Long term power outages. Many downed trees over roads and power lines. Impassable roads from icing and downed trees. Recovery could take many days.

More Than an Inch

What's this?

Storm Track		Reported Snow/Ice Totals
Other Snow/Ice Information

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. Close 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. Close Reported As snow and/or ice reports come into the NWS (you can email reports to phi-report@noaa.gov or Tweet to @NWS_BaltWash), 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. Close

Active Watches/Warnings/Statements


	Gale Warning

	Small Craft Advisory

	Gale Watch

	Hazardous Weather Outlook

Percent Chance That Snow Accumulation Will Be Greater Than...
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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".

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Hover over thumbnails below to view larger image.

>=0.1"	>=1"	>=2"	>=4"	>=6"	>=8"	>=12"	>=18"

Chance of Snow Accumulation
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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.

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Long-Range Forecast

Days 4-5 Forecast Precipitation	Days 6-7 Forecast Precipitation


Days 6-10
Temperature	Precipitation


Days 8-14
TEMPERATURE	PRECIPITATION


Week 3-4
TEMPERATURE	PRECIPITATION

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

RADAR Products

Philadelphia/My Holly, NJ

Northeast Radar

Full U.S. Radar

Adjacent Radars:


	PHI

Useful Winter Weather Information
Historic Mid-Atlantic Winter Storms	SNOWFALL PROBABILITY FORECAST	Emergency manager hazardous weather briefing webpage
Watches, Warnings, & Advisories	How to Measure Snow	PHI/Mt holly winter weather webpage
BE PREPARED!
At Home	On the Road	Outside in the Cold