General Product Information

Certified Snowfall Totals® is an all-inclusive service - perfect for both per-inch and seasonal contracts.  For each location that you sign up for, you get access to a comprehensive database of accurate post-storm reports that includes:

•  Detailed narrative of the storm*
•  Snow/sleet accumulation to the nearest tenth-of-an-inch (Canadian sites have the option to toggle between inches & centimeters)
•  Freezing rain accumulation to the nearest hundredth-of-an-inch*
•  Monthly and seasonal totals
•  Seasonal accumulation threshold tracking

All reports are archived throughout the season for easy retrieval using your account login at any time!

Product Info FAQs

• How do I access my snow and freezing rain totals?

  Once your account is active, you can log in to our easy-to-use web interface where you can filter and search through your locations and their associated storm data.   All the information on the web site can easily be printed or exported to a PDF or Excel file.

  In addition to our online platform, WeatherWorks offers a fast and easy-to-use API to access your snowfall totals.   Click here to see the full API documentation.   For more information and to find out the added benefit of using a Certified Snowfall Totals API, contact us today!

• How quickly after a winter event can I access my Certified Snowfall Totals® report?

  CST reports are created on a state/province/territory basis or in some cases, a regional basis and are generally published within the 48 hours after the conclusion of each winter storm event.   Therefore, the report may not by completed until up to 48 hours after the event has ended in the entire state/province/territory or region.   Additional time may be required for long-duration or back-to-back storms.   You will be notified at the e-mail address on your account when a storm report has been generated for your location(s). Additional time may be required for long-duration, back-to-back storms, & Canadian locations.

• How can I be sure that a report will be generated for my location(s)?

  Any naturally precipitating and accumulating snow, sleet, or freezing rain* will lead to the generation of a Certified Snowfall Totals® report.

  We do not issue a CST in the following circumstances:

  •  Wintry precipitation fell but never accumulated on any surface
  •  Snow already on the ground blew/drifted back onto previously cleared surfaces
  •  There was a threat of wintry precipitation in the forecast but it never materialized
  

  Although we do not issue CSTs in the above cases, we may be able to prepare a custom report for an additional charge. The average cost for a custom report ranges from $75-150.

• Do Certified Snowfall Totals® reports include refreeze events?

  The standard CST service does not address refreeze events (i.e., the freeze-up of standing rainwater or snowmelt).   However, we offer an add-on to the CST service called VeriFreeze^ that does provide detailed information regarding the formation of ice.

  Click to learn more about VeriFreeze

Our Process - The CST Difference

When you purchase WeatherWorks Certified Snowfall Totals® you are receiving the nation's leading source for snow & ice verification. Our service is preferred among snow removal contractors and is #1 among property and facility managers because a meteorologist is directly involved in all phases of the creation of your post-storm reports. From the collection of storm measurements to quality controlling and assigning totals to your locations, there is a trained analyst working for you every step of the way. Below is a brief description of the process our meteorologists use to generate Certified Snowfall Totals™:

First, a professional meteorologist determines where and when wintry precipitation fell by analyzing recorded observations from surface observing stations, Doppler radar imagery, and a network of over 1,000 web cams (among other tools).

Next, our meteorologist gathers snowfall totals from a variety of sources including National Weather Service & Environment Canada cooperative observers and storm spotters, observing networks run by colleges and universities, road and highway department personnel, private weather observers, media, on-line forums, as well as our own staff meteorologists and interns.

Once all the data is collected, our meteorologist follows a detailed process to manually analyze the snowfall totals for spatial and temporal consistency, ensuring any errant or biased observations are removed from the dataset.

Finally, our meteorologist assigns a representative snowfall total to each postal code, using the snowfall data they quality controlled along with their knowledge of the region (e.g., local topography).

Bill or validate invoices confidently with the peace-of-mind that a trained snowfall analyst prepared your post-storm reports. Join the growing community of highly satisfied WeatherWorks Certified Snowfall Totals™ users today!

Definition FAQs

• What is a coating?

  We define a coating of snow or sleet as an accumulation of less than 0.1" / 0.3 cm. There are three types of snow/sleet coatings you may see in our Certified Snowfall Totals® reports:

  Widely Scattered Coating	-	Less than 25% areal coverage of a coating of snow/sleet
  Scattered Coating	-	25 to 75% areal coverage of a coating of snow/sleet
  Coating	-	Greater than 75% areal coverage of a coating of snow/sleet

  We define a coating of freezing rain as an ice accretion of less than 0.10". There are two types of freezing rain coatings you may see in our CST reports:

  Patchy Ice	-	Less than 75% areal coverage of under 0.10” ice accretion
  Coating of Ice	-	Greater than 75% areal coverage of under 0.10” ice accretion

• Do you distinguish between snow and sleet?

  We identify the type(s) of precipitation experienced at a location in the "Type" column.   If only snow fell, the type would be "Snow". If only sleet fell, the type would be "Sleet". If both snow and sleet fell, the type would be "Wintry Mix".

  Although we distinguish between snow and sleet in the "Type" column, the amount that shows up in the "Total" column is a combined snow/sleet measurement.   It is standard practice to record a "solid precipitation measurement" which is made up of both snow and sleet.

• What is the difference between freezing rain and sleet?

  Freezing rain is precipitation that is observed to be “plain rain” when falling, but freezes on contact with the surface, forming a layer of ice.   The ice accumulates on any surface exposed to the rain, including pavements, trees, powerlines, and cars.

  Freezing rain is often confused with sleet, but they are two separate types of precipitation.   Sleet is formed when the cold layer near the surface is thick enough to refreeze the rain droplets into ice pellets.   When sleet is falling, it makes the trade-marked “ping” sound as it bounces off the surface.

  

Process FAQs

• How are the snowfall measurements you collect taken?

  There are a number of acceptable methods for measuring snowfall. The general practice is as follows:

  Snowfall measurements should be taken on a snowboard (i.e., a small piece of plywood painted white) placed on the ground in an open area not subject to drifting.  If no snowboard is available, a wooden deck is an acceptable alternative.

  Measurements are taken using a standard ruler and can be performed as frequently as every 6 hours (clearing the snowboard after each measurement).   The storm-total snowfall is the sum of all measurements taken during the storm, rounded to the nearest 0.1 inch / 0.3 centimeter.

  If snow has blown on to or off of the snowboard, several measurements should be taken from around the area where snow has not drifted, then averaged together.   If the falling snow continually melts on the snow board and never reaches a depth of 0.1 inch / 0.3 centimeter, a trace of snowfall should be reported.   It is important to obtain measurements as soon as possible following a storm’s conclusion due to the fact that newly snowfall can quickly become subject to compaction, settling, sublimation, or melting.

• How are the freezing rain measurements you collect taken?

  Freezing rain results in ice accretion which is measured on exposed, elevated surfaces such as a tree branch or clothesline.

  The total ice resulting from freezing rain is calculated by averaging the ice thickness on both sides of the surface.   Ice is measured this way because accretion does not occur evenly on all surfaces (wind and gravity causes higher ice build-up on certain sides of an object).

  

• The storm that just occurred was not continuous. Will you issue one or two reports?

  We will generally issue two Certified Snowfall Totals® reports if there was at least a 6-hour break in naturally falling wintry precipitation for the majority of the state or region.   However, our meteorologists reserve the right to issue one or two reports based on the evolution of the storm.   If your contract requires a more detailed breakdown of the storm, we can prepare a custom report for an additional charge. The average cost for a custom report ranges from $75-150.

Locations

An integral part of conveying snow and ice information is identifying the precise area where the information is valid. This is why for our CST product we created a custom location database, utilizing geographical data from the Census Bureau, USGS, USPS, & Canada Post. City boundaries and populated place centers are overlaid on top of postal code boundaries to determine valid postal code-City combinations.

Locations FAQs

• Why are some of your postal codes and cities different from the USPS or Canada Post?

  USPS / Canada Post postal codes were designed to make mail delivery more efficient and do not always follow geopolitical boundaries; they can cross cities, counties, and in some cases, state lines.   The USPS / Canada Post will rarely differentiate between parts of postal codes that cross city limits, instead relying on one preferred city name for the entire postal code (leaving you with less choices than actually exist).   These preferred names are usually derived from nearby cities, not necessarily using city boundaries to determine the most appropriate name for the postal code (possibly resulting in a preferred city name with which the postal code has no overlap). Our location database takes into account the potential overlap between city and postal code boundaries, giving you the most accurate and representative location choices possible.

• What is a premium location?

  We designate a location as premium if it experiences a relatively high number (approximately 50 or more) of winter storm events per season.   The substantial number of winter events can be due to frequent lake-effect snowfall as well as high latitude or elevation, among other factors.   Premium locations carry a $90 surcharge on top of the standard rate resulting in a total cost of $140 each.

• Can I make changes to my locations after I sign up?

  Absolutely!  Additional locations can always be added to your account.   Keep in mind that if you add a location that was previously inactive, there will be limited or no storm history and you may not be able to retrieve any data for that site until the next winter event occurs.

  You can remove locations from your account at no charge during the year.

  You can exchange locations of the same type (standard or premium) at no charge through November 30th.  Afterwards, you can add locations to your account at our standard and premium rates ($50 and $140, respectively).   Note that you are only allowed one "swap" per location on your account.

VeriFreeze

VeriFreeze provides daily information regarding the occurrence of ice formation due to a recent refreeze event, as well as related phenomena like black ice. This product is designed to give confidence to justify billing for de-icing activity.

Product Info FAQs

• How was the VeriFreeze pavement temperature model developed?

  The VeriFreeze pavement temperature model uses statistical methods and machine learning algorithms to estimate the pavement temperature associated with relevant meteorological data present for a given postal code.   The model was constructed using three years of hourly pavement temperature data from more than 2000 stations in diverse environments across the United States, comprising nearly 30 million observations total.   These data were carefully quality-controlled and matched with relevant meteorological data that represented the weather conditions that were occurring at each station.

• How accurate is the model?

  The model is intended to provide verification and support for actions taken to prevent runoff and snowmelt water from becoming a liability and slipping hazard.   It provides accurate trends in pavement and air temperatures that may have initiated a service call to proactively prevent icing or treat existing icing.   Note that the pavement temperature can vary considerably based on the material the pavement is composed of, shading, and traffic, so the pavement temperatures predicted are meant to be an average of conditions seen throughout a given postal code.   It is important to use the trendline as your verification. Your vehicle thermometer alerts you at 35 degrees that icing may be present.   VeriFreeze will provide you with an accurate trendline to help support the decisions you made to prevent icing.

• Does the model provide forecasts of pavement temperature or other data important to refreeze?

  At this time, VeriFreeze only provides analysis of events that have already occurred.   It does NOT forecast pavement temperatures out in the future.   If you are interested in beta testing a predictive refreeze product, please contact us at refreeze@weatherworksinc.com.

• What is the probability <32?

  The probability <32 feature in the daily summary is a product designed to assign a measure of confidence in the pavement temperature falling below freezing.   Higher probabilities are typically correlated to pavement temperatures that fall to or just below freezing, but some variability in the probability value may be encountered based on environmental and meteorological conditions.

• Does the precipitation amount refer to how much snow, sleet, or freezing rain I received?

  The precipitation amount refers to the amount of liquid precipitation if it was rain or the liquid equivalent if it was a wintry precipitation type.   This provides support for actions that may have been taken due to wet pavement as temperatures were cooling toward the freezing point.

• I see that the reports are for 10AM – 10AM. What day should I pick if I’m interested in what happened between 2AM and 6AM?

  If you are interested in the overnight hours, simply pick the date that matches the first day in the 24-hour period of interest.   For example, if you wanted to see data from 2AM – 6AM of February 20 – 21, you would pick the February 20th date.

• Can I customize a time range to extract data from?

  To ensure consistent representation across the board, data is provided in a standard daily report that encompasses a 10AM - 10AM window.   Special requests for different time ranges can be directed to refreeze@weatherworksinc.com.

Understanding the Science of Refreeze and Pavement Temperatures

• What is refreeze? What about freeze-up?

  Refreeze refers to the phenomenon whereby water from either runoff or snowmelt turns to ice, typically as a result of air and ground temperatures falling below freezing.   Freeze-up typically refers to areas of melted snow and/or slush freezing into a solid as temperatures drop, becoming even more challenging to remove.   Both refreeze and freeze-up can present a hazard to pedestrians and automobiles and can open snow and ice contractors up to liabilities if left untreated.

• What is black ice?

  Black ice is a phenomenon that occurs when liquid water on ground surfaces that are below freezing turns into a clear transparent sheet or patch of ice regardless of the air temperature.   The source of the water can be either from rain that falls, snow melt water, or runoff water.   This can result in a thin, hard-to-see sheet of ice across the impacted surface.   In some instances, black ice can occur as a result of dense fog at subfreezing temperatures, especially if the ground is moist or damp from previous precipitation.

• What is pavement temperature?

  In the context of VeriFreeze, pavement temperature (or road temperature) refers to the temperature of the surface of a paved surface, usually from a sensor such as those found at a Roadway Weather Information System (RWIS) station that is typically operated by a state DOT.   VeriFreeze was developed using RWIS station data, which are typically located along highways and Interstates across the United States.   Pavement temperatures that are below freezing act as a foundation for liquids to freeze up and turn to ice.

*Currently not available for Canadian locations.

^VeriFreeze is not currently available for Canadian locations