The Tools and Concepts for Forecasting Winter Precipitation

Introduction This informative forecast writing will focus on the weather forecasting tools and concepts that are used to predict winter weather events. There are various types of winter weather events that are analyzed and forecasted including mid-latitude cyclones, ice storms, lake-effect snows and sleet storms. Each of these will be discussed separately. In addition, bust […]

Historic snowstorm in North Texas on 2/12/2010. DFW recorded its greatest 24-hour snowfall of all time (12.5").

General Snow Forecasting

Snow is a precipitation type that results from the build-up of ice deposition upon condensation nuclei. The snowflake size is amplified as ice crystals join together as the crystals move in the wind. A common theme in ice crystal development is the 6-sized structure of the ice crystals. The chemical bonding of ice molecules produces […]

Snow to Liquid Equivalent and Associated Forecasting Pitfalls

The snow-to-liquid equivalent is the amount of liquid precipitation that is produced after melting snow. The temperature profile of the troposphere and the surface temperature are important factors that determine this value. The “average” snow-to-liquid ratio is 10:1. This is saying that if 10 inches of snow fell and that snow was melted it would […]

Does a Warm Winter Mean the Summer Will be Hotter than Normal?

Introduction The title is a question that is frequently asked of meteorologists, especially in the wake of an abnormally warm or cool season; it is a topic of interest among atmospheric scientists and the general public alike.  In this article, we will attempt to answer this question using climatology, casting aside gut feelings and old […]

The Challenges of Forecasting Snow and Other Winter Precipitation in the South

Section 1: Is it Going to be a Big Deal? One of the more difficult forecasts to make is the winter precipitation forecast. The complexity is with determining precipitation type, areal coverage, and whether any winter precipitation will accumulate at the ground surface in the first place. The public is very sensitive to winter forecasts […]

Beware of weather hype this winter. Know your weather source.

Beware of Snow Hype & Weather Hoaxes on Social Media

It’s that time of year… Winter. The season when those unrealistic snow and ice accumulation maps, for an unlikely event 10 days into the future, that often go viral on social media. So, I wanted to briefly discuss the nature of internet weather hype and how you can learn to recognize it. As the National […]

Unlucky 7 Snowiest Cities in the U.S.

Those of us who live around Atlanta, Georgia or Dallas, Texas, who only see around 2 or 3 inches of snow per year on average, can be heard complaining during the winter when a snow event occurs. There are, however, many cities around the nation where considerably more snow falls and it becomes part of the […]

Snow Accumulation (Current): Snow Depth & Percent Coverage

Our high-resolution maps of accumulated snowfall are updated several times a day for the United States and much of Canada. ● Today’s Snow Cover Stats ● Interactive Map Snow Cover Map (Current – High-Resolution) Note: Refresh the browser if data fail to load Today’s Snow-Cover Percent, Depth, & Liquid Equivalent (SWE) These stats include the […]

simulate the formation of snow, sleet, and freezing rain

What determines if snow, sleet, or rain will form?

Explore the type of precipitation Set the air and dew point temperatures by dragging the anchor points and learn what type of precipitation will fall to the ground. Each time you release the mouse button, the simulation starts. Note: Temperature is shown in degrees Celsius. To see the corresponding temperature in degrees Fahrenheit, check out […]

Wind Chill in Atlanta, Wind Chill Chart & Calculator

Currently in AtlantaThe temperature is ºF. The wind chill in Atlanta is . Calculate the windchill Index Windchill Calculation Enter in the air temperature (Tair) in degrees Fahrenheit and wind speed in mph, then click on the Calculate WC to compute the windchill Tair oF wind (mph) OR use dew point temperature Tair oC wind […]

Wind Chill in Texas DFW & Wind Chill Calculator

Currently at Dallas – Fort Worth International AirportThe temperature is ºF. The wind chill is . Calculate the windchill Index Windchill Calculation Enter in the air temperature (Tair) in degrees Fahrenheit and wind speed in mph, then click on the Calculate WC to compute the windchill Tair oF wind (mph) OR use dew point temperature […]

Snow: Dallas/Fort Worth’s Top-20 Largest Snowfalls on Record

This chart shows the largest amounts on record for a calendar day. *Note: Two of the largest calendar-day snowfalls at DFW occurred on consecutive days: 7.8″ on 01-15-1964 4.3″ on 01-16-1964 The greatest snowfall on record at DFW occurred on February 11, 2010 (11.2 inches). The storm total at DFW for that event (Feb 11-12, […]

Atlanta’s Top 20 Snowstorms & Temperature Trends

Atlanta’s biggest snowfall events of all time are listed in the table below. The most snow ever recorded on a single day in Atlanta was on January 23, 1940 when 8.3 inches fell. The top 10 snowstorms in Atlanta have a median accumulation of 4.2 inches. View the full list We often hear the cliche: […]

What is Cold Air Damming (the Wedge)?

Cold-air damming (CAD), often called “the wedge” in the Southeast, is an interesting meteorological feature that can result in tricky forecasts for meteorologists. Topography plays a major role in CAD events, and you need a mountainous range for this feature to develop. While CAD can occur in the Rockies, it is predominant east of the […]

Winter Storm Watch, Advisory, and Warning Criteria for North Texas

When it comes to winter weather, there is no shortage of advisory types.  This page is devoted to the four main winter weather products: Winter Storm Watch, Winter Storm Warning, Winter Weather Advisory, and Ice Storm Warning.  More specifically, I want to discuss the criteria used by the National Weather Service Office in Fort Worth, […]

Weather Myths: Too Warm for the Snow to Stick?

Before I begin this piece, I want to present a challenge.  The following chart shows the actual high and low temperatures for a full month in Atlanta, Georgia. *A condensed version of this writeup was also featured in the Douglas County Sentinel. Challenge: Can you spot the day with a historic snowstorm? During this particular […]

Birmingham’s Winter Storm Watch, Warning, & Advisory Criteria for Alabama

The National Weather Service has sole responsibility for issuing weather watches and warnings.  When it comes to winter weather, there are numerous advisory types ranging from Wind Chill Advisories to Ice Storm and Blizzard Warnings.  This page is devoted to the four main winter weather products:  Winter Storm Watches, Winter Storm Warnings, Winter Weather Advisories, […]

Atlanta’s Winter Storm Watch, Advisory, and Warning Criteria for Georgia

As a NOAA Weather-Ready Nation Ambassador, iWeatherNet strives to create educational content to help you be prepared for any type of severe weather; this includes winter weather. I wanted to take the opportunity to briefly review the various winter weather products issued by the Atlanta National Weather Service in Peachtree City. Other States Central Alabama: […]

Radar image showing both single and multiple snow bands.

Difference Between Single vs. Multiple Lake Effect Snow Bands

In an earlier article, we discussed the dynamics and thermodynamics of lake effect snow. In this post, we discuss the meteorological differences between single-band and multiple-band lake-effect snow events.  Keep in mind that all lake-effect snow events are fueled by moisture and latent heat flux from the relatively warm lake water; these fluxes are already […]

Lake effect snow formation illustration

Lake-Effect Snow: The Physics of Colossal Snow

One of the most awe-inspiring forces of nature is lake-effect snow. The amount of latent energy required to produce the lake-effect convection is astounding, and in some situations, snowfall rates can reach as high as 5 to 6 inches per hour.  In this article, we discuss the atmospheric physics, dynamics, and thermodynamics responsible for the […]