Ice Storm Warning vs Freezing Rain Advisory vs Winter Weather Advisory

What each National Weather Service ice alert means, what happened to the Freezing Rain Advisory, and what an ice storm means for an HVAC or plumbing shop. ForecastBooked checks the active NWS alerts for every ZIP you serve and builds a ready-to-edit kit when an ice storm alert is active.

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The ice alerts, lowest to highest

AlertWhat it meansNWS says
Winter Weather AdvisorySnow, blowing snow, ice, sleet or a mix is expected, but not hazardous enough to meet warning criteria. Since October 1, 2017 this is also the alert for light freezing rain.Be aware.
Winter Storm WatchConditions are favorable for a significant winter storm, including an ice storm.Be prepared.
Ice Storm WarningUsually issued for about 1/4 inch of ice or more. Travel becomes dangerous or impossible, and power lines and tree branches are likely to come down.Take action.

From the NWS winter warnings, watches and advisories page and the NWS 2017 hazard simplification notice, read Oct 23, 2026. Exact criteria vary by local office.

There is no Freezing Rain Advisory anymore

On October 1, 2017, the NWS folded the Freezing Rain Advisory into the Winter Weather Advisory. The NWS said one advisory saves forecasters from canceling a Freezing Rain Advisory and reissuing a Winter Weather Advisory each time the mix of snow, sleet and ice changes. Light ice still gets an alert. It comes as a Winter Weather Advisory, and NWS Cleveland said those begin with the phrase "Light Freezing Rain expected."

On Oct 23, 2026, the api.weather.gov alert list had Ice Storm Warning and Winter Weather Advisory, and no Freezing Rain Advisory or Ice Storm Watch. A coming ice storm shows up first as a Winter Storm Watch.

How much ice it takes depends on where you are

The NWS says Ice Storm Warnings are usually issued for around 1/4 inch of ice or more, and that each local office issues alerts based on local criteria. Three examples, read Oct 23, 2026:

  • NWS Baltimore/Washington (Sterling, VA): an Ice Storm Warning for "¼ inch or more of ice accumulation." A Winter Weather Advisory "for any amount of freezing rain."
  • NWS Caribou, ME: an Ice Storm Warning for "ice accumulation of ½ (one half) inch or more." A Winter Weather Advisory for "any widespread accretion of freezing rain or freezing drizzle on road surfaces."
  • NWS New York, NY: an Ice Storm Warning when freezing rain is expected to produce "flat ice accumulations of 0.5" or greater (radial ice accumulation of 0.2")." A Winter Weather Advisory for "a trace of ice accumulation."

Made-up example: a storm forecast to leave 0.3 inch of ice meets the Baltimore/Washington Ice Storm Warning bar but falls short of the Caribou and New York ones. If you serve ZIPs under more than one office, the same amount of ice can bring different alerts.

Not the same as a Freeze Warning

A Freeze Warning is about temperature. NWS Baltimore/Washington issues frost and freeze alerts in the fall only until the end of the growing season, which it marks by the first widespread freeze. Ice alerts are about freezing rain, and they keep coming through the winter. More in Freeze Watch vs Freeze Warning vs Frost Advisory.

What it means for an HVAC or plumbing shop

The NWS says heavy ice can bring down trees and utility poles, and can disrupt power for days while utilities repair the damage. For a heating customer, that can mean a cold house even when the furnace is fine, and pipes at risk while the power is out.

A Winter Storm Watch is the earlier alert. That is when customers still have time to book a furnace check or ask how to protect their pipes. Once an Ice Storm Warning is out, the NWS strongly discourages travel, so your message shifts to staying safe, what to do if the power goes out, and how to reach you after the storm.

How ForecastBooked handles it

  • Every 3 hours we check the NWS forecast and active alerts for each ZIP you serve.
  • Winter storm kit: an active Winter Storm Watch, Winter Storm Warning or Ice Storm Warning for one of your ZIPs.
  • A Winter Weather Advisory doesn't start a kit, including one for light freezing rain. A hard-freeze kit runs on the forecast instead: a low of 28°F or colder.
  • ForecastBooked builds a ready-to-edit kit on your private kit page: a customer email, a text script, a Google post and a social post. You check it and send it to your own opted-in customers.
  • Plans are $19, $39, $79 a month by number of ZIPs, after a 14-day free trial. See how triggers work.

Questions

What is the difference between an Ice Storm Warning and a Winter Weather Advisory?
An Ice Storm Warning is usually issued for about 1/4 inch of ice or more, enough to make travel dangerous and bring down power lines and tree branches. A Winter Weather Advisory covers lighter freezing rain, snow or sleet that should not reach warning criteria. The NWS puts it as be aware for an advisory, and take action for a warning.
Does the NWS still issue Freezing Rain Advisories?
No. On October 1, 2017 the NWS folded the Freezing Rain Advisory into the Winter Weather Advisory. Light ice now comes as a Winter Weather Advisory, and NWS Cleveland said those alerts begin with the phrase "Light Freezing Rain expected." On Oct 23, 2026, the api.weather.gov alert list had no Freezing Rain Advisory.
Is there an Ice Storm Watch?
Not in the current NWS alert list. On Oct 23, 2026, api.weather.gov listed Ice Storm Warning but no Ice Storm Watch. The NWS Winter Storm Watch definition includes an ice storm.
How much ice does it take for an Ice Storm Warning?
It depends on your local NWS office. NWS Baltimore/Washington uses 1/4 inch or more of ice. NWS Caribou, ME uses 1/2 inch or more. NWS New York, NY uses flat ice of 0.5 inch or more (0.2 inch radial ice).
Is an Ice Storm Warning the same as a Freeze Warning?
No. A Freeze Warning is about temperature, and frost and freeze alerts are issued only until the end of the local growing season (NWS Baltimore/Washington marks that end by the first widespread freeze). Ice Storm Warnings are about freezing rain, and they are issued through the winter.
Which ice alerts start a ForecastBooked kit?
Winter Storm Watch, Winter Storm Warning and Ice Storm Warning start a winter storm kit for a ZIP you serve. A Winter Weather Advisory, including one for light freezing rain, doesn't. ForecastBooked builds a ready-to-edit kit; you send it to your own opted-in customers.

Other NWS alerts: Winter Storm Watch vs Warning vs Winter Weather Advisory · Freeze Watch vs Freeze Warning vs Frost Advisory · Extreme Cold Warning vs Extreme Cold Watch vs Cold Weather Advisory.

Sources