What is the Difference Between a Weather Advisory, Watch or Warning?
The National Weather Service issues advisories, watches and warnings to keep us aware, alert and to help save lives
Tuesday, May 6th, 2014 — Today ,many parts of the Borderland including El Paso and Las Cruces are under a Wind Advisory from 2 P.M.. until 8 P.M.. this evening. There will be strong westerly winds blowing at 20 to 35 mph with potential gusts of 45+mph. The National Weather Service of El Paso issued this yesterday for today to gives us a heads up that this weather scenario is going to happen.
What makes it an advisory and not a High Wind Warning? The same can be said for severe thunderstorms, flood or tornado watches, advisories and warnings. What is the difference? I will explain in today’s “Weather Talk” because it depends on whether it is an Advisory, a Watch or a Warning. Ultimately it is the National Weather Services goal to save lives and those of us on doing weather on TV. are an important part in delivering the message to the masses.
Here are the are the basics. you need to know for all types of weather;
WATCH- essentially means a “chance” this condition will happen and usually covers a large geographical area for a lengthy time period.
ADVISORY- are sort of in between a WATCH and WARNING. The expected weather condition has a pretty good chance of occurring, even a likely chance of occurring, but typically an advisory is used for “less” severe type of weather conditions. A Wind Advisory might be issued or an Urban and Small Stream Flood Advisory issued instead of a High Wind Warning or an Flash Flood Warning.
WARNING- means the said weather is already occurring or is likely to occur and to take proper protective measures. Warnings are usually issued for much smaller geographical areas and usually for shorter more definite time periods.
He are some other products issued by the National Weather Service that I thought I would pass on their definitions of in case you were to hear or come across them.
A SPECIAL WEATHER STATEMENT- Issued when the forecaster wants to pass information on to the public about developing or approaching weather that is not expected to be severe, but nonetheless is significant.
SHORT TERM FORECAST- A short-term forecast designed to give specific, detailed forecast information for the next 1 to 6 hours on a county basis. Both severe and non-severe information is contained in these forecasts which are routinely issued several times per day, and more often during busy weather periods.
OUTLOOK -This is a statement issued when there is a chance of a major weather event happening 3 to 5 days in the future. This is meant to assist people with their long range plans. However, since the outlook is issued so far in advance, the accuracy of the prediction may be limited.
Now there are certain thresholds or criteria that need to be met for winds, floods, storms and tornadoes to be included in a watch, special weather statement, advisory, or warning issued to the public.
I thought I would list a few as defining by the National Weather Service;
HIGH WIND WATCH- Issued when sustained winds of 40 mph or more are expected for 1 hour or longer, or for wind gusts of 58 mph or more with no time limit. A High Wind Watch is issued when these conditions may be met 12 to 48 hours in the future.
WIND ADVISORY -This is issued for average wind speeds between 31 and 39 miles an hour, or for frequent wind gusts between 46 and 57 miles an hour
HIGH WIND WARNING-Issued when sustained winds of 40 mph or more are expected for 1 hour or longer, or for wind gusts of 58 mph or more with no time limit. A High Wind Watch is issued when these conditions may be met 12 to 48 hours in the future.
BLOWING DUST ADVISORY-Issued when blowing dust is expected to reduce visibility to between 1/4 and 1 mile, generally with winds of 25 mph or greater.
FIRE WEATHER WATCH-Issued when dry vegetation and conditions favoring extreme fire danger are expected 12 to 72 hours in the future.
RED FLAG WARNING-Issued when dry vegetation and conditions favoring extreme fire danger are expected, generally within 24 hours.
HEAT ADVISORY-Issued when maximum daytime heat index values are expected to reach or exceed 105°F on at least 2 consecutive days, with intermediate low temperatures of 75°F or higher.
SEVERE THUNDERSTORM WATCH- Is issued by the Storm Prediction Center when conditions are favorable for the development of severe thunderstorms over a larger-scale region. Tornadoes are not expected in such situations, but isolated tornado development cannot be ruled out.
SIGNIFICANT WEATHER ADVISORY- Issued for strong thunderstorms that are below severe levels, but still may have some adverse impacts. This is usually issued for the threat of wind gusts of 40-58 mph or hail up to 1 inch in diameter.
SEVERE THUNDERSTORM WARNING- is issued when there is evidence based on radar or a reliable spotter report that a thunderstorm is producing, or about to produce, wind gusts of 58 mph or greater, structural wind damage, and/or hail 1 inch in diameter or greater.
FLASH FLOOD WATCH-Issued generally when there is the possibility of flash flooding or urban flooding over an area within the next 36 hours.
FLOOD ADVISORY- Issued when flooding is imminent or occurring, generally within the next 1 to 3 hours, but is not expected to substantially threaten life and property.
FLOOD WARNING- Issued when flash flooding is imminent, generally within the next 1 to 3 hours. Usually issued based on observed heavy rainfall (measured or radar estimated), but may also be issued for significant dam breaks that have occurred or are imminent.
TORNADO WATCH- is issued by the Storm Prediction Center when conditions are favorable for the development of severe thunderstorms and tornadoes over a larger-scale region.
TORNADO WARNING- Issued when there is evidence based on radar or a reliable spotter report that a tornado is imminent or occurring.
FREEZE WARNING- Issued when nighttime minimum temperatures are expected to reach 32°F or lower in the growing season. They are usually issued to highlight the first few freezes of the fall, or unusually late freezes in the spring. A Freeze Watch is issued when these conditions may be met 12 to 48 hours in the future.
WINTER WEATHER ADVISORY- Issued for a winter weather event in which there is more than one hazard present, but all precipitation is expected to remain below warning criteria. For example, it would be issued if 2 inches of snow were expected with a small amount of sleet mixing in at times.
WINTER STORM WARNING-This is issued when a dangerous combination of heavy snow, with sleet and/or freezing rain, will occur or has a high probability of occurring within the next 12 hours.
To read about more National Weather Service watches, advisories and warnings that are not listed here go to;
http://www.crh.noaa.gov/arx/seaterm.php and http://www.srh.noaa.gov/oun/?n=spotter-wwa-definitions
Yes, this can get a bit confusing, even to those of us who are meteorologists or in the weather business. There are so many advisories, watches and warnings. They have all been developed by the hard working people at the National Weather Service to keep us aware, alerted and safe from potentially severe and dangerous weather phenomena of all kinds. Their main goal is to save lives and those of us in the media, especially in weather help deliver their extreme weather messages to the public. Just keep in mind the differences between Advisory, Watch and Warning, and be sure to watch NewsChannel 9, go to www.ktsm.com or our Facebook https://www.facebook.com/NewsChannel9ElPaso or twitter https://twitter.com/NC9 more often when bad weather hits.