WATCHES AND WARNINGS


      Most of us have all experienced having some interesting movie or program on TV interrupted by some watch or warning from the National Weather Service. Many of us glance at the message, try to remember which one was the one to worry about, and then decide whether it might be a problem if it does, in fact, happen. In this article we will look at the different watches and warnings issued by the NWS.

      First, there is the difference between a watch and a warning. A watch is issued when there is a better than average chance that foul weather of one sort or another may invade our area during a certain time frame. Indications for this may be a sudden change in barometric pressure, wind direction or other event. A warning is issued when the foul weather in question has begun happening. This might be the spotting of a tornado, severe hail, etc that is happening in one area and headed for another. A warning, therefore, is far more important than a watch, but this certainly does not mean that one should ignore a watch. Watches often turn into warnings!

      Wind advisories are issued when sustained winds reach 25 to 39 miles per hour, or when wind gusts are up to 57 miles per hour. A high wind warning is issued when winds are at least 40 miles per hour, or gusts exceed 57 miles per hour.  Extreme caution should be taken when this warning is issued if you are driving tall vehicles such as trailers, trucks and motor homes. For reference, winds reach hurricane strength when they  reach 74 miles per hour.

      A wind-chill advisory is issued when wind-chill temperatures reach -30 to -35 degrees F. Wind chill is the cooling effect of a combination of wind and actual temperature.

      Flash flood watch means that heavy rains could result in flash floods in a specified area. If this watch is issued, you should be prepared to move to safer grounds if you are in the affected area. A flash flood warning means that flash floods are imminent in the specified area and anyone within that area should move to safe ground immediately.

      Severe thunderstorm watches are issued when thunderstorms with winds exceeding 57 miles per hour and/or hail with a diameter of ¾ inch or more are possible. This becomes a warning when such storms have been sighted or indicated by radar. Be prepared for strong winds, heavy rain and hail. Also, it is not uncommon that tornadoes can form with severe thunderstorms.

      A tornado watch is to alert people that tornadoes could form in an area within a certain time. This becomes a warning when a tornado has been spotted visually or by radar. If this is issued, people should take shelter immediately.

      A snow advisory means to expect 2 inches of snow or more in 12 hours. A winter storm warning means to expect 4 inches of snow or more in 12 hours. A snow storm becomes a blizzard when wind speeds exceed 35 miles per hour for several hours.
 
      A dense fog advisory is issued when dense fog reduces visibility to less than ¼ mile.

      There are also some weather messages important to those who frequent the shore or who boat.

      Small craft advisories are issued to alert mariners that weather conditions might be hazardous to small boats. This may mean winds between 18 and 34 knots ( 21 to 39 miles per hour.)

      Gale warnings mean winds may range between 34 and 47 knots (39 to 54 miles per hour.)

      Storm warnings indicate winds in excess of 47 knots (54 miles per hour.)

      A hurricane watch is issued when a tropical storm or hurricane becomes a threat to a coastal area. Those in the area should be prepared to take precautionary action. A hurricane warning is issued when it appears that a storm will strike an area within 24 hours, and that those in the area are advised to evacuate.

      Foul weather can cause billions of dollars damage every year as well as take a toll on human life. Often the victims were ill prepared or did not head warnings. If you are notified of a watch or warning, take it seriously, it could save your lilfe!
 


Copyright © 2001 Kathy A. Miles and Charles F. Peters II