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NYC Weather Forecast
FOX 5 New York's Mike Woods has the forecast.
NEW YORK - When severe storms are possible, forecasts often include a color-coded map showing a risk from Level 1 to Level 5 — but those numbers do not represent the strength of an individual thunderstorm or tornado.
Who issues the severe weather risk levels?
The outlooks are issued by the National Weather Service’s Storm Prediction Center, which forecasts the potential for organized severe thunderstorms across the United States.
The center considers the chances of tornadoes, damaging wind and large hail when assigning a categorical risk level. The outlook is meant to show where severe storms are most likely and how widespread or intense the activity could become.
Understanding severe thunderstorm risk categories (Graphic by NOAA)
Level 1: Marginal risk
A Level 1, or Marginal risk, means isolated severe thunderstorms are possible.
Storms may be limited in coverage, organization or duration. Most locations inside the shaded area will not necessarily experience severe weather, but a few storms could still produce damaging wind, hail or a tornado.
A Marginal risk should not be interpreted as no risk. It means the threat is relatively low across the overall area, not that every storm will be weak.
Level 2: Slight risk
A Level 2, or Slight risk, means organized severe thunderstorms are possible, but they are not expected to be widespread.
The storms can vary in intensity and may produce damaging wind, large hail or tornadoes.
Despite the word "slight," this is a meaningful severe weather threat. People within the risk area should continue checking the forecast and be prepared to act if watches or warnings are issued.
Level 3: Enhanced risk
A Level 3, or Enhanced risk, means severe storms are expected to be more numerous than during a Slight risk.
There may be a greater concentration of damaging storms, although the intensity can still vary.
An Enhanced risk signals that confidence in a more active severe weather event is increasing and that residents should prepare before storms arrive.
Level 4: Moderate risk
A Level 4, or Moderate risk, is issued when widespread severe weather is likely.
This can include several tornadoes, numerous severe thunderstorms, very large hail or a powerful line of storms producing widespread damaging winds.
Some of the storms are expected to be intense. Moderate risks are uncommon and should be taken seriously.
Level 5: High risk
A Level 5, or High risk, is the most serious category.
It is reserved for situations in which forecasters have high confidence that a severe weather outbreak will occur. That could involve numerous intense, long-track tornadoes or a long-lived complex of thunderstorms producing destructive winds across a widespread area.
High risks are rare because they require a high level of confidence in both the severity and coverage of the expected storms.
Does a lower level mean weak storms?
No.
The levels describe the overall severe weather threat across a region. They do not rate the potential strength of every individual storm.
A Level 1 area could still experience a destructive tornado or damaging wind gust, even though the overall chance of severe weather is lower or the storms are expected to be more isolated.
Likewise, being outside the highest risk area does not mean severe weather is impossible.
What counts as a severe thunderstorm?
The National Weather Service defines a severe thunderstorm as one capable of producing at least one of the following:
- Wind gusts of 58 mph or stronger
- Hail measuring at least 1 inch in diameter
A thunderstorm does not need to produce a tornado to be considered severe. Damaging straight-line winds and large hail can cause significant property damage and create dangerous conditions.
Outlook vs. watch vs. warning
A severe weather outlook identifies the potential for storms across a broad region, sometimes several days in advance.
A watch means severe thunderstorms or tornadoes are possible, and people in the affected area should be prepared.
A warning means severe weather is happening or is imminent. Anyone inside a warning area should take action and move to shelter.
How to prepare
Residents should know where they will go if a warning is issued and make sure they have more than one way to receive weather alerts.
During severe weather, move inside a sturdy building and stay away from windows. Do not wait until a storm arrives to decide where to shelter.
The Source: This article was written using information from the National Weather Service and its Storm Prediction Center.