Houston, Texas Severe Weather: A cold front arrives on November 20, 2023
HOUSTON – The fall and winter severe weather season is underway across the Deep South and a strong cold front will bring the chance of strong storms to Southeast Texas this afternoon.
The greatest severe weather threat will be north and east of the Houston metro area, but anywhere could see a strong storm or two.
The Storm Prediction Center (SPC) has placed much of Southeast Texas under Level 1 out of 5 serious threats (5 is the worst).
However, Grimes, Walker, Polk, San Jacinto and northern Montgomery counties are at threat level two.
Overall, the greatest chance for severe weather will remain across Louisiana and Mississippi.
The main threats in any severe storms will be the potential for wind damage, a fast-moving tornado, and large hail.
The timing of any storms will be from late morning until 6pm before the worst of the weather moves to the east.
The greatest tornado threat is in eastern Texas, Louisiana and Mississippi, where there is a Level 3 severe weather threat. Long-term and violent tornadoes are possible in these locations.
On Tuesday, the weather will turn very windy and colder as a result of this cold front. Wind speeds could reach about 30 to 40 mph in some locations during the afternoon.
This storm system will continue to move eastward, making travel difficult and possible delays up and down the East Coast on Tuesday. Plan ahead if you are traveling by air on Tuesday.
What do SPC threat levels mean?
In terms of risk and severity, here you go Five risk categories And what each of them means, according to SPC:
- Marginal (dark green): This initial level means isolated severe thunderstorms are possible. Storms are likely to be limited in how long they last, the size of the area they cover, and how intense they are.
- Slight (yellow): A slight risk means isolated severe storms are possible, although they are likely to be short-lived and do not have widespread coverage over an area. While they may not be persistent, these storms can still produce isolated severe conditions.
- Enhancer (orange): Under strengthening conditions, several severe storms are possible. This level is characterized by more persistent and widespread storms, some of which may be severe.
- Moderate (red): Jumping to a moderate risk level means severe storms are likely to occur on a larger scale, which may be long-lasting and intense.
- High (purple): An area where severe weather is expected to develop either from several intense, long-tracked tornadoes or from a long-lasting, derrico-producing thunderstorm complex that produces hurricane-force wind gusts and widespread damage. This risk is limited to cases where there is high confidence in widespread coverage of severe weather involving high-intensity events (i.e., violent hurricanes or extremely damaging convective wind events).
What defines severe weather?
The National Weather Service specifies a Severe thunderstorm Like any storm, it results in one or more of the following:
- To the hurricane.
- Damaging winds or speeds of 58 mph (50 knots) or more.
- Hail 1 inch in diameter or larger.
SPC is also defined Large severe thunderstorms Like any storm, it results in one or more of the following:
- The tornado deals damage of EF2 or greater.
- Wind speeds of 75 mph (65 knots) or more.
- Hail 2 inches in diameter or larger.
What is the São Paulo Consensus?
(Text from SPC website)
The Storm Prediction Center (SPC) is part of the National Weather Service (NWS) and the National Centers for Environmental Prediction (NCEP). Our mission is to provide accurate and timely forecasts and watches for severe thunderstorms and tornadoes over the contiguous United States. SPC also monitors hazardous winter weather and fire weather events and issues products specific to those hazards. We use the latest technologies and scientific methods available to achieve this goal.
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