A stalled weather pattern known as an Omega block is driving heavy rain and the potential for flooding and severe weather across the United States this week. The pattern has locked atmospheric flow, preventing typical west-to-east movement.
This configuration takes its name from the Greek letter Omega (Ω) because of the shape it forms in the jet stream. It involves a high-pressure system positioned between two low-pressure systems, effectively blocking normal weather progression. An unusual weather pattern developed across the country, leading to persistent conditions.
The setup is forecast to bring prolonged periods of rain to the South and Northeast. Areas in the Southern Plains and along the Gulf Coast also face concerns. Heavy rain may cause flooding in southern and eastern states.
Forecasters project a threat for flash flooding. Multiple days of rain over the same areas increase the risk, especially across parts of Texas and Louisiana through midweek..Severe thunderstorms are possible in parts of the South. This includes risks of damaging winds and hail. An isolated tornado cannot be ruled out in some areas, particularly across Texas, Louisiana, Arkansas, and Oklahoma early in the week. Monday's Severe Thunderstorm Forecast shows specific risk zones.
In the Northeast, rounds of showers and storms will continue. The potential for flash flooding remains, especially near the New York tri-state area. The FOX Forecast Center noted that a cutoff low-pressure system stalled over the Ohio Valley contributes to funneled precipitation into the region.
The threat of heavy rain and flooding is forecast to persist through Tuesday across eastern Texas into Louisiana, southern Arkansas, and central Mississippi. The Daily Weather Update from FOX Weather detailed the multiday flood threat.
By the latter half of the week, the blocking pattern is expected to weaken, allowing weather systems to move again.
