“Damaging straight-line winds and large hail are the main threats, though an isolated tornado can’t be ruled out,” the weather service said in its latest discussion, noting that storms will be capable of intensifying quickly as they move across the state.

Timing and areas at greatest risk

• Storm window:
  Sunday afternoon through Sunday night, with the strongest storms most likely late afternoon into the evening as a cold front sweeps through.
• Risk area:
  Much of New Jersey is included in a severe weather risk zone, with the greatest concern focused where instability and wind shear overlap—generally central and southern parts of the state.
• Storm character:
  Thunderstorms may form in clusters or a broken line, racing east. Any stronger cell could quickly produce damaging wind gusts and large hail.

Main threats

• Damaging winds:
  Straight-line wind gusts from the strongest storms could be strong enough to down tree limbs, damage unsecured outdoor items and cause scattered power outages. Outside of storms, it will already be breezy to windy as the system approaches.
• Large hail:
  The same strong updrafts that fuel severe winds may also support large hail, which can damage vehicles, roofs and siding.
• Isolated tornado:
  While not the primary hazard, an isolated tornado cannot be ruled out where storms interact with stronger low-level wind shear. Even a brief tornado can cause localized but serious damage.
• Heavy rain and localized flooding:
  Downpours within the strongest storms could lead to ponding on roads and poor-drainage flooding, especially if multiple storms track over the same area.

What this means for New Jersey residents

• Secure loose items:
  Patio furniture, trash cans, signs and decorations should be secured or brought inside before storms arrive to prevent them from becoming projectiles in strong winds.
• Plan around the worst window:
  If possible, avoid unnecessary travel during the late afternoon and evening when the most intense storms are expected. If you must be on the road, be prepared for sudden heavy rain, reduced visibility and gusty crosswinds.
• Stay weather-aware:
  Keep a charged phone, enable wireless emergency alerts, and monitor trusted local sources, NOAA Weather Radio or TV for any severe thunderstorm or tornado warnings that may be issued.
• During a warning:
  If a severe thunderstorm or tornado warning is issued for your area, move indoors immediately, stay away from windows and avoid driving into the warned storm.

Looking ahead

Behind the storms, cooler and drier air will move in, with winds gradually easing later Sunday night into Monday. Temperatures are expected to trend lower after the front passes, but the main story for Sunday remains the risk of severe thunderstorms with damaging winds and large hail across parts of New Jersey.