SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0159 PM CST Fri Dec 19 2025 Valid 192000Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... While strong/gusty winds remain possible across the Mid-Atlantic and Northeast this afternoon and evening, the threat for organized severe thunderstorms is expected to remain low. ...20Z Update... Only minor changes have been made to the existing General Thunderstorm areas. A band of low-topped convection is moving across eastern PA toward northern NJ this afternoon, with sporadic strong to severe gusts noted with this feature. Organized convection is not expected due to negligible buoyancy, but strong deep-layer winds associated with a powerful mid/upper-level trough and attendant cold front moving across the eastern CONUS will continue to support strong/damaging gusts both near and removed from any remaining convection. ..Dean.. 12/19/2025 .PREV DISCUSSION... /ISSUED 1020 AM CST Fri Dec 19 2025/ ...Mid-Atlantic/Northeast... A pronounced mid/upper-level trough with very strong low/mid-level flow will continue moving east-northeastward today across the Mid-Atlantic and Northeast. Associated surface cold front will likewise develop eastward across these regions through the afternoon, and will clear the Atlantic Coast by this evening. A loosely organized, low-topped convective line has moved east of NJ, and should impact parts of Long Island over the next couple of hours. Due to poor lapse rates aloft and limited diurnal heating with continued cloud cover, minimal instability is forecast to be in place ahead of this line. The threat for strong/gusty winds should continue both with gradient winds within the strong low-level warm advection regime and along/behind the front. But given the poor thermodynamic environment and tendency for any additional convection to remain elevated, the Marginal Risk across the Mid-Atlantic/Northeast has been removed with this update.
