242
ACUS48 KWNS 180901
SWOD48
SPC AC 180859

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0359 AM CDT Sat Oct 18 2025

Valid 211200Z - 261200Z

...DISCUSSION...
In the wake of the strong eastern US trough and cold front moving
offshore D3/Monday, a second upper low will deepen over the eastern
US through the first half of next week. As the low deepens,
persistent northwesterly flow aloft and surface high pressure will
build over the central US. Post-frontal offshore flow should limit
surface moisture/instability and resulting thunderstorm chances for
much of the CONUS through Wednesday.

Some thunderstorm potential may return D6/Thursday and D7/Friday as
a southern stream shortwave trough moves from the Southwest into the
southern Plains. Cooling temperatures aloft overspreading modest
moisture return over TX/OK could support some thunderstorm activity.
However, uncertainty on destabilization and stronger vertical shear
remains very high, thereby limiting severe predictability.

Additional thunderstorm chances may develop over the central US next
weekend as another Pacific trough approaches. But, model guidance
remains quite varied on the intensity/evolution as well as available
moisture ahead of this system. Thus, predictability remains too low
for severe probabilities through the extended forecast period.

..Lyons.. 10/18/2025