21. Shortly after, the depression sharply turned north and degenerated into a trough of low pressure , no longer a tropical cyclone. 22. But the ridge's grip will loosen over southern California, allowing a potent trough of low pressure to slip toward the coast. 23. Tropical Disturbance 02F developed within a trough of low pressure to the north-east of the Santa Cruz Islands during November 18. 24. In the wake of the disturbance, a trough of low pressure will be left from the western Dakotas to northwest Texas. 25. After being named the system moved erratically towards the south-southeast, as it interacted with a mid troposphere trough of low pressure . 26. In turn, hot, less dense air will lower barometric pressures, creating a trough of low pressure just east of the Appalachians. 27. Scattered showers and thunderstorms will cover the Northeast on Thursday as a trough of low pressure swings south from Ontario, Canada. 28. During February 26, a tropical depression developed within a trough of low pressure , to the northeast of Rarotonga in the Cook Islands. 29. Widely separated showers and lonely thundershowers will affect the Northeast as a weak trough of low pressure swings east across the region. 30. Debby maintained tropical cyclone status while crossing Florida, but degenerated into a trough of low pressure by 1800 UTC on June 27.
