Next Atlantic tropical system likely this weekend

Aug 23, 2025

Record warmth in the West continues to be a major weather story this weekend. On Friday, a number of record warm temperatures were set, including record highs being tied in Seattle at 89F and set at Death Valley with a new daily record of 124F. Las Vegas set a daily record warm minimum of 89F.

Not only is the airmass over the West unusually warm, it is unusually moist as well. The NOAA satellite blended total precipitable water analysis from this morning shows that values are up to 250% of normal in the region as monsoonal moisture has surged north on the west side of the heat dome across the region.

This means that record warm minimums will be particularly widespread the next couple of days (forecast records for Sunday morning shown above).

Record high temperatures today will be focused in the Northwest where moisture is not as extreme — the higher moisture in the Southwest will keep ambient temperatures a little lower, although humidity will be higher than normal.

Heat risk will be moderate to major over most of the region through the weekend.

The unusual moisture in the Southwest means that there will be scattered thunderstorms across the region with locally heavy rainfall and pockets of flash flooding. A slight risk (level 2 of 4) of excessive rainfall and flash flooding also continues in the Southeast today.

In the tropics, Invest 90L continues to become better organized and is likely to become a tropical cyclone today. Air Force Reconnaissance will be in the system later this afternoon. The system will continue to move north and will not be any land risk other than skirting Bermuda to the east. Meanwhile, Invest 99L continues to move west toward the eastern Caribbean. While conditions are not favorable for development currently, they are forecast to become a bit more conducive in a day or two before becoming more hostile again later in the week. Right now NHC just has low probabilities of development forecast for it.

Programming note: I will be traveling this weekend for a family wedding, so posts may be a bit more irregular and erratic than usual.