WASHINGTON, DC — A fast-moving Pacific jet stream is setting up a broad storm pattern that will bring heavy rain, mountain snow, and colder air to parts of the Southern U.S. starting Friday and lasting through Monday.
The storm track is expected to stretch from Southern California into Texas and then on to Florida, with the Southwest already coming off a very wet fall and Texas seeing one of its wettest Novembers on record.
Forecasters say the setup is being driven by an El Niño pattern over the Pacific and a strong ridge over the interior West, which is helping steer moisture into the southern half of the country.
Why the jet stream is aimed at the southern states
The FOX Forecast Center said the upper-level ridge over the interior West is acting like a barrier, preventing storm systems from moving straight inland. Instead, the ridge is forcing the jet stream to split and send energy farther south.
That allows a cut-off low to form well south of the main atmospheric river corridor that is aimed at the Pacific Northwest. In practical terms, the result is a storm path that favors California, the Desert Southwest, and later the southern Plains rather than the northern tier of the country.
This type of setup can keep rounds of wet weather coming over several days instead of producing just one short-lived system. That is why forecasters are warning about a multi-day stretch of unsettled weather rather than a brief burst of rain.
California faces rain in the valleys and snow in the Sierra Nevada
From Friday through Monday, the incoming low pressure system will pull deep Pacific moisture into California and the Desert Southwest. The biggest impact in California is expected to be a mix of widespread rain at lower elevations and early-season snow in the mountains.
Colder air will support snowfall in the Sierra Nevada region, with the highest elevations likely to see the most accumulation. Winter Storm Watches are already in effect for the Sierra Nevada as the weekend approaches.
Southern California valleys and lower deserts are expected to see steady rainfall as the system taps into that Pacific moisture. The combination of rain at lower levels and snow in the mountains makes the storm particularly notable for travel and outdoor plans across the state.
Texas could see the heaviest rain Saturday and Sunday
The same storm pattern is forecast to push into Texas after affecting the Southwest. Forecasters say the state could see some of the heaviest rain on Saturday and Sunday, with Corpus Christi, Austin, and San Antonio among the places that may be hit hardest.
A level 1 out of 4 flash flood risk is in place for the weekend. That does not guarantee flooding, but it does signal the chance for localized problems if rain falls over the same area for long enough.
Rain totals are still uncertain, but several inches are possible in parts of Texas. The concern is greater because much of the state is already saturated from recent storms, which can make it easier for water to collect on roads and in low-lying areas.
A wet fall has already primed the Southwest for more storms
The new storm pattern is arriving after an unusually wet fall across the Southwest. That background matters because soils and drainage systems may already be strained before the next round of rain even begins.
Texas is also coming off one of the wettest Novembers on record, which adds another layer of concern as more rain is projected to move in this weekend. When a region has already seen repeated soaking rains, even a moderate additional event can create bigger impacts.
Forecasters have not given a precise total for the weekend system yet, but they are warning that the combination of already saturated ground and several more rounds of rain could increase the risk of flooding in some spots.
Florida could get torrential rain early next week
After moving through the southern Plains and Texas, the storm pattern is expected to continue eastward and bring wet weather into Florida early next week. Forecasts call for the possibility of torrential rain as the system keeps pulling moisture across the South.
That means the weather threat is not limited to one region or one day. Instead, the same overall pattern could affect travel, outdoor plans, and local drainage across a wide stretch of the country over several days.
The Florida impacts are still several days away, but the long-range setup suggests that the state could end up under another round of heavy rain after the western and central portions of the system have already done their work.