In combination with Hurricane Polo out of the eastern Pacific and another storm driven by monsoonal winds, the Southwest and Plains are in for days of rainfall, with some locations forecast to receive more than 4 months' worth of September's average rainfall.

Hurricane Polo made landfall on Baja California on Tuesday evening, and its remnants, along with another storm powered by monsoonal moisture, are moving into the Southwest and Plains. Heavy downpours have triggered extreme weather alerts on the app.

The hot spots for highest rain totals are in eastern Colorado, western Kansas and in the Oklahoma and Texas panhandles. Flash flooding is expected. The WeatherRadar turns hues of dark blue to purple in the heaviest downpours.