Pineapple express a flood threat to California, Southwest

Key Points:

• An atmospheric river known as the "pineapple express" is expected to bring heavy rain to the Desert Southwest and Southern California over Halloween weekend, following recent destructive flooding in the region.
• Two rounds of rain are forecast: Thursday and Friday in western Texas, New Mexico, and Arizona, and over the weekend in Southern California and the Southwest, with rain and high mountain snow continuing into Monday.
• The saturated ground from last week's 2 to 5 inches of rain increases the risk of serious flash flooding, especially in the Phoenix metro area, Four Corners, and San Diego County foothills, with wildfire-scorched areas vulnerable to debris flows.
• The atmospheric river, fueled by a southward jet stream plunge from near Hawaii, could bring 2 to 3 times the average moisture for late October, potentially setting near-record moisture levels for Halloween weekend.
• Travelers and outdoor enthusiasts in southern Utah, southern Colorado, and Arizona are advised to reconsider weekend plans due to the threat of fast-moving, life-threatening flash floods and slippery mountain travel conditions.