Is Vance bringing flash flooding to Texas on Halloween? What the forecasts say

What is being shared

On October 29, WeatherNation ran the headline "Tropical Moisture From Vance Raises Flash Flood Concerns Across Texas Ahead of Halloween." It says moisture from Tropical Storm Vance is increasing the threat of heavy rain and flash flooding "as the state prepares for Halloween," and that the rain's timing "could also affect outdoor Halloween activities."

Read quickly, it sounds like a flood threat on trick-or-treat night. The article's own detail is narrower: it says "the greatest concern is Thursday," in western and central Texas.

What the forecasters actually issued

Vance is an eastern Pacific tropical storm. On Thursday morning the National Hurricane Center put it about 115 miles southeast of the tip of Baja California, with 40 mph winds, and expected it to weaken into a remnant low later that day. NHC said moisture from Vance, combined with other Pacific moisture, would bring heavy rain to the Southern Plains and New Mexico "today into Friday."

The Weather Prediction Center has a Slight Risk of excessive rainfall (level 2 of 4) for parts of West and Central Texas and southeastern New Mexico through Friday morning. For Friday, it lowers Texas and Oklahoma to a Marginal Risk (level 1 of 4), with "isolated instances of flash flooding." For Saturday, Halloween, its Slight Risk is in Arizona. A broader Marginal Risk reaches from southern California to western Texas over Friday and Saturday.

Where the Flood Watches are

On Thursday afternoon, NWS had Flood Watches across West Texas, all ending by Friday evening: the Midland-Odessa area, Big Bend and the Davis Mountains (Midland/Odessa office), the South Plains and Rolling Plains around Lubbock, Crockett, Irion, Kimble, Schleicher and Sutton counties (San Angelo office), and Val Verde, Edwards, Kinney and Maverick counties (Austin/San Antonio office). Parts of Hudspeth and eastern El Paso counties were under a watch through late Thursday night.

The biggest totals are in the south. NWS San Angelo says 2 to 4 inches of rain are likely in its watch area, with isolated amounts of 6 inches or more. NWS Austin/San Antonio says there is "a potential for life threatening flooding somewhere in the watch area." No Flash Flood Warning was in force in Texas when we checked on Thursday afternoon.

What the forecasts say about Halloween night

NWS Fort Worth says Halloween night will be "mild and humid," with temperatures in the mid to upper 70s. NWS Corpus Christi expects to "dry out this weekend for a warm and humid Halloween." NWS Austin/San Antonio expects rain chances on Saturday mainly north of US Highway 90, ending Saturday evening.

The Houston area is the one to watch. NWS Houston expects "scattered to numerous showers and storms in the afternoon" on Saturday, with rain chances decreasing in the evening. These are Thursday's forecasts, and they will change, so check again on Saturday.

Your Halloween night plan

Know the words. NWS says a Flood Watch means conditions are favorable for flooding, but "it does not mean flooding will occur." A Flash Flood Warning means a flash flood is imminent or occurring, and if you are in a flood-prone area, move immediately to high ground. Our live Flood Watch and Flash Flood Warning pages and our state pages list what is in force now.

When to call it off: if a Flash Flood Warning covers your neighborhood on Saturday evening, stay in and trick-or-treat another night. If only a watch is in force, go, but stay alert for a warning. NWS says flash floods can develop in minutes, sometimes in areas not getting rain.

Plan the route. Skip creek crossings, low-water crossings and low spots, and stay away from flooded ditches and streams. NWS says just 6 inches of fast-moving water can knock over an adult and 12 inches can carry away most cars, and that water can hide washed-out road surfaces. If you drive kids between neighborhoods, never drive around barriers on a flooded road.

Carry a flashlight. It helps you see standing water on a dark sidewalk, and NWS lists flashlights and a battery-powered radio among the things to keep ready for floods.

What not to do

Don't cancel Halloween across Texas because of a headline, and don't ignore a warning for your own county. Don't walk or drive into moving water, however shallow it looks: NWS says over half of flood drownings happen when a vehicle is driven into flood water, and the next largest share comes from walking into or near it. You don't need to buy anything for this.