Harvey to threaten Texas with flooding rainfall to end the week

Harvey may spread drenching rain, gusty winds and rough surf as far north as Texas beginning late this week.

After moving away from Mexico's Yucatan Peninsula, Harvey will venture northwestward and over the open waters of the Gulf of Mexico on Wednesday.

Harvey will bring localized flooding downpours and gusty thunderstorms to the Yucatan Peninsula into Wednesday.

"We expect Harvey to redevelop and gain some strength over the western part of the Gulf of Mexico spanning Wednesday to early Friday," according to AccuWeather Hurricane Expert Dan Kottlowski.

Heavy rain, gusty thunderstorms and rough surf are to be expected in southern Texas and northeastern Mexico as Harvey approaches. The main threat is likely to be flooding.

The path, strength and forward speed of Harvey will determine the amount of rain, wind and rough surf over northeastern Mexico and Texas.

There is the potential for Harvey to stall over northeastern Mexico and/or southern Texas. If this occurs, then the risk of major flooding will increase with upwards of 10 inches (250 mm) of rain possible in some locations.

"There is the potential for heavy rainfall and significant flooding in the region, even if Harvey remains weak and ventures into northeastern Mexico," Kottlowski said.

From 10 to 20 inches of rain could lead to a flooding disaster, but that could happen if Harvey stalls.

The concern would be for not only flash and urban flooding, but also major river flooding.

Should Harvey travel farther north along the Texas coast, heavy rain and the risk of flooding will correspondingly expand northward along the Gulf coast to perhaps Louisiana.

A storm that tracks farther north is also likely to be stronger and produce more wind impacts because it has more time to spend over the warm waters of the western Gulf of Mexico.

A reasonable amount of rain, on the order of 2-4 inches (50-100 mm), would be beneficial from an agricultural standpoint. This amount of rain can occur if Harvey remains poorly organized and keeps moving along into the south-central United States.

While rainfall has been close to average near the Texas coast, portions of the lower Rio Grande Valley have received less than 25 percent of their average rainfall since June 1.

Rainfall from Houston to Corpus Christi and San Antonio, Texas, has averaged between 50 and 60 percent of normal since the start of June.

Late this week and this weekend, motorists should be prepared for delays. Beachgoers may have to postpone activities.

How far inland drenching rain spreads will depend on how quickly Harvey weakens on the path of the system.