Late-forming tropical weather in both the Gulf of Mexico and the Pacific off the Mexican coast have spawned excessive thunderstorms and, in some cases, heavy rains across most of South Texas and up the coastline into Louisiana.

After three weeks of hot weather that offered only scant showers, mostly on the upper Texas coast, prevailing winds pumped volumes of heavy moisture-laden air into the state last week which collided with a stalled cold front over west and central Texas kicking off broad showers from Brownsville and coastal areas all the way into the Panhandle by the weekend.

Rainfall amounts exceeding 5 inches in two days in some areas caught many farmers by surprise in the Rio Grande Valley where the last of the cotton harvest was underway and the Upper Coastal Bend where cotton harvest was just getting started. In the Valley, the heavy showers dropped substantial rain on baled cotton still standing in the fields and kept farmers from accessing their fields to strip the last of standing cotton.

Hidalgo County Extension Agent Brad Cowan reports most cotton stored in the field in the Mid and Upper Valley was well covered whether by module covering or square bale wrap that provided some protection from the showers. Only about 3 percent of the Valley's cotton acreage remained in the field when the rains began mid-week.

Overall Valley farmers are glad to see the rain, especially sugarcane and citrus producers. In the lower Coastal Bend around Corpus Christi, rainfall amounts ranged between 3 inches to 3.5 inches in parts of western Nueces County. Cotton harvest has all but finished in Nueces County, and most cotton has moved to area gins.

San Patrico and Aransas Counties received variable amounts of rain ranging from just over a half inch up to 3 inches in isolated areas, Ranchers say the rain is a great benefit to pastures and are hopeful soil moisture will remain high for winter grasses.

Some of the heaviest showers fell across parts of the middle and upper Coastal Bend near the Brazos River and also heavy rains were recorded in and around the Metro Houston and Beaumont areas and extending into Southwestern Louisiana. Cotton in the Upper Coastal Bend is just reaching full maturity and rains will show initial harvest after several days of rain. Nearly 5 inches fell along the Brazos watershed and in deep southeastern Texas.

National Weather Service forecasters in Brownsville say much of the rain was generated by Tropical Storm Dolly. The storm lashed Mexico's northeast coast on Tuesday night, the U.S. National Hurricane Center (NHC) said, bringing torrential rain and life threatening flash floods to a broad area of Mexico including the popular coastal city of Veracruz.

Dolly was blowing maximum sustained winds of 45 mph but having made landfall the storm had lost strength by Wednesday evening as heavy bands of rain spread out to the northeast. Coastal flood warnings were issued for most of the Texas coast and heavy rain showers began moving on to the Texas shore by Wednesday evening.

Because of a stalled front across mid-Texas, remnants of Dolly stalled and continued to pump Gulf moisture across large areas of Texas and Mexico over the next two days.

By Friday the stalled front moved further south and clashed with heavy Gulf moisture still streaming in from the Gulf to set off another series of showers that stretched well into the weekend.

Meanwhile tropical weather in the Pacific off the coast of Mexico was pumping extensive moisture into the American Southwest including large areas of Arizona, New Mexico and West Texas. Forecasters say heavy monsoonal rains spirited by tropical influences dropped significant rain across south central New Mexico adding problems for chile pepper farmers near Hatch in the Middle Rio Grande Basin and for chile producers in and around Deming.

New Mexico State University Extension specialists say the rain showers are timely, however, for pecan growers in southern parts of the state. August and September are critical times for nut fill development and rain showers over the weekend are expected to help the state's extensive pecan crop reach maturity. Texas pecan growers also welcome weekend rains for the same reason.

Forecasters say an unusually active late tropical season could bring more showers into Texas and across the Southwest by the end of the week. For more on Dolly, visit http://www.weather.com/news/weather-hurricanes/tropical-storm-dolly-gulf-mexico-20140902