Gulf of Mexico: Tropical Storm Francine tracking north-northwestward over western Gulf of Mexico as of late Sept. 9 /update 1

Tropical Storm Francine is tracking north-northwestward over the western Gulf of Mexico late Sept. 9. As of 22:00 CDT, the system's center of circulation was approximately 205 km (125 miles) south-southeast of the mouth of the Rio Grande River, US.

Forecast models indicate that the storm will strengthen into a category 1 hurricane over the coming hours as it tracks north-northeastward across the Gulf of Mexico before making landfall over southwestern Louisiana, US, the evening of Sept. 11. After landfall, the system is likely to weaken rapidly into a tropical storm as it tracks north-northeastward across Louisiana and western Mississippi early Sept. 11 before weakening further into a tropical depression across eastern Arkansas through the evening of Sept. 12 and dissipating over southeastern Missouri the evening of Sept. 13.

As of late Sept. 9, authorities have issued the following watches and warnings:

• Hurricane Warning: Louisiana coast from Sabine Pass eastward to Morgan City

• Hurricane Watch: Louisiana coast from Morgan City eastward to Grand Isle

• Tropical Storm Warning: Morgan City to Grand Isle, High Island to Sabine Pass, mouth of the Rio Grande to Port Mansfield, and La Pesca Mexico to the mouth of the Rio Grande

• Tropical Storm Watch: Barra del Tordo to La Pesca Mexico, Port Mansfield to High Island Texas, East of Grand Isle Louisiana to Mouth of the Pearl River, including metropolitan New Orleans, Lake Pontchartrain, and Lake Maurepas

• Storm Surge Warning: High Island Texas to the mouth of the Mississippi River, Louisiana and Vermilion Bay

• Storm Surge Watch: mouth of the Mississippi River, Louisiana to the Mississippi/Alabama border, Lake Maurepas, and Lake Pontchartrain

Authorities will likely update and possibly extend the coverage of the weather advisories over the coming hours and days as the storm approaches.

Hurricane conditions are likely within the hurricane warning area and possible in the hurricane watch area Sept. 11. Tropical storm conditions are forecast by early Sept. 11 within the warning areas and are probable in the warning area in Mexico and south Texas through the afternoon of Sept. 10. Tropical storm conditions are possible within the watch area along the northern coast of Mexico late Sept. 9, along portions of the Texas coast in the watch area Sept. 10, and in the watch area in eastern Louisiana Sept. 11.

Francine is forecast to bring storm total rainfall of 10-20 cm (4-8 inches), with local amounts of up to 30 cm (12 inches), from the coast of far northeast Mexico northward over the far lower and far upper Texas coasts, and across much of Louisiana and Mississippi through early Sept. 12. This rainfall would lead to considerable flash and urban flooding.

The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach up to 1.5-3 meters (5-10 feet) from Cameron to Port Fourchon in Louisiana and Vermilion Bay. Lesser amounts of storm surge are forecast across the coast of Louisiana and Texas. Minor coastal flooding is possible along the Mexico coast within areas of onshore flow. Swells from the system are affecting the coast of northeastern Mexico and southern Texas and will probably spread across the northwestern and northern Gulf of Mexico coastline over the coming days. These swells are likely to cause life-threatening surf and rip current conditions.

Authorites in Lousiana, US, have issued a statewide declaration of emergency in advance of the storm. Evacuation orders are in place for parts of Cameron Parish in Louisiana, while mandatory and voluntary evacuations are ongoing in parts of Grand Isle Town in Jefferson Parish. Voluntary evacuations are in place for the city of Pass Christian in Mississippi. Some oil companies have suspended operations on platforms in the Gulf of Mexico.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.