Tropical Update: Harvey and two new developments
Tropical Storm Harvey continues to wreak havoc on south Texas. The storm will sit over the southeast portion of the state and over southwest Louisiana for the next few days. Currently the storm is moving extremely slowly at only 3 mph towards the southeast. That southeast movement actually brings a portion of the storm back over the Gulf of Mexico where warm water has a slight potential to further fuel some of its outer rain bands. The water temperature is not as high as before Harvey made its first pass into the Gulf due to the storm initially churning up colder water from the depths and cooling off the water at the surface. Colder surface temperatures in the Gulf will hinder any stronger development. This is slightly better news for cities in Louisiana who will experience the brunt of the heaviest rainfall over the next 48 hours. Cities such as Alexandria and Lafayette, Louisiana could see up to 6 inches of rain fall over the next day or two.
Southeast Texas will continue to experience heavy rain for the next two days where at least 1-2 feet of rain has already fallen. Rain gauges across the Houston metro show anywhere from 13-25 inches of rain have fallen on the fourth largest city in the United States. The greatest continuing concern will be flooding of the bayous and rivers that flow in and around the city. River gauges at White Oak Bayou and Buffalo Bayou in the heart of Houston are already clocking in at “major flooding” levels due to the heavy rainfall. Flooding is also possible along stretches of the Brazos, Colorado, Guadalupe, Navidad and San Bernard rivers. These rivers typically take weeks, not days, to return to normal levels and could pose a problem for coastal cities downstream which have already been affected by storm surge from Harvey’s onset.
Harvey will eventually weaken by the end of this week as it makes its way northeast. An area of high pressure over Georgia and the Carolinas finally makes its way out to the Atlantic Ocean giving Harvey room to move eastward. Rain and flooding continue to be the biggest issue with the remnants of this storm. Kentuckiana could feel the effects of Harvey this Saturday with the possibility for more rain over the course of the Labor Day weekend.
Another system off the east coast of Georgia has the potential to become our next named storm of the season. The National Hurricane Center is tracking what they call Potential Tropical Cyclone 10 with a 90% possibility of it developing into a tropical depression within the next 48 hours. If it develops, the system will likely hug the east coast for a short period of time before making its way out to sea near the North Carolina/Virginia border.
One final thing to mention is a tropical wave and associated low pressure system currently making its way off the western coast of Africa. The National Hurricane Center gives this storm a 70% chance of development into a depression over the next 5 days with this system forecast to move westward at 15-20 mph over the Atlantic. Hurricane season officially lasts until November 30th.