The National Hurricane Center has declared Invest 91L or Potential Tropical Cyclone Seven as Tropical Storm Gordon this Monday morning.
The storm was declared as a tropical storm as it made landfall on the upper Florida Keys, bringing 45 mph sustained winds. Affecting mainland Florida today, Gordon will track over the Gulf of Mexico, threatening the central Gulf Coast as a strong tropical storm or potentially even a hurricane.
This Monday, Labor Day, all of the action associated with Gordon will be in South Florida and the Florida Keys as the central low pressure swipes right through. Frequent wind gusts of up to 30-50+ mph can be expected along with localized sustained winds of up to 45 mph. Therefore, isolated power outages will be possible. Flash flooding will be another risk, with a widespread 2-4 inches of rainfall through Monday night across South Florida. Localized totals of up to 8 inches cannot be ruled out. The best chance for heavy rain in excess of 4 inches will be in Broward, Miami-Dade, Collier, Henry, Lee, and Monroe counties. One last risk is for a few spin-up tornadoes, which is actually quite common with landfalling tropical cyclones.
Gordon will then pull away from Florida Monday night, moving northwest at a fairly good clip. From this moment up until Tuesday night will be the most crucial time frame for this storm. This is because the cyclone will be located over the Gulf of Mexico. This large body of water provides fuel to these storms, and with sea surface temperatures above-average and in the 80s, there is an abundance of fuel and energy for Gordon to use, likely allowing it to intensity further. There are some questions surrounding how strong the wind shear will be, which is unfavorable for tropical cyclone organization. At this time, though, the model guidance suggests low wind shear along Gordon’s track. Therefore, we think Gordon will strengthen into a strong tropical storm or maybe, just maybe, into a hurricane by Tuesday night. The current forecast from the National Hurricane Center expects sustained winds to reach 70 mph so a Hurricane Watch is in effect for parts for numerous coastal towns.
Gordon will then make landfall between the mouth of the Mississippi River near New Orleans and Mobile, Alabama Tuesday night. Again, the intensity as well as the exact landfall location is still uncertain, but these areas which are currently under the Tropical Storm Warning should prepare for a category 1 hurricane if Gordon were to further strengthen in the Gulf.
One of the risks Gordon will bring to the central Gulf Coast is storm surge. According to the National Hurricane Center, Shell Beach to the Mississippi-Alabama border can expect 3-5 feet of inundation, 2-4 feet from Navarre, Florida to the Mississippi-Alabama border and from Shell Beach to the Mouth of Mississippi River, and 1-2 feet from the Mouth of the Mississippi River to the Louisiana-Texas border. Tropical-storm-force winds (39-73 mph) can also be expected across many areas under the Tropical Storm Warning. These conditions will begin to move in by Tuesday evening. Lastly, there will be heavy rain which may trigger flash flooding. 4-6 inches is forecast over southern Alabama, Mississippi, and Louisiana, with isolated amounts of 8 inches through early Thursday.
Late-week, the ArkLaTex and surrounding areas may experience heavy rain from Gordon as it tracks inland. Flash flooding may also be a concerned, which we will detail when this event comes closer and forecast confidence increases.