From the Spaceflight Meteorology Group:
[ BLUF ]
The National Hurricane Center has upgraded Potential Tropical Cyclone Six to Tropical Storm Francine (max wind 65 mph). As expected, an increase in organization and structure has been identified via satellite and Air Force Reconnaissance Aircraft placing the eye northwest of the initial analysis and shifting the forecast track 85 nm closer to the Gulf coast. The shift toward the coast and trend of the increasing organization of Francine generally increases storm intensity with an earlier upgrade to hurricane status (max winds 74-110 mph @ Tuesday Evening) and likely achieving category two (max winds 96-110 mph) before making landfall in Louisiana.
[ Guidance ]
Guidance remains the same as far as the key features driving the direction/speed of Francine with the adjustment westward for the forming eye. Francine will follow a mid-level ridge/high pressure center as it moves north along the Gulf coast with a mid-level trough/low pressure center pushing it further to the northeast early to mid-week. Tropical Storm Watches have been issued for most of the Texas Coast South and West of the east-side of Galveston Bay and Tropical Storm Warnings issued east of that towards Louisiana with Hurricane Warnings. Peak storm surge expected for Galveston Bay 1-3 feet.
[ Houston/JSC Impacts ]
With the updated forecast track / strengthening of Francine current wind estimates put us around 50-60% chance for 39 mph Tropical Storm Force winds and 10-20% chance for 58 mph winds.
Latest models runs have not captured the eye formation so these wind speeds will be underestimated by ~5-10 mph. Winds expected to start increasing Monday Evening from 8 mph/Gusting 15 mph to 15 mph/Gusting 20 mph by Tuesday Evening. Tuesday afternoon to early evening is the earliest expected arrival time for the 35 mph winds if present. And further increasing to 20 mph/Gusting 25 mph by Wednesday morning and then steadily dropping off over the next 3 days to normal conditions.
Similar arrival times for the precipitation with total rain fall around 2-4 inches (Tuesday-Thursday) with a slight chance of flash flooding (15%). Light showers expected to start Tuesday Morning and peaking around noon and but persisting throughout the evening. Showers will then pick up intensity in the early morning hours of Wednesday and peaking around noon and dissipating by Thursday evening.