Hurricane Francine Forecast Discussion Number 11

By | September 11, 2024

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WTNT41 KNHC 110855
TCDAT1

Hurricane Francine Discussion Number  11
NWS National Hurricane Center Miami FL       AL062024
400 AM CDT Wed Sep 11 2024

As expected, Francine has strengthened and become better organized 
overnight. Radar data and earlier reports from the Air Force 
Hurricane Hunters indicate the eyewall is better defined, with deep 
convection wrapping around the center of the hurricane. The eyewall 
has contracted a bit from earlier, although it was open to the south 
on the last fix and in more recent GMI passive microwave images. 
The microwave data also showed some northeastward vortex tilt with 
height, a sign that Francine is experiencing some effects of 
southwesterly shear. Based on the earlier peak 700-mb flight-level 
winds of 89 kt, the initial intensity is set at 80 kt, with a 
minimum pressure of 977 mb based on aircraft data. Air Force and 
NOAA Hurricane Hunter aircraft are scheduled to investigate Francine 
again this morning. 

The hurricane is moving northeastward at 035/9 kt. A slightly faster 
northeastward motion is forecast today and tonight as the hurricane 
is steered by a mid- to upper-level trough over Texas. This will 
bring the core of Francine toward the Louisiana coast today, with 
landfall expected within the hurricane warning area late this 
afternoon or evening. After landfall, a gradual turn toward the 
north will bring the center of Francine across eastern Louisiana and 
Mississippi. The track guidance is fairly tightly clustered, and the 
latest NHC forecast lies near the center of the guidance envelope 
and very close to the consensus aids.

The structure of Francine could allow for some additional short-term 
strengthening this morning over the very warm Gulf waters, and this 
is reflected in the updated NHC forecast. Southwesterly shear is 
expected to increase over the hurricane later today, and interaction 
with an upper trough should cause drier air to wrap around the 
southern portion of Francine as it nears the coast. Thus, the 
hurricane is not expected to continue strengthening through 
landfall, but will continue to pose a significant risk of 
life-threatening storm surge and damaging winds to locations in the 
warning areas. Once inland, Francine is expected to rapidly weaken, 
quickly lose tropical characteristics, and transition to an 
extratropical cyclone over northern Mississippi.

An experimental cone graphic that includes inland Hurricane and
Tropical Storm Watches and Warnings in the U.S. is now available on
the NHC website. Due to the time needed to compile the inland watch
and warning information, the experimental cone graphic will not be
available as quickly as the operational cone. Once it is available,
the experimental cone graphic can be found from a red weblink above
the operational cone graphic at
www.nhc.noaa.gov/graphics_at1.shtml?cone#contents. Users are
encouraged to take the experimental product survey found below the
experimental cone.

KEY MESSAGES:

1. There is a danger of life-threatening storm surge today for the 
Louisiana and Mississippi coastlines, where a Storm Surge Warning is 
in effect. Residents in the warning area should follow advice, 
including evacuation orders, given by local officials.

2. Damaging and life-threatening hurricane-force winds are expected 
in portions of southern Louisiana later today, where a Hurricane 
Warning is in effect. Tropical storm conditions are expected to 
begin within this area later this morning, and preparations to 
protect life and property should be complete.

3. Francine is expected to bring heavy rainfall and the risk of 
considerable flash and urban flooding across southeastern Louisiana, 
Mississippi, far southern Alabama and northern Florida through 
Thursday night. Flash and urban flooding is probable across the 
Lower Tennessee Valley and Lower Mississippi Valley Wednesday night 
into Friday morning.


FORECAST POSITIONS AND MAX WINDS

INIT  11/0900Z 27.0N  93.8W   80 KT  90 MPH
 12H  11/1800Z 28.5N  92.3W   85 KT 100 MPH
 24H  12/0600Z 30.6N  90.8W   50 KT  60 MPH...INLAND
 36H  12/1800Z 33.0N  90.1W   30 KT  35 MPH...INLAND
 48H  13/0600Z 34.7N  90.3W   25 KT  30 MPH...POST-TROP/EXTRATROP
 60H  13/1800Z 35.3N  90.3W   20 KT  25 MPH...POST-TROP/EXTRATROP
 72H  14/0600Z...DISSIPATED

$$
Forecaster Reinhart

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