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Tropical Storm Franklin Discussion Number  13
NWS National Hurricane Center Miami FL       AL082023
500 PM EDT Wed Aug 23 2023

Franklin is in the process of emerging off the northern coast of the 
Dominican Republic, where surface observations recently showed a 
subtle wind shift in the past couple of hours. Earlier, a NOAA 
reconnaissance mission flew a counterclockwise route around the 
eastern portion of Hispaniola, finding a peak 700-mb wind of 51 kt 
at about the time of the prior advisory. An ASCAT-B pass at around 
the same time also showed a decent swath of tropical-storm-force 
winds along the southern coast of the Dominican Republic. While 
Franklin has been inland for some time now, given the lack of much 
other data, its winds will remain 35 kt for this advisory. An 
Air Force Reserve Reconnaissance mission is soon set to take off 
and should provide more data this evening. 

Franklin's motion is now estimated to be north-northeastward at 
015/11 kt. A large weakness in the flow north of Franklin should 
allow the storm to be steered by mid-level ridging nosing back into 
the eastern Caribbean in the short-term, leading to a rather 
unusual east-northeastward motion over the next 24-48 hours. Then, 
after the remnants of Emily move out of the way, additional ridging 
should build back east of Franklin, blocking it from an immediate 
track out to sea. The track guidance all show the cyclone bending 
back northward for the remainder of the forecast period. While the 
track guidance generally agree on this evolution, the details on 
when and how sharply this turn is remain to be ironed out. 
Ultimately, the consensus aids have changed little this afternoon, 
even if the spread in the ensemble guidance is larger than normal, 
and the NHC track is very similar to the prior one throughout the 
forecast period. 

The biggest hindrance limiting Franklin's initial prospects for 
reintensification is continued moderate westerly vertical wind shear 
between 15-25 kt for the next 24-48 hours. However, sea-surface 
temperatures will be very warm along the forecast track, so this 
shear should not be enough to preclude slow intensification during 
that time span. Afterwards, an upper-level trough is expected to 
cutoff to the southwest of Franklin as the cyclone begins to pivot 
northward, and the storm should find itself in a more favorable 
upper-level environment. Thus, a faster intensification rate is 
anticipated between 72-96 h and Franklin is still expected to become 
a significant hurricane by the end of the forecast period. The 
intensity forecast is in good agreement with the consensus aids, but 
remains lower than some of the more aggressive hurricane-regional 
models (HWRF, HAFS-A/B).
 
KEY MESSAGES:
 
1. Heavy rainfall from Franklin is expected across much of 
Hispaniola into Thursday, which is expected to produce significant 
and potentially life-threatening flash and urban flooding as well 
as mudslides, particularly over the central Dominican Republic.
 
2. Franklin is bringing tropical storm conditions to portions of the 
Dominican Republic, where Tropical Storm Warnings remain in effect, 
and tropical storm conditions are expected to begin within the Turks 
and Caicos Islands tonight. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  23/2100Z 19.8N  70.6W   35 KT  40 MPH...ON THE COAST
 12H  24/0600Z 21.4N  70.1W   40 KT  45 MPH
 24H  24/1800Z 22.5N  68.8W   45 KT  50 MPH
 36H  25/0600Z 23.0N  67.5W   50 KT  60 MPH
 48H  25/1800Z 23.3N  66.3W   55 KT  65 MPH
 60H  26/0600Z 23.8N  65.6W   60 KT  70 MPH
 72H  26/1800Z 24.6N  65.5W   65 KT  75 MPH
 96H  27/1800Z 28.0N  67.0W   85 KT 100 MPH
120H  28/1800Z 31.6N  67.4W   90 KT 105 MPH
 
$$
Forecaster Papin
 
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