####018002422####
WTNT43 KNHC 300238

TCDAT3

 

Tropical Storm Rina Discussion Number   7

NWS National Hurricane Center Miami FL       AL182023

1100 PM AST Fri Sep 29 2023

 

Rina continues to produce persistent but poorly organized shower and

thunderstorm activity well to the east of its exposed surface

center. Despite the apparent lack of organization, a pair of ASCAT 

passes near 00Z revealed that Rina's wind field was both slightly 

larger and stronger than previously estimated. Both ASCAT passes 

showed a large swath of winds of 40-45 kt east and northeast of 

Rina's center. Based on this new information, the intensity of Rina 

has been increased to 45 kt. Both ASCAT passes had slightly higher 

winds in the deep convection that were flagged as marginal for 

rain contamination, so they weren't considered as representative. 

That said, its possible 45 kt could be slightly conservative.

 

With SHIPS-analyzed 850-200 mb shear higher than 40 kt for the next 

24 h, its very unlikely Rina will become any better organized than 

it is now. Nearly all of the dynamical models forecast that Rina 

will dissipate in the next 24 to 48 h. Based on the structure 

information provided by ASCAT, it appears unlikely that the tropical 

storm will dissipate that quickly. Therefore the the NHC official 

forecast is a little more conservative, but still shows Rina slowly 

weakening, close to the intensity consensus. It is worth noting that 

the vortex tracker associated with a few models flipped to Philippe 

beyond 72 h and the tracks are therefore not representative of the 

actual model forecast.

 

Rina is heading northwestward near 10 kt. The combination of

Tropical Storm Philippe to its west-southwest and a subtropical

ridge to the northeast should keep Rina on this general heading for

a couple of days. The NHC track forecast is near the center of the

guidance envelope, between the simple and corrected consensus aids.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  30/0300Z 20.4N  48.8W   45 KT  50 MPH

 12H  30/1200Z 21.1N  50.2W   45 KT  50 MPH

 24H  01/0000Z 22.2N  51.9W   40 KT  45 MPH

 36H  01/1200Z 23.3N  53.7W   35 KT  40 MPH

 48H  02/0000Z 24.8N  55.6W   30 KT  35 MPH...POST-TROP/REMNT LOW

 60H  02/1200Z 26.7N  56.8W   30 KT  35 MPH...POST-TROP/REMNT LOW

 72H  03/0000Z...DISSIPATED

 

$$

Forecaster D. Zelinsky