517  
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  
 
 
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