049  
WTNT43 KNHC 280240  
TCDAT3  
 
POTENTIAL TROPICAL CYCLONE EIGHTEEN DISCUSSION NUMBER 2  
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182017  
1100 PM EDT FRI OCT 27 2017  
 
SATELLITE IMAGERY SHOWS THAT THE DISTURBANCE OVER THE NORTHWESTERN  
CARIBBEAN SEA IS GRADUALLY BECOMING BETTER ORGANIZED WITH INCREASING  
CONVECTIVE BANDING IN THE WESTERN SEMICIRCLE. HOWEVER, EXPERIMENTAL  
SHORTWAVE INFRARED DATA FROM GOES-16 APPEAR TO SHOW THE PRESENCE OF  
MULTIPLE LOW CLOUD SWIRLS, AND IT IS UNCLEAR IF THE DEFINITION OF  
THE CENTER HAS IMPROVED TO THE POINT WHERE THE SYSTEM HAS BECOME A  
TROPICAL CYCLONE. THUS, THE DISTURBANCE REMAINS A POTENTIAL  
TROPICAL CYCLONE AT THIS TIME. THERE ARE NO RECENT OBSERVATIONS OF  
THE WINDS NEAR THE CENTER, SO THE INITIAL INTENSITY REMAINS 35 KT  
BASED ON CONTINUITY FROM THE PREVIOUS ADVISORY.  
 
THE INITIAL MOTION IS AN UNCERTAIN 005/6. A DEEP-LAYER TROUGH AND  
DEVELOPING FRONTAL LOW OVER THE NORTHEASTERN UNITED STATES ARE  
EXPECTED TO CAUSE THE DISTURBANCE TO TURN NORTHEASTWARD AND  
ACCELERATE DURING THE NEXT 24 H, WITH A FAST MOTION TOWARD THE  
NORTHEAST CONTINUING UNTIL THE DISTURBANCE IS ABSORBED BY THE  
MID-LATITUDE SYSTEM. THE TRACK GUIDANCE IS GENERALLY IN GOOD  
AGREEMENT WITH THIS SCENARIO, ALTHOUGH THERE REMAINS SOME  
CROSS-TRACK SPREAD DUE MAINLY TO THE UNCERTAIN CENTER POSITION.  
THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK AND IS IN  
BEST AGREEMENT WITH THE HFIP CORRECTED CONSENSUS MODEL.  
 
ENVIRONMENTAL CONDITIONS APPEAR AT LEAST SOMEWHAT FAVORABLE FOR  
INTENSIFICATION DURING THE NEXT 48 H, WITH LIGHT TO MODERATE SHEAR  
AND STRONG UPPER-LEVEL DIVERGENCE OVER THE SYSTEM. AFTER THAT  
TIME, THE SYSTEM IS EXPECTED TO BE ABSORBED INTO THE AFOREMENTIONED  
MID-LATITUDE SYSTEM AND BECOME A TROUGH ROTATING AROUND THE LARGER  
CIRCULATION. THE NEW INTENSITY FORECAST IS NUDGED UPWARD SLIGHTLY  
FROM THE PREVIOUS FORECAST AND NOW SHOWS A PEAK INTENSITY OF 50 KT  
BEFORE ABSORPTION. HOWEVER, THE FORECAST LIES AT THE LOWER EDGE OF  
THE INTENSITY GUIDANCE, AND IF THE SYSTEM CAN DEVELOP A BETTER-  
DEFINED INNER CORE IT COULD STRENGTHEN MORE THAN CURRENTLY FORECAST.  
 
FORECAST POSITIONS AND MAX WINDS  
 
INIT 28/0300Z 18.2N 84.4W 35 KT 40 MPH...POTENTIAL TROP CYCLONE  
12H 28/1200Z 20.1N 83.4W 40 KT 45 MPH  
24H 29/0000Z 22.9N 81.1W 45 KT 50 MPH...INLAND  
36H 29/1200Z 26.2N 77.4W 45 KT 50 MPH...OVER WATER  
48H 30/0000Z 30.8N 73.0W 50 KT 60 MPH  
72H 31/0000Z...ABSORBED BY EXTRATROPICAL LOW  
 

 
FORECASTER BEVEN  
 
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