189  
WTPZ44 KNHC 280853  
TCDEP4  
 
HURRICANE ULIKA DISCUSSION NUMBER 8  
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192016  
200 AM PDT WED SEP 28 2016  
 
ULIKA HAS CONTINUED TO IMPROVE IN ORGANIZATION, AND RECENT MICROWAVE  
DATA HAVE SHOWN THAT THE CYCLONE HAS MAINTAINED A WELL-DEFINED EYE  
IN THE 89-GHZ CHANNEL DURING THE PAST FEW HOURS. HINTS OF AN EYE  
HAVE ALSO BEEN OBSERVED IN SHORTWAVE INFRARED IMAGERY, EMBEDDED  
WITHIN A COMPACT CENTRAL DENSE OVERCAST. SUBJECTIVE SATELLITE  
INTENSITY ESTIMATES HAVE RISEN TO T4.0/65 KT FROM TAFB AND T3.0/55  
KT FROM SAB, AND THE OBJECTIVE ADT FROM UW-CIMSS IS EVEN HIGHER  
AROUND 75 KT. A COUPLE OF CIMSS AMSU INTENSITY ESTIMATES ALSO  
PROVIDED VALUES OF 60-65 KT SEVERAL HOURS AGO. BASED ON THESE  
DATA, ULIKA IS UPGRADED TO A HURRICANE WITH 65-KT WINDS, AND THIS  
COULD BE CONSERVATIVE.  
 
ULIKA HAS RAPIDLY INTENSIFIED DURING THE PAST 24 HOURS, WHICH IN  
HINDSIGHT WAS PROBABLY HELPED BY THE CYCLONE'S SMALL WIND FIELD AND  
RADIUS OF MAXIMUM WINDS. VERTICAL SHEAR IS EXPECTED TO REMAIN LOW  
FOR ANOTHER 12 HOURS OR SO, WHICH COULD ALLOW ULIKA TO INTENSIFY  
SOME MORE IN THE SHORT TERM. BY 24 HOURS, HOWEVER, SOUTHWESTERLY  
TO WESTERLY VERTICAL SHEAR IS FORECAST TO INCREASE MARKEDLY,  
EXCEEDING 30 KT IN A COUPLE OF DAYS. GIVEN ULIKA'S SMALL SIZE, THE  
CYCLONE WILL BE PARTICULARLY SENSITIVE TO THE INCREASE IN SHEAR,  
AND ITS INTENSITY IS LIKELY TO DECREASE QUICKLY. ULIKA IS EXPECTED  
TO BECOME A REMNANT LOW BY DAY 4 AND THEN DISSIPATE SOUTHEAST OF  
THE HAWAIIAN ISLANDS BY DAY 5. THE NHC INTENSITY FORECAST IS VERY  
CLOSE TO THE INTENSITY CONSENSUS FOR THE ENTIRE FORECAST PERIOD, AND  
IS HIGHER THAN THE PREVIOUS FORECAST DURING THE FIRST 36 HOURS TO  
ACCOUNT FOR ULIKA'S RECENT INTENSIFICATION TREND.  
 
A MID- TO UPPER-LEVEL LOW NORTHWEST OF ULIKA IS STEERING THE  
HURRICANE NORTH-NORTHEASTWARD, OR 030/6 KT. ULIKA IS EXPECTED TO  
TURN NORTHWARD AND NORTHWESTWARD AROUND THIS FEATURE DURING THE NEXT  
COUPLE OF DAYS. AFTER IT BECOMES A WEAKER SYSTEM, IT SHOULD THEN  
COME UNDER GREATER INFLUENCE FROM THE LOW-LEVEL TRADES, TURNING  
WEST-NORTHWESTWARD AND WESTWARD ON DAYS 3 AND 4. WITH THE  
EXCEPTION OF THE GFDL, WHICH IS WELL NORTH OF THE REST OF THE  
GUIDANCE SUITE, ALL OF THE TRACK MODELS ARE TIGHTLY CLUSTERED  
DURING THE FORECAST PERIOD. THE NHC TRACK FORECAST IS THEREFORE  
CLOSE TO THE VARIOUS CONSENSUS AIDS AND NOT TOO DIFFERENT FROM  
THE PREVIOUS ADVISORY.  
 
FORECAST POSITIONS AND MAX WINDS  
 
INIT 28/0900Z 13.9N 139.0W 65 KT 75 MPH  
12H 28/1800Z 14.7N 138.9W 70 KT 80 MPH  
24H 29/0600Z 15.6N 139.1W 65 KT 75 MPH  
36H 29/1800Z 16.4N 139.6W 55 KT 65 MPH  
48H 30/0600Z 17.0N 140.6W 45 KT 50 MPH  
72H 01/0600Z 17.7N 143.3W 35 KT 40 MPH  
96H 02/0600Z 17.7N 147.3W 30 KT 35 MPH...POST-TROP/REMNT LOW  
120H 03/0600Z...DISSIPATED  
 

 
FORECASTER BERG  
 
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