Ignacio Still Cat 4

Ignacio is still a very strong hurricane with winds over 140mph and heading this way. It is expected to weaken to a cat 1 or 2 as it approaches; still extremely dangerous. Surf as high as 20′ can be expected on our Island. Civil Defense is taking no chances and are opening shelters later today as effects should be felt this evening and early Monday. Stay prepared and informed.

THE SATELLITE PRESENTATION OF IGNACIO HAS DEFINITELY DEGRADED SINCE 
THE LAST ADVISORY...WITH A RAGGED 20 NM WIDE EYE BECOMING 
INTERMITTENTLY CLOUD-FILLED AND THE DEEP CONVECTIVE CANOPY BECOMING 
NOTICEABLY SLIMMER ESPECIALLY ACROSS THE WEST AND SOUTHWEST 
QUADRANTS. HOWEVER...SYSTEM SYMMETRY APPEARS TO HAVE RECOVERED A BIT 
SINCE 1200 UTC. ALL THREE SATELLITE CENTERS DERIVED SUBJECTIVE 
DVORAK SATELLITE INTENSITY ESTIMATES OF 6.0...115 KT...LIKE LAST 
TIME. THE DIFFERENCE IS THAT ALL THESE ESTIMATES HAVE LOWER FINAL T 
NUMBERS...DENOTING A WEAKENING TREND. UW-CIMSS ADT WAS 5.8 AT 1200 
UTC...110 KT. IGNACIO INTENSITY LIKELY PEAKED 6 TO 10 HOURS AGO AND 
EVERYTHING SHOWS A WEAKENING SYSTEM NOW. HOWEVER...SINCE WEATHER 
RECONNAISSANCE AIRCRAFT SFMR SHOWED INTENSITY OF ABOUT 125 KT LAST 
EVENING...WE WILL ASSIGN AN INITIAL INTENSITY OF 120 KT FOR THIS 
ADVISORY...LOWER THAN LAST TIME BUT CONTINUED HIGHER THAN SATELLITE 
ESTIMATES ALONE. WEATHER RECONNAISSANCE AIRCRAFT WILL FLY ONCE AGAIN 
IN TIME FOR THE 1800 UTC ANALYSIS CYCLE. 

THE SUSPECTED MORE NORTHERLY SHORT-TERM MOTION NOTED LAST TIME HAS 
PERSISTED LONG ENOUGH TO BECOME OFFICIAL 12 HOUR MOTION...WHICH IS 
NOW 330 DEGREES AT 8 KT. THE STEERING MECHANISM IS THE SAME...WITH A 
WEAKNESS IN THE MID-LEVEL RIDGE EAST OF HAWAII ALLOWING IGNACIO TO 
SLIDE NORTH NORTHWESTWARD. TRACK GUIDANCE CONTINUES TO BE TIGHTLY 
PACKED DEPICTING LITTLE CHANGE FROM LAST TIME. HOWEVER...THE 
GUIDANCE ENVELOPE WIDENED SLIGHTLY AS HWRF SHIFTED RIGHT WHILE GFDL 
SHIFTED LEFT. THE FORECAST TRACK WAS SHIFTED TO THE RIGHT THROUGH 48 
HOURS TO ACCOUNT FOR THE RECENT SWING TO NORTH NORTHWEST MOTION. THE 
REMAINING FORECAST TRACK CLOSELY FITS THE LAST ONE...REMAINING NEAR 
THE LEFT EDGE OF THE GUIDANCE ENVELOPE AND CLOSELY FOLLOWING GFS. 
THIS FORECAST TRACK CHANGE DECREASES 34 KT WIND ONSET PROBABILITIES 
FOR LOCATIONS WITHIN TROPICAL STORM WATCHES...BUT ENOUGH FORECAST 
UNCERTAINTY PERSISTS TO KEEP THESE WATCHES UP FOR NOW. A SMALL 
SYSTEM MOTION CHANGE BACK TO THE NORTHWEST OR WEST NORTHWEST COULD 
GREATLY INCREASE THESE PROBABILITIES. 

SATELLITE LOOP SHOWS IGNACIO IS UNDERGOING INCREASING STRESS DUE TO 
VERTICAL SHEAR. OUTFLOW REMAINS HINDERED TO THE NORTHWEST AND THE 
DEEP CONVECTIVE CANOPY EROSION NOTED SINCE LAST EVENING IS 
CONSISTENT WITH WEST TO WEST SOUTHWEST SHEAR. SHIPS INTENSITY 
GUIDANCE SHOWS 10 TO 15 KT OF SHEAR NOW...WITH SHEAR IN EXCESS OF 20 
KT FORECAST FROM 24 HOURS ONWARD. THIS LIKELY EXPLAINS SHIPS 
DIMINISHING IGNACIO TO TROPICAL STORM STATUS BY 48 HOURS. IN 
CONTRAST...GLOBAL MODELS AND GFDL KEEP THIS SYSTEM QUITE STRONG 
THROUGH THE NEXT FIVE DAYS...WITH LITTLE WEAKENING. HWRF WEAKENS 
IGNACIO...BUT NOT AS FAST AS SHIPS. OUR FORECAST CALLS FOR GRADUAL 
WEAKENING...MAKING IGNACIO A TROPICAL STORM ON DAY FIVE...AS A BLEND 
WITH SHIPS AND HWRF. 

THE NEED FOR TROPICAL STORM WATCHES FOR THE BIG ISLAND AND THE 
ISLANDS OF MAUI COUNTY WILL BE RE-EXAMINED ONCE AIRCRAFT DATA 
BECOMES AVAILABLE LATER THIS MORNING. 

FORECAST POSITIONS AND MAX WINDS
 
INIT  30/1500Z 18.3N 148.4W  120 KT 140 MPH
 12H  31/0000Z 19.1N 149.1W  110 KT 125 MPH
 24H  31/1200Z 20.3N 150.5W  100 KT 115 MPH
 36H  01/0000Z 21.4N 152.0W   90 KT 105 MPH
 48H  01/1200Z 22.4N 153.6W   80 KT  90 MPH
 72H  02/1200Z 24.3N 156.6W   70 KT  80 MPH
 96H  03/1200Z 26.5N 159.9W   65 KT  75 MPH
120H  04/1200Z 28.7N 163.0W   60 KT  70 MPH