VIDEO STORY

• In an interview conducted before 5 p.m. on Sunday, Hawaii County Civil Defense administrator Darryl Oliveira talks about the preliminary preparations underway as Hurricane Guillermo makes ts way towards the Big Island.

Hurricane Guillermo Update – 11 p.m.

• As of 11 p.m. HST Hurricane Guillermo was 680 miles east southeast of Hilo, Hawaii. The storm is moving west northwest at 10 mph.
• Guillermo continues to weaken and is now – just barely – a Category 1 hurricane, with maximum sustained winds of 75 mph. Guillermo is expected to become a tropical storm on Monday.
• There are no coastal watches or warnings in effect, but a watch may be issued for portions of the state as early as Monday morning.
• A High Surf Advisory is now in effect for east facing shores of all islands. The National Weather Service says surf will build to 8 to 12 feet tonight… and 10 to 14 feet Monday through Tuesday.
• Guillermo is expected to move steadily west northwest as it passes across the island chain, reports the National Weather Service, which says “abundant moisture drawn into the circulation will bring the potential for very heavy rainfall and flash flooding on Wednesday and Thursday.”

National Weather Service – 11 p.m.

LATEST SATELLITE IMAGERY CONTINUES TO SHOW DEEP CONVECTION STRUGGLING TO MAINTAIN ITSELF OVER THE LOW LEVEL CIRCULATION CENTER GUILLERMO DUE TO THE INCREASING WESTERLY WIND SHEAR THE SYSTEM IS ENCOUNTERING. THE U.S. 53RD WEATHER RECONNAISSANCE AIRCRAFT CONFIRMED THAT THE SYSTEM IS WEAKENING WHILE SAMPLING THE INNER CORE OF GUILLERMO THIS EVENING…WITH NO FLIGHT LEVEL OR SURFACE WINDS OF 64 KNOTS OR GREATER FOUND. THE CENTRAL PRESSURE OF THE SYSTEM HAD RISEN TO AROUND 990 MB AS WELL. ADDITIONALLY…DVORAK CLASSIFICATIONS WERE 4.5/77KT FROM PHFO AND JTWC AND 4.0/65 KT FROM SAB…WHILE FINAL T NUMBERS WERE LOWER AT 3.5 TO 4.0. FOR THE INITIAL 0600Z INTENSITY WE USED 70 KNOTS WHICH FOLLOWED CLOSELY THE DVORAK NUMBERS…BUT AS A RESULT OF THE AIRCRAFT SAMPLING OF GUILLERMO THE 0900Z INITIAL INTENSITY WILL BE ADJUSTED DOWNWARD TO 65 KNOTS.

THE INITIAL MOTION IS TOWARD THE WEST-NORTHWEST…OR 300 DEGREES… AT 9 KT. A LOW LEVEL RIDGE SITS ABOUT 1500 NM TO THE NORTHWEST OF GUILLERMO…WHILE A NORTH PACIFIC UPPER LEVEL TROUGH HAS CARVED OUT A WEAKNESS IN THE MID TO UPPER LEVEL RIDGE JUST NORTH OF THE HURRICANE. GUILLERMO WILL CONTINUE TO MOVE ON A SIMILAR BEARING FOR THE NEXT FEW DAYS INTO THE WEAKNESS ALOFT…TAKING THE SYSTEM NEAR OR POSSIBLY OVER THE HAWAIIAN ISLANDS ON WEDNESDAY AND THURSDAY. THE TRACK FORECAST HAS BEEN CHANGED LITTLE FROM THE LAST ADVISORY AND REMAINS NEAR A RATHER TIGHT CLUSTER OF GFS…ECMWF…AND THE CONSENSUS MODELS. THE TIGHT CLUSTERING OF THE MODELS THEN SHOWS INCREASING SPREAD BETWEEN 48 HOURS AND 120 HOURS…LIKELY DUE TO THE DIFFERING INTENSITY FORECASTS BY THE VARIOUS MODELS WITH RESPECT TO THE SYSTEM.

THE LATEST UW-CIMSS VERTICAL WIND SHEAR ANALYSIS SHOWED 8 KNOTS FROM 290 DEGREES…WHILE THE LATEST SHIPS ANALYSIS SHOWED 16 KNOTS FROM 285 DEGREES. THIS IS LIKELY RESPONSIBLE FOR THE POOR SATELLITE PRESENTATION AND THE WEAKENING OF THE SYSTEM SINCE THE PREVIOUS ADVISORY. WEAKENING IS EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. AS GUILLERMO CONTINUES TO MOVE INTO THE BREAK IN THE MID TO UPPER LEVEL RIDGE…OUTFLOW WITHIN THE NORTHWEST QUADRANT WILL BECOME FURTHER DISRUPTED AND VERTICAL WIND SHEAR WILL CONTINUE TO SLOWLY INCREASE. THE INTENSITY FORECAST CLOSELY FOLLOWS THE ICON…WITH SHIPS PREDICTING MORE RAPID WEAKENING BEYOND 48 HOURS. THE FORECAST AND INITIAL WIND RADII WERE ADJUSTED BASED ON THE AIRCRAFT DATA AS WELL.

AS GUILLERMO MOVES CLOSER TO HAWAII…WATCHES MAY BE ISSUED MONDAY OR MONDAY NIGHT FOR PORTIONS OF THE STATE. HOWEVER…IT IS STILL TOO SOON TO DETERMINE WITH CERTAINTY WHICH ISLANDS ARE MOST LIKELY TO EXPERIENCE THE GREATEST IMPACTS FROM GUILLERMO. IT IS ALSO IMPORTANT TO NOTE THAT SIGNIFICANT IMPACTS CAN EXTEND WELL AWAY FROM THE CENTER.

ANOTHER RECONNAISSANCE AIRCRAFT MISSION INTO GUILLERMO IS SCHEDULED FOR MONDAY MORNING. THE VALUABLE DATA TRANSMITTED IN REAL-TIME FROM THESE MISSIONS WILL HELP US TO BETTER DETERMINE THE LOCATION…INTENSITY AND SIZE OF THE HURRICANE. IN ADDITION…THE NOAA G-IV JET IS SCHEDULED TO CONDUCT ANOTHER SYNOPTIC SAMPLING MISSION AROUND GUILLERMO MONDAY AFTERNOON. THIS SAMPLING SHOULD HELP IMPROVE THE MODEL INITIALIZATION OF GUILLERMO.