HURRICANE FELICIA ADVISORY NUMBER 23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP082009
1100 PM HST SAT AUG 08 2009

A TROPICAL STORM WATCH REMAINS IN EFFECT FOR THE BIG ISLAND OF HAWAII…AND FOR ALL OF MAUI COUNTY…WHICH INCLUDES THE ISLANDS OF MAUI…KAHOOLAWE…LANAI…AND MOLOKAI. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA…GENERALLY WITHIN THE NEXT 48 HOURS.

INTERESTS IN THE REMAINDER OF THE STATE OF HAWAII…INCLUDING THE ISLANDS OF OAHU…KAUAI…AND NIIHAU…SHOULD CLOSELY MONITOR THE PROGRESS OF FELICIA. A TROPICAL STORM WATCH COULD BE REQUIRED FOR THESE AREAS ON SUNDAY MORNING.

AT 1100 PM HST…0900 UTC…THE CENTER OF HURRICANE FELICIA WAS LOCATED NEAR LATITUDE 20.3 NORTH…LONGITUDE 144.7 WEST OR ABOUT 675 MILES EAST OF HILO…HAWAII AND ABOUT 855 MILES EAST OF HONOLULU…HAWAII.

FELICIA IS MOVING TOWARD THE WEST NEAR 15 MPH AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE THROUGH MONDAY. ON THIS TRACK… FELICIA IS EXPECTED TO BE NEAR OR OVER THE HAWAIIAN ISLANDS BY MONDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH WITH HIGHER GUSTS. FELICIA IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON SCALE. ADDITIONAL ADDITIONAL SLOW WEAKENING IS FORECAST DURING THE NEXT COUPLE OF DAYS. FELICIA IS EXPECTED TO WEAKEN TO A TROPICAL STORM SUNDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 35 MILES FROM THE CENTER…AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115 MILES.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB…29.23 INCHES.

…SUMMARY OF 1100 PM HST INFORMATION…
LOCATION…20.3N 144.7W
MAXIMUM SUSTAINED WINDS…80 MPH
PRESENT MOVEMENT…WEST OR 280 DEGREES AT 15 MPH
MINIMUM CENTRAL PRESSURE…990 MB

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE CENTRAL PACIFIC HURRICANE CENTER AT 200 AM HST FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 500 AM HST.

HURRICANE FELICIA DISCUSSION NUMBER 23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP082009
1100 PM HST SAT AUG 08 2009

HURRICANE FELICIA APPEARS TO BE WEAKENING BASED ON THE LATEST SATELLITE IMAGERY…MICROWAVE DATA AND HURRICANE RECONNAISSANCE AIRCRAFT DATA. THE LATEST AIRCRAFT FIX AT 0729 UTC INDICATED THE CENTRAL PRESSURE HAD FILLED TO 990 MB. THE HIGHEST FLIGHT-LEVEL WINDS WERE 80 KT IN THE NORTHEAST QUADRANT AT 700 MB AROUND 0600 UTC. THERE WERE ALSO SFMR WINDS FOR THE SURFACE OF UP TO 69 KT AROUND THE SAME TIME. A DROPSONDE IN THE NORTHEAST EYEWALL ALSO INDICATED THE AVERAGE LOW-LEVEL WINDS ADJUSTED TO THE SURFACE ARE NEAR 63-68 KT. THESE AIRCRAFT DATA…ALONG WITH DVORAK CI NUMBERS OF 4.0…INDICATE THAT FELICIA HAS WEAKENED TO 70 KT FOR THIS ADVISORY. CONSIDERABLE WARMING OF THE CLOUD TOPS HAS OCCURRED IN THE PAST FEW HOURS ACCORDING TO THE INFRARED SATELLITE IMAGERY. DATA FROM SEVERAL SATELLITES WITH MICROWAVE DATA FROM AROUND 0300 UTC INDICATED THE DEEPEST CONVECTION WAS STARTING TO BE DISPLACED TO THE NORTHEAST OF THE APPARENT CENTER…WHICH MAY SUGGEST INCREASING VERTICAL WIND SHEAR IS STARTING TO AFFECT THE HURRICANE.

THE CURRENT MOTION OF FELICIA IS 280/13…WHICH IS CLOSE TO THE PREVIOUS 12 HOUR MOTION. SOME OF THE MODELS FORECAST FELICIA TO GAIN A LITTLE MORE LATITUDE BEFORE TURNING DUE WEST…WHILE MOST OF THE OTHERS CALL FOR THE HURRICANE TO MOVE AT 270 DEGREES WITHIN 12 TO 24. BEYOND 24 HOURS OR SO…ALL OF THE MODEL GUIDANCE AGREES ON A DUE WESTWARD HEADING ALONG THE SOUTHERN PERIPHERY OF A LOW- TO MID-LEVEL RIDGE…WITH TRACKS CROSSING THE MAIN HAWAII ISLANDS AT VARYING LATITUDES. THE LATEST OFFICIAL TRACK FORECAST CONTINUES DOWN THE CENTER OF THE GUIDANCE ENVELOPE. THERE WAS A SLIGHT NORTHWARD ADJUSTMENT THROUGH THE FIRST 36 HOURS FROM THE PREVIOUS ADVISORY. THE FORWARD MOTION OF THE SYSTEM WAS ALSO SLOWED SLIGHTLY BEYOND 36 HOURS…SINCE THE GUIDANCE WAS QUITE A BIT SLOWER AT THAT TIME. NOTE THAT THERE ARE A NUMBER OF VERY RELIABLE MODELS ON EITHER SIDE OF THE OFFICIAL FORECAST. THEREFORE…THE CENTER OF FELICIA COULD PASS OVER ANY PORTION OF THE MAIN HAWAIIAN ISLANDS DURING THE NEXT 2-3 DAYS.

FELICIA APPEARS TO HAVE BEGUN THE EXPECTED WEAKENING TREND. THE UNDERLYING SEA-SURFACE TEMPERATURES REMAIN NEAR ABOUT 25 CELSIUS…BUT THESE VALUES WILL GRADUALLY WARM ALONG THE FORECAST TRACK THROUGHOUT THE FIVE-DAY FORECAST PERIOD. HOWEVER…WESTERLY VERTICAL WIND SHEAR HAS INCREASED TO NEAR 10 KT…AND IS FORECAST TO INCREASE TO GREATER THAN 20 KT WITHIN 12 TO 24 HOURS. THIS IS ABOUT THE TIME FELICIA IS ON THE DOORSTEP OF THE HAWAIIAN ISLANDS. THE INTENSITY GUIDANCE MODELS RESPOND TO THESE FACTORS BY FORECASTING GRADUAL WEAKENING…BUT ALL OF THEM HOLD ON TO A TROPICAL STORM THROUGH 36 HOURS…AND SOME EVEN TO 72 HOURS. THE NEW OFFICIAL FORECAST INTENSITY IS ADJUSTED SLIGHTLY DOWN FROM THE PREVIOUS ONE TO BE CONSISTENT WITH THE INTENSITY CONSENSUS…ICON.

GIVEN THE UNCERTAINTIES WITH INTENSITY FORECASTING…IT IS IMPORTANT TO POINT OUT THE INTENSITY PROBABILITIES ACCOMPANYING THIS ADVISORY PACKAGE. THAT PRODUCT INDICATES THAT THERE IS ABOUT A 20 PERCENT CHANCE OF FELICIA BEING A TROPICAL STORM IN 48 HOURS WHEN IT IS VERY NEAR THE HAWAIIAN ISLANDS AND ABOUT A 45 PERCENT CHANCE OF IT BEING A TROPICAL DEPRESSION.

THERE IS A CHANCE THAT A TROPICAL STORM WARNING MAY BE NEEDED FOR PARTS OF THE WATCH AREA SUNDAY MORNING…SINCE THE LEAD TIME FOR WARNINGS IN THE CENTRAL PACIFIC BASIN IS 36 HOURS.

The Saffir-Simpson Hurricane Wind Scale
Hurricane Categories Explained: www.nhc.noaa.gov/aboutsshs.shtml

Weather forecasts of all the islands: www.prh.noaa.gov/pr/hnl

Satellite image taken at Aug 9 at 0900 UTC. Images courtesy of NOAA-NASA GOES Project Click on image above for full earth image.

ACTIONS TO TAKE WHEN A HURRICANE NEARS HAWAII
All of Hawaii’s citizens should know what to do during hurricane and tropical storm watches and warnings. Watches and warnings are prepared for the Hawaiian Islands by the National Weather Service Central Pacific Hurricane Center in Honolulu. When watches and warnings are issued, people should closely monitor radio, TV, or NOAA Weather Radio for official bulletins of the storm’s progress and instructions from civil defense authorities. Jim Weyman, director of the Central Pacific Hurricane Center, said, “Although you and your family may have never experienced a hurricane, don’t be complacent! It’s not a matter of if a hurricane will occur, but when one will occur. All of the Hawaiian Islands are at risk for a hurricane and we should all know what actions to take.”

For the Central Pacific Ocean starting with the 2009 hurricane season, a Hurricane/Tropical Storm Watch means hurricane/tropical storm conditions are possible in the specificed area of the Watch, usually within 48 hours.

When a Hurricane or Tropical Storm Watch is issued:

Hurricane preparedness supplies at Home Depot in Hilo. Photography by Baron Sekiya/Hawaii247.com

• Fuel and service family vehicles.
• Prepare to cover all windows and door openings with boards, shutters or other shielding materials.
• Check food and water supplies. Have clean, air-tight containers on hand to store at least two weeks of drinking water (14 gallons per person), and stock up on canned provisions. Keep a small cooler with frozen gel packs handy for packing refrigerated items.
• Check prescription medicines – obtain at least 10 days to 2 weeks supply.
• Stock up on extra batteries for radios, flashlights, and lanterns.
• Store and secure outdoor lawn furniture and other loose, lightweight objects, such as garbage cans and garden tools.
• Check and replenish first-aid supplies.
• Have on hand an extra supply of cash.

For the Central Pacific Ocean starting with the 2009 hurricane season, a Hurricane/Tropical Storm Warning means hurricane/tropical storm conditions are expected in the specified area of the Warning, usually within 36 hours.

When a Hurricane or Tropical Storm Warning is issued:

• Follow instructions issued by civil defense. Leave immediately if ordered to do so.
• Complete preparation activities, such as boarding up windows and storing loose objects.
• Evacuate areas that might be affected by storm surge flooding. If evacuating, leave early.
• Notify neighbors and a family member outside of the warned area of your evacuation plans.

Hawaii County Civil Defense Huricane Preparedness Guide: co.hawaii.hi.us/cd/hpg/main.html

The Hawaii Chapter of the American Red Cross has Hurricane Preparedness Guide