Tropical Storm FLOSSIE (CPAC): Discussions, Analysis and Ima

[Derek Ortt]

Hurricane Watch/TS Warning for the Big Island; however, I believe a Hurricane Warning should have been issued

[Dick Pache]

http://www.prh.noaa.gov/data/HFO/HLSHFO.0708131953

HURRICANE FLOSSIE LOCAL STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
955 AM HST MON AUG 13 2007

...DANGEROUS HURRICANE FLOSSIE APPROACHING THE BIG ISLAND OF
HAWAII...

...NEW INFORMATION...
THE MAYOR OF THE COUNTY OF HAWAII HAS DECLARED A STATE OF EMERGENCY
AND URGES BIG ISLAND RESIDENTS TO STAY TUNED TO LOCAL RADIO
STATIONS FOR INFORMATION ON EVACUATIONS...SCHOOL CLOSURES AND
OTHER PREPAREDNESS ACTIONS.

...AREAS AFFECTED...
THIS STATEMENT RECOMMENDS SPECIFIC ACTIONS TO BE TAKEN BY PERSONS
ON THE BIG ISLAND OF HAWAII.

...WATCHES/WARNINGS...
A HURRICANE WATCH IS IN EFFECT FOR THE BIG ISLAND OF HAWAII. A
HURRICANE WATCH MEANS HURRICANE CONDITIONS ARE POSSIBLE WITHIN 36
HOURS.

A FLASH FLOOD WATCH IS IN EFFECT FOR THE BIG ISLAND OF HAWAII
THROUGH WEDNESDAY.

...STORM INFORMATION...
AT 900 AM HST...THE CENTER OF HURRICANE FLOSSIE WAS LOCATED NEAR
LATITUDE 15.2 NORTH...LONGITUDE 150.4 WEST...OR ABOUT 440 MILES
SOUTHEAST OF HILO...HAWAII. FLOSSIE IS MOVING TOWARD THE WEST
NORTHWEST AT 15 MPH AND THIS MOTION IS EXPECTED TO CONTINUE
THROUGH TONIGHT. MAXIMUM SUSTAINED WINDS ARE NEAR 140 MPH WITH
HIGHER GUSTS. SOME SLIGHT WEAKENING IS FORECAST DURING THE NEXT 24
HOURS.

...PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE ON THE BIG ISLAND...PREPARE FOR THE APPROACHING
HURRICANE. TUNE IN TO YOUR LOCAL RADIO STATION FOR INFORMATION ON
EVACUATIONS...SCHOOL CLOSURES AND OTHER PREPAREDNESS ACTIONS. PREPARE
FOR STRONG GUSTY WINDS AND HEAVY RAINFALL BY SECURING LOOSE
OBJECTS OR BRING THEM INDOORS NOW.

...STORM SURGE FLOOD AND STORM TIDE IMPACTS...
THE FORECAST TRACK OF HURRICANE FLOSSIE WILL BRING 6 TO 10 FT SURF
TO SOUTH FACING SHORES OF THE BIG ISLAND TODAY INCREASING TO 10 TO 15
FT ON TUESDAY. SURF ALONG EAST FACING SHORES OF THE BIG ISLAND WILL
BE
5 TO 8 FT TODAY RISING TO 8 TO 12 FT TUESDAY.

...WIND IMPACTS...
THE STRENGTH OF THE THE WINDS AND DAMAGE DUE TO FLOSSIE ARE
DEPENDANT UPON THE EXACT PATH AND INTENSITY OF THE STORM
SYSTEM...WHICH IS STILL UNCERTAIN AT THIS TIME. THE CURRENT
FORECAST BRINGS EAST TO SOUTHEAST WINDS OF 40 TO 50 MPH WITH
HIGHER GUSTS TO PORTIONS OF THE SOUTHERN BIG ISLAND LATE TUESDAY.
IF THE TRACK OF FLOSSIE SHIFTS NORTHWARD...HURRICANE FORCE WINDS
OF 74 MPH OR GREATER COULD AFFECT SOME AREAS OF THE SOUTHERN BIG
ISLAND LATE TUESDAY.

...FLOODING IMPACTS...
RAINFALL AND FLOODING POTENTIAL VARY GREATLY DEPENDING UPON THE
ACTUAL TRACK OF FLOSSIE. SCATTERED SHOWERS AND THUNDERSTORMS IN
OUTER RAIN BANDS WILL BEGIN TO PASS OVER THE BIG ISLAND BY TUESDAY
AFTERNOON. RAINFALL TOTALS OF WITH 10 INCHES OR GREATER IN THE
KAU DISTRICT...AND 5 TO 10 INCHES MAY BE EXPECTED ON SOUTH AND
EAST FACING SLOPES ELSEWHERE ON THE BIG ISLAND...TUESDAY AND
TUESDAY NIGHT. THESE RAINS HEAVY RAINS MAY PRODUCE FLASH
FLOODING...ESPECIALLY IN THE KAU DISTRICT.

...NEXT UPDATE...
THE NEXT LOCAL STATEMENT WILL BE ISSUED AT 1130 HST OR SOONER IF
NECESSARY.

$$

KODAMA

[clfenwi]

HURRICANE FLOSSIE ADVISORY NUMBER 21
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007
1100 AM HST MON AUG 13 2007

...A TROPICAL STORM WARNING IS IN EFFECT FOR THE BIG ISLAND OF
HAWAII...

...A HURRICANE WATCH REMAINS IN EFFECT FOR THE BIG ISLAND OF
HAWAII...

AT 1100 AM HST...2100Z...THE CENTER OF HURRICANE FLOSSIE WAS
LOCATED NEAR LATITUDE 15.3 NORTH...LONGITUDE 150.6 WEST OR ABOUT
425 MILES SOUTHEAST OF HILO...HAWAII AND ABOUT 635 MILES SOUTHEAST
OF HONOLULU...OAHU.

FLOSSIE IS MOVING TOWARD THE WEST-NORTHWEST NEAR 15 MPH AND THIS
MOTION IS EXPECTED TO CONTINUE THROUGH TODAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 125 MPH WITH HIGHER GUSTS. FLOSSIE
IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON SCALE. LITTLE
CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES FROM THE
CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140
MILES.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 956 MB...28.23 INCHES.

THE MAIN EFFECTS FROM HURRICANE FLOSSIE ARE EXPECTED ON THE BIG
ISLAND TUESDAY AND TUESDAY NIGHT. A TROPICAL STORM WARNING IS NOW
IN EFFECT FOR THE BIG ISLAND. EVERYONE IN HAWAII IS URGED TO
CLOSELY MONITOR FUTURE BULLETINS AS THIS DANGEROUS HURRICANE MOVES
TOWARD THE HAWAIIAN ISLANDS.

REPEATING THE 1100 AM HST POSITION...15.3 N...150.6 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 15 MPH. MAXIMUM SUSTAINED WINDS...
125 MPH. MINIMUM CENTRAL PRESSURE...956 MB.

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

$$

FORECASTER POWELL

[clfenwi]

HURRICANE FLOSSIE DISCUSSION NUMBER 21
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007
1100 AM HST MON AUG 13 2007

HURRICANE FLOSSIE REMAINS A DANGEROUS HURRICANE WITH A CLEAR
WELL-DEFINED EYE AND GOOD OUTFLOW...ESPECIALLY TO THE NORTH.
HOWEVER...CLOUD TOPS HAVE WARMED SLIGHTLY OVER THE PAST SIX HOURS
AND AIRCRAFT RECON EXTRAPOLATED A SURFACE WIND SPEED OF 103 KT AT
1830Z. THIS CONTRASTS WITH A CI OF 6.0 OR 115 KT FROM JTWC AND SAB
AT 1733Z AND 1800Z...RESPECTIVELY. TO SPLIT THE DIFFERENCE...WE WILL
INITIALIZE FLOSSIE AT 110 KT FOR THIS RUN...MAKING FLOSSIE A
CATEGORY 3 HURRICANE ON THE SAFFIR SIMPSON SCALE. THIS DROP IN
INTENSITY MAY BE BRIEF SINCE SATELLITE LOOPS HINT AT A CYCLE OF
EYEWALL CONVECTIVE INTENSITY.

CONSENSUS TRACK GUIDANCE REMAINS TIGHTLY PACKED AND VERY CLOSE TO
GUIDANCE OFFERED SIX HOURS AGO...BUT GFDL HAS SHIFTED TO THE RIGHT.
BAMD AND NOGAPS ARE THE RIGHT AND LEFT OUTLIERS...RESPECTIVELY. OUR
FORECAST TRACK REMAINS ON THE RIGHT SIDE OF THE ENVELOPE DESCRIBED
BY CONSENSUS GUIDANCE...WITH A SLIGHT SPEED UP OF A KNOT OR TWO
THROUGH 96 HOURS. AN INITIAL MOTION OF 295 DEGREES MEANS FLOSSIE
WILL TAKE A PATH VERY SLIGHTLY TO THE RIGHT OF THE PREVIOUS PATH
THROUGH 24 HOURS...WITH THE PATHS MATCHING UP AFTERWARDS. INTENSITY
WILL REMAIN AT 110 KT THROUGH 24 HOURS BASED MAINLY ON
PERSISTENCE...WITH A GRADUAL DECREASE EXPECTED AFTERWARDS AS SHEAR
AND COOLER WATER FINALLY TAKE THEIR TOLL. IT MUST BE NOTED THAT
FLOSSIE HAS BEEN SURPRISINGLY RESILIENT TO COOLER OCEAN TEMPERATURES
SO FAR. AT ANY RATE...WE FORECAST FLOSSIE TO REMAIN AT HURRICANE
STRENGTH THROUGH THE ENTIRE 120 HOUR FORECAST PERIOD.

WE HAVE INCREASED THE 34 KT WIND RADIUS TO 120 NAUTICAL MILES
THROUGH THE NORTHWEST AND NORTHEAST QUADRANTS THROUGH 24
HOURS...BASED ON SCATTEROMETER AND AIRCRAFT DATA. THIS WILL PLACE
THE BIG ISLAND OF HAWAII WITHIN THE RADIUS OF TROPICAL STORM FORCE
WINDS BEGINNING AROUND MIDDAY TUESDAY. A TROPICAL STORM WARNING IS
THEREFORE IN EFFECT FOR THE BIG ISLAND OF HAWAII. A HURRICANE WATCH
REMAINS IN EFFECT. WITH THE CURRENT FORECAST TRACK...THE ISLANDS
FROM MAUI COUNTY TO KAUAI COUNTY ARE NOT EXPECTED TO REQUIRE ANY
TYPES OF WATCHES. HOWEVER...ANY SIGNIFICANT DEVIATION OF THE TRACK
TOWARD THE NORTH MIGHT RESULT IN WATCHES OR WARNINGS FOR ADDITIONAL
AREAS IN THE HAWAIIAN ISLANDS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 13/2100Z 15.3N 150.6W 110 KT
12HR VT 14/0600Z 16.1N 152.4W 110 KT
24HR VT 14/1800Z 17.0N 154.7W 110 KT
36HR VT 15/0600Z 17.9N 156.8W 105 KT
48HR VT 15/1800Z 18.6N 158.9W 100 KT
72HR VT 16/1800Z 20.1N 163.0W 90 KT
96HR VT 17/1800Z 21.3N 167.0W 70 KT
120HR VT 18/1800Z 22.4N 171.3W 65 KT

$$
FORECASTER POWELL

[btangy]

Hurricane Watch/TS Warning for the Big Island; however, I believe a Hurricane Warning should have been issued

I believe a TS warning is appropriate currently given that the only model showing direct landfall is the HWRF which has had a northward bias in almost all of its model runs. Also, since Flossie has a very compact core, the radius of hurricane and TS winds probably doesn't extend very far out from the center.

[btangy]

THIS DROP IN INTENSITY MAY BE BRIEF SINCE SATELLITE LOOPS HINT AT A CYCLE OF
EYEWALL CONVECTIVE INTENSITY.

Hard to tell but the convective pattern is starting to show the typical downshear configuration. Perhaps the start of a larger weakening trend and not just a temporary blip.

[CrazyC83]

Hurricane Watch/TS Warning for the Big Island; however, I believe a Hurricane Warning should have been issued

I believe a TS warning is appropriate currently given that the only model showing direct landfall is the HWRF which has had a northward bias in almost all of its model runs. Also, since Flossie has a very compact core, the radius of hurricane and TS winds probably doesn't extend very far out from the center.

I'm in between. I'd go with the following:

Hurricane Warning - southern Big Island, from Honaunau to Puu Kapukapu

Tropical Storm Warning/Hurricane Watch - remainder of the Big Island

Tropical Storm Watch - Maui, Kahoolawe, Molokai and Lanai

[cyclonic chronic]

based on sat loops, it looks as if flossie is headed for a landfall in Hi. there should've been a watch issued, but to their credit most major counties have issued disaster declarations.

[Sanibel]

Flossie has developed a flat edge to its SE quadrant. This kind of thing sometimes precedes unexpected turns. I don't think that will happen, but it has developed a flat edge.

[DESTRUCTION5]

Why is it so hard to find a loop of her?>

[cyclonic chronic]

Why is it so hard to find a loop of her?>

http://www.ssd.noaa.gov/goes/flt/t6/loop-avn.html

[simplykristi]

HI is unfortunately due to be hit by a hurricane. The last hurricane to hit HI was Iniki in 1992.

Kristi

[cyclonic chronic]

even wgn news here in chicago is "advertising" Flossie for its 9 pm news/weather. they'll be gettin their surf on tonite in Hi. thats for sure

[cyclonic chronic]

wow the hight temp for the Big Island in Hi. is only 73 with a low of 66. idk if this will have any inpact on the storm, just though it curious

[CrazyC83]

My estimate on the intensity: 105 kt/958mb.

I think it might be a landfaller...

[Chacor]

Flossie has developed a flat edge to its SE quadrant. This kind of thing sometimes precedes unexpected turns. I don't think that will happen, but it has developed a flat edge.

Good spot. VDM from 0140Z 14 August had OPEN SE.

[MGC]

Shear is starting to erode the south side of the hurricane. It should start to weaken at a more rapid rate. Still looks to be passing south of the big island.....MGC

[simplykristi]

Glad to hear that the hurricane will weaken... Hopefully, it will pass well south of the big island.

Kristi

[Chacor]

WTPA42 PHFO 140250
TCDCP2

HURRICANE FLOSSIE DISCUSSION NUMBER 22
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007
500 PM HST MON AUG 13 2007

IT APPEARS THAT HURRICANE FLOSSIE IS BEGINNING TO FEEL THE EFFECTS
OF SLIGHTLY COOLER OCEAN TEMPERATURES AND INCREASING SOUTHERLY
SHEAR. WHILE OUTFLOW REMAINS GOOD TO THE NORTH...OUTFLOW APPEARS TO
BE HAMPERED TO THE SOUTH AND WE ARE BEGINNING TO SEE WEAKENING ALONG
THE SOUTHERN FLANK OF THE EYEWALL. CONVECTIVE CLOUD TOPS HAVE WARMED
OVER THE PAST SIX HOURS AND AIRCRAFT OBSERVATIONS SHOWED AN
EXTRAPOLATED SURFACE WIND OF 106 KT AT 0115Z AS WELL AS AN OPEN
EYEWALL ALONG THE SOUTHEAST FLANK. THIS IS IN LINE WITH CI VALUES OF
5.5...102 KT...FROM CPHC...JTWC AND SAB BETWEEN 2330Z AND 0000Z. WE
WILL INITIALIZE FLOSSIE AT 105 KT FOR THIS RUN...KEEPING THIS SYSTEM
AS A SAFFIR-SIMPSON CATEGORY 3 HURRICANE.

CONSENSUS TRACK GUIDANCE REMAINS PACKED THROUGH 24 HOURS...BUT
BEGINS TO DIVERGE SHARPLY AFTERWARDS...WITH CONB SIGNIFICANTLY RIGHT
OF THE OLD TRACK BEYOND 48 HOURS. BAMD REMAINS THE RIGHT OUTLIER.
THE NEW FORECAST TRACK...SITUATED ALONG THE NORTHERN EDGE OF THE
CONSENSUS ENVELOPE THROUGH 24 HOURS...LIES ALONG THE OLD TRACK
THROUGH 48 HOURS...THEN GRADUALLY DEVIATES TO THE RIGHT AT TAU
72...96 AND 120. THE RESULT IS AN ALMOST STRAIGHT LINE TRACK HEADING
TOWARDS THE WEST NORTHWEST. THIS TRACK MODIFICATION DOES NOT BECOME
SIGNIFICANT UNTIL FLOSSIE PASSES WEST OF 160W...BEYOND THE REALM OF
THE MAIN HAWAIIAN ISLANDS. THIS TRACK DOES INCREASE THE RISK FOR THE
NORTHWESTERN HAWAIIAN ISLANDS BEYOND KAUAI. WE FORECAST FLOSSIE WILL
GRADUALLY WEAKEN THROUGH 120 HOURS WITH THE ACCUMULATING EFFECTS OF
OCEAN COOLING AND INCREASING SHEAR...DROPPING BELOW HURRICANE
STRENGTH AT 120 HOURS.

SCATTEROMETER AND AIRCRAFT OBSERVATIONS SHOW THE 120 NM TROPICAL
STORM STRENGTH WIND RADIUS REMAINS VALID WITHIN THE NORTHWEST AND
NORTHEAST QUADRANTS. THIS RADIUS WILL REACH THE BIG ISLAND AS
FLOSSIE PASSES TO THE SOUTH...SO A TROPICAL STORM WARNING REMAINS IN
EFFECT FOR THE BIG ISLAND...AS WELL AS A HURRICANE WATCH. WITH THE
CURRENT FORECAST TRACK...THE ISLANDS FROM MAUI COUNTY TO KAUAI
COUNTY ARE NOT EXPECTED TO REQUIRE ANY TYPES OF WATCHES.
HOWEVER...ANY SIGNIFICANT DEVIATION OF THE TRACK TOWARD THE NORTH
MIGHT RESULT IN WATCHES OR WARNINGS FOR ADDITIONAL AREAS IN THE
HAWAIIAN ISLANDS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 14/0300Z 15.9N 152.0W 105 KT
12HR VT 14/1200Z 16.6N 153.8W 105 KT
24HR VT 15/0000Z 17.6N 156.2W 100 KT
36HR VT 15/1200Z 18.5N 158.5W 95 KT
48HR VT 16/0000Z 19.4N 160.9W 90 KT
72HR VT 17/0000Z 21.1N 165.2W 85 KT
96HR VT 18/0000Z 22.5N 169.0W 70 KT
120HR VT 19/0000Z 24.0N 172.9W 60 KT

$$
FORECASTER POWELL

[Sanibel]

The eye just closed and shifted north from shear giving the illusion of a turn towards the Big Island. But the surface eye is still on track.