Eastern Pacific Tropical systems

[Somerset Squall]

Dalila has now degenerated into a remnant low over cool waters.

TROPICAL DEPRESSION DALILA DISCUSSION NUMBER 23

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP072007

800 AM PDT FRI JUL 27 2007

ENHANCED INFRARED SATELLITE IMAGERY AND AN EARLIER AMSU-B MICROWAVE

OVERPASS SUGGEST THAT DALILA HAS BEEN DEVOID OF DEEP CONVECTION FOR

AT LEAST 12 HOURS. NO INTERMITTENT CONVECTIVE BURSTS HAVE

MATERIALIZED SINCE LAST NIGHT'S QUIKSCAT OVERPASS...WHICH DEPICTED

A VERY SMALL PATCH OF 30 KT WINDS OVER THE NORTHWEST QUADRANT.

ASSUMING A GRADUAL SPINDOWN OF THE VORTEX SINCE THAT PASS...THE

INITIAL INTENSITY IS LOWERED TO 25 KT. THE SYSTEM IS EXPECTED TO

CONTINUE WEAKENING AS A REMNANT LOW OVER THE NEXT COUPLE OF DAYS.

THE INITIAL MOTION IS ESTIMATED AT 290/9. DALILA SHOULD CONTINUE

THROUGH THE FORECAST PERIOD ON A GENERALLY WEST-NORTHWESTWARD

MOTION WITHIN THE EASTERLY FLOW OF A LOW TO MID TROPOSPHERIC HIGH

SITUATED TO THE NORTH-NORTHWEST.

THIS IS THE LAST ADVISORY ISSUED ON TROPICAL DEPRESSION DALILA. FOR

ADDITIONAL INFORMATION ON THE REMNANT LOW PLEASE SEE HIGH SEAS

FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS

HEADER NFDHSFEP1 AND WMO HEADER FZPN02 KWBC.

FORECAST POSITIONS AND MAX WINDS

INITIAL 27/1500Z 23.1N 117.9W 25 KT

12HR VT 28/0000Z 23.6N 119.3W 25 KT...REMNANT LOW

24HR VT 28/1200Z 24.0N 120.9W 20 KT...REMNANT LOW

36HR VT 29/0000Z 24.2N 122.6W 20 KT...REMNANT LOW

48HR VT 29/1200Z 24.2N 124.3W 20 KT...REMNANT LOW

72HR VT 30/1200Z...DISSIPATED

$$

FORECASTER ROBERTS/PASCH

[Somerset Squall]

We now have TD8 in the east pacific. Even though the storms so far haven't been particularly strong (bar Cosme) there ceratainly have been a few around.

The immediate future of TD8 is not certain due to shear and dry air, these hostile conditions could even kill the system off within the next 24 hours. However, shear may ease after 24 hours, and if the storm lasts this long, it could begin to strengthen, and this is what the intensity forecast from the NHC calls for.

000

WTPZ43 KNHC 312031

TCDEP3

TROPICAL DEPRESSION EIGHT-E DISCUSSION NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082007

200 PM PDT TUE JUL 31 2007

SHEARED BUT STRONG CONVECTION HAS PERSISTED FOR ABOUT 12 HR NEAR AND

TO THE WEST OF THE LOW PRESSURE AREA CENTERED ABOUT 1125 MILES

SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. SATELLITE

INTENSITY ESTIMATES ARE 35 KT FROM BOTH TAFB AND SAB. BASED ON

THIS...ADVISORIES ARE INITIATED ON TROPICAL DEPRESSION EIGHT-E WITH

AN INITIAL INTENSITY OF 30 KT...A LITTLE MORE CONSERVATIVE THAN THE

SATELLITE ESTIMATES.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 280/12. WATER VAPOR

IMAGERY AND LARGE-SCALE MODEL SHOW A LARGE DEEP-LAYER RIDGE NORTH

OF THE DEPRESSION...ALBEIT A RIDGE WITH A WEAKNESS CAUSED BY

DEEP-LAYER TROUGHING TO ITS NORTH JUST WEST OF CALIFORNIA. THE

MODELS FORECAST THE RIDGE TO PERSIST WITH LITTLE CHANGE IN STRENGTH

THROUGH 120 HR. THIS SHOULD CAUSE THE DEPRESSION TO MOVE WESTWARD

OR WEST-NORTHWESTWARD AT A SPEED A SLIGHTLY BELOW CLIMATOLOGY. NHC

TRACK GUIDANCE AGREES ON THIS SCENARIO EXCEPT FOR THE NOGAPS...

WHICH MERGES THE DEPRESSION WITH ANOTHER CYCLONE FORMING TO THE

EAST. WHILE THERE IS A BROAD DISTURBANCE EAST OF THE DEPRESSION...

IT CURRENTLY APPEARS UNLIKELY THAT IT WILL DEVELOP FAST ENOUGH FOR

THE NOGAPS TO VERIFY. THUS...THE FORECAST TRACK CALLS FOR A

GENERAL WESTWARD MOTION AT ABOUT 10 KT THROUGH THE FORECAST PERIOD.

ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN INDICATE ABOUT 20

KT OF NORTHEASTERLY VERTICAL WIND SHEAR...AND WATER VAPOR IMAGERY

SHOWS UPPER-LEVEL DRY AIR IMPINGING ON THE DEPRESSION. THE

LARGE-SCALE MODELS ARE NOT IN GOOD AGREEMENT ON THE EVOLUTION OF

THE UPPER-LEVEL WINDS. THE GFS...THE ECMWF...AND THE NOGAPS

FORECAST THE SHEAR TO DECREASE IN LESS THAN 24 HR...WHILE THE

CANADIAN AND THE UKMET FORECAST HOSTILE CONDITIONS TO CONTINUE

BEYOND THAT TIME. FOR NOW...THE INTENSITY FORECAST WILL LEAN MORE

TOWARD THE CANADIAN/UKMET SOLUTIONS AND CALL FOR SLOW STRENGTHENING

AFTER 24 HR. THERE IS A CHANCE THAT THE DEPRESSION WILL NOT

SURVIVE THE FIRST 24 HR DUE TO THE SHEAR AND DRY AIR.

FORECAST POSITIONS AND MAX WINDS

INITIAL 31/2100Z 13.3N 123.8W 30 KT

12HR VT 01/0600Z 13.6N 125.6W 30 KT

24HR VT 01/1800Z 13.9N 127.6W 30 KT

36HR VT 02/0600Z 14.1N 129.8W 35 KT

48HR VT 02/1800Z 14.1N 132.0W 35 KT

72HR VT 03/1800Z 14.0N 136.0W 40 KT

96HR VT 04/1800Z 14.0N 140.0W 45 KT

120HR VT 05/1800Z 14.5N 144.0W 45 KT

$$

FORECASTER BEVEN

[Somerset Squall]

TD8 has been upgraded to Tropical Storm Erick. Erick is moving westwards at 9kt and a similar motion is expected for the rest of the forecast period. Erick is being sheared currently and only very modest strengthening is forecast in the forseeable future.

TROPICAL STORM ERICK DISCUSSION NUMBER 3

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082007

200 AM PDT WED AUG 01 2007

MICROWAVE AND MULTI-CHANNEL INFRARED IMAGERY INDICATE THAT THE

CENTER OF THE CYCLONE IS PROBABLY STILL NEAR THE EASTERN EDGE OF THE

MAIN AREA OF DEEP CONVECTION. DVORAK INTENSITY ESTIMATES REMAIN AT

35 KT...AND THIS IS USED FOR THE ADVISORY INTENSITY. THE CLOUD

PATTERN IS RATHER AMORPHOUS...WITH A LACK OF BANDING FEATURES...

WHICH IS TYPICAL OF A SHEARED TROPICAL CYCLONE. ERICK CONTINUES TO

BE IN AN ENVIRONMENT OF EASTERLY SHEAR DUE TO THE FLOW ON THE

SOUTHERN SIDE OF AN UPPER-TROPOSPHERIC ANTICYCLONE. DYNAMICAL

GUIDANCE SUGGESTS SOME RELAXATION OF THE SHEAR IN ABOUT 36 HOURS

BUT THE THERMODYNAMIC ENVIRONMENT APPEARS TO BE JUST SLIGHTLY

FAVORABLE FOR INTENSIFICATION. THEREFORE ONLY MODEST STRENGTHENING

IS CALLED FOR...AND THE OFFICIAL INTENSITY FORECAST IS A LITTLE

BELOW THE LATEST SHIPS GUIDANCE. AS NOTED EARLIER...THE GLOBAL

MODELS DO NOT INTENSIFY THE CYCLONE.

ALTHOUGH THE CENTER LOCATION IS SOMEWHAT UNCERTAIN...IT IS ESTIMATED

THAT THE STORM IS CONTINUING A GENERAL WESTWARD MOTION AT AROUND 9

KT. A MID-LEVEL RIDGE SHOULD BE MAINTAINED TO THE NORTH OF ERICK

OVER THE NEXT SEVERAL DAYS AS INDICATED BY THE GLOBAL MODELS.

THEREFORE THE CURRENT MOTION IS LIKELY TO MORE OR LESS BE

MAINTAINED FOR MOST IF NOT ALL OF THE FORECAST PERIOD. THE OFFICIAL

FORECAST IS SLIGHTLY SLOWER THAN THE PREVIOUS ONE BUT FASTER THAN

THE DYNAMICAL TRACK MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0900Z 13.0N 125.2W 35 KT

12HR VT 01/1800Z 13.1N 126.8W 35 KT

24HR VT 02/0600Z 13.2N 128.7W 40 KT

36HR VT 02/1800Z 13.3N 130.6W 45 KT

48HR VT 03/0600Z 13.5N 132.4W 45 KT

72HR VT 04/0600Z 13.5N 136.0W 45 KT

96HR VT 05/0600Z 13.5N 139.5W 45 KT

120HR VT 06/0600Z 13.5N 143.0W 45 KT

$$

FORECASTER PASCH

[Somerset Squall]

Erick is struggling with strong easterly shear, but high sea temps could allow some slight strengthening, but by the end of the forecast period a weakening trend is now anticipated as the storm moves over cooler waters.

TROPICAL STORM ERICK DISCUSSION NUMBER 5

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082007

200 PM PDT WED AUG 01 2007

VISIBLE SATELLITE IMAGERY INDICATES THAT STRONG EASTERLY SHEAR

IS TAKING ITS TOLL ON ERICK...WITH THE LOW LEVEL CIRCULATION NOW

ALMOST COMPLETELY EXPOSED ON THE NORTHEAST SIDE OF A WEAKENING BLOB

OF DEEP CONVECTION. WHILE THE SATELLITE SIGNATURE IS SUGGESTIVE OF

A WEAKENING CYCLONE...THE INITIAL INTENSITY IS CONSERVATIVELY HELD

AT 35 KT TO SEE IF THE CURRENT CONVECTIVE TREND PERSISTS. GIVEN THE

CYCLONE IS CURRENTLY OVER SSTS OF ABOUT 28C...SOME STRENGTHENING

REMAINS POSSIBLE IF THE SHEAR DECREASES. HOWEVER...SSTS START

APPROACHING 26C IN 48 HOURS AND THE THERMODYNAMIC ENVIRONMENT

APPEARS MARGINAL. IT WOULD APPEAR THAT ANY STRENGTHENING THAT DOES

OCCUR WOULD NEED TO HAPPEN SOONER RATHER THAN LATER.

ACCORDINGLY...THE OFFICIAL FORECAST ALLOWS FOR A LITTLE

STRENGTHENING IN THE SHORT-TERM FOLLOWED BY SLOW WEAKENING.

BASED ON LATEST VISIBLE IMAGERY...THE LOW LEVEL CIRCULATION IS

MOVING A LITTLE TO THE RIGHT OF THE PREVIOUS FORECAST TRACK OR

ABOUT 285/9. ASSUMING THE SYSTEM CAN MAINTAIN SOME VERTICAL

DEPTH...A MID-LEVEL RIDGE TO THE NORTH IS EXPECTED TO BE

THE PRIMARY STEERING MECHANISM OVER THE NEXT SEVERAL DAYS.

THEREFORE ERICK SHOULD CONTINUE ON A GENERAL WEST-NORTHWESTWARD

HEADING FOR MOST OF THE FORECAST PERIOD. TRACK GUIDANCE CONTINUES

TO TREND NORTHWARD AND SO DOES THE OFFICIAL FORECAST.

THE 34 KT WIND RADII WERE ADJUSTED BASED ON THE LATEST QUIKSCAT DATA

THAT INDICATES TROPICAL STORM FORCE WINDS ARE CONFINED TO THE

SOUTHWEST QUADRANT.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/2100Z 13.6N 127.1W 35 KT

12HR VT 02/0600Z 13.7N 128.4W 35 KT

24HR VT 02/1800Z 13.9N 130.0W 40 KT

36HR VT 03/0600Z 14.2N 131.5W 45 KT

48HR VT 03/1800Z 14.4N 133.3W 45 KT

72HR VT 04/1800Z 14.7N 136.8W 45 KT

96HR VT 05/1800Z 15.0N 139.5W 40 KT

120HR VT 06/1800Z 15.0N 143.0W 40 KT

$$

FORECASTER RHOME

[Somerset Squall]

Erick has weakened to a depression, seems the shear has finally taken it's toll.

TROPICAL DEPRESSION ERICK DISCUSSION NUMBER 8

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082007

800 AM PDT THU AUG 02 2007

THE CLOUD PATTERN OF ERICK HAS BECOME SIGNIFICANTLY LESS ORGANIZED

DURING THE PAST 12 HOURS. IN FACT...VERY FEW NORTHERLY VECTORS IN

LAST NIGHT'S QUIKSCAT AMBIGUITIES SUGGEST THAT THIS SYSTEM COULD BE

AN OPEN WAVE. THE ONLY CONCERN IS THAT THERE MAY BE A NEW CENTER

FORMING TO THE SOUTHWEST OF THE CURRENT POSITION BENEATH A MID-

LEVEL CIRCULATION ALONG THE ITCZ. DVORAK T-NUMBERS ARE 2.0 AND 2.5

FROM TAFB AND SAB RESPECTIVELY. ADDITIONALLY...A 0438Z SSMI/S

MICROWAVE IMAGE, AND A 0538Z ASCAT OVERPASS INTERPRETATION OF

SEVERE VERTICAL DECOUPLING SUPPORT LOWERING THE CYCLONE TO

DEPRESSION STRENGTH.

BASED ON THE CURRENT CONDITION OF THE TROPICAL CYCLONE...AND WITH

THE MODELS SUGGESTING THAT THE 10 TO 15 KT UPPER NORTHERLIES SHOULD

PERSIST DURING THE NEXT 48 HOURS...THE INTENSITY FORECAST IS

ADJUSTED TO REFLECT DEPRESSION STRENGTH THROUGH THE AFOREMENTIONED

PERIOD. BEYOND 48 HOURS...THE SYSTEM SHOULD WEAKEN TO A REMNANT

LOW AS IT PROGRESSES OVER SLIGHTLY COOLER WATERS AND INTO A MORE

STABLE ENVIRONMENT. HOWEVER...IF THE CENTER DOES REFORM CLOSER TO

THE CONVECTION TO THE SOUTHWEST OF THE INITIAL POSITION...

RESTRENGTHENING TO A TROPICAL STORM COULD OCCUR.

THE INITIAL MOTION IS ESTIMATED AT 275/9 WITH A SLIGHT ADJUSTMENT OF

ABOUT 40 NM EAST-NORTHEAST OF THE PREVIOUS FORECAST. ERICK SHOULD

CONTINUE WEST-NORTHWESTWARD WITHIN THE EASTERLY FLOW OF A MID-LEVEL

RIDGE TO THE NORTH. THE OFFICIAL FORECAST IS BASED ON A THE

DYNAMICAL MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 02/1500Z 13.6N 130.2W 30 KT

12HR VT 03/0000Z 13.7N 131.4W 30 KT

24HR VT 03/1200Z 13.9N 133.5W 30 KT

36HR VT 04/0000Z 14.2N 135.2W 30 KT

48HR VT 04/1200Z 14.3N 137.3W 30 KT

72HR VT 05/1200Z 14.5N 142.0W 25 KT...REMNANT LOW

96HR VT 06/1200Z 14.5N 145.5W 25 KT...REMNANT LOW

120HR VT 07/1200Z 14.5N 149.5W 25 KT...REMNANT LOW

$$

FORECASTER ROBERTS/BEVEN

[Somerset Squall]

Erick has dissapated, but there are two new disturbances, both of which could develop over the next few days.

A BROAD AREA OF LOW PRESSURE LOCATED ABOUT 625 MILES SOUTHWEST OF

THE SOUTHERN TIP OF BAJA CALIFORNIA IS MOVING NORTHWESTWARD ABOUT

10 MPH. THE ASSOCIATED SHOWER AND THUNDERSTORM ACTIVITY

REMAINS DISORGANIZED AND DEVELOPMENT...IF ANY...WILL BE SLOW TO

OCCUR.

AN AREA OF DISTURBED WEATHER IS CENTERED ABOUT 600 MILES SOUTH OF

ACAPULCO MEXICO. ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR

SOME DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AS

IT MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH.

[Somerset Squall]

We could have TD9 today.

TROPICAL WEATHER OUTLOOK

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

400 AM PDT MON AUG 6 2007

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE.

AN AREA OF LOW PRESSURE CENTERED ABOUT 850 MILES SOUTHWEST OF

THE SOUTHERN TIP OF BAJA CALIFORNIA IS MOVING WEST-NORTHWEST AT 10

TO 15 MPH. THE ORGANIZATION OF THIS SYSTEM HAS GRADUALLY IMPROVED

EARLY THIS MORNING AND A TROPICAL DEPRESSION COULD FORM WITHIN THIS

AREA LATER TODAY OR TONIGHT.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE

NEXT 48 HOURS.

$$

FORECASTER BROWN

[Somerset Squall]

Well a little slower developing than expected but we now have TD9. Conditions only appear marginally favourable for strengthening so only modest strengthening is forecasted as the storm moves westwards. A jolt to the north could well weaken the cyclone as it is very near the cooler waters to the north.

TROPICAL DEPRESSION NINE-E DISCUSSION NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

200 PM PDT WED AUG 08 2007

THE WEAK LOW PRESSURE AREA THAT HAS BEEN MONITORED FOR THE PAST FEW

DAYS HAS FINALLY ACQUIRED A SUFFICIENT AMOUNT OF ORGANIZED DEEP

CONVECTION TO BE CLASSIFIED AS A TROPICAL DEPRESSION...THE NINTH

TROPICAL CYCLONE OF THIS EASTERN NORTH PACIFIC HURRICANE SEASON.

SATELLITE IMAGES DEPICT TWO...ALBEIT RAGGED...HOOKING BANDS. BASED

ON AN ANALYSIS OF QUIKSCAT DATA FROM A FEW HOURS AGO...THE CURRENT

INTENSITY IS ONLY ABOUT 25 KT. THE SYSTEM IS NEAR THE WESTERN

PERIPHERY OF A LARGE 200 MB ANTICYCLONE AND THE UPPER-LEVEL WINDS

ARE FORECAST TO BE ONLY MARGINALLY FAVORABLE FOR INTENSIFICATION.

THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE SHIPS...

LGEM...AND GFDL GUIDANCE. SHOULD THE CYCLONE MOVE MORE TO THE

NORTH OF THE NHC FORECAST TRACK...STRENGTHENING IS UNLIKELY DUE TO

COOLER SEA SURFACE TEMPERATURES.

THE SYSTEM HAS BEEN MOVING MAINLY WESTWARD AND CURRENT MOTION IS

ABOUT 270/10. NINE-E IS CURRENTLY SITUATED TO THE SOUTH OF A

MID-LEVEL RIDGE. TRACK GUIDANCE CALLS FOR A SLIGHT INCREASE IN

FORWARD SPEED DURING THE NEXT COUPLE OF DAYS. LATER IN THE PERIOD

THE CYCLONE WILL PROBABLY BE NEARING THE WESTERN PERIPHERY OF THE

MID-LEVEL RIDGE...SO A WEST-NORTHWESTWARD TRACK IS FORECAST IN 4-5

DAYS. THE NHC TRACK IS FAIRLY SIMILAR TO THAT FROM THE HWRF MODEL

AND TO THE DYNAMICAL MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 08/2100Z 13.7N 126.5W 25 KT

12HR VT 09/0600Z 13.7N 128.2W 30 KT

24HR VT 09/1800Z 13.6N 130.6W 35 KT

36HR VT 10/0600Z 13.5N 133.0W 40 KT

48HR VT 10/1800Z 13.5N 135.5W 40 KT

72HR VT 11/1800Z 14.0N 140.0W 40 KT

96HR VT 12/1800Z 15.0N 144.0W 40 KT

120HR VT 13/1800Z 16.0N 148.0W 40 KT

$$

FORECASTER PASCH

Also worth watching is the tropical wave coming of Mexico which was 99l in the Atlantic, could well develop as it drifts west-northwestwards over the coming days.

AN AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS... ASSOCIATED WITH

A WESTWARD-MOVING TROPICAL WAVE...IS LOCATED A FEW HUNDRED MILES

SOUTH-SOUTHEAST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. ANY

DEVELOPMENT SHOULD BE SLOW TO OCCUR AS THE WAVE MOVES AWAY FROM

MEXICO.

Edited August 8, 2007 by Somerset Squall

[Somerset Squall]

TD9 organised itself very well overnight and is now a 45kt tropical storm, tropical storm FLOSSIE. Flossie could become a hurricane over the next couple of days because of high sea temps and low shear but weakenig is forecast after that as Flossie moves over cooler waters.

TROPICAL STORM FLOSSIE DISCUSSION NUMBER 3

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

200 AM PDT THU AUG 09 2007

THE CLOUD PATTERN HAS CONTINUED TO BECOME BETTER ORGANIZED DURING

THE PAST FEW HOURS. THERE ARE TWO WELL-DEFINED CYCLONICALLY CURVED

CONVECTIVE BANDS AROUND THE CENTER...AND THE OUTFLOW IS FAIR

IN ALL QUADRANTS. T-NUMBERS FROM BOTH TAFB AND SAB ARE NOW 3.0 ON

THE DVORAK SCALE SUGGESTING AN INITIAL INTENSITY OF 45 KNOTS.

SINCE THE SHEAR IS EXPECTED TO REMAIN LOW AND THE OCEAN IS

WARM...THE OFFICIAL FORECAST CALLS FOR A GRADUAL STRENGTHENING.

FLOSSIE COULD REACH HURRICANE STATUS IN A DAY OR TWO...AS INDICATED

BY SEVERAL OF THE INTENSITY GUIDANCE INCLUDING CLIMATOLOGY. BEYOND

3 DAYS...FLOSSIE IS EXPECTED TO MOVE OVER COOLER WATERS RESULTING

IN GRADUAL WEAKENING.

FLOSSIE IS MOVING TOWARD THE WEST OR 265 DEGREES AT 12 KNOTS.

BECAUSE THE CYCLONE IS WELL EMBEDDED WITHIN A PERSISTENT DEEP-LAYER

EASTERLY FLOW...THIS GENERAL MOTION IS LIKELY TO CONTINUE FOR THE

NEXT 3 DAYS. THEREAFTER...A GRADUAL TURN TO WEST-NORTHWEST IS

POSSIBLE AS THE RIDGE TO THE NORTH OF THE CYCLONE WEAKENS. MOST OF

THE MODELS KEEP FLOSSY MOVING ON A GENERAL STRAIGHT WESTWARD TRACK

WITHIN THE EASTERLY FLOW FOR THE ENTIRE FORECAST PERIOD. THE GFDL

MODEL SHOWS A LITTLE MORE WEST-NORTHWEST TRACK BEYOND 3 DAYS AND SO

DOES THE OFFICIAL FORECAST.

FORECAST POSITIONS AND MAX WINDS

INITIAL 09/0900Z 13.2N 129.6W 45 KT

12HR VT 09/1800Z 13.3N 131.3W 50 KT

24HR VT 10/0600Z 13.3N 133.8W 60 KT

36HR VT 10/1800Z 13.5N 136.0W 65 KT

48HR VT 11/0600Z 13.5N 138.0W 60 KT

72HR VT 12/0600Z 14.0N 142.0W 50 KT

96HR VT 13/0600Z 14.5N 146.0W 45 KT

120HR VT 14/0600Z 16.0N 150.0W 40 KT

$$

FORECASTER AVILA

[Somerset Squall]

Flossie has strengthened further and is not far off becoming the second hurricane of the east pacific season and indeed the second hurricane this year. Outflow is mainly good and sea temps remain high so intensification should continue until waters cool in a couple days.

TROPICAL STORM FLOSSIE DISCUSSION NUMBER 5

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

200 PM PDT THU AUG 09 2007

THE ORGANIZATION OF FLOSSIE CONTINUES TO IMPROVE...WITH A FORMATIVE

EYE APPARENT IN MICROWAVE AND CONVENTIONAL SATELLITE IMAGERY.

DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB WERE 55 KT...AND A

QUIKSCAT PASS FROM 14Z THIS MORNING SUGGESTED THAT WINDS WERE CLOSE

TO OR JUST BELOW THE CONCURRENT SATELLITE ESTIMATES.

CONSEQUENTLY... THE ADVISORY INTENSITY IS INCREASED TO 55 KT.

THE INITIAL MOTION IS 265/13...ABOUT THE SAME AS BEFORE. FLOSSIE

WILL BE MOVING TO THE SOUTH OF A WEAKNESS IN THE SUBTROPICAL RIDGE

OVER THE NEXT DAY OR TWO...WHICH COULD SLOW THE FORWARD MOTION A

BIT...BUT THE SMALL CIRCULATION OF FLOSSIE IS UNLIKELY TO INTERACT

SIGNIFICANTLY WITH THIS WEAKNESS. AFTER THAT...A NARROW MID-LEVEL

RIDGE IS EXPECTED TO KEEP THE CYCLONE ON A WEST OR WEST-NORTHWEST

TRACK THROUGH THE FORECAST PERIOD. MODEL GUIDANCE IS LARGELY

UNCHANGED FROM THIS MORNING...EXCEPT FOR THE UKMET WHICH HAS

SHIFTED NORTH AND IS NOW CLOSE TO THE HWRF...GFDL...AND GFS. THE

OFFICIAL FORECAST FOLLOWS A BLEND OF THESE MODELS. AN ALTERNATIVE

TRACK...FASTER AND FARTHER SOUTH...IS OFFERED BY THE

NOGAPS...ECMWF...AND FSSE.

IN THE SHORT TERM...SOME ADDITIONAL INTENSIFICATION SEEMS LIKELY.

THE OUTFLOW PATTERN IS RESTRICTED TO THE EAST BUT LOOKS GOOD

ELSEWHERE. SSTS ALONG THE PROJECTED TRACK WILL REMAIN ABOVE 27C

FOR ANOTHER 36 HOURS OR SO. THE LOW-LEVEL INFLOW PATTERN DOES NOT

SEEM IDEAL...HOWEVER...WITH A STABLE AIR MASS TO THE NORTHWEST OF

THE CYCLONE AND THE MOIST SOUTHERLY FLOW IN THE SOUTHEAST QUADRANT

SEEMINGLY RUNNING AWAY FROM THE CENTER. MOST...BUT NOT ALL THE

OBJECTIVE GUIDANCE MAKES FLOSSIE A HURRICANE. AFTER 48

HOURS...COOLER SSTS SHOULD INDUCE A WEAKENING TREND. HOW FAST

FLOSSIE DECLINES NEAR THE END OF THE FORECAST PERIOD WILL BE

GOVERNED BY THE UPPER FLOW...WHICH IS FORECAST TO EVOLVE VERY

DIFFERENTLY BY THE VARIOUS LARGE-SCALE MODELS. THE GFS MAINTAINS A

RELATIVELY FAVORABLE UPPER ENVIRONMENT...WHILE THE ECMWF AND UKMET

HAVE MUCH HIGHER SHEAR. IT'S DIFFICULT TO TELL WHICH SCENARIO WILL

VERIFY...BUT THE OFFICIAL FORECAST AT THIS POINT CONSERVATIVELY

ASSUMES THAT THE UPPER FLOW WILL NOT BECOME VERY HOSTILE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 09/2100Z 12.8N 132.4W 55 KT

12HR VT 10/0600Z 12.8N 134.3W 60 KT

24HR VT 10/1800Z 13.0N 136.3W 65 KT

36HR VT 11/0600Z 13.3N 138.4W 65 KT

48HR VT 11/1800Z 13.6N 140.4W 65 KT

72HR VT 12/1800Z 14.5N 144.5W 55 KT

96HR VT 13/1800Z 15.5N 149.0W 50 KT

120HR VT 14/1800Z 16.5N 153.0W 45 KT

$$

FORECASTER FRANKLIN

[Somerset Squall]

Flossie is now a hurricane. Initial strengthening predicted but then weakening due to cooler waters and a less favourable upper level environment.

HURRICANE FLOSSIE DISCUSSION NUMBER 8

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

800 AM PDT FRI AUG 10 2007

INFRARED AND MICROWAVE IMAGERY INDICATE THAT FLOSSIE HAS

STRENGTHENED INTO A HURRICANE. AN EYE FEATURE HAS BECOME APPARENT

IN BOTH CONVENTIONAL AND SHORTWAVE INFRARED GOES IMAGERY...AND IN A

RECENT TRMM OVERPASS. THE OUTFLOW PATTERN CONTINUES TO

IMPROVE...PARTICULARLY OVER THE NORTHERN HALF OF THE CYCLONE... BUT

THE WESTERN PORTION IS RESTRICTED A BIT. DVORAK SATELLITE

INTENSITY ESTIMATES ARE 65 KT FROM SAB AND 77 KT FROM TAFB. THE

INITIAL INTENSITY IS INCREASED TO 65 KT...ON THE LOWER END OF THE

DVORAK ESTIMATES SINCE THE EYE FEATURE HAS BECOME LESS DISTINCT

SINCE 12Z.

SLIGHT STRENGTHENING IS EXPECTED DURING THE NEXT 24 HOURS WHILE

FLOSSIE REMAINS OVER SSTS GREATER THAN 27 CELSIUS. SSTS ALONG THE

FORECAST TRACK DECLINE THEREAFTER...SO GRADUAL WEAKENING IS

FORECAST BEYOND 36-48 HOURS. TOWARD THE END OF THE FORECAST

PERIOD...AN INCREASINGLY UNFAVORABLE ATMOSPHERIC

ENVIRONMENT...ESPECIALLY INDICATED BY THE EUROPEAN MODEL...AND

COOLER SEA SURFACE TEMPERATURES SHOULD INDUCE A CONTINUED WEAKENING

TREND. THE INTENSITY FORECAST IS ADJUSTED UPWARD TO REFLECT THE

CURRENT INTENSITY TREND...AND IS BASED ON A BLEND OF THE

SHIPS...ICON...SUPER-ENSEMBLE...AND THE LGE MODELS.

FLOSSIE IS MOVING AT 275/12...WITHIN THE DEEP EASTERLY FLOW AROUND A

RIDGE SITUATED TO THE NORTH OF THE SYSTEM. THE MAJORITY OF THE

GLOBAL MODELS SUGGEST A PERSISTENT WEST-NORTHWESTWARD TRACK...SOUTH

OF THE HAWAIIAN ISLANDS OVER THE NEXT 5 DAYS. THE GFDL...

HOWEVER...INDICATES A MORE NORTHWESTWARD MOTION BEYOND 24

HOURS...WHICH PLACES THE SYSTEM JUST TO THE NORTHEAST OF THE BIG

ISLAND ON DAY 5. ALTHOUGH THE GFDL SOLUTION CANNOT BE RULED

OUT...LESS EMPHASIS IS PLACED ON IT FOR NOW...BECAUSE A RIGHT OF

TRACK BIAS HAS BEEN IDENTIFIED IN PREVIOUS GFDL FORECASTS FOR

FLOSSIE. THE OFFICIAL FORECAST IS BASED ON A CONSENSUS OF THE

GLOBAL MODELS AND IS SLIGHTLY FASTER THAN THE PREVIOUS PACKAGE

AFTER THE 72 HOUR PERIOD.

FORECAST POSITIONS AND MAX WINDS

INITIAL 10/1500Z 12.7N 136.0W 65 KT

12HR VT 11/0000Z 12.8N 137.9W 65 KT

24HR VT 11/1200Z 13.1N 140.3W 70 KT

36HR VT 12/0000Z 13.5N 142.5W 70 KT

48HR VT 12/1200Z 13.9N 144.7W 65 KT

72HR VT 13/1200Z 14.9N 149.7W 60 KT

96HR VT 14/1200Z 16.5N 155.0W 55 KT

120HR VT 15/1200Z 18.0N 159.0W 45 KT

$$

FORECASTER ROBERTS/KNABB

[Somerset Squall]

Flossie has strengthened by another 10 kts and is now predicted to become a category 2 hurricane. It is the strongest so far this season. The intensity forecast after peak intensity remains the same. It's worth noting that Flossie will soon move into the Central Pacific's area of responsibilty and will be very near Hawaii.

HURRICANE FLOSSIE DISCUSSION NUMBER 9

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

200 PM PDT FRI AUG 10 2007

THE FIRST SEVERAL VISIBLE IMAGES OF THE DAY REVEAL AN INCREASINGLY

DISTINCT EYE...DECENT OUTFLOW IN ALL QUADRANTS...AND THAT

CONVECTION HAS BEEN DEEPENING IN THE NORTHWESTERN QUADRANT WHERE IT

HAD PREVIOUSLY BEEN A BIT THIN. AN SSMIS OVERPASS FROM 1714Z ALSO

DEPICTS A SOLID AND SYMMETRIC EYEWALL WRAPPING ESSENTIALLY ALL THE

WAY AROUND THE CENTER. DVORAK INTENSITY ESTIMATES AT 18Z FROM TAFB

AND SAB WERE A CONSENSUS 77 KT...SO THE ADVISORY INTENSITY IS

ADJUSTED UPWARD TO 75 KT. A QUIKSCAT OVERPASS AT 1525Z COULD NOT

RESOLVE ANY HURRICANE-FORCE WINDS...BUT IT DID CONFIRM THAT

FLOSSIE'S OVERALL WIND FIELD IS FAIRLY SMALL...WITH WINDS OF

TROPICAL STORM FORCE EXTENDING NO FARTHER FROM THE CENTER THAN

ABOUT 60 N MI.

FLOSSIE CONTINUES DUE WESTWARD OR 270 DEGREES AT ABOUT 11 KT...WITH

STEERING PROVIDED BY THE SUBTROPICAL RIDGE TO ITS NORTH. ALL OF

THE MODEL GUIDANCE FORECASTS ENOUGH RIDGING TO PERSIST TO THE NORTH

OF FLOSSIE FOR THE NEXT FIVE DAYS TO FORCE THE SYSTEM GENERALLY

WESTWARD OR WEST-NORTHWESTWARD THROUGHOUT THAT PERIOD. NOTABLE

DIFFERENCES EXIST BETWEEN THE MODELS...HOWEVER...ESPECIALLY IN THE

FUTURE LATITUDE OF FLOSSIE. THE HWRF IS THE NORTHERN OUTLIER BUT

SEEMS TO TAKE THE CYCLONE TOO FAR NORTH EVEN EARLY ON IN THE

FORECAST. MEANWHILE THE ECMWF AND UKMET ARE MUCH FARTHER

SOUTH...ON THE OTHER EXTREME OF THE GUIDANCE ENVELOPE. THE NAVY

MODELS...GFS...AND THE CONSENSUS ARE ROUGHLY IN THE MIDDLE. GIVEN

THE SIGNIFICANT MODEL SPREAD...AND THAT THE CONSENSUS IS CLOSE TO

THE PREVIOUS OFFICIAL FORECAST...NO SIGNIFICANT CHANGES HAVE BEEN

MADE IN THE NEW OFFICIAL TRACK.

OCEAN AND ATMOSPHERIC CONDITIONS APPEAR TO BE CONDUCIVE FOR A LITTLE

MORE INTENSIFICATION. SEA-SURFACE TEMPERATURES ALONG THE FORECAST

TRACK SHOULD REMAIN AT LEAST 27C FOR ABOUT 24 MORE HOURS...WITHIN A

CONTINUED WEAK SHEAR ENVIRONMENT. THE OFFICIAL FORECAST PEAKS AT

85 KT IN 24 HOURS IN CLOSE AGREEMENT WITH ALL AVAILABLE INTENSITY

GUIDANCE. THE WATERS SHOULD GRADUALLY COOL BENEATH FLOSSIE BEYOND

24 HOURS...AND SOUTHERLY WIND SHEAR IS FORECAST BY THE GLOBAL MODELS

TO START INCREASING IN ABOUT THREE DAYS. AS A RESULT...FLOSSIE IS

FORECAST TO SLOWLY WEAKEN ON DAYS TWO AND THREE...FOLLOWED BY MORE

WEAKENING AS A TROPICAL STORM LATE IN THE FORECAST PERIOD. NONE OF

THE AVAILABLE INTENSITY GUIDANCE FORECASTS FLOSSIE TO BE A

HURRICANE BEYOND 72 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 10/2100Z 12.6N 137.2W 75 KT

12HR VT 11/0600Z 12.7N 139.0W 80 KT

24HR VT 11/1800Z 13.1N 141.3W 85 KT

36HR VT 12/0600Z 13.6N 143.6W 80 KT

48HR VT 12/1800Z 14.1N 146.0W 75 KT

72HR VT 13/1800Z 15.0N 150.5W 65 KT

96HR VT 14/1800Z 16.5N 155.0W 55 KT

120HR VT 15/1800Z 18.0N 159.5W 45 KT

$$

FORECASTER KNABB

[Somerset Squall]

Flossie has deepened rapidly overnight, by another 25kts- and is now a cat 3, 100kt hurricane. Additional strengthening is still possible in the next 24 hours or so before Flossie encounters lower sea temps and higher sher on her forecast track which should induce weakening. The forecast however still calls for Flossie to be a tropical storm when it nears Hawaii.

HURRICANE FLOSSIE DISCUSSION NUMBER 11

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

200 AM PDT SAT AUG 11 2007

FLOSSIE HAS UNDERGONE RAPID INTENSIFICATION OVERNIGHT. INFRARED

SATELLITE IMAGERY INDICATES THAT THE HURRICANE HAS A 15 N MI-WIDE

CLEAR EYE EMBEDDED IN DEEP CONVECTION WITH CLOUD TOPS AROUND -75C.

DVORAK INTENSITY ESTIMATES FROM BOTH TAFB AND SAB ARE T5.5/102

KT...AND 6-HR AVERAGED ADT ESTIMATES FROM CIMSS ARE RUNNING AROUND

102 KT AS WELL. BASED ON THIS INFORMATION...THE INITIAL INTENSITY

HAS BEEN RAISED TO 100 KT...AND FLOSSIE IS NOW A CATEGORY THREE

HURRICANE ON THE SAFFIR/SIMPSON HURRICANE SCALE.

FOR THE NEXT 36 TO 48 HOURS...THE SHEAR IS EXPECTED TO BE LESS THAN

10 KT AND SSTS SHOULD REMAIN ABOVE 26C. WITH THAT SAID...SOME

FURTHER STRENGTHENING IS ANTICIPATED...POSSIBLY EVEN MORE THAN

FORECAST...HOWEVER BOTH THE SHIPS AND FSSE INTENSITY GUIDANCE PEAK

FLOSSIE AROUND 100 KT. AFTER TWO OR SO DAYS...THE CYCLONE SHOULD

ENCOUNTER COOLER WATERS AND AN INCREASE IN VERTICAL SHEAR. THE

IMPACT OF THE INCREASING SHEAR IN THE LATER PERIODS OF THE FORECAST

VARIES FROM EACH OF THE MODELS...AND THE OFFICIAL INTENSITY FORECAST

IS A BLEND OF THE SHIPS AND FSSE WHICH HAVE A MORE ACCURATE

INITIALIZATION.

FLOSSIE CONTINUES TO BE STEERED WESTWARD...270/12...UNDER THE

INFLUENCE OF A STRONG RIDGE TO THE NORTH. THE OVERALL MODEL

GUIDANCE IS IN GOOD AGREEMENT THAT THE CYCLONE WILL MOVE TOWARD THE

WEST OR WEST-NORTHWEST FOR THE NEXT TWO OR THREE DAYS. THEREAFTER

THE MODELS DIVERGE...THE NOGAPS AND GFDL SOLUTIONS TAKE A STRONGER

SYSTEM TO THE NORTHWEST WHILE THE UKMET...GFS...AND HWRF GUIDANCE

MAINTAIN A MORE WESTWARD TRACK SOUTH OF THE HAWAIIAN ISLANDS AS A

RESULT OF A MORE WEAKENED SYSTEM. THE OFFICIAL TRACK FORECAST

ESSENTIALLY SPLITS THE DIFFERENCE AND IS CLOSE TO THE PREVIOUS

FORECAST AS WELL AS THE FSSE MODEL.

THIS IS THE LAST ADVISORY ON FLOSSIE FROM THE NATIONAL HURRICANE

CENTER. FUTURE ADVISORIES WILL BE ISSUED BY THE CENTRAL PACIFIC

HURRICANE CENTER IN HONOLULU HAWAII.

FORECAST POSITIONS AND MAX WINDS

INITIAL 11/0900Z 12.6N 139.3W 100 KT

12HR VT 11/1800Z 12.9N 141.1W 105 KT

24HR VT 12/0600Z 13.3N 143.4W 105 KT

36HR VT 12/1800Z 13.8N 145.6W 95 KT

48HR VT 13/0600Z 14.4N 148.0W 85 KT

72HR VT 14/0600Z 15.5N 152.5W 70 KT

96HR VT 15/0600Z 17.0N 156.0W 60 KT

120HR VT 16/0600Z 18.5N 159.0W 45 KT

$$

FORECASTER MAINELLI

[Somerset Squall]

Flossie has continued to rapidly intensify and is now a 115kt, cat 4 hurricane. Further intensification is not anticipated as the storm should weaken as it is beginning to move over cooler waters.

HURRICANE FLOSSIE DISCUSSION NUMBER 12

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

800 AM PDT SAT AUG 11 2007

FLOSSIE HAS CONTINUED TO INTENSIFY THIS MORNING...WITH A MORE

SYMMETRIC AND SOLID RING OF EYEWALL CLOUD TOPS NEAR -75C AROUND

12Z. ACCORDINGLY...SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY

ESTIMATES AT THAT TIME WERE A CONSENSUS T6.0 OR 115 KT...AND THAT

IS THE ADVISORY INTENSITY. AN OVERPASS BY AMSR-E AT 1050Z REVEALS A

SINGLE EYEWALL AND NO APPARENT SIGNS OF ANY IMPENDING INNER CORE

STRUCTURAL CHANGES. SINCE 12Z THE INFRARED CLOUD TOP TEMPERATURES

HAVE RISEN SLIGHTLY...SO IT IS POSSIBLE THAT THE HURRICANE HAS

REACHED AN INTENSITY PLATEAU. THE UNDERLYING SEA-SURFACE

TEMPERATURES ALONG THE FORECAST TRACK WILL BE COOLER FROM THIS

POINT FORWARD...WHILE GLOBAL MODELS INDICATE THAT WIND SHEAR WILL

BEGIN INCREASING IN ABOUT 72 HOURS. THEREFORE THE OFFICIAL FORECAST

CALLS FOR FLOSSIE TO START GRADUALLY WEAKENING LATER TODAY...WITH

THE PACE OF DECLINE PICKING UP WHEN THE SHEAR INCREASES ON DAY 3.

THIS FORECAST IS CLOSE TO A CONSENSUS OF THE VARIOUS INTENSITY

GUIDANCE MODELS. EXCEPT FOR THE FSSE...ALL OF THE INTENSITY

GUIDANCE FORECASTS FLOSSIE TO DROP BELOW HURRICANE STATUS BEYOND 72

HOURS.

THE HURRICANE CONTINUES DUE WESTWARD...AND THE INITIAL MOTION IS A

SLIGHTLY WOBBLY 270 DEGREES AT 10 KNOTS. WE CAN SAY FOR SURE NOW

THAT THE CENTER OF THE CYCLONE HAS CROSSED 140 DEGREES WEST INTO

THE CENTRAL PACIFIC BASIN. ONCE AGAIN THE OFFICIAL TRACK FORECAST

HAS NOT CHANGED APPRECIABLY AND REMAINS ROUGHLY IN THE MIDDLE OF

THE GUIDANCE ENVELOPE. THE GUIDANCE SPREAD REMAINS LARGE...

HOWEVER...ESPECIALLY LATE IN THE FORECAST PERIOD. THE EVENTUAL

TRACK HINGES LARGELY ON JUST HOW STRONG THE SUBTROPICAL RIDGE IS TO

THE NORTH OF FLOSSIE IN A FEW DAYS. MOST OF THE MODELS FORECAST

THE RIDGE CURRENTLY CENTERED OVER HAWAII TO WEAKEN SOMEWHAT...WHICH

SHOULD RESULT IN A TRACK THAT BENDS EVER SO GRADUALLY TO THE RIGHT.

THE MAJORITY OF THE MODELS HOLD ONTO ENOUGH RIDGING TO KEEP THE

CENTER OF A WEAKENING FLOSSIE SOUTH OF THE HAWAIIAN ISLANDS...

ALTHOUGH A TRACK FARTHER NORTH THAN INDICATED BY THE OFFICIAL

FORECAST CANNOT BE RULED OUT.

THIS IS THE LAST ADVISORY ON FLOSSIE FROM THE NATIONAL HURRICANE

CENTER. FUTURE ADVISORIES WILL BE ISSUED BY THE CENTRAL PACIFIC

HURRICANE CENTER IN HONOLULU HAWAII.

FORECAST POSITIONS AND MAX WINDS

INITIAL 11/1500Z 12.7N 140.2W 115 KT

12HR VT 12/0000Z 12.9N 141.8W 115 KT

24HR VT 12/1200Z 13.3N 143.9W 105 KT

36HR VT 13/0000Z 13.7N 146.0W 95 KT

48HR VT 13/1200Z 14.1N 148.1W 85 KT

72HR VT 14/1200Z 15.5N 152.5W 70 KT

96HR VT 15/1200Z 17.0N 156.5W 55 KT

120HR VT 16/1200Z 18.5N 160.0W 45 KT

$$

FORECASTER KNABB

Edited August 11, 2007 by Somerset Squall

[Somerset Squall]

Flossie has continued intensifying quickly and now is a 115kt cat 4 hurricane. More strenthening is not anticipated as the hurricane is now beginning to move over cooler waters.

HURRICANE FLOSSIE DISCUSSION NUMBER 12

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007

800 AM PDT SAT AUG 11 2007

FLOSSIE HAS CONTINUED TO INTENSIFY THIS MORNING...WITH A MORE

SYMMETRIC AND SOLID RING OF EYEWALL CLOUD TOPS NEAR -75C AROUND

12Z. ACCORDINGLY...SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY

ESTIMATES AT THAT TIME WERE A CONSENSUS T6.0 OR 115 KT...AND THAT

IS THE ADVISORY INTENSITY. AN OVERPASS BY AMSR-E AT 1050Z REVEALS A

SINGLE EYEWALL AND NO APPARENT SIGNS OF ANY IMPENDING INNER CORE

STRUCTURAL CHANGES. SINCE 12Z THE INFRARED CLOUD TOP TEMPERATURES

HAVE RISEN SLIGHTLY...SO IT IS POSSIBLE THAT THE HURRICANE HAS

REACHED AN

[tinybill]

http://forecast.mssl.ucl.ac.uk/shadow/trac...namic/main.html

should be over the hawalia islands in about 69 hours at the moment its a cat 4

Edited August 12, 2007 by tinybill

[tinybill]

here are web cams for the area

http://www.webcambiglook.com/hi.shtml

http://www.eng.hawaii.edu/hawaiidot/index.html

http://www.seehawaiilive.com/index.cfm

should people want to watch the storm come in

[Somerset Squall]

Thanks for that TinyBill, certainly one to watch for Hawaii, as the end of the latest discussion highlights. Flossie did strengthen another 5kts to 120kts overnight but has now weakened to 115kts and from her on in Flossie should be a weakening storm. Central pressure 948mb at the moment.

HURRICANE FLOSSIE DISCUSSION NUMBER 15

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007

1100 PM HST SAT AUG 11 2007 HURRICANE FLOSSIE CONTINUES TO HAVE AN EXTREMELY IMPRESSIVE SIGNATURE IN INFRARED SATELLITE IMAGERY THIS EVENING. FLOSSIE HAS A VERY WARM WELL DEFINED 20 NM DIAMETER EYE SURROUNDED BY A RING OF VERY COLD CLOUD TOPS. THE SYSTEM ALSO CONTINUES TO EXHIBIT A REMARKABLE OUTFLOW. HOWEVER...THE PREVIOUS INTENSIFICATION APPEARS TO HAVE BEEN REVERSED DURING THE PAST FEW HOURS. SATELLITE INTENSITY ESTIMATES SUGGESTED A SLIGHT WEAKENING...SO THE CURRENT ADVISORY SHOWED A DECREASE IN THE INITIAL MAXIMUM WIND SPEEDS TO 115 KT.

THE LONG TERM MOTION OF FLOSSIE SOUTH OF THE STRONG MID-PACIFIC OCEAN SUBTROPICAL RIDGE IS TOWARD 280 DEGREES AT 12 KT. THERE CONTINUE TO BE VERY SIGNIFICANT WOBBLES OF THE EYE THAT ARE CLEARLY EVIDENT IN SATELLITE IMAGERY. HOWEVER...IT APPEARS THAT THE THE MEAN TRACK OF FLOSSIE REMAINS VERY CLOSE TO THE PREVIOUS FORECASTS.

THE MOST RECENT OBJECTIVE GUIDANCE PACKAGE RECEIVED AT CPHC HAS SHOWN SOME DECREASE IN THE SPREAD OF THE FORECAST TRACKS AS FLOSSIE APPROACHES THE HAWAIIAN ISLANDS. THE LATEST RUNS OF THE NOGAPS AND GFDL MODELS HAVE SHIFTED MUCH FARTHER TO THE LEFT NOW. AS A RESULT...THE CONSENSUS MODELS HAVE ALSO BEEN NUDGED MORE TO THE LEFT. THIS PROVIDES A LITTLE MORE CONFIDENCE IN THE TRACK FORECAST. THIS FORECAST DOES NOT SHOW ANY SIGNIFICANT DEVIATION FROM THE PREVIOUS TRACK.

THE INTENSITY FORECAST REMAINS THE BIGGEST QUESTION AT THE MOMENT. THE GLOBAL MODELS CONTINUE TO SHOW INCREASING VERTICAL WIND SHEAR IN THE FUTURE PATH OF FLOSSIE. THIS SHEAR APPEARS TO BE THE MOST HOSTILE BEYOND THE 48 HOUR TIME FRAME. SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND DECREASED OCEAN HEAT CONTENT ALONG THE FORECAST TRACK ALSO IMPLY FUTURE WEAKENING OF THE TROPICAL CYCLONE. THE CURRENT INTENSITY FORECAST IS MORE IN LINE WITH THE GFDL GUIDANCE. THERE IS A LITTLE BETTER CONFIDENCE IN THIS MODEL OUTPUT FROM THE GFDL...SINCE THE TRACK HAS MOVED MORE IN LINE WITH THE OTHER TRACK GUIDANCE. KEEP IN MIND THAT OUR ERRORS IN FORECASTING INTENSITY ARE STILL LARGE...ESPECIALLY AT 48 AND 72 HOURS...AND BEYOND.

ALL THOSE WHO ARE FOLLOWING FLOSSIE ARE URGED NOT FOCUS ON THE ACTUAL FORECAST TRACK OF THE CALM EYE. THE STRONG WINDS IN THE EYE WALL SURROUNDING THE CENTER OF THE HURRICANE EXTEND FAR BEYOND THIS LINE. THEREFORE...EVEN THOUGH THE EYE OF FLOSSIE MAY PASS JUST SOUTH OF THE HAWAIIAN ISLANDS...IT COULD STILL BRING STRONG WINDS AND HEAVY RAINS TO PORTIONS OF THE ISLANDS EARLY NEXT WEEK BASED ON THE CURRENT FORECAST. PLEASE CONTINUE TO MONITOR FUTURE ADVISORIES FOR THE LATEST INFORMATION ON THIS VERY STRONG HURRICANE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 12/0900Z 13.6N 143.5W 115 KT

12HR VT 12/1800Z 14.0N 145.2W 110 KT

24HR VT 13/0600Z 14.7N 147.4W 95 KT

36HR VT 13/1800Z 15.4N 149.4W 95 KT

48HR VT 14/0600Z 16.2N 151.4W 90 KT

72HR VT 15/0600Z 17.6N 155.4W 70 KT

96HR VT 16/0600Z 18.9N 159.0W 50 KT

120HR VT 17/0600Z 20.3N 162.3W 45 KT

$$

FORECASTER HOUSTON

Looks like it will be a tropical storm as it is in the vicinity of Hawaii. A direct landfall is not forecasted but Flossie is still likely to provide very strong winds and heavy rain to the island.

[Somerset Squall]

Flossie is point blank refusing to weaken. The pressure has risen to 957mb but it is still packing winds of 115kts and is still a powerful ctegory 4 hurricane. There could be a few problems at Hawaii as Flossie is now forecast to still be a hurricane as it nears the island.

HURRICANE FLOSSIE DISCUSSION NUMBER 19

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007

1100 PM HST SUN AUG 12 2007

CURRENT SATELLITE INTENSITY ESTIMATES FOR FLOSSIE ARE 6.0 FROM SAB AND JTWC...AND 5.5 FROM HFO. THE 0600 UTC ADT ESTIMATE IS 5.9. THEREFORE...THE MAXIMUM SUSTAINED WINDS FOR THIS HURRICANE WILL BE MAINTAINED AT 115 KT FOR THIS ADVISORY. THE UPPER LEVEL OUTFLOW REMAINS RATHER IMPRESSIVE...AND THE APPROXIMATELY 20 NM DIAMETER EYE IS EMBEDDED WITHIN A WELL DEFINED EYEWALL.

THE LATEST MOVEMENT OF FLOSSIE IS TOWARD 285 DEGREES AT 12 KT. ALL OF THE LATEST TRACK GUIDANCE CONTINUES TO BE CLOSELY CLUSTERED THROUGH 36 HOURS. BY 48 HOURS...THERE IS A WIDER SPREAD IN THE TRACK FORECASTS. THE CURRENT FORECAST TRACK IS AN UPDATE OF THE PREVIOUS ADVISORY THROUGH 96 HOURS. THE 120 HOUR POSITION WAS ADJUSTED SLIGHTLY.

THE INTENSITY FORECAST REMAINS DEPENDENT ON THE IMPACT OF INCREASING VERTICAL WIND SHEAR THAT FLOSSIE IS EXPECTED TO FEEL WITHIN THE NEXT 24 TO 36 HOURS. RECENT RUNS OF THE GLOBAL MODELS HAVE BEEN SHOWING THIS SHEAR MAY BE LESS THAN WAS EXPECTED IN THE RUNS MADE 24 HOURS AGO. THEREFORE...THE INTENSITY FORECAST FOR FLOSSIE REMAINS UNCERTAIN.

THE CURRENT TRACK...INTENSITY AND WIND RADII FORECAST MAY REQUIRE WATCHES FOR PORTIONS OF THE HAWAIIAN ISLANDS MONDAY MORNING.

FORECAST POSITIONS AND MAX WINDS

INITIAL 13/0900Z 14.4N 148.2W 115 KT

12HR VT 13/1800Z 15.1N 149.9W 110 KT

24HR VT 14/0600Z 16.0N 152.1W 105 KT

36HR VT 14/1800Z 16.8N 154.2W 100 KT

48HR VT 15/0600Z 17.6N 156.1W 90 KT

72HR VT 16/0600Z 19.1N 159.8W 75 KT

96HR VT 17/0600Z 20.5N 163.7W 60 KT

120HR VT 18/0600Z 21.8N 168.4W 55 KT

$$

FORECASTER HOUSTON

[Somerset Squall]

Believe it or not, Flossie has strengthened in the latest advisory (which came in minutes after I posted the last one). Hurrican warnings are now in force for Hawaii and Flossie is set to remain a hurricane for the rest of the forecast period.

HURRICANE FLOSSIE DISCUSSION NUMBER 20

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007

500 AM HST MON AUG 13 2007

HURRICANE FLOSSIE IS NOT WILLING TO GIVE UP. DESPITE HINTS THAT THE HURRICANE MIGHT MOVE OVER COOLER OCEAN WATER TEMPERATURES...AND THAT IT WOULD EVENTUALLY ENCOUNTER HOSTILE VERTICAL WIND SHEAR...IT CONTINUES TO MAINTAIN ITS INTENSITY. THE LATEST SATELLITE INTENSITY ESTIMATES FROM JTWC AND SAB WERE 6.0...WHILE HFO REPORTED 5.5. THE ADT AT 1200 UTC IS 6.2...WHICH SUGGESTS A MAXIMUM SUSTAINED WIND SPEED OF 120 KT.

THE LATEST TRACK FORECAST IS CLOSE TO THE PREVIOUS ADVISORY PACKAGE. HOWEVER...THE FORECAST HAS BEEN ACCELERATED THROUGH 36 HOURS. THE FORECAST INTENSITY HAS ALSO BEEN INCREASED BASED ON THE GFDL INTENSITY GUIDANCE AND PERSISTENCE. BASED ON THE CURRENT TRACK FORECAST...INTENSITY AND RADII...THIS WILL RESULT IN WINDS OF TROPICAL STORM FORCE REACHING THE BIG ISLAND BY EARLY AFTERNOON TUESDAY. THEREFORE A HURRICANE WATCH IS NOW IN EFFECT FOR THE BIG ISLAND OF HAWAII. WARNINGS MAY BE REQUIRED FOR THE BIG ISLAND LATER TODAY. THIS MAY TAKE THE FORM OF A TROPICAL STORM WARNING IF THE PRESENT TRACK FORECAST APPEARS TO BE VERIFYING. AT THE MOMENT...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 13/1500Z 14.9N 149.5W 120 KT

12HR VT 14/0000Z 15.6N 151.4W 115 KT

24HR VT 14/1200Z 16.6N 153.8W 110 KT

36HR VT 15/0000Z 17.5N 155.8W 105 KT

48HR VT 15/1200Z 18.3N 157.8W 100 KT

72HR VT 16/1200Z 19.7N 161.5W 90 KT

96HR VT 17/1200Z 20.9N 165.2W 70 KT

120HR VT 18/1200Z 22.2N 170.0W 65 KT

[Somerset Squall]

Hurricane Flossie has weakened overnight and has been downgraded to a cat 3 hurricane with sustained winds of 105kts. The eye looks very rugged on the latest satellite image and it looks like Flossie is finally feeling the effects of cool waters and high shear. Hurricane watches are still out for Hawaii and tropical storm warnings have been issued.

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.

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

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

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Intense Hurricane FLOSSIE is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert City(s) and Town(s)

Hilo (19.7 N, 155.1 W)

probability for TS is 55% in about 21 hours

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Hurricane FLOSSIE is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert City(s) and Town(s)

Hilo (19.7 N, 155.1 W)

probability for TS is 65% within 9 hours

this one wont give up will it!

[Somerset Squall]

Indeed, it was a real fighter, and lasted as a hurricane far longer that The Central Pacific Hurricane Centre had ever imagined. I say lasted because this morning, Flossie is no longer a hurricane. It is providing heavy rain and tropical storm force winds to the Big Island, bur shear has torn the system apart and it is now a rapidly weakening storm.

TROPICAL STORM FLOSSIE DISCUSSION NUMBER 27

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007

1100 PM HST TUE AUG 14 2007 STRONG VERTICAL SHEAR IS NOW TEARING FLOSSIE APART.

HURRICANE FLOSSIE SURPRISED US BY MAINTAINING ITS STRENGTH AS LONG AS IT DID...BUT THE SYSTEM HAS WEAKENED RAPIDLY OVER THE PAST SEVERAL HOURS...AND IS NOW DOWN TO TROPICAL STORM STRENGTH. AIRCRAFT RECONNAISSANCE SHOWED THE CENTRAL PRESSURE HAD RISEN TO 993 MB AT 0513 UTC AND SATELLITE IMAGERY SHOWED THE TOPS OF THE SYSTEM SHEARING OFF TO THE NORTHEAST. THE LOW LEVEL CLOUD CENTER IS NOW EMERGING ON THE SOUTHWEST SIDE OF THE HIGH CLOUDS. WITH STRONG SHEAR CONTINUING OVER FLOSSIE WE ARE FORECASTING STEADY WEAKENING WITH ONLY A REMNANT LOW REMAINING BY 120 HOURS.

THE SPREAD IN THE MODEL GUIDANCE INCREASED QUITE A BIT ON THIS PACKAGE BUT WE SEE NO REASON TO DEPART FROM A WEST NORTHWEST TRACK. WE HAVE SHIFTED THE TRACK SLIGHTLY TO THE SOUTH AND SPEEDED IT UP A BIT TO REFLECT A GREATER INFLUENCE OF THE LOW LEVEL STEERING AS FLOSSIE BECOMES A SHALLOW SYSTEM.

FORECAST POSITIONS AND MAX WINDS

INITIAL 15/0900Z 17.5N 156.4W 60 KT

12HR VT 15/1800Z 17.9N 157.8W 50 KT

24HR VT 16/0600Z 18.5N 159.7W 45 KT

36HR VT 16/1800Z 19.1N 161.7W 40 KT

48HR VT 17/0600Z 19.6N 163.9W 35 KT

72HR VT 18/0600Z 20.4N 168.9W 30 KT

96HR VT 19/0600Z 21.3N 174.5W 25 KT...DISSIPATING

120HR VT 20/0600Z 22.0N 179.8E 25 KT...REMNANT LOW

$$

FORECASTER DONALDSON

[Somerset Squall]

Flossie has given up. There is no significant convection left around the centre as southwesterly shear has sheared it all away. Intensity is reduced to 30kt, which is remarked as being a bit generous- I agree, as the system is nothing but a naked swirl of clouds now.

TROPICAL DEPRESSION FLOSSIE DISCUSSION NUMBER 31

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007

1100 PM HST WED AUG 15 2007 CURRENT SATELLITE INTENSITY ESTIMATES ARE 2.0 FROM HFO AND JTWC...AND 3.1 FROM THE UW/CIMSS ADVANCED DVORAK TECHNIQUE (ADT). MANUAL LOCATION OF LOW LEVEL CLOUD CENTER IN LOCALLY RUN ADT GIVES 1.0. THE BURST OF CONVECTION THIS AFTERNOON WAS SHEARED OFF BY SOUTHWESTERLY WINDS ALOFT...AND THERE IS NO SIGN OF ANY REGENERATION OF THE CONVECTION. ALL THAT IS LEFT IS A LOW LEVEL CLOUD SWIRL...SO THE INITIAL INTENSITY HAS BEEN REDUCED TO A GENEROUS 30 KNOTS.

AS STATED IN THE PREVIOUS ADVISORY...THE MUCH WEAKENED FLOSSIE IS EXPECTED TO BE STEERED TOWARD THE WEST BY THE LOW LEVEL TRADE FLOW...AND WILL NOT REGENERATE DUE TO INCREASING SOUTHWESTERLY SHEAR AHEAD OF AN UPPER LEVEL TROUGH. ALTHOUGH AN OCCASIONAL CONVECTIVE FLAREUP MAY OCCUR IN THE NEXT DAY OR SO...IT WILL BE QUICKLY SHEARED TO THE NORTHEAST. THE TRACK FORECAST IS NUDGED SLIGHTLY SOUTHWARD DUE TO AN ADJUSTMENT IN THE 00Z FIX POSITION. THE NEXT ADVISORY WILL LIKELY BE THE LAST.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/0900Z 17.1N 160.7W 30 KT

12HR VT 16/1800Z 17.1N 162.3W 25 KT...REMNANT LOW

24HR VT 17/0600Z 17.3N 164.8W 20 KT...REMNANT LOW

36HR VT 17/1800Z 17.7N 167.5W 20 KT...DISSIPATED

48HR VT 18/0600Z 18.2N 170.2W 20 KT...DISSIPATED

72HR VT 19/0600Z 19.3N 175.7W 20 KT...DISSIPATED

96HR VT 20/0600Z 20.1N 178.9E 10 KT...DISSIPATED

120HR VT 21/0600Z 20.4N 173.5E 10 KT...DISSIPATED

$$

FORECASTER BROWNING