CPAC: TROPICAL DEPRESSION GUILLERMO (10E)

[Kingarabian]

No update for Guillermo from NHC?

[HurricaneRobert]

It's weakened slightly. Now 110 mph with pressure of 958.

[clfenwi]

HURRICANE GUILLERMO DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009
ISSUED BY NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
200 PM PDT SAT AUG 15 2009

GUILLERMO REMAINS A WELL FORMED HURRICANE WITH DEEP CONVECTION
THROUGHOUT THE EYEWALL. THE EYE ITSELF IS PARTIALLY CLOUD-FILLED.
BASED ON A BLEND OF THE SATELLITE INTENSITY ESTIMATES...THE INITIAL
INTENSITY IS DECREASED TO 95 KT.

THE INTENSITY FORECAST IS CHANGED FROM THE PREVIOUS FORECAST...WITH
GRADUAL WEAKENING STARTING WITH THIS CYCLE RATHER THAN AFTER 12
HOURS. THE OFFICIAL FORECAST USES THE ICON BLEND...GFDL...LGEM...
SHIPS...AND HWRF...FOR THE FIRST 48 HOURS. AFTERWARD...THE FORECAST
IS A BLEND OF THE SHIPS AND LGEM.

THE INITIAL MOTION IS 290 DEG AT A SLIGHTLY SLOWER 12 KT. THE
CYCLONE IS MOVING WITHIN THE SOUTHWEST PERIPHERY OF A DEEP-LAYER
RIDGE EXTENDING FROM MEXICO WESTWARD OVER THE EASTERN PACIFIC.
HURRICANE GUILLERMO SHOULD MOVE IN A GENERAL WEST-NORTHWESTWARD
DIRECTION INTO A DEVELOPING WEAKNESS NORTHEAST OF THE HAWAIIAN
ISLANDS ON DAYS 4 AND 5. THE ADVISORY IS AN EXTENSION OF THE
PREVIOUS TRACK AND IS JUST SOUTH OF THE DYNAMICAL MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 15/2100Z 19.2N 134.5W 95 KT
12HR VT 16/0600Z 19.7N 136.5W 90 KT
24HR VT 16/1800Z 20.5N 139.0W 80 KT
36HR VT 17/0600Z 21.4N 141.6W 60 KT
48HR VT 17/1800Z 22.3N 144.1W 50 KT
72HR VT 18/1800Z 24.3N 149.2W 35 KT
96HR VT 19/1800Z 26.5N 154.5W 25 KT
120HR VT 20/1800Z 29.1N 160.7W 20 KT...REMNANT LOW

$$
FORECASTER CRAIG

[Alacane2]

Guillermo's newest advisory has been issued by the Central Pacific Hurricane Center. I guess the NHC had their hands full with Ana and Bill.

[bob rulz]

Guillermo's newest advisory has been issued by the Central Pacific Hurricane Center. I guess the NHC had their hands full with Ana and Bill.

Is that unusual? I don't recall anything like that ever happening but I suppose I don't really pay attention...

[brunota2003]

Guillermo is again grasping for attention...the eye is well defined on visible and IR, and it is trying to clear out yet again.

[clfenwi]

WTPZ45 KNHC 160249
TCDEP5
HURRICANE GUILLERMO DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009
800 PM PDT SAT AUG 15 2009

GUILLERMO HAS MAINTAINED ITS CONVECTIVE VIGOR OVER THE PAST SEVERAL
HOURS AND...IF ANYTHING...HAS DEVELOPED A MORE SYMMETRIC CENTRAL
DENSE OVERCAST SINCE EARLIER THIS AFTERNOON. A RATHER DISTINCT...
CLOUD-FILLED EYE IS ALSO OBSERVED...ALONG WITH A NUMBER OF
REASONABLY WELL-DEFINED BANDING FEATURES. SINCE 1800 UTC...DVORAK
INTENSITY ESTIMATES HAVE INCREASED TO 5.0 FROM TAFB AND SAB AND
SUGGEST THAT THE OVERALL ORGANIZATION OF GUILLERMO HAS AT LEAST
PERSISTED. BASED UPON THESE DATA AND OBJECTIVE DVORAK ESTIMATES AS
HIGH AS 5.6 FROM UW CIMSS ADT ANALYSES...THE OFFICIAL INTENSITY IS
HELD AT 95 KT.

THE INITIAL MOTION IS ESTIMATED AT 290/13...REPRESENTING A SLIGHTLY
MORE WEST-NORTHWESTWARD MOTION SINCE EARLIER TODAY. THE SYNOPTIC
REASONING BEHIND THE FORECAST REMAINS THE SAME. GUILLERMO IS
CURRENTLY MOVING AROUND THE SOUTHWEST PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE EXTENDING FROM THE THE SOUTHERN UNITED STATES
WESTWARD IN THE EAST PACIFIC TO PAST 140W. THIS WEATHER SYSTEM HAS
AND SHOULD CONTINUE TO KEEP GUILLERMO ON A STABLE...WEST-
NORTHWESTWARD TRACK THROUGH 48 HOURS. THEREAFTER...A RETROGRADING
MID- TO UPPER-LEVEL TROUGH IN THE VICINITY OF THE HAWAIIAN ISLANDS
SHOULD BEGIN TO INFLUENCE THE MOTION OF GUILLERMO BY IMPARTING A
SLIGHTLY MORE NORTHWARD COMPONENT OF MOTION. TOWARD THE END OF THE
PERIOD...THE LOW- TO MID-LEVEL FLOW SHOULD GUIDE A WEAKENING
GUILLERMO ON ESSENTIALLY THE SAME TRACK.

UNDER VERY LIGHT SHEAR...GUILLERMO HAS BEEN ABLE TO MAINTAIN ITS
INTENSITY IN SPITE OF MOVING OVER PROGRESSIVELY COOLER WATERS.
HOWEVER...THE CYCLONE SHOULD ENCOUNTER INCREASINGLY HOSTILE
SOUTHWESTERLY SHEAR WITHIN 24 HOURS AND EVEN COOLER SEA SURFACE
TEMPERATURES...WHICH SHOULD FINALLY RESULT IN A DECIDED WEAKENING.
THE OFFICIAL FORECAST IS AN UPDATE OF THE PREVIOUS ADVISORY AND IS
IN BEST AGREEMENT WITH ICON AND LGEM AND CLOSE TO THE FSU SUPER
ENSEMBLE...CALLING FOR GUILLERMO TO BECOME A REMNANT LOW BY DAY 4
AND TO DISSIPATE BY DAY 5.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/0300Z 19.7N 135.9W 95 KT
12HR VT 16/1200Z 20.3N 137.9W 80 KT
24HR VT 17/0000Z 21.1N 140.5W 70 KT
36HR VT 17/1200Z 22.0N 143.1W 55 KT
48HR VT 18/0000Z 23.1N 145.9W 45 KT
72HR VT 19/0000Z 25.5N 151.0W 35 KT
96HR VT 20/0000Z 28.0N 156.5W 25 KT...REMNANT LOW
120HR VT 21/0000Z 30.5N 162.5W 20 KT...DISSIPATED

$$
FORECASTER KIMBERLAIN/AVILA

[CrazyC83]

The 95 kt intensity might be a bit conservative right now. I'd put it at 105 kt.

[Kingarabian]

WTPZ45 KNHC 160249
TCDEP5
HURRICANE GUILLERMO DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009
800 PM PDT SAT AUG 15 2009

GUILLERMO HAS MAINTAINED ITS CONVECTIVE VIGOR OVER THE PAST SEVERAL
HOURS AND...IF ANYTHING...HAS DEVELOPED A MORE SYMMETRIC CENTRAL
DENSE OVERCAST SINCE EARLIER THIS AFTERNOON. A RATHER DISTINCT...
CLOUD-FILLED EYE IS ALSO OBSERVED...ALONG WITH A NUMBER OF
REASONABLY WELL-DEFINED BANDING FEATURES. SINCE 1800 UTC...DVORAK
INTENSITY ESTIMATES HAVE INCREASED TO 5.0 FROM TAFB AND SAB AND
SUGGEST THAT THE OVERALL ORGANIZATION OF GUILLERMO HAS AT LEAST
PERSISTED. BASED UPON THESE DATA AND OBJECTIVE DVORAK ESTIMATES AS
HIGH AS 5.6 FROM UW CIMSS ADT ANALYSES...THE OFFICIAL INTENSITY IS
HELD AT 95 KT.

THE INITIAL MOTION IS ESTIMATED AT 290/13...REPRESENTING A SLIGHTLY
MORE WEST-NORTHWESTWARD MOTION SINCE EARLIER TODAY. THE SYNOPTIC
REASONING BEHIND THE FORECAST REMAINS THE SAME. GUILLERMO IS
CURRENTLY MOVING AROUND THE SOUTHWEST PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE EXTENDING FROM THE THE SOUTHERN UNITED STATES
WESTWARD IN THE EAST PACIFIC TO PAST 140W. THIS WEATHER SYSTEM HAS
AND SHOULD CONTINUE TO KEEP GUILLERMO ON A STABLE...WEST-
NORTHWESTWARD TRACK THROUGH 48 HOURS. THEREAFTER...A RETROGRADING
MID- TO UPPER-LEVEL TROUGH IN THE VICINITY OF THE HAWAIIAN ISLANDS
SHOULD BEGIN TO INFLUENCE THE MOTION OF GUILLERMO BY IMPARTING A
SLIGHTLY MORE NORTHWARD COMPONENT OF MOTION. TOWARD THE END OF THE
PERIOD...THE LOW- TO MID-LEVEL FLOW SHOULD GUIDE A WEAKENING
GUILLERMO ON ESSENTIALLY THE SAME TRACK.

UNDER VERY LIGHT SHEAR...GUILLERMO HAS BEEN ABLE TO MAINTAIN ITS
INTENSITY IN SPITE OF MOVING OVER PROGRESSIVELY COOLER WATERS.
HOWEVER...THE CYCLONE SHOULD ENCOUNTER INCREASINGLY HOSTILE
SOUTHWESTERLY SHEAR WITHIN 24 HOURS AND EVEN COOLER SEA SURFACE
TEMPERATURES...WHICH SHOULD FINALLY RESULT IN A DECIDED WEAKENING.
THE OFFICIAL FORECAST IS AN UPDATE OF THE PREVIOUS ADVISORY AND IS
IN BEST AGREEMENT WITH ICON AND LGEM AND CLOSE TO THE FSU SUPER
ENSEMBLE...CALLING FOR GUILLERMO TO BECOME A REMNANT LOW BY DAY 4
AND TO DISSIPATE BY DAY 5.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/0300Z 19.7N 135.9W 95 KT
12HR VT 16/1200Z 20.3N 137.9W 80 KT
24HR VT 17/0000Z 21.1N 140.5W 70 KT
36HR VT 17/1200Z 22.0N 143.1W 55 KT
48HR VT 18/0000Z 23.1N 145.9W 45 KT
72HR VT 19/0000Z 25.5N 151.0W 35 KT
96HR VT 20/0000Z 28.0N 156.5W 25 KT...REMNANT LOW
120HR VT 21/0000Z 30.5N 162.5W 20 KT...DISSIPATED

$$
FORECASTER KIMBERLAIN/AVILA

The eye looks pretty clear to me.

[cycloneye]

WTPZ45 KNHC 161436
TCDEP5
HURRICANE GUILLERMO DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009
800 AM PDT SUN AUG 16 2009

SATELLITE IMAGES INDICATE THAT THE CLOUD CANOPY ASSOCIATED WITH
GUILLERMO IS BECOMING SOMEWHAT ASYMMETRIC AS THE CYCLONE BEGINS TO
FEEL THE EFFECTS OF INCREASING SHEAR. HOWEVER...THE EYE REMAINS
DISTINCT AND RECENTLY THE EYEWALL CONVECTION HAS INCREASED A BIT.
THE INITIAL INTENSITY IS HELD AT 85 KT. A RAPID WEAKENING IS
LIKELY FOR GUILLERMO BY TONIGHT DUE TO A SIGNIFICANT INCREASE IN
VERTICAL WIND SHEAR AND ITS CONTINUED PASSAGE OVER COOL WATERS. THE
INTENSITY FORECAST IS SIMILAR TO THE LAST ONE AND IS IN GOOD
AGREEMENT WITH THE SHIPS MODEL. GUILLERMO SHOULD TRANSITION TO A
REMNANT LOW IN A FEW DAYS DUE TO VERY STRONG VERTICAL WIND SHEAR.

THE INITIAL MOTION REMAINS 280/13. THERE IS LITTLE CHANGE TO THE
SYNOPTIC REASONING WITH A MID-LEVEL RIDGE TO THE NORTHEAST OF
GUILLERMO STEERING THE HURRICANE ON A WEST-NORTHWEST PATH FOR THE
NEXT SEVERAL DAYS. A LARGE MID- TO UPPER-LEVEL LOW DEVELOPING NEAR
HAWAII WILL LIKELY CAUSE A NORTHWESTWARD BEND IN THE TRACK BY THE
END OF THE FORECAST PERIOD. THE TRACK FORECAST IS BASICALLY AN
UPDATE OF THE PREVIOUS PACKAGE WITH VERY FEW CHANGES IN MODEL
GUIDANCE NOTED.


FORECAST POSITIONS AND MAX WINDS

INITIAL 16/1500Z 20.1N 138.7W 85 KT
12HR VT 17/0000Z 20.6N 140.7W 70 KT
24HR VT 17/1200Z 21.6N 143.5W 55 KT
36HR VT 18/0000Z 22.7N 146.4W 45 KT
48HR VT 18/1200Z 24.0N 149.3W 40 KT
72HR VT 19/1200Z 27.0N 155.0W 30 KT...REMNANT LOW
96HR VT 20/1200Z 31.0N 162.0W 25 KT...REMNANT LOW
120HR VT 21/1200Z...DISSIPATED

$$
FORECASTER BLAKE

[cycloneye]

KNHC 162040
TCDEP5
HURRICANE GUILLERMO DISCUSSION NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009
200 PM PDT SUN AUG 16 2009

VERTICAL WIND SHEAR IS FINALLY TAKING A TOLL ON GUILLERMO...AS
VISIBLE SATELLITE IMAGES SHOWING ONLY A FAINT EYE AND AN ASYMMETRIC
CENTRAL DENSE OVERCAST. THE INITIAL INTENSITY IS REDUCED TO 75 KT.
CONTINUED WEAKENING IS LIKELY WITH THE SHIPS MODEL DIAGNOSING 30 KT
OF SHEAR BEGINNING OVERNIGHT. THE INTENSITY FORECAST IS BASICALLY
AN UPDATE OF THE PREVIOUS ADVISORY AND IS SIMILAR TO A BLEND OF THE
HWRF/SHIPS/LGEM. THE GFDL UNREALISTICALLY RE-INTENSIFIES THE
VORTEX AT THE END OF PERIOD AND IS DISREGARDED AT THIS TIME.

THE INITIAL MOTION HAS NOT CHANGED MUCH AND IS NOW 285/12. GUILLERMO
IS EXPECTED TO MOVE IN BETWEEN A SUBTROPICAL RIDGE TO THE NORTHEAST
AND A MID- TO UPPER-LEVEL TROUGH TO THE WEST OF THE TROPICAL
CYCLONE. THIS PATTERN SHOULD CAUSE A GRADUAL BEND FROM A
WEST-NORTHWEST TO A NORTHWEST TRACK AND SOME INCREASE IN FORWARD
SPEED. THE MODELS ARE VERY TIGHTLY CLUSTERED ON THIS TRACK FOR
SEVERAL DAYS AND NO SIGNIFICANT CHANGES WERE MADE TO THE OFFICIAL
NHC FORECAST. THERE IS SOME SUGGESTION BY SOME MODELS THAT WHATEVER
IS LEFT OF GUILLERMO MIGHT MOVE MORE A LITTLE MORE TO THE WEST AT
THE END OF THE FORECAST PERIOD...AND THE OFFICIAL FORECAST IS
NUDGED IN THAT DIRECTION AT 96 HOURS.

THIS IS THE LAST ADVISORY ON THIS SYSTEM ISSUED BY THE NATIONAL
HURRICANE CENTER. FUTURE DISCUSSION WILL BE ISSUED BY THE CENTRAL
PACIFIC HURRICANE CENTER UNDER AWIPS HEADER TCDCP4 AND WMO HEADER
WTPA44 PHFO.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/2100Z 20.4N 139.8W 75 KT
12HR VT 17/0600Z 21.0N 141.9W 60 KT
24HR VT 17/1800Z 22.0N 144.8W 50 KT
36HR VT 18/0600Z 23.3N 147.9W 40 KT
48HR VT 18/1800Z 24.8N 150.8W 35 KT
72HR VT 19/1800Z 28.5N 157.5W 25 KT...REMNANT LOW
96HR VT 20/1800Z 31.5N 164.0W 20 KT...REMNANT LOW
120HR VT 21/1800Z...DISSIPATED

$$
FORECASTER BLAKE

[Macrocane]

Why is the CPHC issuing advisories on tropical depression 03-C?

[cycloneye]

WTPA44 PHFO 170908
TCDCP4

TROPICAL STORM GUILLERMO DISCUSSION NUMBER 21
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
1100 PM HST SUN AUG 16 2009

SHEAR CONTINUES TO WEAKEN GUILLERMO. THE LOW LEVEL CENTER IS PARTLY
EXPOSED ON THE SOUTHWEST SIDE OF THE SYSTEM. INFRARED SATELLITE
IMAGERY SHOWS ONLY A SMALL AMOUNT OF DEEP CONVECTION...AND THAT IS
DISPLACED ABOUT 60 NM NORTHEAST OF THE CENTER. THE REMAINING HIGH
CLOUDS ARE BECOMING STRETCHED OUT ALONG A NORTH SOUTH AXIS.
GUILLERMO IS CLEARLY WEAKENING RATHER QUICKLY DUE TO STRONG WEST
SOUTHWEST SHEAR. SUBJECTIVE DVORAK ANALYSES KEPT GUILLERMO ABOVE
HURRICANE STRENGTH...BUT THE DVORAK CONSTRAINTS MAY MAKE INTENSITY
ESTIMATES TOO HIGH IN A RAPIDLY SHEARING SYSTEM. GIVEN THE RAPID
DETERIORATION OF THE CLOUD PATTERN IT SEEMS REASONABLE TO DOWNGRADE
GUILLERMO TO TROPICAL STORM STRENGTH.

THE HIGH CLOUDS HAVE NOT YET SHEARED FAR ENOUGH AWAY TO GIVE A CLEAR
VIEW OF THE LOW LEVEL CENTER...SO THE SATELLITE POSITION ESTIMATES
AT 0600 UTC WERE A BIT UNCERTAIN. MICROWAVE PASSES AT 0255 AND 0325
UTC SUGGEST THAT THE CENTER MAY HAVE BEEN FARTHER SOUTH THAN THE
0600 UTC FIXES INDICATED AND OUR 0000 UTC POSITION MAY HAVE BEEN
TOO FAR NORTH. I HAVE RE-BESTED THE 0000 UTC POSITION AND SHIFTED
THE TRACK SLIGHTLY TO THE LEFT. THE TRACK CONTINUES CLOSE TO A
CONSENSUS OF THE DYNAMIC MODELS. WE WILL BE WATCHING TO SEE IF THE
TRACK WILL NEED TO BE SHIFTED FARTHER TO THE LEFT IF GUILLERMO
BECOMES A SHALLOW SYSTEM MORE QUICKLY THAN WE HAVE FORECAST.

GUILLERMO REMAINS OVER COOL...24.5 DEGREES CELSIUS... WATER.
GUILLERMO WILL MOVE OVER WARMER WATER AFTER ABOUT 36 HOURS...BUT IT
MAY NOT MATTER. THERE IS STRONG WEST SOUTHWEST SHEAR ACROSS THE
SYSTEM AND THE SHEAR WILL BECOME EVEN STRONGER OVER THE NEXT 48
HOURS. THIS STRONG SHEAR SHOULD STEADILY WEAKEN GUILLERMO. ONCE
GUILLERMO HAS BEEN REDUCED TO A SHALLOW LOW...WARMER WATER IS
UNLIKELY TO BE ENOUGH TO ALLOW THE SYSTEM TO REGENERATE.


FORECAST POSITIONS AND MAX WINDS

INITIAL 17/0900Z 20.8N 142.6W 60 KT
12HR VT 17/1800Z 21.5N 144.8W 50 KT
24HR VT 18/0600Z 22.8N 147.8W 40 KT
36HR VT 18/1800Z 24.4N 150.7W 35 KT
48HR VT 19/0600Z 26.2N 154.0W 35 KT
72HR VT 20/0600Z 28.9N 161.1W 30 KT...REMNANT LOW
96HR VT 21/0600Z 29.6N 167.8W 25 KT...REMNANT LOW
120HR VT 22/0600Z 29.5N 173.3W 20 KT...REMNANT LOW

$$
FORECASTER DONALDSON

[cycloneye]

WTPA44 PHFO 172100
TCDCP4

TROPICAL STORM GUILLERMO DISCUSSION NUMBER 23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
1100 AM HST MON AUG 17 2009

TROPICAL STORM GUILLERMO MAINTAINS ITS WEAKENING TREND. THE LOW
LEVEL CENTER OF CIRCULATION IS TOTALLY EXPOSED WITH THE CLOSEST
CONVECTION 100 NM NNW OF THE CENTER. THE LATEST MICROWAVE PASS
SHOWS HEAVY RAIN ASSOCIATED WITH THE CONVECTION TO THE NW...AND
QUIKSCAT VERIFIES TROPICAL STORM FORCE WINDS ON THE NORTH SIDE OF
THE CIRCULATION.

STRONG SOUTHWEST SHEAR...IN EXCESS OF 40 KT THIS MORNING...CONTINUES
TO WEAKEN THE SYSTEM...ALONG WITH SST/S BELOW FAVORABLE
TEMPERATURES. WE HAVE DROPPED THE INITIAL INTENSITY TO 45 KT KEEPING
IN LINE WITH THE WEAKENING TREND...COMPLYING WITH DVORAK
CONSTRAINTS AND THE CURRENT ROUND OF SUBJECTIVE DVORAK CI NUMBERS.
THE INITIAL MOTION OF GUILLERMO IS WEST NORTHWEST AT 16 KT AND IS
EXPECTED TO CONTINUE AT THIS DIRECTION AND SPEED THROUGH 48 HOURS.
THE TRACK REMAINS SIMILAR TO THE PREVIOUS FORECAST AND IS IN GOOD
AGREEMENT WITH THE CONSENSUS MODELS. ALL TRACK GUIDANCE REMAINS
TIGHTLY PACKED...WITH EVEN THE LEFT OUTLIER REMAINING NORTH OF THE
MAIN HAWAIIAN ISLANDS AT ALL TIME STEPS.

THIS SYSTEM IS IN SPIN-DOWN MODE...KEPT ALIVE MAINLY THROUGH
MOMENTUM AND A DESIRE TO STAY WITHIN DVORAK CONSTRAINTS. WITH THE
SHEAR AND SST/S CREATING HOSTILE CONDITIONS FOR GUILLERMO...THE
SYSTEM IS EXPECTED TO WEAKEN FURTHER...AND BECOME A REMNANT LOW IN
48 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 17/2100Z 22.3N 146.0W 45 KT
12HR VT 18/0600Z 23.3N 148.4W 40 KT
24HR VT 18/1800Z 24.8N 151.5W 35 KT
36HR VT 19/0600Z 26.2N 154.6W 30 KT
48HR VT 19/1800Z 27.3N 158.2W 25 KT...REMNANT LOW
72HR VT 20/1800Z 28.5N 165.1W 20 KT...DISSIPATING
96HR VT 21/1800Z...DISSIPATED

$$

FORECASTER POWELL/MORRISON

[cycloneye]

WTPA34 PHFO 180245
TCPCP4

BULLETIN
TROPICAL STORM GUILLERMO ADVISORY NUMBER 24
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
500 PM HST MON AUG 17 2009

...TROPICAL STORM GUILLERMO WEAKENING RAPIDLY...

AT 500 PM HST...0300 UTC...THE CENTER OF TROPICAL STORM GUILLERMO
WAS LOCATED NEAR LATITUDE 23.1 NORTH...LONGITUDE 147.8 WEST OR
ABOUT 525 MILES...EAST-NORTHEAST OF HILO HAWAII AND ABOUT 660
MILES...EAST-NORTHEAST OF HONOLULU HAWAII.

GUILLERMO IS MOVING TOWARD THE WEST-NORTHWEST NEAR 20 MPH...AND
THIS MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 48 HOURS THROUGH
SYSTEM DISSIPATION.

MAXIMUM SUSTAINED WINDS ARE NEAR 45 MPH...WITH HIGHER GUSTS.
SYSTEM IS FORECAST TO WEAKEN THROUGH DISSIPATION IN 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES FROM THE
CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB...29.65 INCHES.

...SUMMARY OF 500 PM HST INFORMATION...
LOCATION...23.1N 147.8W
MAXIMUM SUSTAINED WINDS...45 MPH
PRESENT MOVEMENT...WEST-NORTHWEST OR 300 DEGREES AT 20 MPH
MINIMUM CENTRAL PRESSURE...1004 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE CENTRAL PACIFIC HURRICANE
CENTER AT 1100 PM HST.

$$
FORECASTER POWELL/MORRISON

[hcane27]

Why is the CPHC issuing advisories on tropical depression 03-C?

because once the system passed to the west of 140W it comes under the purview of the CPHC in Hawaii

[cycloneye]

TROPICAL STORM GUILLERMO DISCUSSION NUMBER 27
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
1100 AM HST TUE AUG 18 2009

TROPICAL STORM GUILLERMO HAS MANAGED TO MAINTAIN ITS INTENSITY THIS
MORNING DESPITE ITS RAGGED APPEARANCE ON SATELLITE AND BEING IN
AN ENVIRONMENT OF STRONG VERTICAL WIND SHEAR. THE SOUTHWESTERLY
WIND SHEAR...IN EXCESS OF 40 KT ACCORDING TO THE RECENT UW-CIMSS
ANALYSIS...IS BEING CREATED BY AN UPPER LOW CENTERED ABOUT 650
MILES TO THE SOUTHWEST OF GUILLERMO. THIS UPPER LOW IS ALSO
CREATING OUTFLOW ALOFT THAT HAS HELPED TO MAINTAIN DEEP CONVECTION
WITHIN THE NORTH QUADRANT OF GUILLERMO. THIS...TOGETHER WITH A
TIGHT PRESSURE GRADIENT BETWEEN THE SYSTEM AND A 1030 MB SURFACE
HIGH TO THE NORTH...HAS ALLOWED GUILLERMO TO MAINTAIN ITS
INTENSITY.

A MORNING QUIKSCAT PASS INDICATES AN ASYMMETRIC WIND FIELD...WITH A
BROAD AREA OF TROPICAL STORM FORCE WINDS WITHIN THE NORTHERN
QUADRANT AND MUCH WEAKER WINDS TO THE SOUTH. AN AMBIGUITY ANALYSIS
ON THESE DATA CONFIRMED THE PRESENCE OF A CLOSED CIRCULATION...
DESPITE THE RAGGED AND ELONGATED APPEARANCE OF THE LOW LEVEL CENTER
ON VISIBLE SATELLITE. CURRENT INTENSITY VALUES FROM ALL THE FIX
AGENCIES CAME IN AT 2.0...SUGGESTING A WEAKER SYSTEM...BUT THE
UW-CIMSS SATCON ESTIMATE ESTIMATED 39 KT...MAINLY DUE TO AMSU
DETECTING A PERSISTENT WARM CORE ALOFT. THUS...THE INITIAL
INTENSITY IS HELD AT 40 KT.

THE FORECAST CONTINUES TO MOVE GUILLERMO TO THE NORTHWEST OVER THE
NEXT 36 TO 48 HOURS INTO A WEAKNESS IN THE LOW TO MID LEVEL RIDGE
TO THE NORTH CREATED BY THE ABOVE MENTIONED UPPER LOW. DURING THIS
TIME...SOUTHERLY VERTICAL WIND SHEAR SHOULD TAKE ITS TOLL ON
GUILLERMO...WEAKENING THE SYSTEM TO A DEPRESSION BY 24 HOURS AND
NOT ALLOWING IT TO TAKE ADVANTAGE OF WARMING SST ALONG THE TRACK.
AROUND 48 HOURS THE SHEAR WILL SHIFT FROM THE NORTHEAST AND REMOVE
THE DIFLUENT FLOW ALOFT CURRENTLY SUPPORTING CONVECTION. THE
DISSIPATING SYSTEM IS THEN FORECAST TO TURN ON A WESTERLY THEN WEST
SOUTHWEST TRACK AS IT WEAKENS INTO A REMNANT LOW BY 96 HOURS AND
BECOMES STEERED BY THE LOW LEVEL FLOW. THE TRACK SCENARIO FALLS
ROUGHLY IN THE MIDDLE OF THE DYNAMICAL GUIDANCE ENVELOPE AND CLOSE
TO THE HWRF...WHILE THE INTENSITY FORECAST WEAKENS THE SYSTEM
SLIGHTLY FASTER THAN GUIDANCE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 18/2100Z 27.0N 151.2W 40 KT
12HR VT 19/0600Z 28.6N 153.7W 35 KT
24HR VT 19/1800Z 30.0N 157.1W 30 KT
36HR VT 20/0600Z 30.9N 160.5W 30 KT
48HR VT 20/1800Z 31.4N 163.4W 25 KT
72HR VT 21/1800Z 31.2N 169.1W 25 KT...DISSIPATING
96HR VT 22/1800Z 30.4N 174.6W 20 KT...REMNANT LOW
120HR VT 23/1800Z 28.8N 179.9E 20 KT...REMNANT LOW

$$
FORECASTER WROE

[cycloneye]

TROPICAL STORM GUILLERMO DISCUSSION NUMBER 28
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
500 PM HST TUE AUG 18 2009

THE SATELLITE SIGNATURE OF GUILLERMO HAS DEGRADED THIS AFTERNOON AS
THE COVERAGE OF DEEP CONVECTION WITHIN THE NORTHERN QUADRANT
DIMINISHED. ONLY A NARROW BAND OF THUNDERSTORMS PERSISTS ABOUT 100
MILES NORTHWEST OF THE CENTER. WHAT IS LEFT OF THE CONVECTION IS
BEING DRIVEN BY LOW LEVEL CONVERGENCE BETWEEN GUILLERMO AND A
STRONG HIGH TO THE NORTHEAST. MEANWHILE...GUILLERMO REMAINS DEVOID
OF DEEP CONVECTION TO THE SOUTH. AS A RESULT...CI NUMBERS FROM JTWC
AND HFO HAVE DROPPED TO 1.5...AND THE ADT CI FROM UW-CIMSS DROPPED
TO 1.2. AN ASCAT PASS AT 2032Z JUST MISSED GUILLERMO TO THE WEST
BUT DETECTED SOME 35 TO 40 KT WINDS TO THE NORTHWEST OF THE CENTER.
GIVEN THE TRENDS IN CONVECTION AND THE DVORAK NUMBERS BASED ON
SATELLITE SIGNATURE...THE INITIAL INTENSITY IS DROPPED TO 35 KT.

STEADY WEAKENING IS FORECAST AS STRONG SOUTHWESTERLY TO SOUTHERLY
WIND SHEAR PERSISTS OVER THE NEXT 36 HOURS. THE SOUTHWESTERLY
WIND SHEAR...IN EXCESS OF 40 KT ACCORDING TO THE LATEST UW-CIMSS
ANALYSIS...IS BEING PRODUCED BY AN UPPER LOW CENTERED ABOUT 625
MILES TO THE SOUTHWEST OF GUILLERMO. THE SHEAR MAY BRIEFLY RELAX
BEYOND 36 HOURS...BUT THE FORECAST CALLS FOR GUILLERMO TO BE A WEAK
TROPICAL DEPRESSION BY THAT TIME WITH MUCH...IF NOT ALL...OF ITS
WARM CORE DESTROYED. BEYOND THAT TIME...GUILLERMO IS FORECAST TO
ENCOUNTER NORTHERLY WIND SHEAR WHICH IS EXPECTED TO INDUCE FURTHER
WEAKENING TO A REMNANT LOW BY 72 HOURS. IT IS IMPORTANT TO NOTE THAT
THE FORECAST WEAKENING TREND IS FASTER THAN ALL THE INTENSITY
GUIDANCE...WHICH KEEP A STRONGER SYSTEM DESPITE THE VERY HIGH
AMOUNT OF VERTICAL WIND SHEAR.

GUILLERMO IS FORECAST MOVE TO THE NORTHWEST OVER THE NEXT 36 HOURS
INTO A WEAKNESS IN THE LOW TO MID LEVEL RIDGE TO THE NORTH CREATED
BY THE ABOVE MENTIONED UPPER LOW. THE FORECAST HAS BEEN SHIFTED TO
THE NORTH SLIGHTLY TO FOLLOW RECENT TRENDS IN MOTION AND TO BE
ROUGHLY DOWN THE MIDDLE OF THE DYNAMIC GUIDANCE. BEYOND 36 HOURS...
THE TRACK OF GUILLERMO HAS BEEN SLOWED AND SHIFTED NORTHWARD TOWARD
A WEAKNESS IN THE LOW LEVEL RIDGE. IT IS WORTH NOTING THAT MOST OF
THE CONSENSUS AND DYNAMIC MODELS HAVE ALSO SLOWED BEYOND 48 HOURS
AND SHIFTED NORTHWARD...WHILE THE BAM MODELS AND THE NOGAPS SHOW
GUILLERMO RECURVING AND BEING CAUGHT UP IN THE WESTERLIES. THE
FORECAST CALLS FOR GUILLERMO TO DISSIPATE BEFORE THIS COULD OCCUR.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/0300Z 28.1N 152.2W 35 KT
12HR VT 19/1200Z 29.4N 154.5W 30 KT
24HR VT 20/0000Z 30.6N 157.7W 25 KT
36HR VT 20/1200Z 31.5N 161.0W 25 KT
48HR VT 21/0000Z 32.1N 163.8W 20 KT
72HR VT 22/0000Z 32.7N 167.8W 20 KT...DISSIPATING
96HR VT 23/0000Z...DISSIPATED

$$
FORECASTER WROE

[Chacor]

Why is the CPHC issuing advisories on tropical depression 03-C?

That was a computer glitch; the date displayed was from 2006.

Guillermo's newest advisory has been issued by the Central Pacific Hurricane Center. I guess the NHC had their hands full with Ana and Bill.

Is that unusual? I don't recall anything like that ever happening but I suppose I don't really pay attention...

There's a set order for backup stations, the NHC's is the Hydrometeorological Prediction Center in Maryland (at least for Atlantic storms, not sure about Pacific ones). It's possible they requested the CPHC issue the advisory.

[Macrocane]

Thanks for the reply Chacor, better late than never.