CPAC: TROPICAL DEPRESSION GUILLERMO (10E)

[brunota2003]

I'm surprised this system is STILL kicking, and kicking up ACE...it is over some extremely cold waters.

[cycloneye]

TROPICAL STORM GUILLERMO DISCUSSION NUMBER 29
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
1100 PM HST TUE AUG 18 2009

GUILLERMO APPEARS TO BE HANGING ON FOR DEAR LIFE DESPITE NEARLY 40
KNOTS OF SHEAR ANALYZED OVER IT IN THE CIMSS VERTICAL SHEAR
ANALYSIS. A BURST OF NEW CONVECTION OCCURRED ON THE NORTHWEST SIDE
OF GUILLERMO OVER THE PAST FEW HOURS...BUT THE PRESENTATION OF THE
LOW CLOUD FIELD IN INFRARED IMAGERY APPEARS TO HAVE GRADUALLY
DEGRADED. A 0442Z QUIKSCAT PASS IS THE BASIS FOR MAINTAINING
GUILLERMO AS A 35 KT TROPICAL STORM IN THIS ADVISORY PACKAGE.

GUILLERMO IS CURRENTLY OVER SEA SURFACE TEMPERATURES OF ABOUT 26
DEGREES CELSIUS AND IS EXPECTED TO REMAIN OVER MARGINALLY WARM
WATER FOR THE NEXT THREE DAYS. GLOBAL MODELS ARE IN GOOD AGREEMENT
THAT THE SHEAR WILL CONTINUE TO WEAKEN OVER THE NEXT 24 HOURS AS
GUILLERMO MOVES UNDERNEATH THE TROUGH AXIS. AFTER 24 HOURS...THE
SHEAR REINTENSIFIES FROM A NORTHERLY DIRECTION. MOST OF THE
INTENSITY GUIDANCE RESPONDS BY MAINTAINING GUILLERMO AS A TROPICAL
STORM A LITTLE LONGER THAN PREVIOUSLY. WE HAVE SLOWED THE RATE OF
WEAKENING SLIGHTLY WITH THIS FORECAST PACKAGE.

THE INITIAL MOTION IS 310/16. GUILLERMO IS LOCATED TO THE
SOUTH-SOUTHWEST OF A LARGE 1028 MB HIGH OVER THE EASTERN NORTH
PACIFIC. THE DYNAMICAL MODELS KEEP GUILLERMO ON A NORTHWESTWARD
MOTION FOR THE NEXT 36 HOURS. BEYOND 36 HOURS...THE GUIDANCE
SPREAD INCREASES SIGNIFICANTLY...WITH SOME OF THE GUIDANCE
INCLUDING THE UKMET AND NOGAPS SUGGESTING SLOWING...THEN
RECURVATURE...WHILE THE GFS AND ECMWF SUGGEST THAT THE LOW LEVEL
CIRCULATION WILL CONTINUE FARTHER WESTWARD BEFORE DISSIPATING. THE
OFFICIAL FORECAST TRACK HAS BEEN SHIFTED TO THE RIGHT IN A NOD TO
THE CONSENSUS...BUT REMAINS ON THE LEFT SIDE OF THE GUIDANCE
SPREAD.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/0900Z 29.1N 153.5W 35 KT
12HR VT 19/1800Z 30.5N 155.6W 35 KT
24HR VT 20/0600Z 32.1N 158.4W 30 KT
36HR VT 20/1800Z 33.2N 160.8W 30 KT
48HR VT 21/0600Z 34.0N 163.2W 30 KT
72HR VT 22/0600Z 34.9N 166.3W 25 KT...DISSIPATING
96HR VT 23/0600Z...DISSIPATED

$$
FORECASTER R BALLARD

[cycloneye]

TROPICAL STORM GUILLERMO DISCUSSION NUMBER 30
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
500 AM HST WED AUG 19 2009

GUILLERMO CONTINUES TO HAVE LIMITED DEEP CONVECTION TO THE NORTH OF
AN EXPOSED LOW LEVEL CIRCULATION CENTER. LAST EVENING/S QUIKSCAT
PASS...AS WELL AS AN 0738Z ASCAT PASS...SHOW THAT THE STRONGEST
WINDS WITH GUILLERMO REMAIN CONFINED TO THE NORTHERN SEMICIRCLE.
THESE WINDS ARE AT LEAST PARTLY DUE TO THE STRONG PRESSURE GRADIENT
BETWEEN GUILLERMO AND A 1026 MB HIGH TO THE NORTHEAST. WE ARE
MAINTAINING GUILLERMO AS A 35 KT TROPICAL STORM FOR THIS ADVISORY
ISSUANCE BASED ON THE SCATTEROMETER DATA.

THE INITIAL MOTION IS UNCHANGED FROM THE PREVIOUS ADVISORY...310/16.
GUILLERMO IS CURRENTLY MOVING TOWARD A BREAK IN THE SUBTROPICAL
RIDGE TO THE NORTHWEST OF THE CYCLONE. THE TRACK GUIDANCE IS
ESSENTIALLY SPLIT INTO TWO CAMPS. ONE GROUP...INCLUDING NOGAPS...
HWRF...AND UKMET...INDICATE RECURVATURE INTO THE MID-LATITUDE
WESTERLIES AFTER ABOUT 24 HOURS. ON THE OTHER HAND...THE ECMWF...
GFS...AND GFDL MAINTAIN A NORTHWEST MOTION LONGER. IN FACT...THE
ECMWF IS STILL HANGING ON TO THE IDEA THAT GUILLERMO WILL
EVENTUALLY TURN BACK TOWARD THE WEST...WHICH IS STILL PLAUSIBLE IF
THE SYSTEM LOSES ITS REMAINING DEEP CONVECTION FASTER THAN
EXPECTED. THE OFFICIAL FORECAST CLOSELY FOLLOWS THE PREVIOUS
FORECAST THROUGH 24 HOURS...BUT HAS BEEN SHIFTED TO THE RIGHT AFTER
THAT IN AGREEMENT WITH THE MAJORITY OF THE MODEL GUIDANCE.

THE CYCLONE IS MOVING UNDERNEATH A TROPICAL UPPER TROPOSPHERIC
TROUGH THAT IS HELPING TO MAINTAIN DEEP CONVECTION. THE CIMSS SHEAR
ANALYSIS AND GLOBAL MODELS INDICATE THAT LATER TODAY THE CYCLONE
WILL BE MOVING UNDERNEATH A ZONE OF WEAKER SHEAR ALONG THE TROUGH
AXIS...ONLY TO BE REPLACED BY INCREASING NORTHERLY SHEAR ON THE
WEST SIDE OF THE TROUGH STARTING IN ABOUT 48 HOURS. GUILLERMO WILL
BE MOVING OVER SEA SURFACE TEMPERATURES OF 26 DEGREES CELSIUS FOR
THE NEXT 24 HOURS...THEN THE OFFICIAL TRACK TAKES GUILLERMO OVER
COOLER WATER. MOST OF THE INTENSITY GUIDANCE IS IN GOOD AGREEMENT
ABOUT KEEPING THE CYCLONE NEAR ITS CURRENT INTENSITY THROUGH 48
HOURS...AND OUR INTENSITY FORECAST MAINTAINS GUILLERMO AS A
TROPICAL STORM THROUGH 24 HOURS BEFORE BEGINNING A GRADUAL
WEAKENING TREND.


FORECAST POSITIONS AND MAX WINDS

INITIAL 19/1500Z 30.1N 154.9W 35 KT
12HR VT 20/0000Z 31.6N 157.1W 35 KT
24HR VT 20/1200Z 33.3N 159.7W 35 KT
36HR VT 21/0000Z 34.7N 161.9W 30 KT
48HR VT 21/1200Z 35.8N 163.5W 30 KT
72HR VT 22/1200Z 37.5N 165.4W 25 KT...DISSIPATING
96HR VT 23/1200Z...DISSIPATED

$$
FORECASTER R BALLARD

[cycloneye]

TROPICAL DEPRESSION GUILLERMO ADVISORY NUMBER 31
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
1100 AM HST WED AUG 19 2009

...GUILLERMO WEAKENS TO A DEPRESSION FAR NORTH OF THE HAWAIIAN
ISLANDS...

AT 1100 AM HST...2100 UTC...THE CENTER OF TROPICAL DEPRESSION
GUILLERMO WAS LOCATED NEAR LATITUDE 30.8 NORTH...LONGITUDE 155.4
WEST...OR ABOUT 675 MILES NORTH-NORTHEAST OF HONOLULU HAWAII.

GUILLERMO IS MOVING TOWARD THE NORTHWEST NEAR 14 MPH...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 24 HOURS. AFTER
24 HOURS...SOME SLOWING IN FORWARD MOTION...AND A SLIGHT TURN TO
THE NORTH...IS EXPECTED UNTIL DISSIPATION OCCURS IN 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH WITH HIGHER GUSTS. CONTINUED
GRADUAL WEAKENING IS FORECAST UNTIL DISSIPATION OCCURS IN 48 HOURS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1012 MB...29.88 INCHES.

...SUMMARY OF 1100 AM HST INFORMATION...
LOCATION...30.8N 155.4W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTHWEST OR 315 DEGREES AT 14 MPH
MINIMUM CENTRAL PRESSURE...1012 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE CENTRAL PACIFIC HURRICANE
CENTER AT 500 PM HST.

$$

FORECASTER BIRCHARD

[JonathanBelles]

Interesting that Guillermo is supposed to go north. Any chance at the remnants coming back to the east?

[cycloneye]

Last Advisory


WTPA34 PHFO 200312 CCA
TCPCP4

BULLETIN
TROPICAL DEPRESSION GUILLERMO ADVISORY NUMBER 32...CORRECTED
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102009
500 PM HST WED AUG 19 2009

...GUILLERMO DISSIPATING AS A TROPICAL DEPRESSION...

AT 500 PM HST...0300 UTC...THE CENTER OF DISSIPATING TROPICAL
DEPRESSION GUILLERMO WAS LOCATED NEAR LATITUDE 31.7 NORTH...
LONGITUDE 157.0 WEST...OR ABOUT 720 MILES NORTH OF HONOLULU HAWAII.

THE DISSIPATING DEPRESSION IS MOVING TOWARD THE NORTHWEST NEAR 15
MPH. THE REMNANT LOW PRESSURE SYSTEM IS FORECAST TO CONTINUE MOVING
NORTHWEST FOR THE NEXT 24 HOURS. AFTER 24 HOURS...SOME SLOWING IN
FORWARD MOTION...AND A TURN TO THE NORTH...IS EXPECTED UNTIL THE
LOW DISSIPATES IN 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH WITH HIGHER GUSTS...MAINLY
NORTH OF THE CENTER. CONTINUED GRADUAL WEAKENING IS FORECAST UNTIL
DISSIPATION OCCURS IN 48 HOURS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1012 MB...29.88 INCHES.

...SUMMARY OF 500 PM HST INFORMATION...
LOCATION...31.7N 157.0W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTHWEST OR 315 DEGREES AT 15 MPH
MINIMUM CENTRAL PRESSURE...1012 MB

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE CENTRAL PACIFIC
HURRICANE CENTER ON THIS SYSTEM.

$$

FORECASTER BIRCHARD

[brunota2003]

It was nice knowing you, Guillermo...you were entertaining, if not a bit odd.

[Chacor]

Not entirely convinced they should have killed it then. Their reasoning was a lack of central convection, but that had been the case for a while (winds were strong only thanks to the pressure gradient) - and convection had been building to the west of the centre for the first time in days.

Interesting models.

[Chacor]

Can't find an obvious centre on Guillermo IR any more, so perhaps it was right to kill it. Unless the centre is under the convection. In which case then obviously not.

[Cookie]

It was nice knowing you, Guillermo...you were entertaining, if not a bit odd.

agreed