CPAC : TROPICAL DEPRESSION LANA (06E)

Moderator: S2k Moderators

Message
Author
User avatar
cycloneye
Admin
Admin
Posts: 138886
Age: 67
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC : TROPICAL STORM LANA (06E)

#121 Postby cycloneye » Sun Aug 02, 2009 10:00 am

TROPICAL STORM LANA DISCUSSION NUMBER 13
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062009
500 AM HST SUN AUG 02 2009

AT 200 AM HST...1200 UTC...LANA SHOWED NO SIGNS OF WEAKENING IN
SPITE OF THE 25 KT SOUTHWEST SHEAR CALCULATED BY UW-CIMSS TO BE IN
THE AREA. IN FACT...THUNDERSTORMS THAT FORMED 12 HOURS AGO WERE
STILL PRESENT NORTHEAST OF THE LOW LEVEL CIRCULATION CENTER. CLOUD
TOP TEMPERATURES HAVE BEEN STEADY AT -82C...OR ABOUT 52K FEET BASED
ON THE 1200Z HILO RAOB. PHFO AND SAB CAME UP WITH FINAL T NUMBERS
OF 3.0 WHILE JTWC WENT WITH 2.5. THE UW-CIMSS ADT HAD A CI NUMBER
OF 2.9 AT 1200Z AND 3.0 AT 1230Z. THE OFFICIAL INTENSITY ESTIMATE
REMAINS AT 45 KT...BASED ON THE PERSISTENT DEEP CONVECTION AND THE
MAJORITY OF FIXES AT OR CLOSE TO 3.0.

LANA LIES IN DEEP EASTERLY FLOW SOUTH OF A SUBTROPICAL RIDGE LOCATED
NORTH OF HAWAII. GLOBAL MODELS ARE IN GOOD AGREEMENT IN BUILDING
THE LOW- AND MID-LEVEL RIDGE TO THE WEST...KEEPING LANA WELL WITHIN
THE BROAD EASTERLY TRADE WIND BELT. THE WESTERLY FORECAST TRACK WAS
NUDGED SLIGHTLY SOUTH OF THE PREVIOUS TRACK AND REMAINS ON THE
SOUTH SIDE OF THE CLOSELY GROUPED OBJECTIVE AIDES. FORWARD MOTION
IS IN GOOD AGREEMENT WITH MOST OF THE AIDES AND IS AN EXTENSION OF
THE OLD TRACK.

AN UPPER-LEVEL LOW IS FORECAST TO LINGER SOUTHWEST OF KAUAI NEAR 18N
166W FOR THE NEXT 18 TO 24 HOURS...AND IS FORECAST TO MOVE SLOWLY
TO THE NORTHWEST THEREAFTER. SOUTHWEST WINDS ALOFT EAST OF THE LOW
WILL CONTINUE TO RIDE UP OVER THE LOW- AND MID-LEVEL EASTERLIES
RESULTING IN SUBSTANTIAL VERTICAL SHEARING AT LEAST FOR THE NEXT 24
HOURS. THAT SAID...THE FORECAST OF SLOWLY WEAKENING WINDS HAS BEEN
PUSHED BACK 6 HOURS BECAUSE OF LACK OF CHANGE IN INTENSITY OVER THE
LAST 24 HOURS. THE INTENSITY FORECAST IS CLOSE TO ICON...DSHP AND
SHIPS THROUGH 48 HOURS THEN SHIPS AND NGPI THEREAFTER.


FORECAST POSITIONS AND MAX WINDS

INITIAL 02/1500Z 14.4N 158.1W 45 KT
12HR VT 03/0000Z 14.5N 160.4W 40 KT
24HR VT 03/1200Z 14.8N 163.4W 35 KT
36HR VT 04/0000Z 15.2N 166.2W 35 KT
48HR VT 04/1200Z 15.5N 168.9W 30 KT
72HR VT 05/1200Z 16.1N 174.3W 25 KT...DISSIPATING
96HR VT 06/1200Z 16.6N 179.6W 20 KT...REMNANT LOW
120HR VT 07/1200Z 17.1N 174.8E 20 KT...REMNANT LOW

$$
FORECASTER CRAIG

0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 138886
Age: 67
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC : TROPICAL STORM LANA (06E)

#122 Postby cycloneye » Sun Aug 02, 2009 4:21 pm


TROPICAL STORM LANA DISCUSSION NUMBER 14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062009
1100 AM HST SUN AUG 02 2009

AT 800 AM HST...1800 UTC...LANA SHOWED SIGNS OF WEAKENING WITH DEEP
CONVECTION DETERIORATING IN THE NORTHEAST QUADRANT OF THE SYSTEM.
THE LOW LEVEL CLOUD CENTER IS GRADUALLY BECOMING MORE REMOVED FROM
THIS AREA OF DEEP CONVECTION. PHFO AND SAB CAME UP WITH FINAL T
NUMBERS OF 3.0 WHILE JTWC WENT WITH 2.5. DEEP CONVECTION HAS HAD A
HISTORY OF PULSING WITH THIS SYSTEM. THE OFFICIAL INTENSITY
ESTIMATE REMAINS AT 45 KT BUT THE CURRENT INTENSITY MAY BE A BIT
GENEROUS IF DEEP CONVECTION DOES NOT REFORM NEAR THE SYSTEMS CENTER
OVER THE NEXT SEVERAL HOURS.

LANA LIES IN DEEP EASTERLY FLOW SOUTH OF A SUBTROPICAL RIDGE LOCATED
NORTH OF HAWAII. GLOBAL MODELS ARE IN GOOD AGREEMENT IN BUILDING
THE LOW AND MID LEVEL RIDGE TO THE WEST...KEEPING LANA WELL WITHIN
THE BROAD EASTERLY TRADE WIND BELT. THE OFFICIAL TRACK REMAINS
NEARLY THE SAME AS THE PREVIOUS FORECAST AND LIES JUST SOUTH OF THE
VAST MAJORITY OF MODEL CONSENSUS WHICH IS CLOSELY GROUPED OVERALL.
FORWARD MOTION REMAINS IN GOOD AGREEMENT WITH MOST OF THE OBJECTIVE
AIDES AND IS AN EXTENSION OF THE OLD TRACK.

AN ELONGATED UPPER LEVEL TROUGH LIES TO THE WEST AND SOUTHWEST OF
KAUAI. THE UW-CIMSS OUTPUT SHOWS SOUTH TO SOUTHEASTERLY SHEAR
ESTIMATED TO BE ABOUT 25 KT IN THE VICINITY OF LANA. THIS SHOULD
CONTINUE TO INHIBIT ANY CHANCE OF RE-INTENSIFICATION. THIS TROUGH
IS EXPECTED TO MOVE WESTWARD OVER THE NEXT FEW DAYS AND GRADUALLY
WEAKEN WITH TIME. WITH LANA EXPECTED TO REMAIN IN A HOSTILE SHEAR
ENVIRONMENT...GRADUAL WEAKENING IS EXPECTED THROUGH THE FORECAST
PERIOD WHICH IS IN GENERAL AGREEMENT WITH INTENSITY GUIDANCE...WITH
ONLY THE UKMET AND SHIFOR5 KEEPING LANA AS A WEAK TROPICAL STORM
THROUGH 120 HOURS. THIS MAY BE DUE TO WARMER SEA SURFACE
TEMPERATURES ALONG THE FORECAST TRACK WELL SOUTHWEST OF THE MAIN
HAWAIIAN ISLANDS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 02/2100Z 14.5N 158.9W 45 KT
12HR VT 03/0600Z 14.6N 160.9W 40 KT
24HR VT 03/1800Z 15.0N 163.7W 35 KT
36HR VT 04/0600Z 15.3N 166.5W 35 KT
48HR VT 04/1800Z 15.6N 169.6W 30 KT
72HR VT 05/1800Z 16.2N 175.3W 25 KT...DISSIPATING
96HR VT 06/1800Z 16.8N 179.0E 20 KT...REMNANT LOW
120HR VT 07/1800Z 17.4N 173.7E 20 KT...REMNANT LOW

$$
FORECASTER BURKE

0 likes   

RL3AO
Moderator-Pro Met
Moderator-Pro Met
Posts: 16308
Joined: Thu Jun 14, 2007 10:03 pm
Location: NC

Re: CPAC : TROPICAL STORM LANA (06E)

#123 Postby RL3AO » Sun Aug 02, 2009 7:19 pm

Bye-bye.

Image
0 likes   

User avatar
brunota2003
S2K Supporter
S2K Supporter
Posts: 9476
Age: 33
Joined: Sat Jul 30, 2005 9:56 pm
Location: Stanton, KY...formerly Havelock, NC
Contact:

#124 Postby brunota2003 » Sun Aug 02, 2009 7:51 pm

Well, I cant quite call it a remnant low yet...so I cant say that my prediction of it being one by this evening or early tomorrow morning (eastern time) is right. I don't think that last convective burst was truly "organized"...perhaps DMAX and outflow boundary induced?
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 138886
Age: 67
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC : TROPICAL DEPRESSION LANA (06E)

#125 Postby cycloneye » Sun Aug 02, 2009 9:51 pm

Downgraded to depression

TROPICAL DEPRESSION LANA DISCUSSION NUMBER 15
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062009
500 PM HST SUN AUG 02 2009

LANA IS PRACTICALLY VOID OF ANY DEEP CONVECTION IN THE VICINITY OF
THE CIRCULATION CENTER. THUS LANA HAS BEEN DOWNGRADED TO A
DEPRESSION WITH THIS FORECAST PACKAGE. FINAL T NUMBERS RANGE FROM
2.0 TO 3.0 WITH THE HIGHER NUMBERS DUE TO DVORAK CONSTRAINTS.
SATELLITE IMAGERY SHOWS THAT LANA CONSISTS OF A SMALL LOW LEVEL
CLOUD SWIRL. THE PAST COUPLE OF IMAGES INDICATES THAT THE LOW LEVEL
SWIRL IS GRADUALLY DETERIORATING AS WELL. THE OFFICIAL INTENSITY
ESTIMATE IS 30 KT FOR THIS PACKAGE WITH THESE WINDS LIKELY CONFINED
TO THE NORTH SEMICIRCLE OF THE SYSTEM.

LANA REMAINS IN DEEP EASTERLY FLOW SOUTH OF A SUBTROPICAL RIDGE
LOCATED NORTH OF HAWAII. GLOBAL MODELS ARE IN GOOD AGREEMENT IN
BUILDING THE LOW AND MID LEVEL RIDGE TO THE WEST...KEEPING LANA
WELL WITHIN THE BROAD EASTERLY TRADE WIND BELT. THE OFFICIAL TRACK
REMAINS NEARLY THE SAME AS THE PREVIOUS FORECAST AND LIES JUST
SOUTH OF THE VAST MAJORITY OF MODEL CONSENSUS WHICH IS CLOSELY
GROUPED OVERALL. FORWARD MOTION REMAINS IN GOOD AGREEMENT WITH
MOST OF THE OBJECTIVE AIDES AND IS AN EXTENSION OF THE OLD TRACK.

AN ELONGATED UPPER LEVEL TROUGH LIES TO THE SOUTHWEST OF KAUAI. THE
LATEST UW-CIMSS OUTPUT SHOWS SOUTHWESTERLY SHEAR ESTIMATED TO BE
ABOUT 25 KT IN THE VICINITY OF LANA. THIS SHOULD CONTINUE TO INHIBIT
ANY CHANCE OF RE-INTENSIFICATION. THIS TROUGH IS EXPECTED TO MOVE
WESTWARD OVER THE NEXT FEW DAYS AND GRADUALLY WEAKEN WITH TIME.
WITH LANA EXPECTED TO REMAIN IN A HOSTILE SHEAR ENVIRONMENT OVER THE
NEXT FEW DAYS...GRADUAL WEAKENING IS EXPECTED TO CONTINUE WITH LANA
BECOMING A REMNANT LOW IN ABOUT 48 HOURS OR POSSIBLY SOONER. THIS
IS IN GOOD AGREEMENT WITH MOST OF THE INTENSITY GUIDANCE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 03/0300Z 14.5N 160.9W 30 KT
12HR VT 03/1200Z 14.7N 163.2W 30 KT
24HR VT 04/0000Z 15.1N 166.2W 25 KT...DISSIPATING
36HR VT 04/1200Z 15.4N 169.0W 25 KT...DISSIPATING
48HR VT 05/0000Z 15.7N 171.8W 20 KT...REMNANT LOW
72HR VT 06/0000Z 16.3N 177.8W 20 KT...REMNANT LOW
96HR VT 07/0000Z 16.9N 176.7E 20 KT...REMNANT LOW
120HR VT 08/0000Z 17.5N 171.3E 20 KT...REMNANT LOW

$$
FORECASTER BURKE


0 likes   

User avatar
brunota2003
S2K Supporter
S2K Supporter
Posts: 9476
Age: 33
Joined: Sat Jul 30, 2005 9:56 pm
Location: Stanton, KY...formerly Havelock, NC
Contact:

#126 Postby brunota2003 » Sun Aug 02, 2009 10:08 pm

I still hold with my prediction of a remnant low within the next 12 hours. I also am guessing that the remnant low will open up within the next 24 to 36 hours (if not sooner). Unless something happens, I think the last advisory will be written at 5 am ET, and it will probably be considered a remnant low. It has been devoid of convective activity for 3 to 6 hours now (depends on what you consider the convection in the NE quad, well away from the LLC).
0 likes   

User avatar
wxmann_91
Category 5
Category 5
Posts: 8013
Age: 32
Joined: Fri Jul 15, 2005 2:49 pm
Location: Southern California
Contact:

#127 Postby wxmann_91 » Mon Aug 03, 2009 12:47 am

Lana has been in the right entrance region of an upper jet which is typically associated with stronger upper divergence and increase vertical motion. That's whats been keeping Lana alive, and what has been responsible for the periodic convective bursts.
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 138886
Age: 67
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC : TROPICAL DEPRESSION LANA (06E)

#128 Postby cycloneye » Mon Aug 03, 2009 5:19 am

TROPICAL DEPRESSION LANA DISCUSSION NUMBER 16
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062009
1100 PM HST SUN AUG 02 2009

LANA IS DEVOID OF DEEP CONVECTION WITHIN 60 NM OF CENTER AS OF 800
PM HST...0600 UTC MONDAY...KEEPING THIS SYSTEM NO STRONGER THAN
DEPRESSION STATUS FOR THIS FORECAST PACKAGE. CPHC HAD TO RELY ON
MET TO DERIVE A CURRENT INTENSITY OF 2.0...WHILE JTWC JUDGED THIS
SYSTEM TOO WEAK TO CLASSIFY. SATELLITE LOOPS SHOW THAT LANA IS
MARKED BY A SWIRL OF LOW CLOUDS...WHILE SCATTERED TO SPOTTY BROKEN
HIGH CLOUDS FLY ACROSS THE CENTER TOWARDS THE NORTHEAST. THE
OFFICIAL INITIAL INTENSITY IS SET AT 30 KT WITH THESE WINDS LIKELY
CONFINED TO THE NORTHERN SEMICIRCLE.

LANA REMAINS IN DEEP EASTERLY FLOW SOUTH OF THE SUBTROPICAL RIDGE.
GLOBAL MODELS CONTINUE TO BUILD THIS RIDGE AS LANA MOVES
WESTWARD...KEEPING LANA WELL WITHIN THE BROAD EASTERLY TRADE WIND
BELT. THE OFFICIAL TRACK REMAINS THE SAME AS THE PREVIOUS
PACKAGE...LYING JUST SOUTH OF THE MAJORITY OF CLOSELY GROUPED MODEL
CONSENSUS. SYSTEM MOTION REMAINS IN GOOD AGREEMENT WITH MOST OF THE
OBJECTIVE AIDES.

HIGH CLOUDS MOVING RAPIDLY ACROSS THIS SYSTEM TOWARDS THE NORTHEAST
BETRAY THE PRESENCE OF DEBILITATING SHEAR. UW-CIMMS OUTPUT SHOWS
SOUTHWESTERLY SHEAR AT ABOUT 26 KT ACROSS LANA...WHILE SHIPS
INITIALIZES AT 34 KT FROM THE SAME DIRECTION. SHIPS FORECASTS SHEAR
TO REMAIN CHIEFLY IN THE 30 TO 40 KT RANGE THROUGH THE NEXT 120
HOURS. INDIVIDUAL THUNDERSTORMS LOVE SHEAR...SO CONVECTION MAY
OCCASIONALLY FLARE NEAR THE CENTER IN THE NEAR FUTURE...BUT WITH
SHEAR THIS STRONG LANA IS UNLIKELY TO REDEVELOP INTO A STRONGER
TROPICAL SYSTEM AS A WHOLE. THEREFORE...THE INTENSITY FORECAST
CALLS FOR LANA TO WEAKEN INTO A REMNANT LOW BY 36 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 03/0900Z 14.5N 162.0W 30 KT
12HR VT 03/1800Z 14.8N 164.2W 25 KT
24HR VT 04/0600Z 15.2N 167.3W 20 KT...DISSIPATING
36HR VT 04/1800Z 15.5N 170.2W 20 KT...REMNANT LOW
48HR VT 05/0600Z 15.8N 173.1W 20 KT...REMNANT LOW

$$
FORECASTER POWELL
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 37
Joined: Thu May 20, 2004 4:34 pm
Location: Key West, FL
Contact:

#129 Postby HURAKAN » Mon Aug 03, 2009 7:55 am

Image

CPHC keeps delaying the inevitable
0 likes   

User avatar
somethingfunny
ChatStaff
ChatStaff
Posts: 3926
Age: 35
Joined: Thu May 31, 2007 10:30 pm
Location: McKinney, Texas

Re:

#130 Postby somethingfunny » Mon Aug 03, 2009 8:06 am

HURAKAN wrote:
CPHC keeps delaying the inevitable


If this were the highlight of your entire year at work, wouldn't you want it to last as long as possible too?
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 37
Joined: Thu May 20, 2004 4:34 pm
Location: Key West, FL
Contact:

Re: Re:

#131 Postby HURAKAN » Mon Aug 03, 2009 8:15 am

somethingfunny wrote:
HURAKAN wrote:
CPHC keeps delaying the inevitable


If this were the highlight of your entire year at work, wouldn't you want it to last as long as possible too?


I understand that but even Dvorak is saying "Jim, it's dead."

03/1200 UTC 14.9N 163.1W TOO WEAK LANA -- Central Pacific
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 37
Joined: Thu May 20, 2004 4:34 pm
Location: Key West, FL
Contact:

Re: CPAC : TROPICAL DEPRESSION LANA (06E)

#132 Postby HURAKAN » Mon Aug 03, 2009 12:54 pm

Image

Image

Lana giving a good fight
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 138886
Age: 67
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC : TROPICAL DEPRESSION LANA (06E)

#133 Postby cycloneye » Mon Aug 03, 2009 1:00 pm

Last advisory written

TROPICAL DEPRESSION LANA DISCUSSION NUMBER 17
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062009
500 AM HST MON AUG 03 2009

THE STRONG VERTICAL WIND SHEAR CONTINUES TO TAKE ITS TOLL ON
TROPICAL DEPRESSION LANA. THE LATEST UW-CIMSS ENVIRONMENTAL VERTICAL
WIND SHEAR ANALYSIS INDICATED VALUES OF 25 KT FROM 230 DEG. THE
CENTER OF THE LOW LEVEL CIRCULATION CENTER...WHICH HAS BEEN DEVOID
OF DEEP CONVECTION SINCE SUNDAY...WAS DIFFICULT TO LOCATE AT 200 AM
HST...1200 UTC...THIS MORNING. FIXES FROM PHFO...JTWC AND SAB WERE
RATHER TIGHTLY CLUSTERED...EVEN THOUGH THE ACTUAL CIRCULATION HAS
BECOME MUCH LESS DEFINED IN INFRARED IMAGERY DURING THE PAST 6
HOURS. BASED ON THE LATEST INITIAL POSITION...LANA IS MOVING 280/14.
ALL OF THE SATELLITE AGENCIES INDICATED THE SYSTEM WAS TOO WEAK TO
CLASSIFY...WITH PHFO GIVING A T-NUMBER OF 1.5 BASED ON MET. THE
CURRENT UW-CIMSS INTENSITY ANALYSIS INDICATED A CI OF 1.0.
THEREFORE...THE INITIAL INTENSITY IS REDUCED TO 25 KT.

THE STEERING OF TROPICAL DEPRESSION LANA...WHICH IS BEING CARRIED BY
THE LOW-LEVEL FLOW DUE TO ITS LACK OF DEEP CONVECTION...IS BEING
CONTROLLED BY THE SUBTROPICAL RIDGE LOCATED TO THE NORTH OF THE
SYSTEM NEAR LATITUDE 28N. THIS RIDGING IS FORECAST TO REMAIN IN
PLACE FOR AT LEAST THE NEXT FEW DAYS...SO NO MAJOR CHANGES TO THE
FORECAST TRACK WERE MADE FOR THIS PACKAGE. HOWEVER...THE FORECAST
TRACK FOR LANA...OR ITS REMNANTS...WAS NUDGED SLIGHTLY TO THE RIGHT
IN DEFERENCE TO BAMS/BAMM...AS WELL AS THE TRACK CONSENSUS.

IN REGARD TO THE INTENSITY FORECAST...DESPITE WARM SSTS AND
INCREASINGLY FAVORABLE OCEAN HEAT CONTENT BASED ON THE LATEST CIRA
ANALYSIS...THE STRONG VERTICAL WIND SHEAR WILL BE THE LIMITING
FACTOR FOR LANA AS A VIABLE TROPICAL CYCLONE. THE LATEST SHIPS
FORECAST INDICATES SHEAR WILL BE INCREASING TO 30 KT OR GREATER
LATER TODAY. THIS FORECAST APPEARS TO BE REASONABLE SINCE WATER
VAPOR IMAGERY DEPICTS AN UPPER TROPOSPHERIC LOW CENTERED NEAR 17N
168W...OR ABOUT 350 NM NORTHWEST OF LANA. THE GFS MODEL INDICATES
THIS LOW WILL TRAVEL WESTWARD AS A COMPANION OF LANA DURING THE NEXT
FEW DAYS. THERE DOES NOT APPEAR TO BE A CHANCE FOR THE SYSTEM TO
EVER RECOVER FROM THIS HOSTILE ENVIRONMENT. THEREFORE...THIS WILL BE
THE LAST ADVISORY FOR TROPICAL DEPRESSION LANA ISSUED BY THE CENTRAL
PACIFIC HURRICANE CENTER.

FORECAST POSITIONS AND MAX WINDS

INITIAL 03/1500Z 14.9N 163.6W 25 KT...DISSIPATING
12HR VT 04/0000Z 15.3N 165.8W 20 KT...REMNANT LOW
24HR VT 04/1200Z 15.8N 168.7W 20 KT...REMNANT LOW
36HR VT 05/0000Z 16.3N 171.6W 20 KT...REMNANT LOW
48HR VT 05/1200Z 16.8N 174.5W 20 KT...REMNANT LOW

$$
FORECASTER HOUSTON
0 likes   


Return to “2009”

Who is online

Users browsing this forum: No registered users and 27 guests