CPAC: TROPICAL DEPRESSION NEKI (03C)

Moderator: S2k Moderators

Message
Author
User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: HURRICANE NEKI (03C)

#161 Postby cycloneye » Thu Oct 22, 2009 10:10 pm

HURRICANE NEKI DISCUSSION NUMBER 18
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 PM HST THU OCT 22 2009

HURRICANE NEKI IS SLOWLY WEAKENING AS STRONG SOUTHWESTERLY SHEAR
CONTINUES TO IMPACT THE SYSTEM. FIXES FROM CPHC...JTWC...AND SAB
ALL CAME IN WITH CI VALUES OF 4.5 TO 5.0. RECENT IR SATELLITE
IMAGERY SHOWS WARMING CLOUD TOPS SO THE INITIAL INTENSITY HAS BEEN
LOWERED TO 85 KT.

MODELS ARE IN GOOD AGREEMENT WITH A CONTINUED NORTH-NORTHEAST MOTION
IN THE SHORT TERM THEN A TURN MORE TO THE NORTHEAST WITH GRADUAL
ACCELERATION EXPECTED AS THE SYSTEM INTERACTS WITH AN ENCROACHING
FRONT AND ITS ASSOCIATED UPPER LEVEL TROUGH. THE LATEST FORECAST
TRACK IS PRETTY MUCH DOWN THE MIDDLE OF THE GUIDANCE AND ESSENTIALLY
UNCHANGED FROM THE PREVIOUS FORECAST.

NEKI WILL REMAIN OVER 26 C OR WARMER WATER THROUGH ABOUT 36
HOURS...THEN MOVE ACROSS COOLER WATERS THROUGH THE REST OF ITS
FORECAST TRACK. THE LATEST UW-CIMSS VERTICAL WIND SHEAR PRODUCT
SHOWS SOUTHWEST SHEAR OF 26 KT. THIS STRONG SHEAR IS EXPECTED TO
CONTINUE FOR THE NEXT SEVERAL DAYS AND WILL BE THE PRIMARY KEY IN
THE WEAKENING PROCESS. MODELS ARE IN SOME DISAGREEMENT ON THE
SPEED OF THIS WEAKENING PROCESS WITH SHIPS SHOWING A REMNANT LOW IN
72 HOURS WHILE HWFI STILL SHOWING A STRONG TROPICAL STORM THROUGH
96 HOURS. THE GFDI KEEPS NEKI A HURRICANE THROUGH 84 HOURS WHICH
SEEMS UNREASONABLE DUE TO THE INCREASING SHEAR. NEKI IS FORECAST TO
WEAKEN TO A TROPICAL STORM BY 48 HOURS...THEN TO A DEPRESSION BY 120
HOURS WHEN THE SYSTEM WILL LIKELY BE CLASSIFIED AS EXTRATROPICAL.

ON ITS CURRENT TRACK...NEKI IS LIKELY BEGINNING TO IMPACT THE
PAPAHANAUMOKUAKEA NATIONAL MONUMENT NEAR FRENCH FRIGATE SHOALS.
CONDITIONS IN THE PARTS OF THE WARNING AREA WILL CONTINUE TO
DETERIORATE TONIGHT AND EARLY FRIDAY...AND A HURRICANE WARNING
REMAINS IN EFFECT FOR THE MONUMENT FROM NIHOA ISLAND TO MARO REEF.
LARGE SWELLS FROM THE SOUTH WILL CONTINUE TO BUILD LATE TODAY AND
TONIGHT ACROSS THE WARNING AREA WITH SEAS GREATER THAN 20 FT AND
SURF UP 25 FT EXPECTED.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/0300Z 22.1N 166.0W 85 KT
12HR VT 23/1200Z 23.7N 165.6W 80 KT
24HR VT 24/0000Z 25.7N 164.7W 75 KT
36HR VT 24/1200Z 27.8N 163.4W 65 KT
48HR VT 25/0000Z 29.9N 161.9W 60 KT
72HR VT 26/0000Z 33.9N 158.8W 45 KT
96HR VT 27/0000Z 37.9N 155.4W 35 KT
120HR VT 28/0000Z 42.3N 151.7W 30 KT...EXTRATROPICAL

$$
FORECASTER BURKE

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#162 Postby cycloneye » Fri Oct 23, 2009 10:20 am

WTPA42 PHFO 231506
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER 20
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 AM HST FRI OCT 23 2009

NEKI HAS WEAKENED SIGNIFICANTLY OVER THE PAST 12 HOURS. OVER THE
PAST 6 HOURS IN PARTICULAR...NEKI HAS STRUGGLED TO MAINTAIN DEEP
CONVECTION AND AT 430 AM HST ITS ARGUABLE IF THERE IS ANY AT ALL.
AGENCY DVORAK ESTIMATES CAME IN AT 3.5 3.5 AND 2.5 FROM PHFO SAB AND
PGTW RESPECTIVELY...THE LATTER BREAKING CONSTRAINTS. COMBINED WITH
THE POOR SATELLITE PRESENTATION...SEE NO REASON TO MAINTAIN
HURRICANE STRENGTH AND HAVE DOWNGRADED NEKI TO A TROPICAL STORM. THE
RAPID WEAKENING ALSO PRESENTS A CHALLENGE ON THE CENTER POSITION.
BELIEVE WHAT LITTLE CONVECTION EXISTS IS BEING SHEARED CONSIDERABLY
TO THE NORTH AND EAST...SO RELIED ON LIMITED MICROWAVE IMAGERY AND
SIMPLE EXTRAPOLATION FOR THE 1200 UTC POSITION.

MODELS ARE IN GOOD AGREEMENT AND BETTER REFLECT THE SLOW DOWN OF
NEKI OVER THE PAST 24 HOURS. AS A RESULT...THE ENTIRE FORECAST TRACK
WAS PULLED BACK EVEN FURTHER FROM THE PREVIOUS PACKAGE. THROUGH 48
HOURS...EXPECT LESS THAN 10 KT OF FORWARD MOTION WITH NO SIGNIFICANT
ENVIRONMENTAL PUSH. AFTER 48 HOURS...A WEAKENED NEKI WILL PICK UP
SOME SPEED AS IT STARTS TO BE ABSORBED INTO A MUCH LARGER LOW
PRESSURE SYSTEM TRACKING ACROSS THE NORTH PACIFIC. THE LATEST
FORECAST IS SLIGHTLY RIGHT OF CENTER DOWN THE GUIDANCE
ENVELOPE...AND CLOSE TO THE GFDL AND HWRF.

SHIPS CONTINUES TO INDICATE INCREASING SHEAR AND COOLER SEA SURFACE
TEMPERATURES IN THE COMING DAYS. THE CURRENT SHEAR IS REALLY BEATING
NEKI DOWN. HAVE LOWERED THE FORECAST INTENSITY ACROSS THE
BOARD...MAKING NEKI A REMNANT LOW AT 72 HOURS.

ON ITS CURRENT TRACK...NEKI WILL CONTINUE TO IMPACT PORTIONS OF THE
PAPAHANAUMOKUAKEA NATIONAL MONUMENT BETWEEN MARO REEF AND NIHOA
TODAY. THE HURRICANE WARNING FOR THE MONUMENT FROM NIHOA ISLAND TO
MARO REEF IS CANCELLED AND REPLACED BY A TROPICAL STORM WARNING FOR
THE SAME AREA. LARGE SWELLS FROM THE SOUTH WILL CONTINUE TO IMPACT
PORTIONS OF THE WARNING AREA TODAY AND TONIGHT. SEAS UP TO 20 FT AND
SURF UP TO 25 FEET WILL CONTINUE TO BATTER ISLANDS IN THE WARNING
AREA...ESPECIALLY AROUND FRENCH FRIGATE SHOALS. SEAS AND SURF WILL
BEGIN TO SUBSIDE TONIGHT AS NEKI WEAKENS FURTHER.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/1500Z 22.8N 165.6W 60 KT
12HR VT 24/0000Z 23.7N 165.4W 55 KT
24HR VT 24/1200Z 24.9N 164.9W 45 KT
36HR VT 25/0000Z 26.2N 164.0W 40 KT
48HR VT 25/1200Z 27.4N 162.9W 30 KT
72HR VT 26/1200Z 30.5N 160.3W 25 KT...REMNANT LOW
96HR VT 27/1200Z 36.6N 156.9W 20 KT...DISSIPATING

$$
FORECASTER TANABE


0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

#163 Postby HURAKAN » Fri Oct 23, 2009 1:15 pm

Image

Going down fast
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

#164 Postby HURAKAN » Fri Oct 23, 2009 2:17 pm

Image

Becoming exposed
0 likes   

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#165 Postby cycloneye » Fri Oct 23, 2009 4:23 pm

TROPICAL STORM NEKI DISCUSSION NUMBER 21
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 AM HST FRI OCT 23 2009

SATELLITE IMAGERY SHOWS THAT NEKI CONTINUES TO DETERIORATE THIS
MORNING. VISIBLE IMAGES ARE NOW REVEALING A PARTIALLY EXPOSED LLCC.
THE LAYERED CLOUDS AND WHAT REMAINS OF THE DEEP CONVECTION HAVE
BEEN PUSHED TO THE NORTHEAST OF THE CENTER BY 25 TO 30 KT OF
SOUTHWESTERLY SHEAR...AS ANALYZED IN THE UW/CIMSS SHEAR ANALYSIS.
CURRENT INTENSITY ESTIMATES FROM PHFO...JTWC...AND SAB WERE A
CONSENSUS 3.5 AND SO THE INTENSITY ESTIMATE WAS SET TO 55 KT FOR
THIS ADVISORY.

THE INITIAL MOTION ESTIMATE IS 025/4. NEKI IS LOCATED IN A COL
BETWEEN SUBTROPICAL HIGH PRESSURE CENTERS TO THE EAST AND WEST...
THE LOWER EQUATORIAL PRESSURE TO THE SOUTH...AND A SERIES OF
EXTRATROPICAL LOW PRESSURE CENTERS PASSING BY TO THE NORTH. THE
MID-LATITUDE SHORTWAVE TROUGHS PASSING BY TO THE NORTH OF NEKI WILL
LEAVE THE CYCLONE BEHIND...WITH HIGH PRESSURE BUILDING TO THE NORTH
THROUGH 36 TO 48 HOURS. THIS WILL KEEP NEKI IN RELATIVELY WEAK
STEERING CURRENTS. BEYOND 48 HOURS...A MUCH STRONGER MID-LATITUDE
TROUGH IS EXPECTED TO SWEEP NEKI INTO THE WESTERLIES. THERE IS SOME
DISAGREEMENT ABOUT THE EVOLUTION OF WHAT IS LEFT OF NEKI AFTER
THAT...WHETHER THE CYCLONE BEGINS TO MERGE WITH EXTRATROPICAL LOW
PRESSURE...OR WHETHER THE LOW LEVEL CENTER BECOMES BECOMES ELONGATED
AND TORN APART. THE OFFICIAL FORECAST IS CLOSE TO...BUT SOMEWHAT
SLOWER THAN THE PREVIOUS FORECAST IN THE SHORT TERM...WITH A SLIGHT
ADJUSTMENT TO THE LEFT IN THE LONGER TERM.

STRONG SOUTHWEST SHEAR IS EXPECTED TO CONTINUE OVER THE CYCLONE
THROUGH AT LEAST THE NEXT 48 HOURS. SOME OF THE GLOBAL MODELS
SUGGEST THAT SHEAR WILL WEAKEN BEYOND 48 HOURS...BUT BY THEN NEKI
WILL BE APPROACHING THE MUCH COLDER WATERS OF THE NORTH PACIFIC.
AGAIN...IT IS UNCERTAIN HOW MUCH BAROCLINIC ENHANCEMENT NEKI COULD
GET IN THE LONGER RANGE. LITTLE CHANGE TO THE INTENSITY FORECAST
WAS MADE THROUGH 36 HOURS...WITH A SLIGHTLY SLOWER WEAKENING TREND
INDICATED FOR 48 HOURS AND BEYOND.

THE CLOSEST AVAILABLE OBSERVATION...FROM BUOY 51001...INDICATED
WINDS GUSTING TO 35 KT AT 1750 UTC. BASED ON THIS...AND MORE
IMPORTANTLY ON THE VERY TIMELY QUIKSCAT WIND PASS FROM 1705 UTC...
WE HAVE MADE SOME ADJUSTMENTS TO THE WIND RADII. NEKI/S RELATIVELY
CLOSE APPROACH TO THE MAIN HAWAIIAN ISLANDS IS A SOBERING REMINDER
THAT WE STILL HAVE MORE THAN A MONTH TO GO IN HURRICANE SEASON.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/2100Z 23.1N 165.3W 55 KT
12HR VT 24/0600Z 23.7N 165.1W 50 KT
24HR VT 24/1800Z 24.8N 164.6W 45 KT
36HR VT 25/0600Z 25.8N 164.0W 40 KT
48HR VT 25/1800Z 27.1N 163.2W 35 KT
72HR VT 26/1800Z 30.6N 161.1W 30 KT...DISSIPATING
96HR VT 27/1800Z 36.9N 157.4W 25 KT...EXTRATROPICAL

$$
FORECASTER R BALLARD

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#166 Postby cycloneye » Sat Oct 24, 2009 6:17 am

WTPA42 PHFO 240901
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER 23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 PM HST FRI OCT 23 2009

THE LATEST UW/CIMSS ESTIMATE OF VERTICAL WIND SHEAR AFFECTING
TROPICAL STORM NEKI IS 23 KT FROM 256 DEGREES. THIS HOSTILE
ENVIRONMENT IS BEING CREATED IN PART DUE TO AN UPPER TROPOSPHERIC
TROUGH...WHICH IS EVIDENT IMMEDIATELY TO THE WEST AND NORTHWEST OF
NEKI ACCORDING TO LOOPS OF WATER VAPOR IMAGERY AND SATELLITE DERIVED
UPPER LEVEL WINDS. THERE IS ALSO A LARGE UPPER LEVEL ANTICYCLONE
LOCATED SOUTH OF THE ALOHA STATE NEAR 17N 160W. THE TROPICAL STORM
IS CERTAINLY FEELING THESE ADVERSE CONDITIONS BASED ON ITS
APPEARANCE IN SATELLITE IMAGERY THIS EVENING. A HUGE SWATH OF CIRRUS
CLOUDS IS STREAMING MORE THAN 500 NM TOWARD THE NORTHEAST AWAY FROM
THE REMAINING CENTRAL DENSE OVERCAST...OR CDO...LOCATED NEAR THE
CENTER. THE SOUTHWESTERN EDGE OF THE CDO ALSO HAS A DISTINCT
BOUNDARY INDICATING THE INHIBITION OF THE OUTFLOW IN THAT PORTION OF
THE STORM DUE TO THE RELATIVELY STRONG UPPER LEVEL SOUTHWESTERLY
WINDS.

THE POOR APPEARANCE OF TROPICAL STORM NEKI IN SATELLITE IMAGERY ALSO
CAUSES PROBLEMS FOR THOSE OF US WHO ARE TRYING TO DETERMINE THE
LOCATION OF ITS LOW LEVEL CENTER. THERE IS SOME SPREAD IN THE
POSITIONS FROM SAB...JTWC AND PHFO. HOWEVER...NEKI HAS BEEN MOVING
RATHER SLOWLY...SO IT APPEARS TO BE CLOSE TO THE LATEST OFFICIAL
POSITION...WHICH YIELDS A MOVEMENT OF 025 DEG/04 KT. ALSO...BASED ON
CURRENT INTENSITY ESTIMATES OF T3.0-3.5...THE INTENSITY IS
MAINTAINED AT 55 KT FOR THIS ADVISORY.

THE CURRENT TRACK FORECAST IS AN UPDATE OF THE PREVIOUS ONE WITH
SOME MINOR TWEAKS THROUGH 48 HOURS. WEAK STEERING CONDITIONS WILL
LIKELY CONTINUE THROUGH THAT TIME PERIOD. NEKI WILL LIKELY
ACCELERATE BEYOND 48 HOURS ONCE IT IS PICKED UP BY A NEW LARGE
AMPLITUDE UPPER LEVEL TROUGH THAT IS FORECAST TO DIG TOWARD THE EAST
SOUTHEAST. THE INTENSITY FORECAST IS ALSO UNCHANGED THROUGH DAY 2.
HAVE KEPT GALE FORCE WINDS IN THE 72/96 HOUR PERIOD WHEN NEKI IS
EXPECTED TO BE TRANSITIONING INTO AN EXTRATROPICAL SYSTEM. HAVE ALSO
ADJUSTED THE WIND RADII...PARTICULARLY IN THE SOUTHEAST QUADRANT...
TO ACCOUNT FOR THE MORE NORTHEASTWARD MOTION OF THE STORM. THE 0530
UTC QUIKSCAT PASS THAT CAME IN A FEW MINUTES AGO APPEARS TO SUPPORT
THE INITIAL WIND RADII.

WILL HAVE TO DETERMINE LATER TONIGHT IF ADVERSE WEATHER AND SEA
CONDITIONS ARE BEGINNING TO SUBSIDE IN THE TROPICAL STORM WARNING
AREA. FOR THE MOMENT...THERE IS NO CHANGE IN THE WARNINGS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 24/0900Z 23.8N 164.9W 55 KT
12HR VT 24/1800Z 24.6N 164.5W 50 KT
24HR VT 25/0600Z 25.6N 164.0W 45 KT
36HR VT 25/1800Z 26.7N 163.4W 40 KT
48HR VT 26/0600Z 28.3N 163.0W 35 KT
72HR VT 27/0600Z 35.0N 160.0W 35 KT...BECOMING EXTRATROPICAL
96HR VT 28/0600Z 47.0N 152.0W 35 KT...EXTRATROPICAL

$$
FORECASTER HOUSTON

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#167 Postby cycloneye » Sat Oct 24, 2009 10:20 am

TROPICAL STORM NEKI DISCUSSION NUMBER 24
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 AM HST SAT OCT 24 2009

HOSTILE ATMOSPHERIC CONDITIONS CONTINUE TO AFFECT TROPICAL STORM
NEKI EARLY THIS MORNING. THE LATEST UW/CIMSS ESTIMATE OF VERTICAL
WIND SHEAR AFFECTING NEKI IS 23 KT FROM 246 DEGREES. THESE ADVERSE
CONDITIONS ARE PARTIALLY DUE TO AN UPPER TROPOSPHERIC TROUGH...
WHICH IS EVIDENT IMMEDIATELY TO THE WEST OF NEKI ACCORDING TO LOOPS
OF WATER VAPOR IMAGERY AND SATELLITE DERIVED UPPER LEVEL WINDS.
THERE IS ALSO A LARGE UPPER LEVEL ANTICYCLONE CENTERED NEAR 15N
160W. THE OVERALL APPEARANCE OF THE TROPICAL STORM CONTINUES TO
DETERIORATE THIS MORNING. AN IMPRESSIVE SWATH OF CIRRUS CLOUDS IS
STREAMING MORE THAN 400 NM TOWARD THE NORTHEAST AWAY FROM THE
REMAINING DEEP CONVECTION. THE OUTFLOW IN THE SOUTHWESTERN
SEMICIRCLE OF THE STORM IS ALSO BEING IMPEDED DUE TO THE RELATIVELY
STRONG UPPER LEVEL SOUTHWESTERLY WINDS. IN ADDITION TO THE HARSH
ATMOSPHERIC ENVIRONMENT AFFECTING NEKI...IT IS ALSO MOVING OVER
COOLER SEA SURFACE TEMPERATURES...WITH VALUES NEAR 26 TO 27 DEGREES
C. OCEAN HEAT CONTENT VALUES ALSO CONTINUE TO DECREASE ACCORDING TO
THE LATEST CIRA ANALYSIS.

IT IS DIFFICULT TO FIND THE LOW LEVEL CIRCULATION CENTER OF TROPICAL
STORM NEKI IN INFRARED SATELLITE IMAGERY. THERE IS A SPREAD IN THE
POSITIONS FROM THE SATELLITE FIX AGENCIES...SAB...JTWC AND PHFO.
NEKI CONTINUES TO MOVE RATHER SLOWLY...SO IT APPEARS TO BE CLOSE TO
THE LATEST OFFICIAL POSITION. BASED ON THE LATEST TRACK...NEKI IS
MOVING TOWARD 045 DEG AT 6 KT. CURRENT INTENSITY ESTIMATES YIELD T
NUMBERS OF 3.0. A QUIKSCAT PASS FROM AROUND 0531 UTC INDICATED NEKI
HAD SOME UNFLAGGED 50 KT WINDS EARLIER TONIGHT. THEREFORE...WILL
DECREASE NEKI TO AN INITIAL INTENSITY OF 50 KT FOR THIS FORECAST.

THE CURRENT TRACK FORECAST IS AN UPDATE OF THE PREVIOUS ONE WITH
SUBTLE CHANGES MADE THROUGH 48 HOURS. WEAK STEERING CONDITIONS WILL
LIKELY CONTINUE THROUGH THAT TIME PERIOD. NEKI IS FORECAST TO
ACCELERATE BEYOND DAY 2 WHEN IT WILL LIKELY BE CAUGHT UP IN THE
WESTERLIES WHEN A LARGE AMPLITUDE UPPER LEVEL TROUGH IS FORECAST TO
DIG RAPIDLY TOWARD THE EAST SOUTHEAST. THE INTENSITY FORECAST
CONTINUES TO REFLECT THE WEAKENING TREND THAT IS EVIDENT IN ALL OF
THE GUIDANCE. HAVE KEPT GALE FORCE WINDS IN THE 72/96 HOUR PERIOD
WHEN NEKI IS EXPECTED TO BE TRANSITIONING INTO AN EXTRATROPICAL
SYSTEM OVER THE NORTHERN PACIFIC OCEAN. NOTE...SOME OF THE MODELS
NOW INDICATE NEKI WILL BE SHEARED APART AND COMPLETELY LOSE ITS
IDENTITY WITHIN 72-96 HOURS. THEREFORE...DO NOT BE SURPRISED IF IT
IS NO LONGER IDENTIFIABLE IN 3 OR 4 DAYS.

WILL HAVE TO DETERMINE LATER THIS MORNING IF ADVERSE WEATHER
CONDITIONS ARE BEGINNING TO SUBSIDE IN THE TROPICAL STORM WARNING
AREA FROM NIHOA ISLAND TO FRENCH FRIGATE SHOALS. ATMOSPHERIC
CONDITIONS HAVE IMPROVED ENOUGH WEST OF FRENCH FRIGATE SHOALS TO
ALLOW THE CANCELLATION OF THE TROPICAL STORM WARNING FOR THAT AREA.
NOTE THAT DUE TO CLOSE PROXIMITY OF NEKI...AND ITS SLOW FORWARD
MOTION...ROUGH SEAS AND LARGE BREAKING WAVES WILL CONTINUE TO OCCUR
ACROSS THE MOST OF THE PAPAHANAUMOKUAKEA NATIONAL MONUMENT FROM MARO
REEF TO NIHOA ISLAND FOR MUCH OF TODAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 24/1500Z 24.3N 164.2W 50 KT
12HR VT 25/0000Z 25.1N 163.7W 45 KT
24HR VT 25/1200Z 26.3N 163.0W 45 KT
36HR VT 26/0000Z 27.7N 162.5W 40 KT
48HR VT 26/1200Z 30.0N 161.8W 35 KT
72HR VT 27/1200Z 39.0N 158.0W 35 KT...BECOMING EXTRATROPICAL
96HR VT 28/1200Z 45.0N 146.0W 35 KT...EXTRATROPICAL

$$
FORECASTER HOUSTON

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#168 Postby cycloneye » Sat Oct 24, 2009 6:52 pm

TROPICAL STORM NEKI DISCUSSION NUMBER 25
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 AM HST SAT OCT 24 2009

TROPICAL STORM NEKI CONTINUES TO BE IMPACTED BY SOUTHWESTERLY SHEAR
THIS MORNING WITH INFRARED AND MICROWAVE DATA SHOWING DEEP
CONVECTION DISPLACED SLIGHTLY TO THE NORTHEAST OF THE SYSTEM/S
CENTER. CIMSS ANALYSIS DATA FROM 1800 UTC SHOWED OVER 26 KT OF
VERTICAL SHEAR FROM THE SOUTHWEST. DVORAK DATA FROM PHFO...SAB AND
JTWC ALL INDICATED AN INTENSITY OF 45 KT. HOWEVER...A SCATTEROMETER
PASS FROM AROUND 1640 UTC SHOWED UNFLAGGED 50 KT WINDS SOUTHEAST OF
THE CENTER. GIVEN THE RECENT SCATTEROMETER DATA AND THE RELATIVELY
STEADY STATE PRESENTATION IN THE GOES SATELLITE DATA...THE INITIAL
INTENSITY WILL BE KEPT AT 50 KT FOR THIS FORECAST PACKAGE.

NEKI IS MOVING IN A WEAK STEERING CURRENT WITH A WEAK MIDLEVEL RIDGE
TO THE SOUTHEAST OVER THE MAIN HAWAIIAN ISLANDS AND A TROUGH FAR TO
THE NORTH. LITTLE CHANGE IS EXPECTED OVER THE NEXT 36 TO 48
HOURS...AFTER WHICH A SHORTWAVE TROUGH WILL MOVE IN FROM THE WEST
AND ABSORB NEKI. THE MAIN DYNAMICAL MODELS SHOW MORE OF A NORTHWARD
TRACK THAN PREVIOUSLY INDICATED SO THE FORECAST HAS BEEN NUDGED A
BIT TO THE WEST ACCORDINGLY. RECENT SATELLITE IMAGES ALSO SUPPORT
THIS TREND.

THE CENTER OF NEKI IS CURRENTLY OVER MARGINAL SEA SURFACE
TEMPERATURES AND THE VERTICAL SHEAR IS NOT EXPECTED TO EASE
SIGNIFICANTLY. THUS...NEKI IS FORECAST TO WEAKEN SLOWLY OVER THE
NEXT COUPLE OF DAYS...FOLLOWED BY A TRANSITION TO AN EXTRATROPICAL
STATE AS THE PREVIOUSLY MENTIONED SHORTWAVE TROUGH EXERTS ITS
INFLUENCE.

THE LATEST BUOY AND SCATTEROMETER DATA WARRANT KEEPING THE TROPICAL
STORM WARNING UP FOR THE PAPAHANAUMOKUAKEA NATIONAL MONUMENT FOR
THIS FORECAST PACKAGE. CONDITIONS SHOULD IMPROVE AS NEKI MOVES
AWAY FROM THE AREA AND THE WARNING MAY BE DROPPED LATER TODAY
PENDING THE RESULTS OF FURTHER DATA ANALYSIS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 24/2100Z 24.8N 163.9W 50 KT
12HR VT 25/0600Z 25.6N 163.7W 45 KT
24HR VT 25/1800Z 26.6N 163.7W 45 KT
36HR VT 26/0600Z 27.8N 163.9W 40 KT
48HR VT 26/1800Z 30.4N 163.9W 35 KT...BECOMING EXTRATROPICAL
72HR VT 27/1800Z 39.6N 159.3W 35 KT...EXTRATROPICAL

$$
FORECASTER KODAMA


0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

#169 Postby HURAKAN » Sat Oct 24, 2009 6:54 pm

Image

Image

Latest
0 likes   

User avatar
Macrocane
Category 5
Category 5
Posts: 4198
Age: 29
Joined: Sun May 24, 2009 5:35 pm
Location: El Salvador

Re: CPAC: TROPICAL STORM NEKI (03C)

#170 Postby Macrocane » Sat Oct 24, 2009 7:47 pm

It doesn't look like it's weakening too much, it looks better than a lot of TS on the ATlantic thi season.
0 likes   

User avatar
Aslkahuna
Professional-Met
Professional-Met
Posts: 4550
Joined: Thu Feb 06, 2003 5:00 pm
Location: Tucson, AZ
Contact:

Re: CPAC: TROPICAL STORM NEKI (03C)

#171 Postby Aslkahuna » Sat Oct 24, 2009 8:49 pm

Although the downstream pattern is not too horribly favorable, it should be noted that CENPAC hurricanes like their WPAC brethren can and have given the US West Coast fits as ET remnants. Classic case, Iwa in 1982 which after blasting HI as the worst storm there until 1992, the ET remnant came into CA with winds gusting over 100 mph, severe weather and heavy rains. That system went on to dump heavy snow in Utah.

Steve
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

#172 Postby HURAKAN » Sat Oct 24, 2009 9:03 pm

Image

Latest
0 likes   

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#173 Postby cycloneye » Sat Oct 24, 2009 10:11 pm

WTPA42 PHFO 250243
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER 26
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 PM HST SAT OCT 24 2009

DEEP CONVECTION HAS REMAINED PERSISTENT NEAR THE CENTER OF NEKI
THROUGHOUT THE DAY. IN FACT...A 24 HOUR LOOP OF GOES IMAGES REVEALS
VERY LITTLE CHANGE IN OVERALL CHARACTER OTHER THAN A SLIGHT
REDUCTION IN UPPER LEVEL OUTFLOW TO THE NORTHEAST. CIMSS DATA FROM
0000 UTC CONTINUES TO SHOW STRONG VERTICAL SHEAR...28 KTS
WORTH...FROM THE WEST-SOUTHWEST. DVORAK INTENSITY ESTIMATES FROM
PHFO...SAB AND JTWC ALL MAINTAIN NEKI AT 50 KT. ASCAT PASSES MISSED
THE SYSTEM ENTIRELY SO THERE WAS NO HELP FROM THAT PLATFORM. WHILE
CIMSS ADT GIVES AN INTENSITY OF 41 KT AT 0000 UTC...THE NOD WILL BE
GIVEN TO THE SUBJECTIVE ESTIMATES BASED ON THE OVERALL SATELLITE
PRESENTATION.

THERE HAS BEEN NO SIGNIFICANT CHANGE TO THE FORECAST RATIONALE FOR
THIS CYCLE. NEKI IS MOVING IN A WEAK STEERING CURRENT WITH A WEAK
MIDLEVEL RIDGE TO THE SOUTHEAST OVER THE MAIN HAWAIIAN ISLANDS AND
A TROUGH FAR TO THE NORTH. A SIGNIFICANT SHORT WAVE TROUGH IS
EXPECTED TO MOVE IN FROM THE WEST AND ABSORB NEKI. ALL OF THE MAIN
DYNAMICAL MODELS AGREE WITH THIS GENERAL SCENARIO THOUGH DIFFER IN
THE DETAILS. THE FORECAST CLOSELY FOLLOWS THE PREVIOUS FORECAST
WITH SLIGHT ADJUSTMENTS IN SPEED AND IS ON THE EAST SIDE OF THE
DYNAMICAL GUIDANCE ENVELOPE. IN ANY CASE...NEKI IS EXPECTED TO BE A
NON-ENTITY AS A TROPICAL SYSTEM BY TUESDAY EVENING.

NEKI IS MOVING OVER MARGINAL AND DECREASING SEA SURFACE
TEMPERATURES. THIS ALONG WITH SIGNIFICANT LEVELS OF VERTICAL SHEAR
SUPPORTS A WEAKENING TREND AS INDICATED BY THE MAIN INTENSITY
OBJECTIVE AIDS. THUS...FORECAST CALLS FOR NEKI TO WEAKEN SLOWLY
OVER THE NEXT COUPLE OF DAYS...FOLLOWED BY A TRANSITION TO AN
EXTRATROPICAL STATE ON TUESDAY.

THE LATEST BUOY DATA INDICATE IMPROVING WIND AND SEA CONDITIONS.
THEREFORE...THE TROPICAL STORM WARNING FOR THE PAPAHANAUMOKUAKEA
NATIONAL MONUMENT WILL BE DISCONTINUED AS OF 500 PM HST.


FORECAST POSITIONS AND MAX WINDS

INITIAL 25/0300Z 25.3N 163.8W 50 KT
12HR VT 25/1200Z 26.0N 163.7W 45 KT
24HR VT 26/0000Z 27.2N 163.7W 45 KT
36HR VT 26/1200Z 28.9N 163.7W 40 KT
48HR VT 27/0000Z 31.7N 163.0W 40 KT...BECOMING EXTRATROPICAL
72HR VT 28/0000Z 43.0N 156.5W 30 KT...EXTRATROPICAL

$$
FORECASTER KODAMA

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

Re: CPAC: TROPICAL STORM NEKI (03C)

#174 Postby HURAKAN » Sun Oct 25, 2009 1:16 am

Image

Image

Holding
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

#175 Postby HURAKAN » Sun Oct 25, 2009 7:37 am

WTPA32 PHFO 250845
TCPCP2

BULLETIN
TROPICAL STORM NEKI ADVISORY NUMBER 27
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 PM HST SAT OCT 24 2009

...TROPICAL STORM NEKI STALLS FAR NORTHWEST OF THE MAIN HAWAIIAN
ISLANDS...

AT 1100 PM HST...0900 UTC...THE CENTER OF TROPICAL STORM NEKI WAS
LOCATED NEAR LATITUDE 24.8 NORTH...LONGITUDE 163.9 WEST OR ABOUT
345 MILES NORTHWEST OF LIHUE...HAWAII AND ABOUT 165 MILES
EAST-NORTHEAST OF FRENCH FRIGATE SHOALS.

NEKI IS NEARLY STATIONARY...BUT IS EXPECTED TO BEGIN MOVING SLOWLY
NORTHWARD BY SUNDAY MORNING. THIS SLOW NORTHWARD MOTION IS FORECAST
TO CONTINUE THROUGH SUNDAY NIGHT AND EARLY MONDAY. BY LATE
MONDAY...NEKI WILL LIKELY BEGIN TO ACCELERATE TOWARD THE NORTH
NORTHEAST OVER THE OPEN WATERS OF THE NORTH CENTRAL PACIFIC OCEAN.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 60 MPH WITH HIGHER GUSTS. NEKI
IS EXPECTED TO GRADUALLY WEAKEN FROM SUNDAY THROUGH MONDAY MORNING.
BY LATE MONDAY...NEKI MAY BEGIN TO TRANSITION INTO AN EXTRATROPICAL
SYSTEM AS IT ACCELERATES TOWARD THE NORTH NORTHEAST.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115 MILES FROM THE
CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB...29.59 INCHES.

...SUMMARY OF 1100 PM HST INFORMATION...
LOCATION...24.8N 163.9W
MAXIMUM SUSTAINED WINDS...60 MPH
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...1002 MB

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

$$
FORECASTER HOUSTON



WTPA42 PHFO 251031 CCB
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER 27
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 PM HST SAT OCT 24 2009

NEKI/S GENERAL APPEARANCE HAS NOT CHANGED MUCH IN INFRARED SATELLITE
IMAGERY OVER THE PAST 24 HOURS. IN FACT LOOKING AT THE IMAGE FROM
EXACTLY 24 HOURS AGO...IT APPEARS THE DEEP CONVECTION IS MORE
CONCENTRATED THAN IT WAS YESTERDAY EVENING AT THIS TIME. HOWEVER...
BASED ON MICROWAVE IMAGERY FROM A FEW HOURS AGO...SIGNS OF THE
INITIAL DECOUPLING OF THE LOW-LEVEL CIRCULATION CENTER...OR LLCC...
FROM THE CORE OF THE DEEPEST CONVECTION APPEARS TO BE TAKING PLACE.
THIS MAY ACTUALLY BE AN INDICATION OF TILTING OF THE SYSTEM WITH
HEIGHT TOWARD THE NORTHEAST. THIS IS NOT UNEXPECTED...SINCE THE
LATEST UW/CIMSS ESTIMATE OF ENVIRONMENTAL VERTICAL WIND SHEAR IN THE
VICINITY OF NEKI IS FROM 262 DEGREES AT 29 KT. THIS SHEAR IS THE
RESULT OF A LARGE UPPER TROPOSPHERIC TROUGH LOCATED JUST WEST OF
NEKI.

IN ADDITION TO THE ADVERSE SHEARING CONDITIONS...NEKI IS ALSO
ENCOUNTERING A BUBBLE HIGH AT THE SURFACE DUE NORTH OF ITS PRESENT
LOCATION. ALL OF THE FIX AGENCIES...PHFO...JTWC AND SAB...INDICATE
THE LLCC HAS STALLED COMPARED WITH THE POSITIONS PROVIDED FOR 0000
UTC. IT IS POSSIBLE THAT NEKI HAS ACTUALLY DONE A SMALL ANTICYCLONIC
LOOP DURING THE PAST SEVERAL HOURS. FOR THIS ADVISORY...HAVE MADE
NEKI NEARLY STATIONARY. THE CURRENT INTENSITY ESTIMATES FROM THE
SAME FIX AGENCIES RANGED FROM 2.5 TO 3.0. THE 0505 UTC QUIKSCAT PASS
OVER NEKI INDICATED SOME 50 KT WIND BARBS WITHOUT RAIN FLAGS. DUE TO
THE LACK OF SIGNIFICANT CHANGE IN THE SYSTEM AND THE QUIKSCAT
DATA...WILL MAINTAIN NEKI AS A 50 KT TROPICAL STORM FOR THIS
ADVISORY.

THE SMALL HIGH DUE NORTH OF NEKI IS EXPECTED TO CONTINUE PROPAGATING
SLOWLY EASTWARD DURING THE NEXT 12 TO 24 HOURS. AS A RESULT...THE
LATEST INDIVIDUAL AND CONSENSUS TRACK GUIDANCE CONTINUE TO SHOW
THE SYSTEM WILL BEGIN TO MOVE SLOWLY NORTHWARD WITHIN THE NEXT 12
HOURS. THE GUIDANCE THEN MOVES NEKI AT A SLIGHTLY FASTER FORWARD
SPEED TOWARD THE NORTH DURING THE NEXT 24 TO 36 HOURS. THEREFORE...
HAVE NUDGED THE LATEST FORECAST TRACK CLOSER TO THE GUIDANCE...
ESPECIALLY THE TVCN.

NEKI IS FORECAST TO CONTINUE MOVING OVER COOLER SEA SURFACE
TEMPERATURES AND LOWER OCEAN HEAT CONTENT VALUES DURING THE NEXT
COUPLE OF DAYS. THE COOLING TREND OF THE UNDERLYING OCEAN COMBINED
WITH STRONG VERTICAL WIND SHEAR CONTINUES TO SUPPORT THE WEAKENING
TREND FROM THE PREVIOUS FORECAST. AS IN THE PREVIOUS FORECAST...AN
EXTRATROPICAL TRANSITION IS EXPECTED STARTING ON DAY 2...WITH A
COMPLETE TRANSITION WITHIN 3 DAYS. NOTE...WOULD STILL NOT BE
SURPRISED IF NEKI IS COMPLETELY SHEARED APART BEYOND 48 HOURS WHEN
IT ENCOUNTERS THE STRONG WESTERLIES AND IS ABSORBED BY A
MID-LATITUDE SYSTEM OVER THE NORTH CENTRAL PACIFIC OCEAN.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/0900Z 24.8N 163.9W 50 KT
12HR VT 25/1800Z 25.6N 164.0W 45 KT
24HR VT 26/0600Z 27.2N 164.1W 40 KT
36HR VT 26/1800Z 29.6N 163.8W 40 KT
48HR VT 27/0600Z 33.1N 162.0W 40 KT...BECOMING EXTRATROPICAL
72HR VT 28/0600Z 45.1N 155.0W 30 KT...EXTRATROPICAL

$$
FORECASTER HOUSTON
0 likes   

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#176 Postby cycloneye » Sun Oct 25, 2009 10:50 am

TROPICAL STORM NEKI DISCUSSION NUMBER 28
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 AM HST SUN OCT 25 2009

THE LOW-LEVEL CIRCULATION OF NEKI APPEARS TO BE DECOUPLING FROM ITS
ASSOCIATED DEEP CONVECTION. THE CUMULONIMBUS CLOUDS...WHICH HAD BEEN
RATHER PERSISTENT LAST EVENING...ARE NOW PULSING THIS MORNING. THESE
SIGNS OF A LESS HEALTHY TROPICAL CYCLONE ARE UNDERSTANDABLE WHEN
CONSIDERING THE LATEST UW/CIMSS ESTIMATE OF ENVIRONMENTAL VERTICAL
WIND SHEAR IN THE VICINITY OF NEKI IS NOW A STRONG 31 KT FROM DUE
WEST. THESE HOSTILE ENVIRONMENTAL CONDITIONS ARE MAINLY THE RESULT
OF A LARGE UPPER TROPOSPHERIC TROUGH LOCATED JUST WEST NORTHWEST OF
NEKI.

A 1023 MB SURFACE HIGH IS LOCATED NEAR 38N 165W...OR ABOUT 825 NM
NORTH OF NEKI. THE PRESENCE OF THIS ANTICYCLONE...WHICH IS MOVING
RAPIDLY TOWARD THE NORTHEAST...HAS DISRUPTED NEKI/S NORTHWARD MOTION
SINCE SATURDAY AFTERNOON. AT THE SAME TIME...THE DECOUPLING OF THE
LOW LEVEL CENTER DUE TO THE STRONG SHEAR ALLOWED THE SURFACE
SIGNATURE OF NEKI TO BEGIN DRIFTING TOWARD THE WEST LAST NIGHT. THIS
SLOW WESTWARD DRIFT WAS ALSO SUGGESTED IN THE LATEST POSITION
ESTIMATES PROVIDED BY THE SATELLITE ANALYSTS AT SAB...PHFO AND JTWC.
IT ALSO APPEARS THAT NEKI MAY HAVE COMPLETED A SMALL ANTICYCLONIC
LOOP SATURDAY NIGHT. FOR THIS ADVISORY...HAVE INDICATED NEKI/S
CURRENT MOTION IS 290 DEGREES AT 5 KT. THE CURRENT INTENSITY
ESTIMATES FROM THE SAME FIX AGENCIES RANGED FROM 2.5 TO 3.0. DUE TO
THESE INTENSITY ESTIMATES AND THE OBVIOUS DETERIORATION OF THE
TROPICAL STORM IN SATELLITE IMAGERY...HAVE WEAKENED NEKI TO 45 KT
FOR THE INITIAL INTENSITY IN THIS ADVISORY.

AFTER THE SURFACE HIGH FAR NORTH OF NEKI SLIPS RAPIDLY AWAY TO THE
NORTHEAST LATER TODAY...THE INDIVIDUAL AND CONSENSUS TRACK GUIDANCE
CONTINUE TO SHOW THE SYSTEM WILL BEGIN TO MOVE SLOWLY TOWARD THE
NORTH NORTHWEST BY EARLY THIS AFTERNOON. THE GUIDANCE THEN MOVES
NEKI AT A SLIGHTLY FASTER FORWARD SPEED TOWARD THE NORTH LATER
TONIGHT. AT THE SAME TIME...NEKI IS FORECAST TO CONTINUE MOVING OVER
COOLER SEA SURFACE TEMPERATURES AND LOWER OCEAN HEAT CONTENT VALUES
TODAY AND TONIGHT. THE COOLING TREND OF THE UNDERLYING OCEAN
COMBINED WITH STRONG VERTICAL WIND SHEAR CONTINUES TO SUPPORT
ADDITIONAL WEAKENING LATER TODAY AND TONIGHT.

AS IN THE PREVIOUS FORECAST...AN EXTRATROPICAL TRANSITION IS
EXPECTED TO BEGIN BY MID-DAY MONDAY WHEN A LARGE AMPLITUDE UPPER
LEVEL TROUGH AND A STRONG SURFACE FRONT BEGIN TO INTERACT WITH NEKI.
THESE FEATURES WILL LIKELY CAUSE NEKI TO BEGIN ACCELERATING RAPIDLY
TOWARD THE NORTH NORTHEAST BY MONDAY AFTERNOON. A COMPLETE
TRANSITION TO AN EXTRATROPICAL GALE LOW IS EXPECTED BY LATE MONDAY
NIGHT. NOTE...DO NOT BE SURPRISED IF NEKI IS COMPLETELY SHEARED
BEYOND RECOGNITION...AS THE GFS AND ECMWF MODELS INDICATE...MONDAY
NIGHT WHEN IT ENCOUNTERS THE STRONG WESTERLIES AND IS ABSORBED BY
THE MID-LATITUDE SYSTEM OVER THE NORTH CENTRAL PACIFIC OCEAN.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/1500Z 24.8N 164.6W 45 KT
12HR VT 26/0000Z 25.7N 165.0W 40 KT
24HR VT 26/1200Z 27.5N 165.2W 35 KT
36HR VT 27/0000Z 30.9N 164.3W 35 KT...BECOMING EXTRATROPICAL
48HR VT 27/1200Z 37.2N 161.0W 35 KT...EXTRATROPICAL

$$
FORECASTER HOUSTON

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
cycloneye
Storm2k Moderator
Storm2k Moderator
Posts: 110077
Age: 61
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: CPAC: TROPICAL STORM NEKI (03C)

#177 Postby cycloneye » Sun Oct 25, 2009 4:23 pm

PHFO 252059
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER 29
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 AM HST SUN OCT 25 2009

NEKI MANAGES TO HANG ON IN THE FACE OF UNFRIENDLY VERTICAL SHEAR AND
SPUTTERING DEEP CONVECTION THIS MORNING. USING 1730 UTC
IMAGERY...PHFO AND JTWC GAVE CI VALUES FOR NEKI OF 3.0 AND
2.5...RESPECTIVELY. A 1630 UTC SCATTEROMETER PASS SHOWS A SMALL 45
KT WIND PATCH WITHIN THE NORTHEAST QUADRANT...ABOUT 50 NM OUT. A
LARGER 45 KT PATCH OF WINDS LIES 145 TO 180 NM NORTHEAST OF CENTER.
INITIAL NEKI INTENSITY IS THEREFORE SET AT 45 KT. THE 45 KT WIND
PATCH FARTHER FROM THE CENTER MAY BE GRADIENT WIND NOT DIRECTLY
ASSOCIATED WITH THE SYSTEM MAX WIND BAND...BUT THE INITIAL
NORTHEAST QUADRANT GALE RADIUS HAS BEEN EXTENDED TO 180 NM. THIS
RADIUS CONTRACTS TO 140 NM AT TAU 12...THEN MATCHES SMALLER RADII
SET IN THE PREVIOUS PACKAGE FOR ALL SUBSEQUENT TAU.

FIRST VISIBLE IMAGERY SHOWS THE LOW LEVEL CIRCULATION CENTER OF NEKI
EMERGING FROM DEEP CONVECTION TO THE EAST NORTHEAST. IT REMAINS
RATHER UNCLEAR WHETHER THIS CENTER MOVED AT ALL OVER THE PAST 6
HOURS OR SO...BUT IMAGES SINCE 1800 UTC HINT AT A SLOW DRIFT TO THE
WEST NORTHWEST. INITIAL MOTION IS THEREFORE SET AT 290 DEGREES AT 2
KT.

THE 1800 UTC UW/CIMSS VERTICAL SHEAR PRODUCT SHOWS ABOUT 23 KT OF
WESTERLY SHEAR...A DROP FROM ABOUT 31 KT NOTED AT 1200 UTC. HOWEVER
THIS SHEAR...SUPPLIED BY A LARGE UPPER TROPOSPHERIC TROUGH LOCATED
JUST WEST NORTHWEST OF NEKI...REMAINS STRONG ENOUGH TO BE
DETRIMENTAL TO THE HEALTH OF THIS SYSTEM. NEKI SITS RIGHT ON THE 26
DEGREE C SST ISOTHERM...SO IT SEEMS CLEAR THAT NEKI WOULD NOT
INTENSIFY EVEN IT WERE TO SIT STILL. TRACK GUIDANCE CONTINUES TO
SWING NEKI TOWARD THE NORTH LATER TODAY...THEN TOWARD THE NORTHEAST
TONIGHT AND AFTERWARD. THE FORECAST TRACK BEYOND 24 HOURS IS
UNCHANGED FROM THE LAST PACKAGE...WITH TAU 3 AND 12 FORECAST
POSITIONS ALTERED SLIGHTLY TO THE LEFT TO RECONCILE THE CURRENT
WESTERLY DRIFT WITH THE FORECAST SWING TO THE NORTH. THIS TRACK
WILL TAKE NEKI OVER COOLER WATER AND INTO THE PATH OF INCREASING
SHEAR...SO GRADUAL WEAKENING IS EXPECTED.

THE TROPICAL LIFE OF THIS SYSTEM MAY BE A SHORT 48 HOURS. NEKI IS
EXPECTED TO UNDERGO EXTRATROPICAL TRANSITION BEYOND 36 HOURS AS A
LARGE AMPLITUDE UPPER LEVEL TROUGH AND A STRONG SURFACE FRONT BEGIN
TO INTERACT WITH IT. THIS INTERACTION WILL ALSO CAUSE NEKI TO
ACCELERATE AS IT MOVES TOWARDS THE NORTHEAST. THE TRANSITION FROM
TROPICAL LOW TO EXTRATROPICAL GALE SHOULD BE COMPLETE BY EARLY
TUESDAY MORNING.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/2100Z 24.8N 164.9W 45 KT
12HR VT 26/0600Z 26.0N 165.2W 40 KT
24HR VT 26/1800Z 28.9N 164.3W 35 KT
36HR VT 27/0600Z 33.7N 162.2W 35 KT...BECOMING EXTRATROPICAL
48HR VT 27/1800Z 40.5N 158.6W 35 KT...EXTRATROPICAL

$$
FORECASTER POWELL

0 likes   
Visit the Caribbean-Central America Weather Thread where you can find at first post web cams,radars
and observations from Caribbean basin members Click Here

User avatar
Cyclenall
Category 5
Category 5
Posts: 6452
Joined: Thu Jun 08, 2006 10:01 pm
Location: Ontario Canada

#178 Postby Cyclenall » Sun Oct 25, 2009 6:19 pm

With the westward drift, Neki actually looks better now then it did 7 hours ago with a better shape and deeper convection. It's still exposed though.
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

Re: CPAC: TROPICAL STORM NEKI (03C)

#179 Postby HURAKAN » Sun Oct 25, 2009 6:31 pm

Image

Image

Exposed
0 likes   

User avatar
HURAKAN
Professional-Met
Professional-Met
Posts: 46086
Age: 31
Joined: Thu May 20, 2004 4:34 pm
Location: Houston, TX
Contact:

#180 Postby HURAKAN » Sun Oct 25, 2009 10:17 pm

WTPA42 PHFO 260245
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER 30
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 PM HST SUN OCT 25 2009

NEKI IS SLOWLY SPINNING DOWN AS IT INITIALLY MOVES WESTWARD. USING
2330 UTC IMAGERY...PHFO AND JTWC BOTH GAVE CI VALUES OF 2.5. SAB
DID THE SAME WITH 0000 UTC IMAGERY. SINCE THE LOW LEVEL CIRCULATION
CENTER CONTINUES TO MOVE FARTHER AWAY FROM DEEP CONVECTION...AND
BECAUSE THIS CENTER IS BEGINNING TO LOSE DEFINITION ALONG ITS NORTH
SIDE...INITIAL NEKI INTENSITY THIS TIME IS DECREASED TO 40 KT. THE
INITIAL NORTHEAST QUADRANT GALE RADIUS HAS BEEN DECREASED TO 165
NM...WITH THE RADIUS CONTRACTED TO 140 NM AT TAU 12...THEN MATCHED
WITH SMALLER RADII SET IN THE PREVIOUS PACKAGE FOR ALL SUBSEQUENT
TAU.

SINCE 0000 UTC...SATELLITE LOOP SHOWS NEKI IS MOVING ALMOST DUE WEST
AFTER MOVING NORTHWEST DURING THE PREVIOUS 6 HOURS. INITIAL MOTION
IS SET AT 275 DEGREES AT 5 KT...BUT THIS IS REALLY AN AVERAGE 3 HOUR
MOTION SINCE 0000 UTC. INSTANTANEOUS 1 HOUR MOTION AT 0130 UTC WOULD
SUGGEST A TRACK FARTHER NORTH OF DUE WEST...BUT THIS MAY BE DUE TO
WOBBLING OR TO AN OPTICAL ILLUSION CAUSED BY THE LOSS OF DEFINITION
ON THE NORTHERN FLANK OF THE CENTER. THE 5 KT INITIAL SPEED IS A TAD
FASTER THAN THAT SEEN 6 HOURS AGO.

THE 0000 UTC UW/CIMSS VERTICAL SHEAR PRODUCT SHOWS ABOUT 21 KT OF
WESTERLY SHEAR...A DROP FROM ABOUT 23 KT NOTED AT 1800 UTC...AND
FROM 31 KT NOTED AT 1200 UTC. HOWEVER THIS SHEAR...SUPPLIED BY A
LARGE UPPER TROPOSPHERIC TROUGH LOCATED JUST WEST NORTHWEST OF
NEKI...REMAINS STRONG ENOUGH TO BE DETRIMENTAL TO THE HEALTH OF THIS
SYSTEM. NEKI SITS RIGHT ON THE 26 DEGREE C SST ISOTHERM...SO IT
SEEMS CLEAR THAT NEKI WOULD NOT INTENSIFY EVEN IF IT WERE TO SIT
STILL. IN SPITE OF CONTINUED SLOW MOVEMENT TO THE WEST...TRACK
GUIDANCE ALMOST UNANIMOUSLY SWINGS NEKI TOWARD THE NORTH
TONIGHT...THEN TOWARD THE NORTHEAST MONDAY AND AFTERWARD. THE
FORECAST TRACK IS SHIFTED AGAIN TO THE LEFT FROM THE PREVIOUS
TRACK...THIS TIME AT ALL TAU...TO RECONCILE THE CURRENT WESTERLY
MOVEMENT WITH THE FORECAST SWING TO THE NORTH. THIS TRACK WILL TAKE
NEKI OVER COOLER WATER AND INTO THE PATH OF INCREASING SHEAR...SO
GRADUAL WEAKENING IS EXPECTED.

NEKI IS EXPECTED TO UNDERGO EXTRATROPICAL TRANSITION BEYOND 36 HOURS
AS A LARGE AMPLITUDE UPPER LEVEL TROUGH AND A STRONG SURFACE FRONT
BEGIN TO INTERACT WITH IT. THIS INTERACTION WILL ALSO CAUSE NEKI TO
ACCELERATE AS IT MOVES TOWARDS THE NORTHEAST. THE TRANSITION FROM
TROPICAL STORM TO EXTRATROPICAL GALE SHOULD BE COMPLETE BY MIDDAY
TUESDAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/0300Z 25.0N 165.3W 40 KT
12HR VT 26/1200Z 26.8N 165.5W 40 KT
24HR VT 27/0000Z 31.0N 163.7W 35 KT
36HR VT 27/1200Z 36.7N 160.9W 35 KT...BECOMING EXTRATROPICAL
48HR VT 28/0000Z 43.1N 157.3W 35 KT...EXTRATROPICAL

$$
FORECASTER POWELL
0 likes   


Return to “2009”

Who is online

Users browsing this forum: No registered users and 1 guest