CPAC: TROPICAL DEPRESSION NEKI (03C)

[cycloneye]

TROPICAL STORM NEKI DISCUSSION NUMBER 31
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 PM HST SUN OCT 25 2009

THE LOW LEVEL CIRCULATION CENTER OF NEKI REMAINS TUCKED UNDER THE
WEST SIDE OF A PERSISTENT CONVECTIVE CLUSTER. THE FIX AGENCIES
REPORT A CI OF 2.5 BASED ON A SHEAR PATTERN...WITH LITTLE OR NO
CHANGE IN INTENSITY OVER THE LAST 24 HOURS. THE INITIAL INTENSITY
OF NEKI HAS BEEN LOWERED TO 35 KT IN AGREEMENT WITH THE FIX DATA.

NEKI IS LOCATED ON THE SOUTHWEST END OF A LARGE SUBTROPICAL RIDGE
AND SOUTHEAST OF AN EQUALLY LARGE AND INTENSIFYING MID-LATITUDE
LOW. OVER THE LAST 24 HOURS THE STEERING WINDS WERE LIGHT OUT OF
THE EAST-SOUTHEAST AROUND THE RIDGE AND IN THE GENERAL DIRECTION OF
THE LOW...RESULTING IN THE WEST-NORTHWEST DRIFT OF NEKI. THE
SURFACE LOW AND FRONT EXTENDING SOUTHWEST OF THE LOW...ALONG WITH A
LONGWAVE UPPER LEVEL TROUGH...HAVE MOVED TO THE EAST HOWEVER...
PLACING NEKI IN INCREASINGLY STRONGER SOUTHERLY STEERING WINDS.

WITH THE DEEP LAYER MEAN FLOW NOW INCREASING OUT OF THE SOUTH AND
SOUTHWEST...THE VERTICAL SHEAR AS CALCULATED BY UW-CIMSS HAS
DROPPED OFF...AND IS NO LONGER A MAJOR PLAYER. THE SHEAR IS NOT
EXPECTED TO INCREASE...SO NEKI IS KEPT AT 35 KT THROUGH THE NEXT 36
HOURS. THE LARGEST 35 KT WIND RADII IS IN THE NORTHEAST QUADRANT
WHERE THERE IS A TIGHT PRESSURE GRADIENT BETWEEN NEKI AND THE
RIDGE. THE INTENSITY FORECAST IS IN THE MIDDLE OF THE ENVELOP...
CLOSEST TO GFNI AND AVNI.

WITH NEKI UNDER THE INCREASING INFLUENCE OF THE STRENGTHENING LOW TO
THE NORTHWEST...IT/S FORWARD MOTION SHOULD DRAMATICALLY INCREASE
OVER THE NEXT 36 HOURS. THE TRACK FORECAST WHICH REFLECTS THIS IS IN
THE MIDDLE OF THE OBJECTIVE AIDES...AND IS CLOSEST TO THE VARIOUS
CONSENSUS FORECASTS. NEKI IS FORECAST TO TRANSITION INTO AN
EXTRATROPICAL LOW AND BE ABSORBED INTO THE MID-LATITUDE LOW IN 24 TO
36 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/0900Z 25.9N 165.5W 35 KT
12HR VT 26/1800Z 27.7N 165.3W 35 KT
24HR VT 27/0600Z 32.0N 164.0W 35 KT...EXTRATROPICAL
36HR VT 27/1800Z 38.5N 160.9W 35 KT...EXTRATROPICAL
48HR VT 28/0600Z...EXTRATROPICAL

$$
FORECASTER CRAIG

[HURAKAN]

Latest

[somethingfunny]

This thing is still hanging around? I would have expected Neki to be in the Gulf of Alaska by this point.

Even though the windstorm had the potential to be devastating, I think Hawaiians could have appreciated a track which threaded the core inbetween the islands and brought days of beneficial rains:

[HURAKAN]

Going down, intensity-wise

[cycloneye]

TROPICAL DEPRESSION NEKI DISCUSSION NUMBER 33
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
1100 AM HST MON OCT 26 2009

THE FIRST VISIBLE IMAGES OF THE MORNING REVEALED AN ELLIPTICAL LLCC
THAT IS STARTING TO ACCELERATE NORTHWARD. THE REMAINING DEEP
CONVECTION IS MORE THAN 3/4 OF A DEGREE TO THE SOUTH OF THE EXPOSED
LOW LEVEL CENTER. THE 1700 UTC UW/CIMSS SATCON INTENSITY ESTIMATE
WAS 29 KNOTS...AND THE AVERAGE OF THE FINAL T AND CURRENT INTENSITY
NUMBERS FROM PHFO...SAB...AND JTWC WAS 2.2. THUS THE INITIAL
INTENSITY IS BEING LOWERED TO 30 KT FOR THIS ADVISORY.

NEKI/S TIME AS A TROPICAL CYCLONE IS WINDING DOWN. THE CYCLONE IS
CURRENTLY OVER SUB-27C SEA SURFACE TEMPERATURES AND IS APPROACHING
A SHARP GRADIENT IN SST. MODERATE SOUTHWEST SHEAR IS LIKELY GOING
TO INCREASE AS THE CYCLONE CONTINUES NORTH. FINALLY...A STRONG
AUTUMN COLD FRONT IS APPROACHING NEKI FROM THE WEST. NEKI WILL
CONTINUE TO PICK UP SPEED IN THE LOW-LEVEL SOUTHERLY FLOW AHEAD OF
THIS FRONT AND IS EXPECTED TO BECOME A REMNANT LOW OR DISSIPATE
WITHIN 24 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/2100Z 28.1N 165.7W 30 KT
12HR VT 27/0600Z 30.7N 165.6W 30 KT...DISSIPATING
24HR VT 27/1800Z 35.7N 163.8W 25 KT...REMNANT LOW
36HR VT 28/0600Z...REMNANT LOW

$$

FORECASTER R BALLARD

[cycloneye]

Final Advisory

TROPICAL DEPRESSION NEKI DISCUSSION NUMBER 34
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP032009
500 PM HST MON OCT 26 2009

ALL THAT IS LEFT OF NEKI IS AN ILL-DEFINED...ELONGATED SWIRL OF LOW
CLOUDS. ALTHOUGH THERE WERE NO RECENT SCATTEROMETER PASSES
AVAILABLE...NEKI APPEARS TO BE JUST A SURFACE TROUGH IN SATELLITE
IMAGERY. DECREASING SEA SURFACE TEMPERATURES ALONG THE TRACK AND
INCREASING VERTICAL SHEAR SHOULD PREVENT REDEVELOPMENT AS A TROPICAL
CYCLONE. THUS...THIS IS THE FINAL ADVISORY ON NEKI.

FORECAST POSITIONS AND MAX WINDS

INITIAL 27/0300Z 30.3N 164.9W 30 KT
12HR VT 27/1200Z 34.6N 163.6W 30 KT...DISSIPATING
24HR VT 28/0000Z...DISSIPATED

$$
FORECASTER R BALLARD