SPAC: ZENA: Post-Tropical

[jaguarjace]

97P INVEST 160404 0600 13.6S 161.5E SHEM 20 1004


THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.9S
161.6E, IS NOW LOCATED NEAR 12.9S 161.6E, APPROXIMATELY 259 NM SOUTH-
SOUTHEAST OF HONIARA, SOLOMON ISLANDS. RECENT ANIMATED MULTI-
SPECTRAL SATELLITE IMAGERY DEPICTS DEEPENING BUT DISORGANIZED
CONVECTION EMBEDDED WITHIN AN ELONGATED AREA OF TROUGHING STRETCHING
EASTWARD FROM THE SOLOMON ISLANDS TOWARDS FIJI. A 040420Z MHS
89GHZ MICROWAVE IMAGE INDICATES THE CONVECTION IS STRAIGHT
LINE IN NATURE, HOWEVER, THE 032256Z METOP-A ASCAT IMAGE SUGGESTS AN
EMERGING LOW LEVEL CIRCULATION CENTER WITH WINDS OF 15 TO 20 KNOTS
ALONG THE NORTHERN AND SOUTHERN PERIPHERIES. THE UPPER-LEVEL
ENVIRONMENT SHOWS FAIR CONDITIONS FOR DEVELOPMENT WITH RESPECTABLE
DIVERGENCE, SUPPORTED BY A POINT SOURCE, BEING OFFSET BY MODERATE TO
HIGH (20 TO 30 KNOTS) VERTICAL WIND SHEAR. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[jaguarjace]

TCFA issued


WTPS22 PGTW 042130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 13.6S 162.7E TO 17.2S 171.2E
WITHIN THE NEXT 06 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT
IMAGERY AT 041800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.8S 163.1E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 08
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.9S
161.6E IS NOW LOCATED NEAR 13.8S 163.1E, APPROXIMATELY 385 NM
NORTHWEST OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS FORMATIVE, DEEP CONVECTIVE BANDING WRAPPING INTO THE
SYSTEM. A 041714Z SSMIS 91 GHZ IMAGE REVEALS TIGHTLY CURVED
CONVECTIVE BANDING WRAPPING INTO A WELL-DEFINED LOW-LEVEL
CIRCULATION CENTER. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT WITH LOW-MODERATE (10 TO 20 KNOTS) VERTICAL WIND SHEAR
(VWS) AND RADIAL OUTFLOW. DYNAMIC MODEL GUIDANCE IS IN FAIR
AGREEMENT ON 97P TRACKING SOUTHEASTWARD, AND STEERED BY A NEAR
EQUATORIAL RIDGE TO THE NORTH. THIS SYSTEM HAS A SHORT WINDOW FOR
INTENSIFICATION OVER THE NEXT 36 TO 48 HOURS UNDER A FAVORABLE UPPER-
LEVEL ENVIRONMENT. AFTER TAU 48, 97P WILL BEGIN TO WEAKEN AS IT
ENCOUNTERS UNFAVORABLE VWS ASSOCIATED WITH AN APPROACHING TROUGH.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED TO BE NEAR 25 TO 30
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB.
THE POTENTIAL FOR DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
052130Z.//
NNNN

[jaguarjace]

TROPICAL DISTURBANCE ADVISORY NUMBER A1 ISSUED FROM RSMC NADI
Apr 050033 UTC.

TROPICAL DEPRESSION TD16F CENTRE 1002HPA WAS ANALYSED NEAR 14.0S
163.5S AT 042100UTC. POSITION FAIR BASED ON HR GOES EIR IMAGERY AND
PERIPHERAL SURFACE REPORTS. DEPRESSION MOVING SOUTHEAST AT ABOUT 06
KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT
ABOUT 30 KNOTS.

DEEP CONVECTION HAS INCREASED WITH BANDS TRYING TO WRAP AROUND LLCC.
ORGANIZATION HAS IMPROVED IN THE LAST 24 HOURS. CYCLONIC CIRCULATION
EXTENDS TO 500 HPA. SST AROUND 31 DEGREE CELCIUS. SYSTEM LIES TO THE
EAST OF AN UPPER TROUGH AND IS BEING SOUTHEASTWARD BY A NORTHWESTERLY
DEEP LAYER MEAN FLOW IN AN AREA OF LOW ENVIRONEMNTAL SHEAR. DVORAK
ANALYSIS BASED ON 0.40 WRAP YIELDS A DT=2.0, MET AND PT AGREE. FT
BASED ON DT THUS, YEILDING T2.0/2.0/D1.0/24HRS.

GLOBAL SYSTEMS HAVE PICKED UP ON THE SYSTEM AND MAINTAIN A
SOUTHEASTWARD MOVEMENT WITH FURTHER INTENSIFICATION.

POTENTIAL FOR TD16F TO DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 12
TO 24 HOURS IS HIGH.

FORECASTS :
AT 12 HRS VALID AT 050900 UTC 14.6S 164.8W MOV ESE AT 08KT WITH 30 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 052100 UTC 15.6S 166.8W MOV ESE AT 09KT WITH 30 KT
CLOSE TO CENTRE.

OUTLOOK :
AT 36 HRS VALID AT 060900 UTC 16.6S 168.8W MOV ESE AT 10KT WITH 35 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 062100 UTC 17.3S 170.9W MOV ESE AT 10KT WITH 35 KT
CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON TD16F WILL BE ISSUED
AROUND 050200 UTC.

97P INVEST 160405 0000 14.1S 164.1E SHEM 30 1000

[jaguarjace]

Vanuatu Meteorology and Geo-Hazards Department
TROPICAL CYCLONE WARNING CENTRE PORT VILA

TROPICAL CYCLONE FORECAST TRACK MAP
Tropical Low

Tropical Cyclone Forecast Track Map Number 1 issued at 11:36 am VUT Tuesday 5 April 2016

[stormwise]

JTWC listed 35kts 18P.EIGHTEEN

Code: Select all

REMARKS:
050900Z POSITION NEAR 15.3S 167.3E.
TROPICAL CYCLONE (TC) 18P (EIGHTEEN), LOCATED APPROXIMATELY 718 NM
WEST-NORTHWEST OF SUVA, FIJI, HAS TRACKED EAST-SOUTHEASTWARD AT
18 KNOTS OVER THE PAST SIX HOURS. CURRENTLY THE SYSTEM IS TRACKING
OVER THE NORTHERN SECTION OF THE ISLAND OF ESPIRITU SANTO. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL
CIRCULATION CENTER WITH IMPROVED DEEP CONVECTIVE BANDING. A 050700Z
SSMIS 91GHZ IMAGE SHOWS A COMPACT CONVECTIVE CORE WITH DEEP
CONVECTIVE BANDING WRAPPING TIGHTLY AROUND A WELL-DEFINED CENTER.
SURFACE OBSERVATIONS FROM NVSS (91554) INDICATE EASTERLY SUSTAINED
WINDS OF 21 KNOTS WITH SLP NEAR 998MB (HOWEVER, THIS SITE IS LOCATED
ON THE SOUTHEAST CORNER OF ESPIRITU SANTO THUS LIKELY SHIELDED BY
THE 5000 TO 6000 FOOT NORTH-SOUTH ORIENTED MOUNTAIN RANGE ALONG THE
WEST COAST). THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS BASED ON
DVORAK ESTIMATES OF 35 KNOTS FROM ALL AGENCIES. UPPER-LEVEL ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT WITH LOW-MODERATE (10 TO 20 KNOTS)
VERTICAL WIND SHEAR (VWS) AND RADIAL OUTFLOW. TC 18P IS FORECAST TO
TRACK EAST-SOUTHEASTWARD TO EASTWARD THROUGH THE FORECAST PERIOD AS
IT TRACKS WITHIN ENHANCED FLOW BETWEEN THE SUBTROPICAL RIDGE AND A
BROAD SHORTWAVE TROUGH. DYNAMIC GUIDANCE IS IN TIGHT AGREEMENT,
THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. TC
18P IS FORECAST TO INTENSIFY THROUGH TAU 24 UNDER FAVORABLE
CONDITIONS. AFTER TAU 24, INCREASING VERTICAL WIND SHEAR ASSOCIATED
WITH THE SUBTROPICAL WESTERLIES WILL SERVE TO RAPIDLY WEAKEN THE
SYSTEM LEADING TO DISSIPATION BY TAU 48. AFTER TAU 48, THE REMNANTS
ARE EXPECTED TO BECOME QUASI-STATIONARY IN THE FIJI REGION AS A LOW-
LEVEL HIGH BUILDS IN. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 050600Z IS
12 FEET. NEXT WARNINGS AT 052100Z AND 060900Z. THIS CANCELS AND
SUPERSEDES REF A (WTPS22 PGTW 042130).//

Timing of that high that would build the ridge is interesting, may see a similar u turn as Winston.

[Yellow Evan]

05/1130 UTC 15.5S 167.5E T3.0/3.0 18P -- Southwest Pacific

[cycloneye]

Is TC ZENA.

[Alyono]

looks like a 70 kt cyclone

[cycloneye]

[stormwise]

On this presentation i assume 80-90 kts.

[jaguarjace]

RSMC Nadi Tropical Cyclone Warning Centre

TROPICAL CYCLONE FORECAST TRACK MAP
Severe Tropical Cyclone ZENA

Tropical Cyclone Warning Number 14 issued 0118 UTC Wednesday 6 April 2016

[Yellow Evan]

18P ZENA 160406 0000 17.7S 172.8E SHEM 90 956

JTWC has been pretty good as of lately.

[stormwise]

Kandavu may get hurricane strength winds from Zena .

[1900hurricane]

It had a nice showing briefly, but it looks like it is beginning to fall apart now.